import os
import uuid
import json
from flask import Flask, request, render_template, jsonify, send_file
from werkzeug.utils import secure_filename
from pdf_comparator import PDFComparator
import tempfile
import shutil

app = Flask(__name__)
app.config['MAX_CONTENT_LENGTH'] = 16 * 1024 * 1024  # 16MB max file size
app.config['UPLOAD_FOLDER'] = 'uploads'
app.config['RESULTS_FOLDER'] = 'results'

# Ensure directories exist
os.makedirs(app.config['UPLOAD_FOLDER'], exist_ok=True)
os.makedirs(app.config['RESULTS_FOLDER'], exist_ok=True)

ALLOWED_EXTENSIONS = {'pdf'}

def allowed_file(filename):
    return '.' in filename and filename.rsplit('.', 1)[1].lower() in ALLOWED_EXTENSIONS

@app.route('/')
def index():
    return render_template('index.html')

@app.route('/upload', methods=['POST'])
def upload_files():
    if 'pdf1' not in request.files or 'pdf2' not in request.files:
        return jsonify({'error': 'Both PDF files are required'}), 400
    
    pdf1 = request.files['pdf1']
    pdf2 = request.files['pdf2']
    
    if pdf1.filename == '' or pdf2.filename == '':
        return jsonify({'error': 'Both PDF files are required'}), 400
    
    if not (allowed_file(pdf1.filename) and allowed_file(pdf2.filename)):
        return jsonify({'error': 'Only PDF files are allowed'}), 400
    
    # Create unique session directory
    session_id = str(uuid.uuid4())
    session_dir = os.path.join(app.config['UPLOAD_FOLDER'], session_id)
    os.makedirs(session_dir, exist_ok=True)
    
    # Save uploaded files
    pdf1_path = os.path.join(session_dir, secure_filename(pdf1.filename))
    pdf2_path = os.path.join(session_dir, secure_filename(pdf2.filename))
    
    pdf1.save(pdf1_path)
    pdf2.save(pdf2_path)
    
    try:
        # Initialize PDF comparator
        comparator = PDFComparator()
        
        # Perform comparison
        results = comparator.compare_pdfs(pdf1_path, pdf2_path, session_id)
        
        # Save results
        results_path = os.path.join(app.config['RESULTS_FOLDER'], f'{session_id}_results.json')
        with open(results_path, 'w') as f:
            json.dump(results, f, indent=2)
        
        return jsonify({
            'success': True,
            'session_id': session_id,
            'results': results
        })
        
    except Exception as e:
        return jsonify({'error': str(e)}), 500

@app.route('/results/<session_id>')
def get_results(session_id):
    results_path = os.path.join(app.config['RESULTS_FOLDER'], f'{session_id}_results.json')
    
    if not os.path.exists(results_path):
        return jsonify({'error': 'Results not found'}), 404
    
    with open(results_path, 'r') as f:
        results = json.load(f)
    
    return jsonify(results)

@app.route('/download/<session_id>/<filename>')
def download_file(session_id, filename):
    file_path = os.path.join(app.config['UPLOAD_FOLDER'], session_id, filename)
    
    if not os.path.exists(file_path):
        return jsonify({'error': 'File not found'}), 404
    
    return send_file(file_path, as_attachment=True)

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