import subprocess
import json
import time
from flask import Flask, request, jsonify
from I2C_Function import analyze_data, read_data
from flask_cors import CORS
from threading import Lock

app = Flask(__name__)
CORS(app)

initialized = False
lock = Lock()  # Sperre (Lock) für die analyze_data-Methode

@app.route('/trng/randomNum/init', methods=['GET'])
def initialize_generator():
    global initialized  # Zugriff auf die globale Variable
    
    with lock:  # Sperre (Lock) verwenden, um sicherzustellen, dass nur ein Thread die Methode ausführt
        if initialized:
            return jsonify({'message': 'random number generator already initialized'}), 200

        result = analyze_data(int(1), int(1), startup=True)

        if result is True:
            initialized = True
            return jsonify({'message': 'successful operation; random number generator is ready and random numbers can be requested'}), 200
        else:
            return jsonify({'error': 'Unable to initialize the random number generator within a timeout of 60 seconds.'}), 555


@app.route('/trng/randomNum/getRandom', methods=['GET'])
def get_random_numbers():
    global initialized  # Zugriff auf die globale Variable
    quantity = request.args.get('quantity')
    bits = request.args.get('numBits')

    if not quantity.isdigit() or not bits.isdigit():
        return jsonify({'error': 'Invalid input. Quantity and bits must be numeric.'}), 400

    if int(quantity) <= 0 or int(bits) <= 0:
        return jsonify({'error': 'Invalid input. Quantity and bits must be positive integers.'}), 400
    
    if not initialized:
        return jsonify({'error': 'system not ready; try init'}), 432

    with lock:  # Sperre (Lock) verwenden, um sicherzustellen, dass nur ein Thread die Methode ausführt
        random_numbers = analyze_data(int(quantity), int(bits), startup=False)
    
    if random_numbers is False:
        return jsonify({'error': 'Unable to generate random numbers.'}), 500
    if random_numbers:
        response_data = {
        'status': 'successful operation; HEX-encoded bit arrays (with leading zeros if required)',
        'randomNumbers': random_numbers
        }
        return jsonify(response_data), 200
        
    else:
        return jsonify({'error': 'Unable to generate random numbers.'}), 500
    
@app.route('/trng/randomNum/shutdown', methods=['GET'])
def shutdown_generator(): 
    global initialized  # Zugriff auf die globale Variable

    with lock:  # Sperre (Lock) verwenden, um sicherzustellen, dass nur ein Thread die Methode ausführt
        initialized = False

    return jsonify({'message': "successful operation; random number generator has been set to 'standby mode'"}), 200

if __name__ == '__main__':
    cert_path = '/etc/nginx/ssl/cert-gmtrom.pem'
    key_path = '/etc/nginx/ssl/cert-gmtrom-key.pem'

    app.run(host='0.0.0.0', ssl_context=(cert_path, key_path))