from PIL import Image
import os
from typing import Literal, Optional
from io import BytesIO

def compress_image_file(
    input_path: str,
    output_path: str,
    quality: int = 85,
    format: Literal["JPEG", "PNG", "WEBP"] = "JPEG",
    max_width: Optional[int] = None,
    max_height: Optional[int] = None
) -> str:
    """
    Compress an image file from disk.
    """
    try:
        if not os.path.splitext(output_path)[1]:
            extension_map = {"JPEG": ".jpg", "PNG": ".png", "WEBP": ".webp"}
            output_path = output_path + extension_map[format]
        
        with Image.open(input_path) as img:
            if format == "JPEG" and img.mode in ("RGBA", "P"):
                img = img.convert("RGB")
            
            if max_width or max_height:
                img.thumbnail((max_width or img.width, max_height or img.height), Image.Resampling.LANCZOS)
            
            save_kwargs = {"format": format, "optimize": True}
            if format in ["JPEG", "WEBP"]:
                save_kwargs["quality"] = quality
            
            img.save(output_path, **save_kwargs)

        original_size = os.path.getsize(input_path) / 1024 / 1024  
        compressed_size = os.path.getsize(output_path) / 1024 / 1024 
        reduction = (1 - compressed_size/original_size) * 100
        
        return f"✅ Compressed successfully!\nOriginal: {original_size:.2f}MB → Compressed: {compressed_size:.2f}MB\nReduction: {reduction:.1f}%"
    
    except Exception as e:
        return f"❌ Error: {str(e)}"

def compress_image_memory(image: Image.Image, quality: int = 80, format: str = "JPEG") -> Image.Image:
    """
    Compress an image in memory and return the compressed image.
    """
    if format == "JPEG" and image.mode in ("RGBA", "P"):
        image = image.convert("RGB")
    
    output = BytesIO()
    save_kwargs = {"format": format, "optimize": True}
    
    if format in ["JPEG", "WEBP"]:
        save_kwargs["quality"] = quality
    
    image.save(output, **save_kwargs)
    output.seek(0)
    
    return Image.open(output)