<?php
/**
 * WordPress Imagick Image Editor
 *
 * @package WordPress
 * @subpackage Image_Editor
 */

/**
 * WordPress Image Editor Class for Image Manipulation through Imagick PHP Module
 *
 * @since 3.5.0
 *
 * @see WP_Image_Editor
 */
class WP_Image_Editor_Imagick extends WP_Image_Editor {
	/**
	 * Imagick object.
	 *
	 * @var Imagick
	 */
	protected $image;

	public function __destruct() {
		if ( $this->image instanceof Imagick ) {
			// We don't need the original in memory anymore.
			$this->image->clear();
			$this->image->destroy();
		}
	}

	/**
	 * Checks to see if current environment supports Imagick.
	 *
	 * We require Imagick 2.2.0 or greater, based on whether the queryFormats()
	 * method can be called statically.
	 *
	 * @since 3.5.0
	 *
	 * @param array $args
	 * @return bool
	 */
	public static function test( $args = array() ) {

		// First, test Imagick's extension and classes.
		if ( ! extension_loaded( 'imagick' ) || ! class_exists( 'Imagick', false ) || ! class_exists( 'ImagickPixel', false ) ) {
			return false;
		}

		if ( version_compare( phpversion( 'imagick' ), '2.2.0', '<' ) ) {
			return false;
		}

		$required_methods = array(
			'clear',
			'destroy',
			'valid',
			'getimage',
			'writeimage',
			'getimageblob',
			'getimagegeometry',
			'getimageformat',
			'setimageformat',
			'setimagecompression',
			'setimagecompressionquality',
			'setimagepage',
			'setoption',
			'scaleimage',
			'cropimage',
			'rotateimage',
			'flipimage',
			'flopimage',
			'readimage',
		);

		// Now, test for deep requirements within Imagick.
		if ( ! defined( 'imagick::COMPRESSION_JPEG' ) ) {
			return false;
		}

		$class_methods = array_map( 'strtolower', get_class_methods( 'Imagick' ) );
		if ( array_diff( $required_methods, $class_methods ) ) {
			return false;
		}

		return true;
	}

	/**
	 * Checks to see if editor supports the mime-type specified.
	 *
	 * @since 3.5.0
	 *
	 * @param string $mime_type
	 * @return bool
	 */
	public static function supports_mime_type( $mime_type ) {
		$imagick_extension = strtoupper( self::get_extension( $mime_type ) );

		if ( ! $imagick_extension ) {
			return false;
		}

		// setIteratorIndex is optional unless mime is an animated format.
		// Here, we just say no if you are missing it and aren't loading a jpeg.
		if ( ! method_exists( 'Imagick', 'setIteratorIndex' ) && 'image/jpeg' !== $mime_type ) {
				return false;
		}

		try {
			// phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged
			return ( (bool) @Imagick::queryFormats( $imagick_extension ) );
		} catch ( Exception $e ) {
			return false;
		}
	}

	/**
	 * Loads image from $this->file into new Imagick Object.
	 *
	 * @since 3.5.0
	 *
	 * @return true|WP_Error True if loaded; WP_Error on failure.
	 */
	public function load() {
		if ( $this->image instanceof Imagick ) {
			return true;
		}

		if ( ! is_file( $this->file ) && ! preg_match( '|^https?://|', $this->file ) ) {
			return new WP_Error( 'error_loading_image', __( 'File doesn’t exist?' ), $this->file );
		}

		/*
		 * Even though Imagick uses less PHP memory than GD, set higher limit
		 * for users that have low PHP.ini limits.
		 */
		wp_raise_memory_limit( 'image' );

		try {
			$this->image    = new Imagick();
			$file_extension = strtolower( pathinfo( $this->file, PATHINFO_EXTENSION ) );
			$filename       = $this->file;

			if ( 'pdf' === $file_extension ) {
				$filename = $this->pdf_setup();
			}

			// Reading image after Imagick instantiation because `setResolution`
			// only applies correctly before the image is read.
			$this->image->readImage( $filename );

			if ( ! $this->image->valid() ) {
				return new WP_Error( 'invalid_image', __( 'File is not an image.' ), $this->file );
			}

			// Select the first frame to handle animated images properly.
			if ( is_callable( array( $this->image, 'setIteratorIndex' ) ) ) {
				$this->image->setIteratorIndex( 0 );
			}

			$this->mime_type = $this->get_mime_type( $this->image->getImageFormat() );
		} catch ( Exception $e ) {
			return new WP_Error( 'invalid_image', $e->getMessage(), $this->file );
		}

		$updated_size = $this->update_size();
		if ( is_wp_error( $updated_size ) ) {
			return $updated_size;
		}

		return $this->set_quality();
	}

	/**
	 * Sets Image Compression quality on a 1-100% scale.
	 *
	 * @since 3.5.0
	 *
	 * @param int $quality Compression Quality. Range: [1,100]
	 * @return true|WP_Error True if set successfully; WP_Error on failure.
	 */
	public function set_quality( $quality = null ) {
		$quality_result = parent::set_quality( $quality );
		if ( is_wp_error( $quality_result ) ) {
			return $quality_result;
		} else {
			$quality = $this->get_quality();
		}

		try {
			if ( 'image/jpeg' === $this->mime_type ) {
				$this->image->setImageCompressionQuality( $quality );
				$this->image->setImageCompression( imagick::COMPRESSION_JPEG );
			} else {
				$this->image->setImageCompressionQuality( $quality );
			}
		} catch ( Exception $e ) {
			return new WP_Error( 'image_quality_error', $e->getMessage() );
		}

		return true;
	}

	/**
	 * Sets or updates current image size.
	 *
	 * @since 3.5.0
	 *
	 * @param int $width
	 * @param int $height
	 * @return true|WP_Error
	 */
	protected function update_size( $width = null, $height = null ) {
		$size = null;
		if ( ! $width || ! $height ) {
			try {
				$size = $this->image->getImageGeometry();
			} catch ( Exception $e ) {
				return new WP_Error( 'invalid_image', __( 'Could not read image size.' ), $this->file );
			}
		}

		if ( ! $width ) {
			$width = $size['width'];
		}

		if ( ! $height ) {
			$height = $size['height'];
		}

		return parent::update_size( $width, $height );
	}

	/**
	 * Resizes current image.
	 *
	 * At minimum, either a height or width must be provided.
	 * If one of the two is set to null, the resize will
	 * maintain aspect ratio according to the provided dimension.
	 *
	 * @since 3.5.0
	 *
	 * @param int|null $max_w Image width.
	 * @param int|null $max_h Image height.
	 * @param bool     $crop
	 * @return bool|WP_Error
	 */
	public function resize( $max_w, $max_h, $crop = false ) {
		if ( ( $this->size['width'] == $max_w ) && ( $this->size['height'] == $max_h ) ) {
			return true;
		}

		$dims = image_resize_dimensions( $this->size['width'], $this->size['height'], $max_w, $max_h, $crop );
		if ( ! $dims ) {
			return new WP_Error( 'error_getting_dimensions', __( 'Could not calculate resized image dimensions' ) );
		}

		list( $dst_x, $dst_y, $src_x, $src_y, $dst_w, $dst_h, $src_w, $src_h ) = $dims;

		if ( $crop ) {
			return $this->crop( $src_x, $src_y, $src_w, $src_h, $dst_w, $dst_h );
		}

		// Execute the resize.
		$thumb_result = $this->thumbnail_image( $dst_w, $dst_h );
		if ( is_wp_error( $thumb_result ) ) {
			return $thumb_result;
		}

		return $this->update_size( $dst_w, $dst_h );
	}

	/**
	 * Efficiently resize the current image
	 *
	 * This is a WordPress specific implementation of Imagick::thumbnailImage(),
	 * which resizes an image to given dimensions and removes any associated profiles.
	 *
	 * @since 4.5.0
	 *
	 * @param int    $dst_w       The destination width.
	 * @param int    $dst_h       The destination height.
	 * @param string $filter_name Optional. The Imagick filter to use when resizing. Default 'FILTER_TRIANGLE'.
	 * @param bool   $strip_meta  Optional. Strip all profiles, excluding color profiles, from the image. Default true.
	 * @return bool|WP_Error
	 */
	protected function thumbnail_image( $dst_w, $dst_h, $filter_name = 'FILTER_TRIANGLE', $strip_meta = true ) {
		$allowed_filters = array(
			'FILTER_POINT',
			'FILTER_BOX',
			'FILTER_TRIANGLE',
			'FILTER_HERMITE',
			'FILTER_HANNING',
			'FILTER_HAMMING',
			'FILTER_BLACKMAN',
			'FILTER_GAUSSIAN',
			'FILTER_QUADRATIC',
			'FILTER_CUBIC',
			'FILTER_CATROM',
			'FILTER_MITCHELL',
			'FILTER_LANCZOS',
			'FILTER_BESSEL',
			'FILTER_SINC',
		);

		/**
		 * Set the filter value if '$filter_name' name is in the allowed list and the related
		 * Imagick constant is defined or fall back to the default filter.
		 */
		if ( in_array( $filter_name, $allowed_filters, true ) && defined( 'Imagick::' . $filter_name ) ) {
			$filter = constant( 'Imagick::' . $filter_name );
		} else {
			$filter = defined( 'Imagick::FILTER_TRIANGLE' ) ? Imagick::FILTER_TRIANGLE : false;
		}

		/**
		 * Filters whether to strip metadata from images when they're resized.
		 *
		 * This filter only applies when resizing using the Imagick editor since GD
		 * always strips profiles by default.
		 *
		 * @since 4.5.0
		 *
		 * @param bool $strip_meta Whether to strip image metadata during resizing. Default true.
		 */
		if ( apply_filters( 'image_strip_meta', $strip_meta ) ) {
			$this->strip_meta(); // Fail silently if not supported.
		}

		try {
			/*
			 * To be more efficient, resample large images to 5x the destination size before resizing
			 * whenever the output size is less that 1/3 of the original image size (1/3^2 ~= .111),
			 * unless we would be resampling to a scale smaller than 128x128.
			 */
			if ( is_callable( array( $this->image, 'sampleImage' ) ) ) {
				$resize_ratio  = ( $dst_w / $this->size['width'] ) * ( $dst_h / $this->size['height'] );
				$sample_factor = 5;

				if ( $resize_ratio < .111 && ( $dst_w * $sample_factor > 128 && $dst_h * $sample_factor > 128 ) ) {
					$this->image->sampleImage( $dst_w * $sample_factor, $dst_h * $sample_factor );
				}
			}

			/*
			 * Use resizeImage() when it's available and a valid filter value is set.
			 * Otherwise, fall back to the scaleImage() method for resizing, which
			 * results in better image quality over resizeImage() with default filter
			 * settings and retains backward compatibility with pre 4.5 functionality.
			 */
			if ( is_callable( array( $this->image, 'resizeImage' ) ) && $filter ) {
				$this->image->setOption( 'filter:support', '2.0' );
				$this->image->resizeImage( $dst_w, $dst_h, $filter, 1 );
			} else {
				$this->image->scaleImage( $dst_w, $dst_h );
			}

			// Set appropriate quality settings after resizing.
			if ( 'image/jpeg' === $this->mime_type ) {
				if ( is_callable( array( $this->image, 'unsharpMaskImage' ) ) ) {
					$this->image->unsharpMaskImage( 0.25, 0.25, 8, 0.065 );
				}

				$this->image->setOption( 'jpeg:fancy-upsampling', 'off' );
			}

			if ( 'image/png' === $this->mime_type ) {
				$this->image->setOption( 'png:compression-filter', '5' );
				$this->image->setOption( 'png:compression-level', '9' );
				$this->image->setOption( 'png:compression-strategy', '1' );
				$this->image->setOption( 'png:exclude-chunk', 'all' );
			}

			/*
			 * If alpha channel is not defined, set it opaque.
			 *
			 * Note that Imagick::getImageAlphaChannel() is only available if Imagick
			 * has been compiled against ImageMagick version 6.4.0 or newer.
			 */
			if ( is_callable( array( $this->image, 'getImageAlphaChannel' ) )
				&& is_callable( array( $this->image, 'setImageAlphaChannel' ) )
				&& defined( 'Imagick::ALPHACHANNEL_UNDEFINED' )
				&& defined( 'Imagick::ALPHACHANNEL_OPAQUE' )
			) {
				if ( $this->image->getImageAlphaChannel() === Imagick::ALPHACHANNEL_UNDEFINED ) {
					$this->image->setImageAlphaChannel( Imagick::ALPHACHANNEL_OPAQUE );
				}
			}

			// Limit the bit depth of resized images to 8 bits per channel.
			if ( is_callable( array( $this->image, 'getImageDepth' ) ) && is_callable( array( $this->image, 'setImageDepth' ) ) ) {
				if ( 8 < $this->image->getImageDepth() ) {
					$this->image->setImageDepth( 8 );
				}
			}

			if ( is_callable( array( $this->image, 'setInterlaceScheme' ) ) && defined( 'Imagick::INTERLACE_NO' ) ) {
				$this->image->setInterlaceScheme( Imagick::INTERLACE_NO );
			}
		} catch ( Exception $e ) {
			return new WP_Error( 'image_resize_error', $e->getMessage() );
		}
	}

	/**
	 * Create multiple smaller images from a single source.
	 *
	 * Attempts to create all sub-sizes and returns the meta data at the end. This
	 * may result in the server running out of resources. When it fails there may be few
	 * "orphaned" images left over as the meta data is never returned and saved.
	 *
	 * As of 5.3.0 the preferred way to do this is with `make_subsize()`. It creates
	 * the new images one at a time and allows for the meta data to be saved after
	 * each new image is created.
	 *
	 * @since 3.5.0
	 *
	 * @param array $sizes {
	 *     An array of image size data arrays.
	 *
	 *     Either a height or width must be provided.
	 *     If one of the two is set to null, the resize will
	 *     maintain aspect ratio according to the provided dimension.
	 *
	 *     @type array $size {
	 *         Array of height, width values, and whether to crop.
	 *
	 *         @type int  $width  Image width. Optional if `$height` is specified.
	 *         @type int  $height Image height. Optional if `$width` is specified.
	 *         @type bool $crop   Optional. Whether to crop the image. Default false.
	 *     }
	 * }
	 * @return array An array of resized images' metadata by size.
	 */
	public function multi_resize( $sizes ) {
		$metadata = array();

		foreach ( $sizes as $size => $size_data ) {
			$meta = $this->make_subsize( $size_data );

			if ( ! is_wp_error( $meta ) ) {
				$metadata[ $size ] = $meta;
			}
		}

		return $metadata;
	}

	/**
	 * Create an image sub-size and return the image meta data value for it.
	 *
	 * @since 5.3.0
	 *
	 * @param array $size_data {
	 *     Array of size data.
	 *
	 *     @type int  $width  The maximum width in pixels.
	 *     @type int  $height The maximum height in pixels.
	 *     @type bool $crop   Whether to crop the image to exact dimensions.
	 * }
	 * @return array|WP_Error The image data array for inclusion in the `sizes` array in the image meta,
	 *                        WP_Error object on error.
	 */
	public function make_subsize( $size_data ) {
		if ( ! isset( $size_data['width'] ) && ! isset( $size_data['height'] ) ) {
			return new WP_Error( 'image_subsize_create_error', __( 'Cannot resize the image. Both width and height are not set.' ) );
		}

		$orig_size  = $this->size;
		$orig_image = $this->image->getImage();

		if ( ! isset( $size_data['width'] ) ) {
			$size_data['width'] = null;
		}

		if ( ! isset( $size_data['height'] ) ) {
			$size_data['height'] = null;
		}

		if ( ! isset( $size_data['crop'] ) ) {
			$size_data['crop'] = false;
		}

		$resized = $this->resize( $size_data['width'], $size_data['height'], $size_data['crop'] );

		if ( is_wp_error( $resized ) ) {
			$saved = $resized;
		} else {
			$saved = $this->_save( $this->image );

			$this->image->clear();
			$this->image->destroy();
			$this->image = null;
		}

		$this->size  = $orig_size;
		$this->image = $orig_image;

		if ( ! is_wp_error( $saved ) ) {
			unset( $saved['path'] );
		}

		return $saved;
	}

	/**
	 * Crops Image.
	 *
	 * @since 3.5.0
	 *
	 * @param int  $src_x   The start x position to crop from.
	 * @param int  $src_y   The start y position to crop from.
	 * @param int  $src_w   The width to crop.
	 * @param int  $src_h   The height to crop.
	 * @param int  $dst_w   Optional. The destination width.
	 * @param int  $dst_h   Optional. The destination height.
	 * @param bool $src_abs Optional. If the source crop points are absolute.
	 * @return bool|WP_Error
	 */
	public function crop( $src_x, $src_y, $src_w, $src_h, $dst_w = null, $dst_h = null, $src_abs = false ) {
		if ( $src_abs ) {
			$src_w -= $src_x;
			$src_h -= $src_y;
		}

		try {
			$this->image->cropImage( $src_w, $src_h, $src_x, $src_y );
			$this->image->setImagePage( $src_w, $src_h, 0, 0 );

			if ( $dst_w || $dst_h ) {
				// If destination width/height isn't specified,
				// use same as width/height from source.
				if ( ! $dst_w ) {
					$dst_w = $src_w;
				}
				if ( ! $dst_h ) {
					$dst_h = $src_h;
				}

				$thumb_result = $this->thumbnail_image( $dst_w, $dst_h );
				if ( is_wp_error( $thumb_result ) ) {
					return $thumb_result;
				}

				return $this->update_size();
			}
		} catch ( Exception $e ) {
			return new WP_Error( 'image_crop_error', $e->getMessage() );
		}
		return $this->update_size();
	}

	/**
	 * Rotates current image counter-clockwise by $angle.
	 *
	 * @since 3.5.0
	 *
	 * @param float $angle
	 * @return true|WP_Error
	 */
	public function rotate( $angle ) {
		/**
		 * $angle is 360-$angle because Imagick rotates clockwise
		 * (GD rotates counter-clockwise)
		 */
		try {
			$this->image->rotateImage( new ImagickPixel( 'none' ), 360 - $angle );

			// Normalise EXIF orientation data so that display is consistent across devices.
			if ( is_callable( array( $this->image, 'setImageOrientation' ) ) && defined( 'Imagick::ORIENTATION_TOPLEFT' ) ) {
				$this->image->setImageOrientation( Imagick::ORIENTATION_TOPLEFT );
			}

			// Since this changes the dimensions of the image, update the size.
			$result = $this->update_size();
			if ( is_wp_error( $result ) ) {
				return $result;
			}

			$this->image->setImagePage( $this->size['width'], $this->size['height'], 0, 0 );
		} catch ( Exception $e ) {
			return new WP_Error( 'image_rotate_error', $e->getMessage() );
		}
		return true;
	}

	/**
	 * Flips current image.
	 *
	 * @since 3.5.0
	 *
	 * @param bool $horz Flip along Horizontal Axis
	 * @param bool $vert Flip along Vertical Axis
	 * @return true|WP_Error
	 */
	public function flip( $horz, $vert ) {
		try {
			if ( $horz ) {
				$this->image->flipImage();
			}

			if ( $vert ) {
				$this->image->flopImage();
			}

			// Normalise EXIF orientation data so that display is consistent across devices.
			if ( is_callable( array( $this->image, 'setImageOrientation' ) ) && defined( 'Imagick::ORIENTATION_TOPLEFT' ) ) {
				$this->image->setImageOrientation( Imagick::ORIENTATION_TOPLEFT );
			}
		} catch ( Exception $e ) {
			return new WP_Error( 'image_flip_error', $e->getMessage() );
		}

		return true;
	}

	/**
	 * Check if a JPEG image has EXIF Orientation tag and rotate it if needed.
	 *
	 * As ImageMagick copies the EXIF data to the flipped/rotated image, proceed only
	 * if EXIF Orientation can be reset afterwards.
	 *
	 * @since 5.3.0
	 *
	 * @return bool|WP_Error True if the image was rotated. False if no EXIF data or if the image doesn't need rotation.
	 *                       WP_Error if error while rotating.
	 */
	public function maybe_exif_rotate() {
		if ( is_callable( array( $this->image, 'setImageOrientation' ) ) && defined( 'Imagick::ORIENTATION_TOPLEFT' ) ) {
			return parent::maybe_exif_rotate();
		} else {
			return new WP_Error( 'write_exif_error', __( 'The image cannot be rotated because the embedded meta data cannot be updated.' ) );
		}
	}

	/**
	 * Saves current image to file.
	 *
	 * @since 3.5.0
	 *
	 * @param string $destfilename
	 * @param string $mime_type
	 * @return array|WP_Error {'path'=>string, 'file'=>string, 'width'=>int, 'height'=>int, 'mime-type'=>string}
	 */
	public function save( $destfilename = null, $mime_type = null ) {
		$saved = $this->_save( $this->image, $destfilename, $mime_type );

		if ( ! is_wp_error( $saved ) ) {
			$this->file      = $saved['path'];
			$this->mime_type = $saved['mime-type'];

			try {
				$this->image->setImageFormat( strtoupper( $this->get_extension( $this->mime_type ) ) );
			} catch ( Exception $e ) {
				return new WP_Error( 'image_save_error', $e->getMessage(), $this->file );
			}
		}

		return $saved;
	}

	/**
	 * @param Imagick $image
	 * @param string  $filename
	 * @param string  $mime_type
	 * @return array|WP_Error
	 */
	protected function _save( $image, $filename = null, $mime_type = null ) {
		list( $filename, $extension, $mime_type ) = $this->get_output_format( $filename, $mime_type );

		if ( ! $filename ) {
			$filename = $this->generate_filename( null, null, $extension );
		}

		try {
			// Store initial format.
			$orig_format = $this->image->getImageFormat();

			$this->image->setImageFormat( strtoupper( $this->get_extension( $mime_type ) ) );
			$this->make_image( $filename, array( $image, 'writeImage' ), array( $filename ) );

			// Reset original format.
			$this->image->setImageFormat( $orig_format );
		} catch ( Exception $e ) {
			return new WP_Error( 'image_save_error', $e->getMessage(), $filename );
		}

		// Set correct file permissions.
		$stat  = stat( dirname( $filename ) );
		$perms = $stat['mode'] & 0000666; // Same permissions as parent folder, strip off the executable bits.
		chmod( $filename, $perms );

		return array(
			'path'      => $filename,
			/** This filter is documented in wp-includes/class-wp-image-editor-gd.php */
			'file'      => wp_basename( apply_filters( 'image_make_intermediate_size', $filename ) ),
			'width'     => $this->size['width'],
			'height'    => $this->size['height'],
			'mime-type' => $mime_type,
		);
	}

	/**
	 * Streams current image to browser.
	 *
	 * @since 3.5.0
	 *
	 * @param string $mime_type The mime type of the image.
	 * @return bool|WP_Error True on success, WP_Error object on failure.
	 */
	public function stream( $mime_type = null ) {
		list( $filename, $extension, $mime_type ) = $this->get_output_format( null, $mime_type );

		try {
			// Temporarily change format for stream.
			$this->image->setImageFormat( strtoupper( $extension ) );

			// Output stream of image content.
			header( "Content-Type: $mime_type" );
			print $this->image->getImageBlob();

			// Reset image to original format.
			$this->image->setImageFormat( $this->get_extension( $this->mime_type ) );
		} catch ( Exception $e ) {
			return new WP_Error( 'image_stream_error', $e->getMessage() );
		}

		return true;
	}

	/**
	 * Strips all image meta except color profiles from an image.
	 *
	 * @since 4.5.0
	 *
	 * @return true|WP_Error True if stripping metadata was successful. WP_Error object on error.
	 */
	protected function strip_meta() {

		if ( ! is_callable( array( $this->image, 'getImageProfiles' ) ) ) {
			/* translators: %s: ImageMagick method name. */
			return new WP_Error( 'image_strip_meta_error', sprintf( __( '%s is required to strip image meta.' ), '<code>Imagick::getImageProfiles()</code>' ) );
		}

		if ( ! is_callable( array( $this->image, 'removeImageProfile' ) ) ) {
			/* translators: %s: ImageMagick method name. */
			return new WP_Error( 'image_strip_meta_error', sprintf( __( '%s is required to strip image meta.' ), '<code>Imagick::removeImageProfile()</code>' ) );
		}

		/*
		 * Protect a few profiles from being stripped for the following reasons:
		 *
		 * - icc:  Color profile information
		 * - icm:  Color profile information
		 * - iptc: Copyright data
		 * - exif: Orientation data
		 * - xmp:  Rights usage data
		 */
		$protected_profiles = array(
			'icc',
			'icm',
			'iptc',
			'exif',
			'xmp',
		);

		try {
			// Strip profiles.
			foreach ( $this->image->getImageProfiles( '*', true ) as $key => $value ) {
				if ( ! in_array( $key, $protected_profiles, true ) ) {
					$this->image->removeImageProfile( $key );
				}
			}
		} catch ( Exception $e ) {
			return new WP_Error( 'image_strip_meta_error', $e->getMessage() );
		}

		return true;
	}

	/**
	 * Sets up Imagick for PDF processing.
	 * Increases rendering DPI and only loads first page.
	 *
	 * @since 4.7.0
	 *
	 * @return string|WP_Error File to load or WP_Error on failure.
	 */
	protected function pdf_setup() {
		try {
			// By default, PDFs are rendered in a very low resolution.
			// We want the thumbnail to be readable, so increase the rendering DPI.
			$this->image->setResolution( 128, 128 );

			// When generating thumbnails from cropped PDF pages, Imagemagick uses the uncropped
			// area (resulting in unnecessary whitespace) unless the following option is set.
			$this->image->setOption( 'pdf:use-cropbox', true );

			// Only load the first page.
			return $this->file . '[0]';
		} catch ( Exception $e ) {
			return new WP_Error( 'pdf_setup_failed', $e->getMessage(), $this->file );
		}
	}

}


<?php
/**
 * Base WordPress Image Editor
 *
 * @package WordPress
 * @subpackage Image_Editor
 */

/**
 * Base image editor class from which implementations extend
 *
 * @since 3.5.0
 */
abstract class WP_Image_Editor {
	protected $file              = null;
	protected $size              = null;
	protected $mime_type         = null;
	protected $default_mime_type = 'image/jpeg';
	protected $quality           = false;
	protected $default_quality   = 82;

	/**
	 * Each instance handles a single file.
	 *
	 * @param string $file Path to the file to load.
	 */
	public function __construct( $file ) {
		$this->file = $file;
	}

	/**
	 * Checks to see if current environment supports the editor chosen.
	 * Must be overridden in a subclass.
	 *
	 * @since 3.5.0
	 *
	 * @abstract
	 *
	 * @param array $args
	 * @return bool
	 */
	public static function test( $args = array() ) {
		return false;
	}

	/**
	 * Checks to see if editor supports the mime-type specified.
	 * Must be overridden in a subclass.
	 *
	 * @since 3.5.0
	 *
	 * @abstract
	 *
	 * @param string $mime_type
	 * @return bool
	 */
	public static function supports_mime_type( $mime_type ) {
		return false;
	}

	/**
	 * Loads image from $this->file into editor.
	 *
	 * @since 3.5.0
	 * @abstract
	 *
	 * @return bool|WP_Error True if loaded; WP_Error on failure.
	 */
	abstract public function load();

	/**
	 * Saves current image to file.
	 *
	 * @since 3.5.0
	 * @abstract
	 *
	 * @param string $destfilename
	 * @param string $mime_type
	 * @return array|WP_Error {'path'=>string, 'file'=>string, 'width'=>int, 'height'=>int, 'mime-type'=>string}
	 */
	abstract public function save( $destfilename = null, $mime_type = null );

	/**
	 * Resizes current image.
	 *
	 * At minimum, either a height or width must be provided.
	 * If one of the two is set to null, the resize will
	 * maintain aspect ratio according to the provided dimension.
	 *
	 * @since 3.5.0
	 * @abstract
	 *
	 * @param int|null $max_w Image width.
	 * @param int|null $max_h Image height.
	 * @param bool     $crop
	 * @return bool|WP_Error
	 */
	abstract public function resize( $max_w, $max_h, $crop = false );

	/**
	 * Resize multiple images from a single source.
	 *
	 * @since 3.5.0
	 * @abstract
	 *
	 * @param array $sizes {
	 *     An array of image size arrays. Default sizes are 'small', 'medium', 'large'.
	 *
	 *     @type array $size {
	 *         @type int  $width  Image width.
	 *         @type int  $height Image height.
	 *         @type bool $crop   Optional. Whether to crop the image. Default false.
	 *     }
	 * }
	 * @return array An array of resized images metadata by size.
	 */
	abstract public function multi_resize( $sizes );

	/**
	 * Crops Image.
	 *
	 * @since 3.5.0
	 * @abstract
	 *
	 * @param int  $src_x   The start x position to crop from.
	 * @param int  $src_y   The start y position to crop from.
	 * @param int  $src_w   The width to crop.
	 * @param int  $src_h   The height to crop.
	 * @param int  $dst_w   Optional. The destination width.
	 * @param int  $dst_h   Optional. The destination height.
	 * @param bool $src_abs Optional. If the source crop points are absolute.
	 * @return bool|WP_Error
	 */
	abstract public function crop( $src_x, $src_y, $src_w, $src_h, $dst_w = null, $dst_h = null, $src_abs = false );

	/**
	 * Rotates current image counter-clockwise by $angle.
	 *
	 * @since 3.5.0
	 * @abstract
	 *
	 * @param float $angle
	 * @return bool|WP_Error
	 */
	abstract public function rotate( $angle );

	/**
	 * Flips current image.
	 *
	 * @since 3.5.0
	 * @abstract
	 *
	 * @param bool $horz Flip along Horizontal Axis
	 * @param bool $vert Flip along Vertical Axis
	 * @return bool|WP_Error
	 */
	abstract public function flip( $horz, $vert );

	/**
	 * Streams current image to browser.
	 *
	 * @since 3.5.0
	 * @abstract
	 *
	 * @param string $mime_type The mime type of the image.
	 * @return bool|WP_Error True on success, WP_Error object or false on failure.
	 */
	abstract public function stream( $mime_type = null );

	/**
	 * Gets dimensions of image.
	 *
	 * @since 3.5.0
	 *
	 * @return array {
	 *     Dimensions of the image.
	 *
	 *     @type int $width  The image width.
	 *     @type int $height The image height.
	 * }
	 */
	public function get_size() {
		return $this->size;
	}

	/**
	 * Sets current image size.
	 *
	 * @since 3.5.0
	 *
	 * @param int $width
	 * @param int $height
	 * @return true
	 */
	protected function update_size( $width = null, $height = null ) {
		$this->size = array(
			'width'  => (int) $width,
			'height' => (int) $height,
		);
		return true;
	}

	/**
	 * Gets the Image Compression quality on a 1-100% scale.
	 *
	 * @since 4.0.0
	 *
	 * @return int Compression Quality. Range: [1,100]
	 */
	public function get_quality() {
		if ( ! $this->quality ) {
			$this->set_quality();
		}

		return $this->quality;
	}

	/**
	 * Sets Image Compression quality on a 1-100% scale.
	 *
	 * @since 3.5.0
	 *
	 * @param int $quality Compression Quality. Range: [1,100]
	 * @return true|WP_Error True if set successfully; WP_Error on failure.
	 */
	public function set_quality( $quality = null ) {
		if ( null === $quality ) {
			/**
			 * Filters the default image compression quality setting.
			 *
			 * Applies only during initial editor instantiation, or when set_quality() is run
			 * manually without the `$quality` argument.
			 *
			 * The WP_Image_Editor::set_quality() method has priority over the filter.
			 *
			 * @since 3.5.0
			 *
			 * @param int    $quality   Quality level between 1 (low) and 100 (high).
			 * @param string $mime_type Image mime type.
			 */
			$quality = apply_filters( 'wp_editor_set_quality', $this->default_quality, $this->mime_type );

			if ( 'image/jpeg' === $this->mime_type ) {
				/**
				 * Filters the JPEG compression quality for backward-compatibility.
				 *
				 * Applies only during initial editor instantiation, or when set_quality() is run
				 * manually without the `$quality` argument.
				 *
				 * The WP_Image_Editor::set_quality() method has priority over the filter.
				 *
				 * The filter is evaluated under two contexts: 'image_resize', and 'edit_image',
				 * (when a JPEG image is saved to file).
				 *
				 * @since 2.5.0
				 *
				 * @param int    $quality Quality level between 0 (low) and 100 (high) of the JPEG.
				 * @param string $context Context of the filter.
				 */
				$quality = apply_filters( 'jpeg_quality', $quality, 'image_resize' );
			}

			if ( $quality < 0 || $quality > 100 ) {
				$quality = $this->default_quality;
			}
		}

		// Allow 0, but squash to 1 due to identical images in GD, and for backward compatibility.
		if ( 0 === $quality ) {
			$quality = 1;
		}

		if ( ( $quality >= 1 ) && ( $quality <= 100 ) ) {
			$this->quality = $quality;
			return true;
		} else {
			return new WP_Error( 'invalid_image_quality', __( 'Attempted to set image quality outside of the range [1,100].' ) );
		}
	}

	/**
	 * Returns preferred mime-type and extension based on provided
	 * file's extension and mime, or current file's extension and mime.
	 *
	 * Will default to $this->default_mime_type if requested is not supported.
	 *
	 * Provides corrected filename only if filename is provided.
	 *
	 * @since 3.5.0
	 *
	 * @param string $filename
	 * @param string $mime_type
	 * @return array { filename|null, extension, mime-type }
	 */
	protected function get_output_format( $filename = null, $mime_type = null ) {
		$new_ext = null;

		// By default, assume specified type takes priority.
		if ( $mime_type ) {
			$new_ext = $this->get_extension( $mime_type );
		}

		if ( $filename ) {
			$file_ext  = strtolower( pathinfo( $filename, PATHINFO_EXTENSION ) );
			$file_mime = $this->get_mime_type( $file_ext );
		} else {
			// If no file specified, grab editor's current extension and mime-type.
			$file_ext  = strtolower( pathinfo( $this->file, PATHINFO_EXTENSION ) );
			$file_mime = $this->mime_type;
		}

		// Check to see if specified mime-type is the same as type implied by
		// file extension. If so, prefer extension from file.
		if ( ! $mime_type || ( $file_mime == $mime_type ) ) {
			$mime_type = $file_mime;
			$new_ext   = $file_ext;
		}

		// Double-check that the mime-type selected is supported by the editor.
		// If not, choose a default instead.
		if ( ! $this->supports_mime_type( $mime_type ) ) {
			/**
			 * Filters default mime type prior to getting the file extension.
			 *
			 * @see wp_get_mime_types()
			 *
			 * @since 3.5.0
			 *
			 * @param string $mime_type Mime type string.
			 */
			$mime_type = apply_filters( 'image_editor_default_mime_type', $this->default_mime_type );
			$new_ext   = $this->get_extension( $mime_type );
		}

		if ( $filename ) {
			$dir = pathinfo( $filename, PATHINFO_DIRNAME );
			$ext = pathinfo( $filename, PATHINFO_EXTENSION );

			$filename = trailingslashit( $dir ) . wp_basename( $filename, ".$ext" ) . ".{$new_ext}";
		}

		return array( $filename, $new_ext, $mime_type );
	}

	/**
	 * Builds an output filename based on current file, and adding proper suffix
	 *
	 * @since 3.5.0
	 *
	 * @param string $suffix
	 * @param string $dest_path
	 * @param string $extension
	 * @return string filename
	 */
	public function generate_filename( $suffix = null, $dest_path = null, $extension = null ) {
		// $suffix will be appended to the destination filename, just before the extension.
		if ( ! $suffix ) {
			$suffix = $this->get_suffix();
		}

		$dir = pathinfo( $this->file, PATHINFO_DIRNAME );
		$ext = pathinfo( $this->file, PATHINFO_EXTENSION );

		$name    = wp_basename( $this->file, ".$ext" );
		$new_ext = strtolower( $extension ? $extension : $ext );

		if ( ! is_null( $dest_path ) ) {
			$_dest_path = realpath( $dest_path );
			if ( $_dest_path ) {
				$dir = $_dest_path;
			}
		}

		return trailingslashit( $dir ) . "{$name}-{$suffix}.{$new_ext}";
	}

	/**
	 * Builds and returns proper suffix for file based on height and width.
	 *
	 * @since 3.5.0
	 *
	 * @return string|false suffix
	 */
	public function get_suffix() {
		if ( ! $this->get_size() ) {
			return false;
		}

		return "{$this->size['width']}x{$this->size['height']}";
	}

	/**
	 * Check if a JPEG image has EXIF Orientation tag and rotate it if needed.
	 *
	 * @since 5.3.0
	 *
	 * @return bool|WP_Error True if the image was rotated. False if not rotated (no EXIF data or the image doesn't need to be rotated).
	 *                       WP_Error if error while rotating.
	 */
	public function maybe_exif_rotate() {
		$orientation = null;

		if ( is_callable( 'exif_read_data' ) && 'image/jpeg' === $this->mime_type ) {
			$exif_data = @exif_read_data( $this->file );

			if ( ! empty( $exif_data['Orientation'] ) ) {
				$orientation = (int) $exif_data['Orientation'];
			}
		}

		/**
		 * Filters the `$orientation` value to correct it before rotating or to prevemnt rotating the image.
		 *
		 * @since 5.3.0
		 *
		 * @param int    $orientation EXIF Orientation value as retrieved from the image file.
		 * @param string $file        Path to the image file.
		 */
		$orientation = apply_filters( 'wp_image_maybe_exif_rotate', $orientation, $this->file );

		if ( ! $orientation || 1 === $orientation ) {
			return false;
		}

		switch ( $orientation ) {
			case 2:
				// Flip horizontally.
				$result = $this->flip( true, false );
				break;
			case 3:
				// Rotate 180 degrees or flip horizontally and vertically.
				// Flipping seems faster and uses less resources.
				$result = $this->flip( true, true );
				break;
			case 4:
				// Flip vertically.
				$result = $this->flip( false, true );
				break;
			case 5:
				// Rotate 90 degrees counter-clockwise and flip vertically.
				$result = $this->rotate( 90 );

				if ( ! is_wp_error( $result ) ) {
					$result = $this->flip( false, true );
				}

				break;
			case 6:
				// Rotate 90 degrees clockwise (270 counter-clockwise).
				$result = $this->rotate( 270 );
				break;
			case 7:
				// Rotate 90 degrees counter-clockwise and flip horizontally.
				$result = $this->rotate( 90 );

				if ( ! is_wp_error( $result ) ) {
					$result = $this->flip( true, false );
				}

				break;
			case 8:
				// Rotate 90 degrees counter-clockwise.
				$result = $this->rotate( 90 );
				break;
		}

		return $result;
	}

	/**
	 * Either calls editor's save function or handles file as a stream.
	 *
	 * @since 3.5.0
	 *
	 * @param string|stream $filename
	 * @param callable      $function
	 * @param array         $arguments
	 * @return bool
	 */
	protected function make_image( $filename, $function, $arguments ) {
		$stream = wp_is_stream( $filename );
		if ( $stream ) {
			ob_start();
		} else {
			// The directory containing the original file may no longer exist when using a replication plugin.
			wp_mkdir_p( dirname( $filename ) );
		}

		$result = call_user_func_array( $function, $arguments );

		if ( $result && $stream ) {
			$contents = ob_get_contents();

			$fp = fopen( $filename, 'w' );

			if ( ! $fp ) {
				ob_end_clean();
				return false;
			}

			fwrite( $fp, $contents );
			fclose( $fp );
		}

		if ( $stream ) {
			ob_end_clean();
		}

		return $result;
	}

	/**
	 * Returns first matched mime-type from extension,
	 * as mapped from wp_get_mime_types()
	 *
	 * @since 3.5.0
	 *
	 * @param string $extension
	 * @return string|false
	 */
	protected static function get_mime_type( $extension = null ) {
		if ( ! $extension ) {
			return false;
		}

		$mime_types = wp_get_mime_types();
		$extensions = array_keys( $mime_types );

		foreach ( $extensions as $_extension ) {
			if ( preg_match( "/{$extension}/i", $_extension ) ) {
				return $mime_types[ $_extension ];
			}
		}

		return false;
	}

	/**
	 * Returns first matched extension from Mime-type,
	 * as mapped from wp_get_mime_types()
	 *
	 * @since 3.5.0
	 *
	 * @param string $mime_type
	 * @return string|false
	 */
	protected static function get_extension( $mime_type = null ) {
		$extensions = explode( '|', array_search( $mime_type, wp_get_mime_types(), true ) );

		if ( empty( $extensions[0] ) ) {
			return false;
		}

		return $extensions[0];
	}
}


<?php
/**
 * WordPress List utility class
 *
 * @package WordPress
 * @since 4.7.0
 */

/**
 * List utility.
 *
 * Utility class to handle operations on an array of objects.
 *
 * @since 4.7.0
 */
class WP_List_Util {
	/**
	 * The input array.
	 *
	 * @since 4.7.0
	 * @var array
	 */
	private $input = array();

	/**
	 * The output array.
	 *
	 * @since 4.7.0
	 * @var array
	 */
	private $output = array();

	/**
	 * Temporary arguments for sorting.
	 *
	 * @since 4.7.0
	 * @var array
	 */
	private $orderby = array();

	/**
	 * Constructor.
	 *
	 * Sets the input array.
	 *
	 * @since 4.7.0
	 *
	 * @param array $input Array to perform operations on.
	 */
	public function __construct( $input ) {
		$this->output = $input;
		$this->input  = $input;
	}

	/**
	 * Returns the original input array.
	 *
	 * @since 4.7.0
	 *
	 * @return array The input array.
	 */
	public function get_input() {
		return $this->input;
	}

	/**
	 * Returns the output array.
	 *
	 * @since 4.7.0
	 *
	 * @return array The output array.
	 */
	public function get_output() {
		return $this->output;
	}

	/**
	 * Filters the list, based on a set of key => value arguments.
	 *
	 * @since 4.7.0
	 *
	 * @param array  $args     Optional. An array of key => value arguments to match
	 *                         against each object. Default empty array.
	 * @param string $operator Optional. The logical operation to perform. 'AND' means
	 *                         all elements from the array must match. 'OR' means only
	 *                         one element needs to match. 'NOT' means no elements may
	 *                         match. Default 'AND'.
	 * @return array Array of found values.
	 */
	public function filter( $args = array(), $operator = 'AND' ) {
		if ( empty( $args ) ) {
			return $this->output;
		}

		$operator = strtoupper( $operator );

		if ( ! in_array( $operator, array( 'AND', 'OR', 'NOT' ), true ) ) {
			return array();
		}

		$count    = count( $args );
		$filtered = array();

		foreach ( $this->output as $key => $obj ) {
			$matched = 0;

			foreach ( $args as $m_key => $m_value ) {
				if ( is_array( $obj ) ) {
					// Treat object as an array.
					if ( array_key_exists( $m_key, $obj ) && ( $m_value == $obj[ $m_key ] ) ) {
						$matched++;
					}
				} elseif ( is_object( $obj ) ) {
					// Treat object as an object.
					if ( isset( $obj->{$m_key} ) && ( $m_value == $obj->{$m_key} ) ) {
						$matched++;
					}
				}
			}

			if ( ( 'AND' === $operator && $matched === $count )
				|| ( 'OR' === $operator && $matched > 0 )
				|| ( 'NOT' === $operator && 0 === $matched )
			) {
				$filtered[ $key ] = $obj;
			}
		}

		$this->output = $filtered;

		return $this->output;
	}

	/**
	 * Plucks a certain field out of each object in the list.
	 *
	 * This has the same functionality and prototype of
	 * array_column() (PHP 5.5) but also supports objects.
	 *
	 * @since 4.7.0
	 *
	 * @param int|string $field     Field from the object to place instead of the entire object
	 * @param int|string $index_key Optional. Field from the object to use as keys for the new array.
	 *                              Default null.
	 * @return array Array of found values. If `$index_key` is set, an array of found values with keys
	 *               corresponding to `$index_key`. If `$index_key` is null, array keys from the original
	 *               `$list` will be preserved in the results.
	 */
	public function pluck( $field, $index_key = null ) {
		$newlist = array();

		if ( ! $index_key ) {
			/*
			 * This is simple. Could at some point wrap array_column()
			 * if we knew we had an array of arrays.
			 */
			foreach ( $this->output as $key => $value ) {
				if ( is_object( $value ) ) {
					$newlist[ $key ] = $value->$field;
				} else {
					$newlist[ $key ] = $value[ $field ];
				}
			}

			$this->output = $newlist;

			return $this->output;
		}

		/*
		 * When index_key is not set for a particular item, push the value
		 * to the end of the stack. This is how array_column() behaves.
		 */
		foreach ( $this->output as $value ) {
			if ( is_object( $value ) ) {
				if ( isset( $value->$index_key ) ) {
					$newlist[ $value->$index_key ] = $value->$field;
				} else {
					$newlist[] = $value->$field;
				}
			} else {
				if ( isset( $value[ $index_key ] ) ) {
					$newlist[ $value[ $index_key ] ] = $value[ $field ];
				} else {
					$newlist[] = $value[ $field ];
				}
			}
		}

		$this->output = $newlist;

		return $this->output;
	}

	/**
	 * Sorts the list, based on one or more orderby arguments.
	 *
	 * @since 4.7.0
	 *
	 * @param string|array $orderby       Optional. Either the field name to order by or an array
	 *                                    of multiple orderby fields as $orderby => $order.
	 * @param string       $order         Optional. Either 'ASC' or 'DESC'. Only used if $orderby
	 *                                    is a string.
	 * @param bool         $preserve_keys Optional. Whether to preserve keys. Default false.
	 * @return array The sorted array.
	 */
	public function sort( $orderby = array(), $order = 'ASC', $preserve_keys = false ) {
		if ( empty( $orderby ) ) {
			return $this->output;
		}

		if ( is_string( $orderby ) ) {
			$orderby = array( $orderby => $order );
		}

		foreach ( $orderby as $field => $direction ) {
			$orderby[ $field ] = 'DESC' === strtoupper( $direction ) ? 'DESC' : 'ASC';
		}

		$this->orderby = $orderby;

		if ( $preserve_keys ) {
			uasort( $this->output, array( $this, 'sort_callback' ) );
		} else {
			usort( $this->output, array( $this, 'sort_callback' ) );
		}

		$this->orderby = array();

		return $this->output;
	}

	/**
	 * Callback to sort the list by specific fields.
	 *
	 * @since 4.7.0
	 *
	 * @see WP_List_Util::sort()
	 *
	 * @param object|array $a One object to compare.
	 * @param object|array $b The other object to compare.
	 * @return int 0 if both objects equal. -1 if second object should come first, 1 otherwise.
	 */
	private function sort_callback( $a, $b ) {
		if ( empty( $this->orderby ) ) {
			return 0;
		}

		$a = (array) $a;
		$b = (array) $b;

		foreach ( $this->orderby as $field => $direction ) {
			if ( ! isset( $a[ $field ] ) || ! isset( $b[ $field ] ) ) {
				continue;
			}

			if ( $a[ $field ] == $b[ $field ] ) {
				continue;
			}

			$results = 'DESC' === $direction ? array( 1, -1 ) : array( -1, 1 );

			if ( is_numeric( $a[ $field ] ) && is_numeric( $b[ $field ] ) ) {
				return ( $a[ $field ] < $b[ $field ] ) ? $results[0] : $results[1];
			}

			return 0 > strcmp( $a[ $field ], $b[ $field ] ) ? $results[0] : $results[1];
		}

		return 0;
	}
}


<?php
/**
 * Locale API: WP_Locale_Switcher class
 *
 * @package WordPress
 * @subpackage i18n
 * @since 4.7.0
 */

/**
 * Core class used for switching locales.
 *
 * @since 4.7.0
 */
class WP_Locale_Switcher {
	/**
	 * Locale stack.
	 *
	 * @since 4.7.0
	 * @var string[]
	 */
	private $locales = array();

	/**
	 * Original locale.
	 *
	 * @since 4.7.0
	 * @var string
	 */
	private $original_locale;

	/**
	 * Holds all available languages.
	 *
	 * @since 4.7.0
	 * @var array An array of language codes (file names without the .mo extension).
	 */
	private $available_languages = array();

	/**
	 * Constructor.
	 *
	 * Stores the original locale as well as a list of all available languages.
	 *
	 * @since 4.7.0
	 */
	public function __construct() {
		$this->original_locale     = determine_locale();
		$this->available_languages = array_merge( array( 'en_US' ), get_available_languages() );
	}

	/**
	 * Initializes the locale switcher.
	 *
	 * Hooks into the {@see 'locale'} filter to change the locale on the fly.
	 *
	 * @since 4.7.0
	 */
	public function init() {
		add_filter( 'locale', array( $this, 'filter_locale' ) );
	}

	/**
	 * Switches the translations according to the given locale.
	 *
	 * @since 4.7.0
	 *
	 * @param string $locale The locale to switch to.
	 * @return bool True on success, false on failure.
	 */
	public function switch_to_locale( $locale ) {
		$current_locale = determine_locale();
		if ( $current_locale === $locale ) {
			return false;
		}

		if ( ! in_array( $locale, $this->available_languages, true ) ) {
			return false;
		}

		$this->locales[] = $locale;

		$this->change_locale( $locale );

		/**
		 * Fires when the locale is switched.
		 *
		 * @since 4.7.0
		 *
		 * @param string $locale The new locale.
		 */
		do_action( 'switch_locale', $locale );

		return true;
	}

	/**
	 * Restores the translations according to the previous locale.
	 *
	 * @since 4.7.0
	 *
	 * @return string|false Locale on success, false on failure.
	 */
	public function restore_previous_locale() {
		$previous_locale = array_pop( $this->locales );

		if ( null === $previous_locale ) {
			// The stack is empty, bail.
			return false;
		}

		$locale = end( $this->locales );

		if ( ! $locale ) {
			// There's nothing left in the stack: go back to the original locale.
			$locale = $this->original_locale;
		}

		$this->change_locale( $locale );

		/**
		 * Fires when the locale is restored to the previous one.
		 *
		 * @since 4.7.0
		 *
		 * @param string $locale          The new locale.
		 * @param string $previous_locale The previous locale.
		 */
		do_action( 'restore_previous_locale', $locale, $previous_locale );

		return $locale;
	}

	/**
	 * Restores the translations according to the original locale.
	 *
	 * @since 4.7.0
	 *
	 * @return string|false Locale on success, false on failure.
	 */
	public function restore_current_locale() {
		if ( empty( $this->locales ) ) {
			return false;
		}

		$this->locales = array( $this->original_locale );

		return $this->restore_previous_locale();
	}

	/**
	 * Whether switch_to_locale() is in effect.
	 *
	 * @since 4.7.0
	 *
	 * @return bool True if the locale has been switched, false otherwise.
	 */
	public function is_switched() {
		return ! empty( $this->locales );
	}

	/**
	 * Filters the locale of the WordPress installation.
	 *
	 * @since 4.7.0
	 *
	 * @param string $locale The locale of the WordPress installation.
	 * @return string The locale currently being switched to.
	 */
	public function filter_locale( $locale ) {
		$switched_locale = end( $this->locales );

		if ( $switched_locale ) {
			return $switched_locale;
		}

		return $locale;
	}

	/**
	 * Load translations for a given locale.
	 *
	 * When switching to a locale, translations for this locale must be loaded from scratch.
	 *
	 * @since 4.7.0
	 *
	 * @global Mo[] $l10n An array of all currently loaded text domains.
	 *
	 * @param string $locale The locale to load translations for.
	 */
	private function load_translations( $locale ) {
		global $l10n;

		$domains = $l10n ? array_keys( $l10n ) : array();

		load_default_textdomain( $locale );

		foreach ( $domains as $domain ) {
			if ( 'default' === $domain ) {
				continue;
			}

			unload_textdomain( $domain );
			get_translations_for_domain( $domain );
		}
	}

	/**
	 * Changes the site's locale to the given one.
	 *
	 * Loads the translations, changes the global `$wp_locale` object and updates
	 * all post type labels.
	 *
	 * @since 4.7.0
	 *
	 * @global WP_Locale $wp_locale WordPress date and time locale object.
	 *
	 * @param string $locale The locale to change to.
	 */
	private function change_locale( $locale ) {
		// Reset translation availability information.
		_get_path_to_translation( null, true );

		$this->load_translations( $locale );

		$GLOBALS['wp_locale'] = new WP_Locale();

		/**
		 * Fires when the locale is switched to or restored.
		 *
		 * @since 4.7.0
		 *
		 * @param string $locale The new locale.
		 */
		do_action( 'change_locale', $locale );
	}
}


<?php
/**
 * Locale API: WP_Locale class
 *
 * @package WordPress
 * @subpackage i18n
 * @since 4.6.0
 */

/**
 * Core class used to store translated data for a locale.
 *
 * @since 2.1.0
 * @since 4.6.0 Moved to its own file from wp-includes/locale.php.
 */
class WP_Locale {
	/**
	 * Stores the translated strings for the full weekday names.
	 *
	 * @since 2.1.0
	 * @var array
	 */
	public $weekday;

	/**
	 * Stores the translated strings for the one character weekday names.
	 *
	 * There is a hack to make sure that Tuesday and Thursday, as well
	 * as Sunday and Saturday, don't conflict. See init() method for more.
	 *
	 * @see WP_Locale::init() for how to handle the hack.
	 *
	 * @since 2.1.0
	 * @var array
	 */
	public $weekday_initial;

	/**
	 * Stores the translated strings for the abbreviated weekday names.
	 *
	 * @since 2.1.0
	 * @var array
	 */
	public $weekday_abbrev;

	/**
	 * Stores the translated strings for the full month names.
	 *
	 * @since 2.1.0
	 * @var array
	 */
	public $month;

	/**
	 * Stores the translated strings for the month names in genitive case, if the locale specifies.
	 *
	 * @since 4.4.0
	 * @var array
	 */
	public $month_genitive;

	/**
	 * Stores the translated strings for the abbreviated month names.
	 *
	 * @since 2.1.0
	 * @var array
	 */
	public $month_abbrev;

	/**
	 * Stores the translated strings for 'am' and 'pm'.
	 *
	 * Also the capitalized versions.
	 *
	 * @since 2.1.0
	 * @var array
	 */
	public $meridiem;

	/**
	 * The text direction of the locale language.
	 *
	 * Default is left to right 'ltr'.
	 *
	 * @since 2.1.0
	 * @var string
	 */
	public $text_direction = 'ltr';

	/**
	 * The thousands separator and decimal point values used for localizing numbers.
	 *
	 * @since 2.3.0
	 * @var array
	 */
	public $number_format;

	/**
	 * Constructor which calls helper methods to set up object variables.
	 *
	 * @since 2.1.0
	 */
	public function __construct() {
		$this->init();
		$this->register_globals();
	}

	/**
	 * Sets up the translated strings and object properties.
	 *
	 * The method creates the translatable strings for various
	 * calendar elements. Which allows for specifying locale
	 * specific calendar names and text direction.
	 *
	 * @since 2.1.0
	 *
	 * @global string $text_direction
	 * @global string $wp_version     The WordPress version string.
	 */
	public function init() {
		// The weekdays.
		$this->weekday[0] = /* translators: Weekday. */ __( 'Sunday' );
		$this->weekday[1] = /* translators: Weekday. */ __( 'Monday' );
		$this->weekday[2] = /* translators: Weekday. */ __( 'Tuesday' );
		$this->weekday[3] = /* translators: Weekday. */ __( 'Wednesday' );
		$this->weekday[4] = /* translators: Weekday. */ __( 'Thursday' );
		$this->weekday[5] = /* translators: Weekday. */ __( 'Friday' );
		$this->weekday[6] = /* translators: Weekday. */ __( 'Saturday' );

		// The first letter of each day.
		$this->weekday_initial[ __( 'Sunday' ) ]    = /* translators: One-letter abbreviation of the weekday. */ _x( 'S', 'Sunday initial' );
		$this->weekday_initial[ __( 'Monday' ) ]    = /* translators: One-letter abbreviation of the weekday. */ _x( 'M', 'Monday initial' );
		$this->weekday_initial[ __( 'Tuesday' ) ]   = /* translators: One-letter abbreviation of the weekday. */ _x( 'T', 'Tuesday initial' );
		$this->weekday_initial[ __( 'Wednesday' ) ] = /* translators: One-letter abbreviation of the weekday. */ _x( 'W', 'Wednesday initial' );
		$this->weekday_initial[ __( 'Thursday' ) ]  = /* translators: One-letter abbreviation of the weekday. */ _x( 'T', 'Thursday initial' );
		$this->weekday_initial[ __( 'Friday' ) ]    = /* translators: One-letter abbreviation of the weekday. */ _x( 'F', 'Friday initial' );
		$this->weekday_initial[ __( 'Saturday' ) ]  = /* translators: One-letter abbreviation of the weekday. */ _x( 'S', 'Saturday initial' );

		// Abbreviations for each day.
		$this->weekday_abbrev[ __( 'Sunday' ) ]    = /* translators: Three-letter abbreviation of the weekday. */ __( 'Sun' );
		$this->weekday_abbrev[ __( 'Monday' ) ]    = /* translators: Ttree-letter abbreviation of the weekday. */ __( 'Mon' );
		$this->weekday_abbrev[ __( 'Tuesday' ) ]   = /* translators: Three-letter abbreviation of the weekday. */ __( 'Tue' );
		$this->weekday_abbrev[ __( 'Wednesday' ) ] = /* translators: Three-letter abbreviation of the weekday. */ __( 'Wed' );
		$this->weekday_abbrev[ __( 'Thursday' ) ]  = /* translators: Three-letter abbreviation of the weekday. */ __( 'Thu' );
		$this->weekday_abbrev[ __( 'Friday' ) ]    = /* translators: Three-letter abbreviation of the weekday. */ __( 'Fri' );
		$this->weekday_abbrev[ __( 'Saturday' ) ]  = /* translators: Three-letter abbreviation of the weekday. */ __( 'Sat' );

		// The months.
		$this->month['01'] = /* translators: Month name. */ __( 'January' );
		$this->month['02'] = /* translators: Month name. */ __( 'February' );
		$this->month['03'] = /* translators: Month name. */ __( 'March' );
		$this->month['04'] = /* translators: Month name. */ __( 'April' );
		$this->month['05'] = /* translators: Month name. */ __( 'May' );
		$this->month['06'] = /* translators: Month name. */ __( 'June' );
		$this->month['07'] = /* translators: Month name. */ __( 'July' );
		$this->month['08'] = /* translators: Month name. */ __( 'August' );
		$this->month['09'] = /* translators: Month name. */ __( 'September' );
		$this->month['10'] = /* translators: Month name. */ __( 'October' );
		$this->month['11'] = /* translators: Month name. */ __( 'November' );
		$this->month['12'] = /* translators: Month name. */ __( 'December' );

		// The months, genitive.
		$this->month_genitive['01'] = /* translators: Month name, genitive. */ _x( 'January', 'genitive' );
		$this->month_genitive['02'] = /* translators: Month name, genitive. */ _x( 'February', 'genitive' );
		$this->month_genitive['03'] = /* translators: Month name, genitive. */ _x( 'March', 'genitive' );
		$this->month_genitive['04'] = /* translators: Month name, genitive. */ _x( 'April', 'genitive' );
		$this->month_genitive['05'] = /* translators: Month name, genitive. */ _x( 'May', 'genitive' );
		$this->month_genitive['06'] = /* translators: Month name, genitive. */ _x( 'June', 'genitive' );
		$this->month_genitive['07'] = /* translators: Month name, genitive. */ _x( 'July', 'genitive' );
		$this->month_genitive['08'] = /* translators: Month name, genitive. */ _x( 'August', 'genitive' );
		$this->month_genitive['09'] = /* translators: Month name, genitive. */ _x( 'September', 'genitive' );
		$this->month_genitive['10'] = /* translators: Month name, genitive. */ _x( 'October', 'genitive' );
		$this->month_genitive['11'] = /* translators: Month name, genitive. */ _x( 'November', 'genitive' );
		$this->month_genitive['12'] = /* translators: Month name, genitive. */ _x( 'December', 'genitive' );

		// Abbreviations for each month.
		$this->month_abbrev[ __( 'January' ) ]   = /* translators: Three-letter abbreviation of the month. */ _x( 'Jan', 'January abbreviation' );
		$this->month_abbrev[ __( 'February' ) ]  = /* translators: Three-letter abbreviation of the month. */ _x( 'Feb', 'February abbreviation' );
		$this->month_abbrev[ __( 'March' ) ]     = /* translators: Three-letter abbreviation of the month. */ _x( 'Mar', 'March abbreviation' );
		$this->month_abbrev[ __( 'April' ) ]     = /* translators: Three-letter abbreviation of the month. */ _x( 'Apr', 'April abbreviation' );
		$this->month_abbrev[ __( 'May' ) ]       = /* translators: Three-letter abbreviation of the month. */ _x( 'May', 'May abbreviation' );
		$this->month_abbrev[ __( 'June' ) ]      = /* translators: Three-letter abbreviation of the month. */ _x( 'Jun', 'June abbreviation' );
		$this->month_abbrev[ __( 'July' ) ]      = /* translators: Three-letter abbreviation of the month. */ _x( 'Jul', 'July abbreviation' );
		$this->month_abbrev[ __( 'August' ) ]    = /* translators: Three-letter abbreviation of the month. */ _x( 'Aug', 'August abbreviation' );
		$this->month_abbrev[ __( 'September' ) ] = /* translators: Three-letter abbreviation of the month. */ _x( 'Sep', 'September abbreviation' );
		$this->month_abbrev[ __( 'October' ) ]   = /* translators: Three-letter abbreviation of the month. */ _x( 'Oct', 'October abbreviation' );
		$this->month_abbrev[ __( 'November' ) ]  = /* translators: Three-letter abbreviation of the month. */ _x( 'Nov', 'November abbreviation' );
		$this->month_abbrev[ __( 'December' ) ]  = /* translators: Three-letter abbreviation of the month. */ _x( 'Dec', 'December abbreviation' );

		// The meridiems.
		$this->meridiem['am'] = __( 'am' );
		$this->meridiem['pm'] = __( 'pm' );
		$this->meridiem['AM'] = __( 'AM' );
		$this->meridiem['PM'] = __( 'PM' );

		// Numbers formatting.
		// See https://www.php.net/number_format

		/* translators: $thousands_sep argument for https://www.php.net/number_format, default is ',' */
		$thousands_sep = __( 'number_format_thousands_sep' );

		// Replace space with a non-breaking space to avoid wrapping.
		$thousands_sep = str_replace( ' ', ' ', $thousands_sep );

		$this->number_format['thousands_sep'] = ( 'number_format_thousands_sep' === $thousands_sep ) ? ',' : $thousands_sep;

		/* translators: $dec_point argument for https://www.php.net/number_format, default is '.' */
		$decimal_point = __( 'number_format_decimal_point' );

		$this->number_format['decimal_point'] = ( 'number_format_decimal_point' === $decimal_point ) ? '.' : $decimal_point;

		// Set text direction.
		if ( isset( $GLOBALS['text_direction'] ) ) {
			$this->text_direction = $GLOBALS['text_direction'];

			/* translators: 'rtl' or 'ltr'. This sets the text direction for WordPress. */
		} elseif ( 'rtl' === _x( 'ltr', 'text direction' ) ) {
			$this->text_direction = 'rtl';
		}
	}

	/**
	 * Retrieve the full translated weekday word.
	 *
	 * Week starts on translated Sunday and can be fetched
	 * by using 0 (zero). So the week starts with 0 (zero)
	 * and ends on Saturday with is fetched by using 6 (six).
	 *
	 * @since 2.1.0
	 *
	 * @param int $weekday_number 0 for Sunday through 6 Saturday.
	 * @return string Full translated weekday.
	 */
	public function get_weekday( $weekday_number ) {
		return $this->weekday[ $weekday_number ];
	}

	/**
	 * Retrieve the translated weekday initial.
	 *
	 * The weekday initial is retrieved by the translated
	 * full weekday word. When translating the weekday initial
	 * pay attention to make sure that the starting letter does
	 * not conflict.
	 *
	 * @since 2.1.0
	 *
	 * @param string $weekday_name Full translated weekday word.
	 * @return string Translated weekday initial.
	 */
	public function get_weekday_initial( $weekday_name ) {
		return $this->weekday_initial[ $weekday_name ];
	}

	/**
	 * Retrieve the translated weekday abbreviation.
	 *
	 * The weekday abbreviation is retrieved by the translated
	 * full weekday word.
	 *
	 * @since 2.1.0
	 *
	 * @param string $weekday_name Full translated weekday word.
	 * @return string Translated weekday abbreviation.
	 */
	public function get_weekday_abbrev( $weekday_name ) {
		return $this->weekday_abbrev[ $weekday_name ];
	}

	/**
	 * Retrieve the full translated month by month number.
	 *
	 * The $month_number parameter has to be a string
	 * because it must have the '0' in front of any number
	 * that is less than 10. Starts from '01' and ends at
	 * '12'.
	 *
	 * You can use an integer instead and it will add the
	 * '0' before the numbers less than 10 for you.
	 *
	 * @since 2.1.0
	 *
	 * @param string|int $month_number '01' through '12'.
	 * @return string Translated full month name.
	 */
	public function get_month( $month_number ) {
		return $this->month[ zeroise( $month_number, 2 ) ];
	}

	/**
	 * Retrieve translated version of month abbreviation string.
	 *
	 * The $month_name parameter is expected to be the translated or
	 * translatable version of the month.
	 *
	 * @since 2.1.0
	 *
	 * @param string $month_name Translated month to get abbreviated version.
	 * @return string Translated abbreviated month.
	 */
	public function get_month_abbrev( $month_name ) {
		return $this->month_abbrev[ $month_name ];
	}

	/**
	 * Retrieve translated version of meridiem string.
	 *
	 * The $meridiem parameter is expected to not be translated.
	 *
	 * @since 2.1.0
	 *
	 * @param string $meridiem Either 'am', 'pm', 'AM', or 'PM'. Not translated version.
	 * @return string Translated version
	 */
	public function get_meridiem( $meridiem ) {
		return $this->meridiem[ $meridiem ];
	}

	/**
	 * Global variables are deprecated.
	 *
	 * For backward compatibility only.
	 *
	 * @deprecated For backward compatibility only.
	 *
	 * @global array $weekday
	 * @global array $weekday_initial
	 * @global array $weekday_abbrev
	 * @global array $month
	 * @global array $month_abbrev
	 *
	 * @since 2.1.0
	 */
	public function register_globals() {
		$GLOBALS['weekday']         = $this->weekday;
		$GLOBALS['weekday_initial'] = $this->weekday_initial;
		$GLOBALS['weekday_abbrev']  = $this->weekday_abbrev;
		$GLOBALS['month']           = $this->month;
		$GLOBALS['month_abbrev']    = $this->month_abbrev;
	}

	/**
	 * Checks if current locale is RTL.
	 *
	 * @since 3.0.0
	 * @return bool Whether locale is RTL.
	 */
	public function is_rtl() {
		return 'rtl' === $this->text_direction;
	}

	/**
	 * Register date/time format strings for general POT.
	 *
	 * Private, unused method to add some date/time formats translated
	 * on wp-admin/options-general.php to the general POT that would
	 * otherwise be added to the admin POT.
	 *
	 * @since 3.6.0
	 */
	public function _strings_for_pot() {
		/* translators: Localized date format, see https://www.php.net/date */
		__( 'F j, Y' );
		/* translators: Localized time format, see https://www.php.net/date */
		__( 'g:i a' );
		/* translators: Localized date and time format, see https://www.php.net/date */
		__( 'F j, Y g:i a' );
	}
}


<?php
/**
 * WP_MatchesMapRegex helper class
 *
 * @package WordPress
 * @since 4.7.0
 */

/**
 * Helper class to remove the need to use eval to replace $matches[] in query strings.
 *
 * @since 2.9.0
 */
class WP_MatchesMapRegex {
	/**
	 * store for matches
	 *
	 * @var array
	 */
	private $_matches;

	/**
	 * store for mapping result
	 *
	 * @var string
	 */
	public $output;

	/**
	 * subject to perform mapping on (query string containing $matches[] references
	 *
	 * @var string
	 */
	private $_subject;

	/**
	 * regexp pattern to match $matches[] references
	 *
	 * @var string
	 */
	public $_pattern = '(\$matches\[[1-9]+[0-9]*\])'; // Magic number.

	/**
	 * constructor
	 *
	 * @param string $subject subject if regex
	 * @param array  $matches data to use in map
	 */
	public function __construct( $subject, $matches ) {
		$this->_subject = $subject;
		$this->_matches = $matches;
		$this->output   = $this->_map();
	}

	/**
	 * Substitute substring matches in subject.
	 *
	 * static helper function to ease use
	 *
	 * @param string $subject subject
	 * @param array  $matches data used for substitution
	 * @return string
	 */
	public static function apply( $subject, $matches ) {
		$oSelf = new WP_MatchesMapRegex( $subject, $matches );
		return $oSelf->output;
	}

	/**
	 * do the actual mapping
	 *
	 * @return string
	 */
	private function _map() {
		$callback = array( $this, 'callback' );
		return preg_replace_callback( $this->_pattern, $callback, $this->_subject );
	}

	/**
	 * preg_replace_callback hook
	 *
	 * @param array $matches preg_replace regexp matches
	 * @return string
	 */
	public function callback( $matches ) {
		$index = intval( substr( $matches[0], 9, -1 ) );
		return ( isset( $this->_matches[ $index ] ) ? urlencode( $this->_matches[ $index ] ) : '' );
	}
}


<?php
/**
 * Meta API: WP_Meta_Query class
 *
 * @package WordPress
 * @subpackage Meta
 * @since 4.4.0
 */

/**
 * Core class used to implement meta queries for the Meta API.
 *
 * Used for generating SQL clauses that filter a primary query according to metadata keys and values.
 *
 * WP_Meta_Query is a helper that allows primary query classes, such as WP_Query and WP_User_Query,
 *
 * to filter their results by object metadata, by generating `JOIN` and `WHERE` subclauses to be attached
 * to the primary SQL query string.
 *
 * @since 3.2.0
 */
class WP_Meta_Query {
	/**
	 * Array of metadata queries.
	 *
	 * See WP_Meta_Query::__construct() for information on meta query arguments.
	 *
	 * @since 3.2.0
	 * @var array
	 */
	public $queries = array();

	/**
	 * The relation between the queries. Can be one of 'AND' or 'OR'.
	 *
	 * @since 3.2.0
	 * @var string
	 */
	public $relation;

	/**
	 * Database table to query for the metadata.
	 *
	 * @since 4.1.0
	 * @var string
	 */
	public $meta_table;

	/**
	 * Column in meta_table that represents the ID of the object the metadata belongs to.
	 *
	 * @since 4.1.0
	 * @var string
	 */
	public $meta_id_column;

	/**
	 * Database table that where the metadata's objects are stored (eg $wpdb->users).
	 *
	 * @since 4.1.0
	 * @var string
	 */
	public $primary_table;

	/**
	 * Column in primary_table that represents the ID of the object.
	 *
	 * @since 4.1.0
	 * @var string
	 */
	public $primary_id_column;

	/**
	 * A flat list of table aliases used in JOIN clauses.
	 *
	 * @since 4.1.0
	 * @var array
	 */
	protected $table_aliases = array();

	/**
	 * A flat list of clauses, keyed by clause 'name'.
	 *
	 * @since 4.2.0
	 * @var array
	 */
	protected $clauses = array();

	/**
	 * Whether the query contains any OR relations.
	 *
	 * @since 4.3.0
	 * @var bool
	 */
	protected $has_or_relation = false;

	/**
	 * Constructor.
	 *
	 * @since 3.2.0
	 * @since 4.2.0 Introduced support for naming query clauses by associative array keys.
	 * @since 5.1.0 Introduced $compare_key clause parameter, which enables LIKE key matches.
	 * @since 5.3.0 Increased the number of operators available to $compare_key. Introduced $type_key,
	 *              which enables the $key to be cast to a new data type for comparisons.
	 *
	 * @param array $meta_query {
	 *     Array of meta query clauses. When first-order clauses or sub-clauses use strings as
	 *     their array keys, they may be referenced in the 'orderby' parameter of the parent query.
	 *
	 *     @type string $relation Optional. The MySQL keyword used to join
	 *                            the clauses of the query. Accepts 'AND', or 'OR'. Default 'AND'.
	 *     @type array  ...$0 {
	 *         Optional. An array of first-order clause parameters, or another fully-formed meta query.
	 *
	 *         @type string $key         Meta key to filter by.
	 *         @type string $compare_key MySQL operator used for comparing the $key. Accepts '=', '!='
	 *                                   'LIKE', 'NOT LIKE', 'IN', 'NOT IN', 'REGEXP', 'NOT REGEXP', 'RLIKE',
	 *                                   'EXISTS' (alias of '=') or 'NOT EXISTS' (alias of '!=').
	 *                                   Default is 'IN' when `$key` is an array, '=' otherwise.
	 *         @type string $type_key    MySQL data type that the meta_key column will be CAST to for
	 *                                   comparisons. Accepts 'BINARY' for case-sensitive regular expression
	 *                                   comparisons. Default is ''.
	 *         @type string $value       Meta value to filter by.
	 *         @type string $compare     MySQL operator used for comparing the $value. Accepts '=',
	 *                                   '!=', '>', '>=', '<', '<=', 'LIKE', 'NOT LIKE',
	 *                                   'IN', 'NOT IN', 'BETWEEN', 'NOT BETWEEN', 'REGEXP',
	 *                                   'NOT REGEXP', 'RLIKE', 'EXISTS' or 'NOT EXISTS'.
	 *                                   Default is 'IN' when `$value` is an array, '=' otherwise.
	 *         @type string $type        MySQL data type that the meta_value column will be CAST to for
	 *                                   comparisons. Accepts 'NUMERIC', 'BINARY', 'CHAR', 'DATE',
	 *                                   'DATETIME', 'DECIMAL', 'SIGNED', 'TIME', or 'UNSIGNED'.
	 *                                   Default is 'CHAR'.
	 *     }
	 * }
	 */
	public function __construct( $meta_query = false ) {
		if ( ! $meta_query ) {
			return;
		}

		if ( isset( $meta_query['relation'] ) && 'OR' === strtoupper( $meta_query['relation'] ) ) {
			$this->relation = 'OR';
		} else {
			$this->relation = 'AND';
		}

		$this->queries = $this->sanitize_query( $meta_query );
	}

	/**
	 * Ensure the 'meta_query' argument passed to the class constructor is well-formed.
	 *
	 * Eliminates empty items and ensures that a 'relation' is set.
	 *
	 * @since 4.1.0
	 *
	 * @param array $queries Array of query clauses.
	 * @return array Sanitized array of query clauses.
	 */
	public function sanitize_query( $queries ) {
		$clean_queries = array();

		if ( ! is_array( $queries ) ) {
			return $clean_queries;
		}

		foreach ( $queries as $key => $query ) {
			if ( 'relation' === $key ) {
				$relation = $query;

			} elseif ( ! is_array( $query ) ) {
				continue;

				// First-order clause.
			} elseif ( $this->is_first_order_clause( $query ) ) {
				if ( isset( $query['value'] ) && array() === $query['value'] ) {
					unset( $query['value'] );
				}

				$clean_queries[ $key ] = $query;

				// Otherwise, it's a nested query, so we recurse.
			} else {
				$cleaned_query = $this->sanitize_query( $query );

				if ( ! empty( $cleaned_query ) ) {
					$clean_queries[ $key ] = $cleaned_query;
				}
			}
		}

		if ( empty( $clean_queries ) ) {
			return $clean_queries;
		}

		// Sanitize the 'relation' key provided in the query.
		if ( isset( $relation ) && 'OR' === strtoupper( $relation ) ) {
			$clean_queries['relation'] = 'OR';
			$this->has_or_relation     = true;

			/*
			* If there is only a single clause, call the relation 'OR'.
			* This value will not actually be used to join clauses, but it
			* simplifies the logic around combining key-only queries.
			*/
		} elseif ( 1 === count( $clean_queries ) ) {
			$clean_queries['relation'] = 'OR';

			// Default to AND.
		} else {
			$clean_queries['relation'] = 'AND';
		}

		return $clean_queries;
	}

	/**
	 * Determine whether a query clause is first-order.
	 *
	 * A first-order meta query clause is one that has either a 'key' or
	 * a 'value' array key.
	 *
	 * @since 4.1.0
	 *
	 * @param array $query Meta query arguments.
	 * @return bool Whether the query clause is a first-order clause.
	 */
	protected function is_first_order_clause( $query ) {
		return isset( $query['key'] ) || isset( $query['value'] );
	}

	/**
	 * Constructs a meta query based on 'meta_*' query vars
	 *
	 * @since 3.2.0
	 *
	 * @param array $qv The query variables
	 */
	public function parse_query_vars( $qv ) {
		$meta_query = array();

		/*
		 * For orderby=meta_value to work correctly, simple query needs to be
		 * first (so that its table join is against an unaliased meta table) and
		 * needs to be its own clause (so it doesn't interfere with the logic of
		 * the rest of the meta_query).
		 */
		$primary_meta_query = array();
		foreach ( array( 'key', 'compare', 'type', 'compare_key', 'type_key' ) as $key ) {
			if ( ! empty( $qv[ "meta_$key" ] ) ) {
				$primary_meta_query[ $key ] = $qv[ "meta_$key" ];
			}
		}

		// WP_Query sets 'meta_value' = '' by default.
		if ( isset( $qv['meta_value'] ) && '' !== $qv['meta_value'] && ( ! is_array( $qv['meta_value'] ) || $qv['meta_value'] ) ) {
			$primary_meta_query['value'] = $qv['meta_value'];
		}

		$existing_meta_query = isset( $qv['meta_query'] ) && is_array( $qv['meta_query'] ) ? $qv['meta_query'] : array();

		if ( ! empty( $primary_meta_query ) && ! empty( $existing_meta_query ) ) {
			$meta_query = array(
				'relation' => 'AND',
				$primary_meta_query,
				$existing_meta_query,
			);
		} elseif ( ! empty( $primary_meta_query ) ) {
			$meta_query = array(
				$primary_meta_query,
			);
		} elseif ( ! empty( $existing_meta_query ) ) {
			$meta_query = $existing_meta_query;
		}

		$this->__construct( $meta_query );
	}

	/**
	 * Return the appropriate alias for the given meta type if applicable.
	 *
	 * @since 3.7.0
	 *
	 * @param string $type MySQL type to cast meta_value.
	 * @return string MySQL type.
	 */
	public function get_cast_for_type( $type = '' ) {
		if ( empty( $type ) ) {
			return 'CHAR';
		}

		$meta_type = strtoupper( $type );

		if ( ! preg_match( '/^(?:BINARY|CHAR|DATE|DATETIME|SIGNED|UNSIGNED|TIME|NUMERIC(?:\(\d+(?:,\s?\d+)?\))?|DECIMAL(?:\(\d+(?:,\s?\d+)?\))?)$/', $meta_type ) ) {
			return 'CHAR';
		}

		if ( 'NUMERIC' === $meta_type ) {
			$meta_type = 'SIGNED';
		}

		return $meta_type;
	}

	/**
	 * Generates SQL clauses to be appended to a main query.
	 *
	 * @since 3.2.0
	 *
	 * @param string $type              Type of meta, eg 'user', 'post'.
	 * @param string $primary_table     Database table where the object being filtered is stored (eg wp_users).
	 * @param string $primary_id_column ID column for the filtered object in $primary_table.
	 * @param object $context           Optional. The main query object.
	 * @return array|false {
	 *     Array containing JOIN and WHERE SQL clauses to append to the main query.
	 *
	 *     @type string $join  SQL fragment to append to the main JOIN clause.
	 *     @type string $where SQL fragment to append to the main WHERE clause.
	 * }
	 */
	public function get_sql( $type, $primary_table, $primary_id_column, $context = null ) {
		$meta_table = _get_meta_table( $type );
		if ( ! $meta_table ) {
			return false;
		}

		$this->table_aliases = array();

		$this->meta_table     = $meta_table;
		$this->meta_id_column = sanitize_key( $type . '_id' );

		$this->primary_table     = $primary_table;
		$this->primary_id_column = $primary_id_column;

		$sql = $this->get_sql_clauses();

		/*
		 * If any JOINs are LEFT JOINs (as in the case of NOT EXISTS), then all JOINs should
		 * be LEFT. Otherwise posts with no metadata will be excluded from results.
		 */
		if ( false !== strpos( $sql['join'], 'LEFT JOIN' ) ) {
			$sql['join'] = str_replace( 'INNER JOIN', 'LEFT JOIN', $sql['join'] );
		}

		/**
		 * Filters the meta query's generated SQL.
		 *
		 * @since 3.1.0
		 *
		 * @param array  $sql               Array containing the query's JOIN and WHERE clauses.
		 * @param array  $queries           Array of meta queries.
		 * @param string $type              Type of meta.
		 * @param string $primary_table     Primary table.
		 * @param string $primary_id_column Primary column ID.
		 * @param object $context           The main query object.
		 */
		return apply_filters_ref_array( 'get_meta_sql', array( $sql, $this->queries, $type, $primary_table, $primary_id_column, $context ) );
	}

	/**
	 * Generate SQL clauses to be appended to a main query.
	 *
	 * Called by the public WP_Meta_Query::get_sql(), this method is abstracted
	 * out to maintain parity with the other Query classes.
	 *
	 * @since 4.1.0
	 *
	 * @return array {
	 *     Array containing JOIN and WHERE SQL clauses to append to the main query.
	 *
	 *     @type string $join  SQL fragment to append to the main JOIN clause.
	 *     @type string $where SQL fragment to append to the main WHERE clause.
	 * }
	 */
	protected function get_sql_clauses() {
		/*
		 * $queries are passed by reference to get_sql_for_query() for recursion.
		 * To keep $this->queries unaltered, pass a copy.
		 */
		$queries = $this->queries;
		$sql     = $this->get_sql_for_query( $queries );

		if ( ! empty( $sql['where'] ) ) {
			$sql['where'] = ' AND ' . $sql['where'];
		}

		return $sql;
	}

	/**
	 * Generate SQL clauses for a single query array.
	 *
	 * If nested subqueries are found, this method recurses the tree to
	 * produce the properly nested SQL.
	 *
	 * @since 4.1.0
	 *
	 * @param array $query Query to parse (passed by reference).
	 * @param int   $depth Optional. Number of tree levels deep we currently are.
	 *                     Used to calculate indentation. Default 0.
	 * @return array {
	 *     Array containing JOIN and WHERE SQL clauses to append to a single query array.
	 *
	 *     @type string $join  SQL fragment to append to the main JOIN clause.
	 *     @type string $where SQL fragment to append to the main WHERE clause.
	 * }
	 */
	protected function get_sql_for_query( &$query, $depth = 0 ) {
		$sql_chunks = array(
			'join'  => array(),
			'where' => array(),
		);

		$sql = array(
			'join'  => '',
			'where' => '',
		);

		$indent = '';
		for ( $i = 0; $i < $depth; $i++ ) {
			$indent .= '  ';
		}

		foreach ( $query as $key => &$clause ) {
			if ( 'relation' === $key ) {
				$relation = $query['relation'];
			} elseif ( is_array( $clause ) ) {

				// This is a first-order clause.
				if ( $this->is_first_order_clause( $clause ) ) {
					$clause_sql = $this->get_sql_for_clause( $clause, $query, $key );

					$where_count = count( $clause_sql['where'] );
					if ( ! $where_count ) {
						$sql_chunks['where'][] = '';
					} elseif ( 1 === $where_count ) {
						$sql_chunks['where'][] = $clause_sql['where'][0];
					} else {
						$sql_chunks['where'][] = '( ' . implode( ' AND ', $clause_sql['where'] ) . ' )';
					}

					$sql_chunks['join'] = array_merge( $sql_chunks['join'], $clause_sql['join'] );
					// This is a subquery, so we recurse.
				} else {
					$clause_sql = $this->get_sql_for_query( $clause, $depth + 1 );

					$sql_chunks['where'][] = $clause_sql['where'];
					$sql_chunks['join'][]  = $clause_sql['join'];
				}
			}
		}

		// Filter to remove empties.
		$sql_chunks['join']  = array_filter( $sql_chunks['join'] );
		$sql_chunks['where'] = array_filter( $sql_chunks['where'] );

		if ( empty( $relation ) ) {
			$relation = 'AND';
		}

		// Filter duplicate JOIN clauses and combine into a single string.
		if ( ! empty( $sql_chunks['join'] ) ) {
			$sql['join'] = implode( ' ', array_unique( $sql_chunks['join'] ) );
		}

		// Generate a single WHERE clause with proper brackets and indentation.
		if ( ! empty( $sql_chunks['where'] ) ) {
			$sql['where'] = '( ' . "\n  " . $indent . implode( ' ' . "\n  " . $indent . $relation . ' ' . "\n  " . $indent, $sql_chunks['where'] ) . "\n" . $indent . ')';
		}

		return $sql;
	}

	/**
	 * Generate SQL JOIN and WHERE clauses for a first-order query clause.
	 *
	 * "First-order" means that it's an array with a 'key' or 'value'.
	 *
	 * @since 4.1.0
	 *
	 * @global wpdb $wpdb WordPress database abstraction object.
	 *
	 * @param array  $clause       Query clause (passed by reference).
	 * @param array  $parent_query Parent query array.
	 * @param string $clause_key   Optional. The array key used to name the clause in the original `$meta_query`
	 *                             parameters. If not provided, a key will be generated automatically.
	 * @return array {
	 *     Array containing JOIN and WHERE SQL clauses to append to a first-order query.
	 *
	 *     @type string $join  SQL fragment to append to the main JOIN clause.
	 *     @type string $where SQL fragment to append to the main WHERE clause.
	 * }
	 */
	public function get_sql_for_clause( &$clause, $parent_query, $clause_key = '' ) {
		global $wpdb;

		$sql_chunks = array(
			'where' => array(),
			'join'  => array(),
		);

		if ( isset( $clause['compare'] ) ) {
			$clause['compare'] = strtoupper( $clause['compare'] );
		} else {
			$clause['compare'] = isset( $clause['value'] ) && is_array( $clause['value'] ) ? 'IN' : '=';
		}

		$non_numeric_operators = array(
			'=',
			'!=',
			'LIKE',
			'NOT LIKE',
			'IN',
			'NOT IN',
			'EXISTS',
			'NOT EXISTS',
			'RLIKE',
			'REGEXP',
			'NOT REGEXP',
		);

		$numeric_operators = array(
			'>',
			'>=',
			'<',
			'<=',
			'BETWEEN',
			'NOT BETWEEN',
		);

		if ( ! in_array( $clause['compare'], $non_numeric_operators, true ) && ! in_array( $clause['compare'], $numeric_operators, true ) ) {
			$clause['compare'] = '=';
		}

		if ( isset( $clause['compare_key'] ) ) {
			$clause['compare_key'] = strtoupper( $clause['compare_key'] );
		} else {
			$clause['compare_key'] = isset( $clause['key'] ) && is_array( $clause['key'] ) ? 'IN' : '=';
		}

		if ( ! in_array( $clause['compare_key'], $non_numeric_operators, true ) ) {
			$clause['compare_key'] = '=';
		}

		$meta_compare     = $clause['compare'];
		$meta_compare_key = $clause['compare_key'];

		// First build the JOIN clause, if one is required.
		$join = '';

		// We prefer to avoid joins if possible. Look for an existing join compatible with this clause.
		$alias = $this->find_compatible_table_alias( $clause, $parent_query );
		if ( false === $alias ) {
			$i     = count( $this->table_aliases );
			$alias = $i ? 'mt' . $i : $this->meta_table;

			// JOIN clauses for NOT EXISTS have their own syntax.
			if ( 'NOT EXISTS' === $meta_compare ) {
				$join .= " LEFT JOIN $this->meta_table";
				$join .= $i ? " AS $alias" : '';

				if ( 'LIKE' === $meta_compare_key ) {
					$join .= $wpdb->prepare( " ON ($this->primary_table.$this->primary_id_column = $alias.$this->meta_id_column AND $alias.meta_key LIKE %s )", '%' . $wpdb->esc_like( $clause['key'] ) . '%' );
				} else {
					$join .= $wpdb->prepare( " ON ($this->primary_table.$this->primary_id_column = $alias.$this->meta_id_column AND $alias.meta_key = %s )", $clause['key'] );
				}

				// All other JOIN clauses.
			} else {
				$join .= " INNER JOIN $this->meta_table";
				$join .= $i ? " AS $alias" : '';
				$join .= " ON ( $this->primary_table.$this->primary_id_column = $alias.$this->meta_id_column )";
			}

			$this->table_aliases[] = $alias;
			$sql_chunks['join'][]  = $join;
		}

		// Save the alias to this clause, for future siblings to find.
		$clause['alias'] = $alias;

		// Determine the data type.
		$_meta_type     = isset( $clause['type'] ) ? $clause['type'] : '';
		$meta_type      = $this->get_cast_for_type( $_meta_type );
		$clause['cast'] = $meta_type;

		// Fallback for clause keys is the table alias. Key must be a string.
		if ( is_int( $clause_key ) || ! $clause_key ) {
			$clause_key = $clause['alias'];
		}

		// Ensure unique clause keys, so none are overwritten.
		$iterator        = 1;
		$clause_key_base = $clause_key;
		while ( isset( $this->clauses[ $clause_key ] ) ) {
			$clause_key = $clause_key_base . '-' . $iterator;
			$iterator++;
		}

		// Store the clause in our flat array.
		$this->clauses[ $clause_key ] =& $clause;

		// Next, build the WHERE clause.

		// meta_key.
		if ( array_key_exists( 'key', $clause ) ) {
			if ( 'NOT EXISTS' === $meta_compare ) {
				$sql_chunks['where'][] = $alias . '.' . $this->meta_id_column . ' IS NULL';
			} else {
				/**
				 * In joined clauses negative operators have to be nested into a
				 * NOT EXISTS clause and flipped, to avoid returning records with
				 * matching post IDs but different meta keys. Here we prepare the
				 * nested clause.
				 */
				if ( in_array( $meta_compare_key, array( '!=', 'NOT IN', 'NOT LIKE', 'NOT EXISTS', 'NOT REGEXP' ), true ) ) {
					// Negative clauses may be reused.
					$i                     = count( $this->table_aliases );
					$subquery_alias        = $i ? 'mt' . $i : $this->meta_table;
					$this->table_aliases[] = $subquery_alias;

					$meta_compare_string_start  = 'NOT EXISTS (';
					$meta_compare_string_start .= "SELECT 1 FROM $wpdb->postmeta $subquery_alias ";
					$meta_compare_string_start .= "WHERE $subquery_alias.post_ID = $alias.post_ID ";
					$meta_compare_string_end    = 'LIMIT 1';
					$meta_compare_string_end   .= ')';
				}

				switch ( $meta_compare_key ) {
					case '=':
					case 'EXISTS':
						$where = $wpdb->prepare( "$alias.meta_key = %s", trim( $clause['key'] ) ); // phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared
						break;
					case 'LIKE':
						$meta_compare_value = '%' . $wpdb->esc_like( trim( $clause['key'] ) ) . '%';
						$where              = $wpdb->prepare( "$alias.meta_key LIKE %s", $meta_compare_value ); // phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared
						break;
					case 'IN':
						$meta_compare_string = "$alias.meta_key IN (" . substr( str_repeat( ',%s', count( $clause['key'] ) ), 1 ) . ')';
						$where               = $wpdb->prepare( $meta_compare_string, $clause['key'] ); // phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared
						break;
					case 'RLIKE':
					case 'REGEXP':
						$operator = $meta_compare_key;
						if ( isset( $clause['type_key'] ) && 'BINARY' === strtoupper( $clause['type_key'] ) ) {
							$cast = 'BINARY';
						} else {
							$cast = '';
						}
						$where = $wpdb->prepare( "$alias.meta_key $operator $cast %s", trim( $clause['key'] ) ); // phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared
						break;

					case '!=':
					case 'NOT EXISTS':
						$meta_compare_string = $meta_compare_string_start . "AND $subquery_alias.meta_key = %s " . $meta_compare_string_end;
						$where               = $wpdb->prepare( $meta_compare_string, $clause['key'] ); // phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared
						break;
					case 'NOT LIKE':
						$meta_compare_string = $meta_compare_string_start . "AND $subquery_alias.meta_key LIKE %s " . $meta_compare_string_end;

						$meta_compare_value = '%' . $wpdb->esc_like( trim( $clause['key'] ) ) . '%';
						$where              = $wpdb->prepare( $meta_compare_string, $meta_compare_value ); // phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared
						break;
					case 'NOT IN':
						$array_subclause     = '(' . substr( str_repeat( ',%s', count( $clause['key'] ) ), 1 ) . ') ';
						$meta_compare_string = $meta_compare_string_start . "AND $subquery_alias.meta_key IN " . $array_subclause . $meta_compare_string_end;
						$where               = $wpdb->prepare( $meta_compare_string, $clause['key'] ); // phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared
						break;
					case 'NOT REGEXP':
						$operator = $meta_compare_key;
						if ( isset( $clause['type_key'] ) && 'BINARY' === strtoupper( $clause['type_key'] ) ) {
							$cast = 'BINARY';
						} else {
							$cast = '';
						}

						$meta_compare_string = $meta_compare_string_start . "AND $subquery_alias.meta_key REGEXP $cast %s " . $meta_compare_string_end;
						$where               = $wpdb->prepare( $meta_compare_string, $clause['key'] ); // phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared
						break;
				}

				$sql_chunks['where'][] = $where;
			}
		}

		// meta_value.
		if ( array_key_exists( 'value', $clause ) ) {
			$meta_value = $clause['value'];

			if ( in_array( $meta_compare, array( 'IN', 'NOT IN', 'BETWEEN', 'NOT BETWEEN' ), true ) ) {
				if ( ! is_array( $meta_value ) ) {
					$meta_value = preg_split( '/[,\s]+/', $meta_value );
				}
			} else {
				$meta_value = trim( $meta_value );
			}

			switch ( $meta_compare ) {
				case 'IN':
				case 'NOT IN':
					$meta_compare_string = '(' . substr( str_repeat( ',%s', count( $meta_value ) ), 1 ) . ')';
					$where               = $wpdb->prepare( $meta_compare_string, $meta_value );
					break;

				case 'BETWEEN':
				case 'NOT BETWEEN':
					$where = $wpdb->prepare( '%s AND %s', $meta_value[0], $meta_value[1] );
					break;

				case 'LIKE':
				case 'NOT LIKE':
					$meta_value = '%' . $wpdb->esc_like( $meta_value ) . '%';
					$where      = $wpdb->prepare( '%s', $meta_value );
					break;

				// EXISTS with a value is interpreted as '='.
				case 'EXISTS':
					$meta_compare = '=';
					$where        = $wpdb->prepare( '%s', $meta_value );
					break;

				// 'value' is ignored for NOT EXISTS.
				case 'NOT EXISTS':
					$where = '';
					break;

				default:
					$where = $wpdb->prepare( '%s', $meta_value );
					break;

			}

			if ( $where ) {
				if ( 'CHAR' === $meta_type ) {
					$sql_chunks['where'][] = "$alias.meta_value {$meta_compare} {$where}";
				} else {
					$sql_chunks['where'][] = "CAST($alias.meta_value AS {$meta_type}) {$meta_compare} {$where}";
				}
			}
		}

		/*
		 * Multiple WHERE clauses (for meta_key and meta_value) should
		 * be joined in parentheses.
		 */
		if ( 1 < count( $sql_chunks['where'] ) ) {
			$sql_chunks['where'] = array( '( ' . implode( ' AND ', $sql_chunks['where'] ) . ' )' );
		}

		return $sql_chunks;
	}

	/**
	 * Get a flattened list of sanitized meta clauses.
	 *
	 * This array should be used for clause lookup, as when the table alias and CAST type must be determined for
	 * a value of 'orderby' corresponding to a meta clause.
	 *
	 * @since 4.2.0
	 *
	 * @return array Meta clauses.
	 */
	public function get_clauses() {
		return $this->clauses;
	}

	/**
	 * Identify an existing table alias that is compatible with the current
	 * query clause.
	 *
	 * We avoid unnecessary table joins by allowing each clause to look for
	 * an existing table alias that is compatible with the query that it
	 * needs to perform.
	 *
	 * An existing alias is compatible if (a) it is a sibling of `$clause`
	 * (ie, it's under the scope of the same relation), and (b) the combination
	 * of operator and relation between the clauses allows for a shared table join.
	 * In the case of WP_Meta_Query, this only applies to 'IN' clauses that are
	 * connected by the relation 'OR'.
	 *
	 * @since 4.1.0
	 *
	 * @param array $clause       Query clause.
	 * @param array $parent_query Parent query of $clause.
	 * @return string|false Table alias if found, otherwise false.
	 */
	protected function find_compatible_table_alias( $clause, $parent_query ) {
		$alias = false;

		foreach ( $parent_query as $sibling ) {
			// If the sibling has no alias yet, there's nothing to check.
			if ( empty( $sibling['alias'] ) ) {
				continue;
			}

			// We're only interested in siblings that are first-order clauses.
			if ( ! is_array( $sibling ) || ! $this->is_first_order_clause( $sibling ) ) {
				continue;
			}

			$compatible_compares = array();

			// Clauses connected by OR can share joins as long as they have "positive" operators.
			if ( 'OR' === $parent_query['relation'] ) {
				$compatible_compares = array( '=', 'IN', 'BETWEEN', 'LIKE', 'REGEXP', 'RLIKE', '>', '>=', '<', '<=' );

				// Clauses joined by AND with "negative" operators share a join only if they also share a key.
			} elseif ( isset( $sibling['key'] ) && isset( $clause['key'] ) && $sibling['key'] === $clause['key'] ) {
				$compatible_compares = array( '!=', 'NOT IN', 'NOT LIKE' );
			}

			$clause_compare  = strtoupper( $clause['compare'] );
			$sibling_compare = strtoupper( $sibling['compare'] );
			if ( in_array( $clause_compare, $compatible_compares, true ) && in_array( $sibling_compare, $compatible_compares, true ) ) {
				$alias = $sibling['alias'];
				break;
			}
		}

		/**
		 * Filters the table alias identified as compatible with the current clause.
		 *
		 * @since 4.1.0
		 *
		 * @param string|bool   $alias        Table alias, or false if none was found.
		 * @param array         $clause       First-order query clause.
		 * @param array         $parent_query Parent of $clause.
		 * @param WP_Meta_Query $this         WP_Meta_Query object.
		 */
		return apply_filters( 'meta_query_find_compatible_table_alias', $alias, $clause, $parent_query, $this );
	}

	/**
	 * Checks whether the current query has any OR relations.
	 *
	 * In some cases, the presence of an OR relation somewhere in the query will require
	 * the use of a `DISTINCT` or `GROUP BY` keyword in the `SELECT` clause. The current
	 * method can be used in these cases to determine whether such a clause is necessary.
	 *
	 * @since 4.3.0
	 *
	 * @return bool True if the query contains any `OR` relations, otherwise false.
	 */
	public function has_or_relation() {
		return $this->has_or_relation;
	}
}


<?php
/**
 * Meta API: WP_Metadata_Lazyloader class
 *
 * @package WordPress
 * @subpackage Meta
 * @since 4.5.0
 */

/**
 * Core class used for lazy-loading object metadata.
 *
 * When loading many objects of a given type, such as posts in a WP_Query loop, it often makes
 * sense to prime various metadata caches at the beginning of the loop. This means fetching all
 * relevant metadata with a single database query, a technique that has the potential to improve
 * performance dramatically in some cases.
 *
 * In cases where the given metadata may not even be used in the loop, we can improve performance
 * even more by only priming the metadata cache for affected items the first time a piece of metadata
 * is requested - ie, by lazy-loading it. So, for example, comment meta may not be loaded into the
 * cache in the comments section of a post until the first time get_comment_meta() is called in the
 * context of the comment loop.
 *
 * WP uses the WP_Metadata_Lazyloader class to queue objects for metadata cache priming. The class
 * then detects the relevant get_*_meta() function call, and queries the metadata of all queued objects.
 *
 * Do not access this class directly. Use the wp_metadata_lazyloader() function.
 *
 * @since 4.5.0
 */
class WP_Metadata_Lazyloader {
	/**
	 * Pending objects queue.
	 *
	 * @since 4.5.0
	 * @var array
	 */
	protected $pending_objects;

	/**
	 * Settings for supported object types.
	 *
	 * @since 4.5.0
	 * @var array
	 */
	protected $settings = array();

	/**
	 * Constructor.
	 *
	 * @since 4.5.0
	 */
	public function __construct() {
		$this->settings = array(
			'term'    => array(
				'filter'   => 'get_term_metadata',
				'callback' => array( $this, 'lazyload_term_meta' ),
			),
			'comment' => array(
				'filter'   => 'get_comment_metadata',
				'callback' => array( $this, 'lazyload_comment_meta' ),
			),
		);
	}

	/**
	 * Adds objects to the metadata lazy-load queue.
	 *
	 * @since 4.5.0
	 *
	 * @param string $object_type Type of object whose meta is to be lazy-loaded. Accepts 'term' or 'comment'.
	 * @param array  $object_ids  Array of object IDs.
	 * @return bool|WP_Error True on success, WP_Error on failure.
	 */
	public function queue_objects( $object_type, $object_ids ) {
		if ( ! isset( $this->settings[ $object_type ] ) ) {
			return new WP_Error( 'invalid_object_type', __( 'Invalid object type.' ) );
		}

		$type_settings = $this->settings[ $object_type ];

		if ( ! isset( $this->pending_objects[ $object_type ] ) ) {
			$this->pending_objects[ $object_type ] = array();
		}

		foreach ( $object_ids as $object_id ) {
			// Keyed by ID for faster lookup.
			if ( ! isset( $this->pending_objects[ $object_type ][ $object_id ] ) ) {
				$this->pending_objects[ $object_type ][ $object_id ] = 1;
			}
		}

		add_filter( $type_settings['filter'], $type_settings['callback'] );

		/**
		 * Fires after objects are added to the metadata lazy-load queue.
		 *
		 * @since 4.5.0
		 *
		 * @param array                  $object_ids  Array of object IDs.
		 * @param string                 $object_type Type of object being queued.
		 * @param WP_Metadata_Lazyloader $lazyloader  The lazy-loader object.
		 */
		do_action( 'metadata_lazyloader_queued_objects', $object_ids, $object_type, $this );
	}

	/**
	 * Resets lazy-load queue for a given object type.
	 *
	 * @since 4.5.0
	 *
	 * @param string $object_type Object type. Accepts 'comment' or 'term'.
	 * @return bool|WP_Error True on success, WP_Error on failure.
	 */
	public function reset_queue( $object_type ) {
		if ( ! isset( $this->settings[ $object_type ] ) ) {
			return new WP_Error( 'invalid_object_type', __( 'Invalid object type.' ) );
		}

		$type_settings = $this->settings[ $object_type ];

		$this->pending_objects[ $object_type ] = array();
		remove_filter( $type_settings['filter'], $type_settings['callback'] );
	}

	/**
	 * Lazy-loads term meta for queued terms.
	 *
	 * This method is public so that it can be used as a filter callback. As a rule, there
	 * is no need to invoke it directly.
	 *
	 * @since 4.5.0
	 *
	 * @param mixed $check The `$check` param passed from the 'get_term_metadata' hook.
	 * @return mixed In order not to short-circuit `get_metadata()`. Generally, this is `null`, but it could be
	 *               another value if filtered by a plugin.
	 */
	public function lazyload_term_meta( $check ) {
		if ( ! empty( $this->pending_objects['term'] ) ) {
			update_termmeta_cache( array_keys( $this->pending_objects['term'] ) );

			// No need to run again for this set of terms.
			$this->reset_queue( 'term' );
		}

		return $check;
	}

	/**
	 * Lazy-loads comment meta for queued comments.
	 *
	 * This method is public so that it can be used as a filter callback. As a rule, there is no need to invoke it
	 * directly, from either inside or outside the `WP_Query` object.
	 *
	 * @since 4.5.0
	 *
	 * @param mixed $check The `$check` param passed from the {@see 'get_comment_metadata'} hook.
	 * @return mixed The original value of `$check`, so as not to short-circuit `get_comment_metadata()`.
	 */
	public function lazyload_comment_meta( $check ) {
		if ( ! empty( $this->pending_objects['comment'] ) ) {
			update_meta_cache( 'comment', array_keys( $this->pending_objects['comment'] ) );

			// No need to run again for this set of comments.
			$this->reset_queue( 'comment' );
		}

		return $check;
	}
}