app.py

import os
import subprocess
from flask import Flask, request, send_file, jsonify
from werkzeug.utils import secure_filename
from flask_cors import CORS  # Import CORS for handling cross-origin requests

# Define directories for uploads and outputs
UPLOAD_FOLDER = 'uploads_gradio'
OUTPUT_FOLDER = 'outputs_gradio'

# Create directories if they don't exist
os.makedirs(UPLOAD_FOLDER, exist_ok=True)
os.makedirs(OUTPUT_FOLDER, exist_ok=True)

# Initialize Flask app
app = Flask(__name__)
app.config['UPLOAD_FOLDER'] = UPLOAD_FOLDER

# Enable CORS for all routes (optional, adjust origins as needed)
CORS(app)

# Allowed file extensions
ALLOWED_EXTENSIONS = {'.png', '.jpg', '.jpeg', '.bmp'}

def allowed_file(filename):
    """Check if the file has an allowed extension."""
    _, ext = os.path.splitext(filename)
    return ext.lower() in ALLOWED_EXTENSIONS

def animate_image(file_path):
    """
    Process the uploaded image and generate an animated GIF.

    Args:
        file_path (str): Path to the uploaded file.

    Returns:
        str: Path to the generated GIF.
    """
    if not file_path:
        raise ValueError("No file uploaded.")

    input_path = file_path
    filename = os.path.basename(input_path)
    base, ext = os.path.splitext(filename)

    # Define the annotation directory for this specific image
    char_anno_dir = os.path.join(OUTPUT_FOLDER, f"{base}_out")
    os.makedirs(char_anno_dir, exist_ok=True)

    # Validate file extension
    if ext.lower() not in ALLOWED_EXTENSIONS:
        raise ValueError("Unsupported file type. Please upload an image file (png, jpg, jpeg, bmp).")

    try:
        # Run the image_to_animation.py script with required arguments
        subprocess.run([
            'python', 'examples/image_to_animation.py',
            input_path, char_anno_dir
        ], check=True)

        # Path to the generated GIF
        gif_path = os.path.join(char_anno_dir, "video.gif")

        if os.path.exists(gif_path):
            return gif_path
        else:
            raise FileNotFoundError("Animation failed to generate. Please ensure the input image contains clear humanoid drawings.")

    except subprocess.CalledProcessError as e:
        raise RuntimeError(f"Error during processing: {e}")
    except Exception as e:
        raise RuntimeError(f"Unexpected error: {e}")

@app.route('/animate', methods=['POST'])
def animate():
    """
    Endpoint to receive an image and return the animated GIF.
    """
    if 'file' not in request.files:
        return jsonify({"error": "No file part in the request."}), 400

    file = request.files['file']

    if file.filename == '':
        return jsonify({"error": "No file selected for uploading."}), 400

    if file and allowed_file(file.filename):
        filename = secure_filename(file.filename)
        input_path = os.path.join(app.config['UPLOAD_FOLDER'], filename)
        file.save(input_path)

        try:
            gif_path = animate_image(input_path)
            return send_file(
                gif_path,
                mimetype='image/gif',
                as_attachment=True,
                attachment_filename=f"{os.path.splitext(filename)[0]}.gif"
            )
        except Exception as e:
            return jsonify({"error": str(e)}), 500
    else:
        return jsonify({"error": "Allowed file types are png, jpg, jpeg, bmp."}), 400

@app.route('/', methods=['GET'])
def index():
    """
    Root endpoint to provide basic information.
    """
    return jsonify({
        "message": "Animated Drawings API",
        "endpoints": {
            "/animate": "POST an image to receive an animated GIF."
        }
    })

@app.route('/health', methods=['GET'])
def health():
    """
    Health check endpoint.
    """
    return jsonify({"status": "healthy"}), 200

if __name__ == '__main__':
    # Use the PORT environment variable provided by Hugging Face Spaces or default to 7860
    port = int(os.getenv("PORT", "7860"))
    app.run(host='0.0.0.0', port=port)