import os
import io
import json
import hashlib
from datetime import datetime
from PIL import Image

from flask import Flask, request, jsonify
from flask_cors import CORS
import google.generativeai as genai

app = Flask(__name__)
CORS(app)  # Enable CORS for all routes

# Use the Gemini API key from the environment, or set it here for testing.
api_key = os.environ.get('Gemini', 'YOUR_GEMINI_API_KEY')

def configure_gemini(api_key):
    genai.configure(api_key=api_key)
    return genai.GenerativeModel('gemini-2.0-flash-thinking-exp')

def process_receipt(model, image):
    prompt = (
        "Analyze this image and determine if it's a receipt. If it is a receipt, extract:\n"
        " - Total amount (as float)\n"
        " - List of items purchased (array of strings)\n"
        " - Date of transaction (DD/MM/YYYY format)\n"
        " - Receipt number (as string)\n"
        "Return JSON format with keys: is_receipt (boolean), total, items, date, receipt_number.\n"
        "If not a receipt, return {\"is_receipt\": false}"
    )
    response = model.generate_content([prompt, image])
    return response.text

@app.route('/process-receipt', methods=['POST'])
def process_receipt_endpoint():
    try:
        if 'receipt' not in request.files:
            return jsonify({'error': 'No file uploaded'}), 400

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

        # Read file bytes and compute a hash (for duplicate checking or logging)
        image_bytes = file.read()
        file_hash = hashlib.md5(image_bytes).hexdigest()

        # Open the image using Pillow
        image = Image.open(io.BytesIO(image_bytes))

        # Configure Gemini and process the receipt image
        model = configure_gemini(api_key)
        result_text = process_receipt(model, image)

        # Attempt to extract JSON from the response text
        json_start = result_text.find('{')
        json_end = result_text.rfind('}')
        if json_start == -1 or json_end == -1:
            return jsonify({'error': 'Invalid response format', 'raw': result_text}), 500

        json_str = result_text[json_start:json_end+1]
        # Clean up any markdown formatting if necessary
        json_str = json_str.replace('```json', '').replace('```', '')
        data = json.loads(json_str)

        # Optionally, add metadata to the response
        data['file_hash'] = file_hash
        data['timestamp'] = datetime.now().isoformat()

        return jsonify(data)
    except Exception as e:
        return jsonify({'error': str(e)}), 500

if __name__ == '__main__':
    # The server listens on all interfaces at port 7860.
    app.run(debug=True, host="0.0.0.0", port=7860)