import os
import logging
from dataclasses import dataclass


@dataclass
class EmailConfig:
    smtp_server: str
    smtp_port: int
    smtp_security: str  # 'ssl' | 'starttls' | 'none'
    from_email: str
    to_email: str
    username: str
    password: str


@dataclass
class AppConfig:
    check_interval: int
    log_level: str
    always_notify_on_startup: bool
    webhook_url: str | None
    discord_webhook: str | None
    data_dir: str
    log_dir: str
    email: EmailConfig | None
    run_daily_at: str | None


def _resolve_dir(env_key: str, default_subdir: str) -> str:
    # Prefer explicit env var
    val = os.getenv(env_key)
    if val:
        return val
    # Prefer Docker paths if present
    docker_path = f"/app/{default_subdir}"
    if os.path.isdir(docker_path):
        return docker_path
    # Fallback to local ./subdir
    return os.path.join(os.getcwd(), default_subdir)


def load_email_config() -> EmailConfig | None:
    required = [
        'EMAIL_SMTP_SERVER', 'EMAIL_FROM', 'EMAIL_TO', 'EMAIL_USERNAME', 'EMAIL_PASSWORD'
    ]
    if not all(os.getenv(k) for k in required):
        return None

    security = os.getenv('EMAIL_SMTP_SECURITY', 'starttls').lower()
    default_port = 465 if security == 'ssl' else 587 if security == 'starttls' else 25
    smtp_port = int(os.getenv('EMAIL_SMTP_PORT', default_port))

    return EmailConfig(
        smtp_server=os.getenv('EMAIL_SMTP_SERVER', ''),
        smtp_port=smtp_port,
        smtp_security=security,
        from_email=os.getenv('EMAIL_FROM', ''),
        to_email=os.getenv('EMAIL_TO', ''),
        username=os.getenv('EMAIL_USERNAME', ''),
        password=os.getenv('EMAIL_PASSWORD', ''),
    )


def setup_logging(level: str, log_dir: str) -> logging.Logger:
    os.makedirs(log_dir, exist_ok=True)
    logging.basicConfig(
        level=getattr(logging, level.upper(), logging.INFO),
        format='%(asctime)s - %(levelname)s - %(message)s',
        handlers=[
            logging.FileHandler(os.path.join(log_dir, 'crawler.log')),
            logging.StreamHandler(),
        ],
    )
    return logging.getLogger(__name__)


def load_config() -> AppConfig:
    check_interval = int(os.getenv('CHECK_INTERVAL', 300))
    log_level = os.getenv('LOG_LEVEL', 'INFO')
    always_notify_on_startup = os.getenv('ALWAYS_NOTIFY_ON_STARTUP', 'false').lower() in ('1', 'true', 'yes')
    webhook_url = os.getenv('WEBHOOK_URL')
    discord_webhook = os.getenv('DISCORD_WEBHOOK')
    data_dir = _resolve_dir('DATA_DIR', 'data')
    log_dir = _resolve_dir('LOG_DIR', 'logs')
    run_daily_at = os.getenv('RUN_DAILY_AT')  # e.g., "12:00"

    return AppConfig(
        check_interval=check_interval,
        log_level=log_level,
        always_notify_on_startup=always_notify_on_startup,
        webhook_url=webhook_url,
        discord_webhook=discord_webhook,
        data_dir=data_dir,
        log_dir=log_dir,
        email=load_email_config(),
        run_daily_at=run_daily_at,
    )