"""Resolve model cache dir + clean up stale YouTube downloads."""

import os
import time
from pathlib import Path


_DEFAULT_CACHE = Path("output/cache/models")
_OUTPUT_DIR = Path("output")
_YOUTUBE_DIR = _OUTPUT_DIR / "youtube"


def get_model_cache_dir():
    """Resolve model cache dir from MODEL_CACHE_DIR env, fall back to output/cache/models.

    Sets HF_HOME, HUGGINGFACE_HUB_CACHE, TORCH_HOME so all framework caches share it.
    """
    env_dir = os.getenv("MODEL_CACHE_DIR")
    cache_dir = Path(env_dir) if env_dir else _DEFAULT_CACHE
    cache_dir.mkdir(parents=True, exist_ok=True)
    cache_str = str(cache_dir.resolve())

    os.environ.setdefault("HF_HOME", cache_str)
    os.environ.setdefault("HUGGINGFACE_HUB_CACHE", cache_str)
    os.environ.setdefault("TORCH_HOME", cache_str)

    return cache_dir


def get_output_dir():
    return _OUTPUT_DIR


def get_youtube_output_dir():
    return _YOUTUBE_DIR


def ensure_dirs():
    _OUTPUT_DIR.mkdir(parents=True, exist_ok=True)
    _YOUTUBE_DIR.mkdir(parents=True, exist_ok=True)


def cleanup_old_videos(directory=None, max_age_days=7, min_age_seconds=3600):
    """Delete files older than `max_age_days`, skipping anything younger than `min_age_seconds`.

    Best-effort: logs but never raises.
    """
    target = Path(directory) if directory else _YOUTUBE_DIR
    if not target.exists():
        return

    now = time.time()
    max_age_seconds = max_age_days * 86400

    for entry in target.iterdir():
        try:
            if not entry.is_file():
                continue
            mtime = entry.stat().st_mtime
            age = now - mtime
            if age < min_age_seconds:
                continue
            if age > max_age_seconds:
                entry.unlink()
                print(f"[cache_manager] removed stale download: {entry.name} (age {age/86400:.1f}d)")
        except OSError as exc:
            print(f"[cache_manager] cleanup failed for {entry}: {exc}")