# backend/config.py
import os
from datetime import timedelta

class Config:
    """Base configuration"""
    # Flask
    SECRET_KEY = os.environ.get('SECRET_KEY', 'dev-secret-key-change-in-production')
    
    # Database
    SQLALCHEMY_TRACK_MODIFICATIONS = False
    SQLALCHEMY_ENGINE_OPTIONS = {
        'pool_recycle': 300,
        'pool_pre_ping': True,
        'pool_size': 10,
        'max_overflow': 20
    }
    
    # JWT
    JWT_SECRET_KEY = os.environ.get('JWT_SECRET_KEY', 'jwt-secret-key-change-in-production')
    JWT_ACCESS_TOKEN_EXPIRES = timedelta(hours=1)
    JWT_REFRESH_TOKEN_EXPIRES = timedelta(days=30)
    JWT_TOKEN_LOCATION = ['headers']
    JWT_HEADER_NAME = 'Authorization'
    JWT_HEADER_TYPE = 'Bearer'
    JWT_IDENTITY_CLAIM = 'sub'
    JWT_BLACKLIST_ENABLED = True
    JWT_ERROR_MESSAGE_KEY = 'message'
    
    # CORS
    CORS_ORIGINS = os.environ.get('CORS_ORIGINS', 'https://app.synzhi.com').split(',')
    CORS_SUPPORTS_CREDENTIALS = True
    
    # Cache
    CACHE_TYPE = os.environ.get('CACHE_TYPE', 'SimpleCache')
    CACHE_DEFAULT_TIMEOUT = 300
    
    # File Upload
    MAX_CONTENT_LENGTH = 16 * 1024 * 1024  # 16MB max file size
    
    # Pagination
    DEFAULT_PAGE_SIZE = 20
    MAX_PAGE_SIZE = 100


class DevelopmentConfig(Config):
    """Development configuration"""
    DEBUG = True
    TESTING = False
    
    # Database for development - can be overridden by env vars
    SQLALCHEMY_DATABASE_URI = os.environ.get(
        'DEV_DATABASE_URL',
        'sqlite:///dev.db'
    )


class TestingConfig(Config):
    """Testing configuration"""
    DEBUG = False
    TESTING = True
    
    SQLALCHEMY_DATABASE_URI = os.environ.get(
        'TEST_DATABASE_URL',
        'sqlite:///test.db'
    )
    
    # Use faster hashing for tests
    JWT_ACCESS_TOKEN_EXPIRES = timedelta(seconds=5)
    JWT_REFRESH_TOKEN_EXPIRES = timedelta(seconds=10)


class ProductionConfig(Config):
    """Production configuration"""
    DEBUG = False
    TESTING = False
    
    # Database from environment
    SQLALCHEMY_DATABASE_URI = os.environ.get('DATABASE_URL')
    
    # More strict security
    JWT_COOKIE_SECURE = True
    JWT_COOKIE_SAMESITE = 'Lax'
    
    # Session settings
    SESSION_COOKIE_SECURE = True
    SESSION_COOKIE_HTTPONLY = True
    SESSION_COOKIE_SAMESITE = 'Lax'
    
    # Rate limiting
    RATELIMIT_ENABLED = True
    RATELIMIT_DEFAULT = "100/hour"
    
    # SSL
    PREFERRED_URL_SCHEME = 'https'


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