from __future__ import annotations

import sys
from pathlib import Path
from typing import List

from models import AlbumScan, AUDIO_EXTENSIONS, IMAGE_EXTENSIONS, TRACKLIST_EXTENSIONS


def _is_hidden(name: str) -> bool:
    return name.startswith(".") or name.startswith("_")


def scan_album(album_dir: Path) -> AlbumScan:
    result = AlbumScan(album_dir=album_dir)

    for dirpath, dirnames, filenames in album_dir.walk() if hasattr(album_dir, "walk") else _os_walk(album_dir):
        dirnames[:] = [d for d in dirnames if not _is_hidden(d)]
        current = Path(dirpath) if isinstance(dirpath, str) else dirpath

        for name in filenames:
            if _is_hidden(name):
                continue
            p = current / name
            ext = p.suffix.lower()

            if ext in AUDIO_EXTENSIONS:
                result.audio_files.append(p)
            elif ext in IMAGE_EXTENSIONS:
                result.image_files.append(p)
            elif ext in TRACKLIST_EXTENSIONS:
                result.tracklist_files.append(p)
            else:
                result.other_files.append(p)

    result.audio_files.sort()
    result.image_files.sort()
    result.tracklist_files.sort()
    return result


def _os_walk(album_dir: Path):
    import os
    return os.walk(
        album_dir,
        followlinks=False,
        onerror=lambda e: print(f"⚠️ Scan-Fehler: {e}", file=sys.stderr),
    )


def collect_album_dirs(root: Path) -> List[Path]:
    dirs: List[Path] = []
    try:
        for item in sorted(root.iterdir()):
            if item.is_dir() and not _is_hidden(item.name):
                dirs.append(item)
    except (PermissionError, OSError) as e:
        print(f"⚠️ Lesefehler {root}: {e}", file=sys.stderr)
    return dirs