import os
import platform
import secrets
from dotenv import load_dotenv

# Load environment variables from .env file
load_dotenv()

def get_system_encoding():
    """Get the system's preferred encoding with UTF-8 fallback."""
    try:
        # Try to get the preferred encoding
        import locale
        preferred_encoding = locale.getpreferredencoding(False)

        # Ensure it's UTF-8 or a compatible encoding
        if preferred_encoding.lower() not in ['utf-8', 'utf8', 'utf_8']:
            # On Windows, try to set UTF-8
            if platform.system() == 'Windows':
                try:
                    os.environ['PYTHONIOENCODING'] = 'utf-8'
                    preferred_encoding = 'utf-8'
                except:
                    preferred_encoding = 'utf-8'
            else:
                preferred_encoding = 'utf-8'

        return preferred_encoding
    except:
        return 'utf-8'

class Config:
    """Base configuration class."""

    # Set default encoding
    DEFAULT_ENCODING = get_system_encoding()

    # Supabase configuration
    SUPABASE_URL = os.environ.get('SUPABASE_URL') or ''
    SUPABASE_KEY = os.environ.get('SUPABASE_KEY') or ''

    # LinkedIn OAuth configuration
    CLIENT_ID = os.environ.get('CLIENT_ID') or ''
    CLIENT_SECRET = os.environ.get('CLIENT_SECRET') or ''
    REDIRECT_URL = os.environ.get('REDIRECT_URL') or ''

    # Hugging Face configuration
    # Check for lowercase hugging_key first (for dev), then uppercase HUGGING_KEY (for production)
    HUGGING_KEY = os.environ.get('hugging_key') or os.environ.get('HUGGING_KEY') or ''

    # JWT configuration - generate a secure key if not provided
    JWT_SECRET_KEY = os.environ.get('JWT_SECRET_KEY') or os.environ.get('SECRET_KEY') or secrets.token_hex(32)

    # Database configuration
    DATABASE_URL = os.environ.get('DATABASE_URL') or ''

    # Application configuration - generate a secure key if not provided
    SECRET_KEY = os.environ.get('SECRET_KEY') or secrets.token_hex(32)
    DEBUG = os.environ.get('DEBUG', 'False').lower() == 'true'

    # Scheduler configuration
    SCHEDULER_ENABLED = os.environ.get('SCHEDULER_ENABLED', 'True').lower() == 'true'

    # Unicode/Encoding configuration
    FORCE_UTF8 = os.environ.get('FORCE_UTF8', 'True').lower() == 'true'
    UNICODE_LOGGING = os.environ.get('UNICODE_LOGGING', 'True').lower() == 'true'

    # Environment detection
    ENVIRONMENT = os.environ.get('ENVIRONMENT', 'development').lower()
    IS_WINDOWS = platform.system() == 'Windows'
    IS_DOCKER = os.environ.get('DOCKER_CONTAINER', '').lower() == 'true'

    # Set environment-specific encoding settings
    if FORCE_UTF8:
        os.environ['PYTHONIOENCODING'] = 'utf-8'
        os.environ['PYTHONUTF8'] = '1'

    # Debug and logging settings
    LOG_LEVEL = os.environ.get('LOG_LEVEL', 'INFO' if ENVIRONMENT == 'production' else 'DEBUG')
    UNICODE_SAFE_LOGGING = UNICODE_LOGGING and not IS_WINDOWS

    # Celery configuration
    CELERY_BROKER_URL = os.environ.get('CELERY_BROKER_URL', 'redis://localhost:6379/0')
    CELERY_RESULT_BACKEND = os.environ.get('CELERY_RESULT_BACKEND', 'redis://localhost:6379/0')

    # Validate required configuration values
    @classmethod
    def validate_config(cls):
        """Validate that all required config values are set."""
        required_vars = ['SUPABASE_URL', 'SUPABASE_KEY', 'JWT_SECRET_KEY']
        missing_vars = []

        for var in required_vars:
            if not getattr(cls, var, None) or getattr(cls, var) == 'your-secret-key-change-in-production':
                missing_vars.append(var)

        if missing_vars:
            raise ValueError(f"Missing required environment variables: {', '.join(missing_vars)}. Please check your .env file.")

# Validate configuration after class definition
Config.validate_config()