import os
from flask import Flask, request, jsonify
from werkzeug.utils import secure_filename
from transformers import pipeline
from pdf2image import convert_from_path
from PIL import Image

# Initialize Flask app
app = Flask(__name__)

# Set upload folder
UPLOAD_FOLDER = 'uploads'
os.makedirs(UPLOAD_FOLDER, exist_ok=True)
app.config['UPLOAD_FOLDER'] = UPLOAD_FOLDER

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

# Load TrOCR Model
ocr_pipeline = pipeline("image-to-text", model="microsoft/trocr-small-printed")

def allowed_file(filename):
    """Check if the file has an allowed extension."""
    return '.' in filename and filename.rsplit('.', 1)[1].lower() in ALLOWED_EXTENSIONS

def extract_text_from_image(image_path):
    """Extract text from a single image using TrOCR."""
    image = Image.open(image_path).convert("RGB")
    text = ocr_pipeline(image)[0]['generated_text']
    return text

def extract_text_from_pdf(pdf_path):
    """Convert PDF to images and extract text from each page."""
    images = convert_from_path(pdf_path)
    extracted_text = ""

    for img in images:
        text = extract_text_from_image(img)
        extracted_text += text + "\n"

    return extracted_text.strip()

@app.route('/upload', methods=['POST'])
def upload_file():
    """Handle file upload and text extraction."""
    if 'file' not in request.files:
        return jsonify({"error": "No file uploaded"}), 400

    file = request.files['file']
    if file.filename == '':
        return jsonify({"error": "No file selected"}), 400

    if not allowed_file(file.filename):
        return jsonify({"error": "Invalid file type. Allowed: PNG, JPG, JPEG, PDF."}), 400

    # Save uploaded file
    filename = secure_filename(file.filename)
    file_path = os.path.join(app.config['UPLOAD_FOLDER'], filename)
    file.save(file_path)

    # Process image or PDF
    if filename.lower().endswith(".pdf"):
        extracted_text = extract_text_from_pdf(file_path)
    else:
        extracted_text = extract_text_from_image(file_path)

    return jsonify({"extracted_text": extracted_text})

# Run Flask App
if __name__ == '__main__':
    app.run(host='0.0.0.0', port=5000, debug=True)