在消费达到一定条件时取消订阅安全吗？

from flask import Flask, request, jsonify

app = Flask(__name__)

@app.route('/unsubscribe', methods=['POST'])
def unsubscribe():
    user_id = request.json.get('user_id')
    subscription_id = request.json.get('subscription_id')
    
    # 验证用户身份和订阅信息
    if not validate_user(user_id) or not validate_subscription(subscription_id):
        return jsonify({'status': 'error', 'message': 'Invalid user or subscription'}), 400
    
    # 取消订阅
    if cancel_subscription(subscription_id):
        return jsonify({'status': 'success', 'message': 'Subscription cancelled successfully'}), 200
    else:
        return jsonify({'status': 'error', 'message': 'Failed to cancel subscription'}), 500

def validate_user(user_id):
    # 实现用户验证逻辑
    pass

def validate_subscription(subscription_id):
    # 实现订阅验证逻辑
    pass

def cancel_subscription(subscription_id):
    # 实现取消订阅逻辑
    pass

if __name__ == '__main__':
    app.run()