import os
import logging
from dataclasses import dataclass, field

logger = logging.getLogger(__name__)


@dataclass
class NasConfig:
    index: int
    name: str
    container_path: str


@dataclass
class Settings:
    db_host: str
    db_port: int
    db_name: str
    db_user: str
    db_password: str
    scan_interval_hours: int
    video_extensions: frozenset[str]
    nas_list: list[NasConfig]

    @property
    def db_url(self) -> str:
        return (
            f"mysql://{self.db_user}:{self.db_password}"
            f"@{self.db_host}:{self.db_port}/{self.db_name}"
            "?charset=utf8mb4"
        )


def _discover_nas() -> list[NasConfig]:
    """Detect mounted NAS volumes inside the container (/nas/nas1, /nas/nas2, …)."""
    nas_base = "/nas"
    entries: list[NasConfig] = []
    idx = 1
    while True:
        container_path = f"{nas_base}/nas{idx}"
        if not os.path.isdir(container_path):
            break
        # Attempt to read the name from env (set by generate-compose.py indirectly via NAS_X)
        env_key = f"NAS_{idx}"
        raw = os.getenv(env_key, "")
        if raw and "|" in raw:
            name = raw.split("|", 1)[0].strip()
        else:
            name = f"NAS {idx}"
        entries.append(NasConfig(index=idx, name=name, container_path=container_path))
        idx += 1
    if not entries:
        logger.warning("No NAS volumes found at %s/nasX — scanner will have nothing to scan", nas_base)
    return entries


def load_settings() -> Settings:
    raw_ext = os.getenv("VIDEO_EXTENSIONS", ".mkv,.mp4,.avi,.m4v,.mov,.wmv,.ts,.m2ts,.iso")
    extensions = frozenset(e.strip().lower() for e in raw_ext.split(",") if e.strip())

    return Settings(
        db_host=os.getenv("DB_HOST", "db"),
        db_port=int(os.getenv("DB_PORT", "3306")),
        db_name=os.getenv("DB_NAME", "mediatracker"),
        db_user=os.getenv("DB_USER", "mediatracker"),
        db_password=os.getenv("DB_PASSWORD", "changeme_db"),
        scan_interval_hours=int(os.getenv("SCAN_INTERVAL_HOURS", "6")),
        video_extensions=extensions,
        nas_list=_discover_nas(),
    )