import os

class Config:
    """Base configuration class"""
    # Flask settings
    SECRET_KEY = os.environ.get('SECRET_KEY') or 'dev-secret-key-change-in-production'
    DEBUG = os.environ.get('FLASK_DEBUG', 'True').lower() == 'true'
    
    # JWT settings
    JWT_SECRET_KEY = os.environ.get('JWT_SECRET_KEY') or 'jwt-secret-string-change-in-production'
    JWT_ACCESS_TOKEN_EXPIRES = int(os.environ.get('JWT_ACCESS_TOKEN_EXPIRES', 3600))  # 1 hour default
    JWT_ALGORITHM = 'HS256'
    
    # Upload settings
    UPLOAD_FOLDER = os.path.join(os.path.dirname(os.path.dirname(os.path.abspath(__file__))), 'uploads')
    ALLOWED_EXTENSIONS = {'csv'}
    MAX_CONTENT_LENGTH = 16 * 1024 * 1024  # 16MB max file size
    
    # API settings
    HOST = os.environ.get('HOST', '0.0.0.0')
    PORT = int(os.environ.get('PORT', 5000))
    
    # Request timeout
    REQUEST_TIMEOUT = 30


class DevelopmentConfig(Config):
    """Development configuration"""
    DEBUG = True


class ProductionConfig(Config):
    """Production configuration"""
    DEBUG = False
    SECRET_KEY = os.environ.get('SECRET_KEY')


class TestingConfig(Config):
    """Testing configuration"""
    TESTING = True
    DEBUG = True


# Configuration dictionary
config = {
    'development': DevelopmentConfig,
    'production': ProductionConfig,
    'testing': TestingConfig,
    'default': DevelopmentConfig
}