import os

class Config:
    SECRET_KEY = os.getenv('SECRET_KEY', 'your-secret-key')
    SQLALCHEMY_DATABASE_URI = os.getenv('DATABASE_URL', 'sqlite:////tmp/app.db')
    SQLALCHEMY_TRACK_MODIFICATIONS = False
    CELERY_BROKER_URL = os.getenv('CELERY_BROKER_URL', 'redis://localhost:6379/0')
    CELERY_RESULT_BACKEND = os.getenv('CELERY_RESULT_BACKEND', 'redis://localhost:6379/0')
    OPENAI_API_KEY = os.getenv('OPENAI_API_KEY', 'your-openai-api-key')
    INSTANCE_PATH = '/tmp/instance'  # Set a writable instance path

class DevelopmentConfig(Config):
    DEBUG = True

class ProductionConfig(Config):
    DEBUG = False

class TestingConfig(Config):
    TESTING = True
    SQLALCHEMY_DATABASE_URI = 'sqlite:///:memory:'