import os
from datetime import timedelta
from dotenv import load_dotenv

# Load environment variables
load_dotenv()


class Config:
    """Base configuration class with common settings."""
    
    # Flask Core
    SECRET_KEY = os.getenv('SECRET_KEY', 'dev-secret-key-change-this')
    
    # Request handling
    MAX_CONTENT_LENGTH = None  # No limit for admin uploads (1GB+)
    SEND_FILE_MAX_AGE_DEFAULT = 0  # Disable caching for development
    
    # Upload timeout settings (for large file uploads)
    UPLOAD_TIMEOUT = int(os.getenv('UPLOAD_TIMEOUT', 900))  # 15 minutes default
    
    # Database
    SQLALCHEMY_DATABASE_URI = os.getenv('DATABASE_URL', 'sqlite:///app.db')
    SQLALCHEMY_TRACK_MODIFICATIONS = False
    SQLALCHEMY_ENGINE_OPTIONS = {
        'pool_pre_ping': True,
        'pool_recycle': 300,
    }
    
    # Rate Limiting
    RATE_LIMIT_ENABLED = os.getenv('RATE_LIMIT_ENABLED', 'true').lower() == 'true'
    RATELIMIT_DEFAULT = os.getenv('RATE_LIMIT_DEFAULT', '100 per hour')
    RATELIMIT_STORAGE_URL = os.getenv('RATE_LIMIT_STORAGE_URL', 'memory://')
    RATELIMIT_HEADERS_ENABLED = True
    
    # CORS
    CORS_ORIGINS = os.getenv('CORS_ORIGINS', '*').split(',')
    
    # Logging
    LOG_LEVEL = os.getenv('LOG_LEVEL', 'INFO')
    LOG_FILE = os.getenv('LOG_FILE', 'logs/app.log')
    
    # Security
    SESSION_COOKIE_SECURE = os.getenv('SESSION_COOKIE_SECURE', 'false').lower() == 'true'
    SESSION_COOKIE_HTTPONLY = os.getenv('SESSION_COOKIE_HTTPONLY', 'true').lower() == 'true'
    SESSION_COOKIE_SAMESITE = os.getenv('SESSION_COOKIE_SAMESITE', 'Lax')
    PERMANENT_SESSION_LIFETIME = timedelta(hours=24)
    
    # JSON Settings
    JSON_SORT_KEYS = False
    JSONIFY_PRETTYPRINT_REGULAR = True
    
    # JWT Configuration
    JWT_SECRET_KEY = os.getenv('JWT_SECRET_KEY', SECRET_KEY)
    JWT_ACCESS_TOKEN_EXPIRES = timedelta(hours=1)
    JWT_REFRESH_TOKEN_EXPIRES = timedelta(days=1)
    JWT_ALGORITHM = 'HS256'
    
    # Email Configuration
    MAIL_SERVER = os.getenv('MAIL_SERVER', 'smtp.gmail.com')
    MAIL_PORT = int(os.getenv('MAIL_PORT', 587))
    MAIL_USE_TLS = os.getenv('MAIL_USE_TLS', 'true').lower() == 'true'
    MAIL_USE_SSL = os.getenv('MAIL_USE_SSL', 'false').lower() == 'true'
    MAIL_USERNAME = os.getenv('MAIL_USERNAME', '')
    MAIL_PASSWORD = os.getenv('MAIL_PASSWORD', '')
    MAIL_DEFAULT_SENDER = os.getenv('MAIL_DEFAULT_SENDER', MAIL_USERNAME)
    
    # Email Verification Settings
    VERIFICATION_CODE_EXPIRY = 30  # minutes
    MAX_VERIFICATION_ATTEMPTS = 5
    MAX_RESEND_PER_HOUR = 3
    
    # File Upload Settings
    UPLOAD_FOLDER = 'static/uploads'
    MAX_PHOTOS_PER_PROPERTY = 20  # Maximum 20 photos per property
    ALLOWED_EXTENSIONS = {'jpg', 'jpeg', 'png', 'webp'}
    
    # Orphaned file cleanup settings
    ORPHANED_FILE_MAX_AGE_HOURS = 24  # Delete files older than 24 hours with no DB record


class DevelopmentConfig(Config):
    """Development environment configuration."""
    DEBUG = True
    TESTING = False
    LOG_LEVEL = 'DEBUG'


class ProductionConfig(Config):
    """Production environment configuration."""
    DEBUG = False
    TESTING = False
    SESSION_COOKIE_SECURE = True
    
    # Override with PostgreSQL in production
    # Make sure to set DATABASE_URL in production .env
    SQLALCHEMY_ENGINE_OPTIONS = {
        'pool_size': 10,
        'pool_recycle': 3600,
        'pool_pre_ping': True,
        'max_overflow': 20,
    }


class TestingConfig(Config):
    """Testing environment configuration."""
    TESTING = True
    DEBUG = True
    SQLALCHEMY_DATABASE_URI = 'sqlite:///:memory:'
    RATE_LIMIT_ENABLED = False


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


def get_config():
    """Get the appropriate configuration based on FLASK_ENV."""
    env = os.getenv('FLASK_ENV', 'production')
    return config.get(env, config['default'])