from __future__ import annotations

import shutil
import uuid
from pathlib import Path
from typing import Tuple

from fastapi import UploadFile

from ..core.config import get_settings

settings = get_settings()


def cleanup_old_audio_files(max_files: int | None = None) -> None:
    """Remove old audio files from the static directory to save space."""
    max_files = max_files or settings.max_audio_files
    audio_dir = settings.audio_dir
    audio_dir.mkdir(parents=True, exist_ok=True)

    files = sorted(audio_dir.glob("*") , key=lambda f: f.stat().st_mtime if f.exists() else 0)
    if len(files) <= max_files:
        return

    for old_file in files[:-max_files]:
        try:
            old_file.unlink()
        except OSError:
            continue


def save_upload_file(upload: UploadFile) -> Path:
    """Persist an UploadFile to the temporary directory and return its path."""
    tmp_dir = settings.tmp_dir
    tmp_dir.mkdir(parents=True, exist_ok=True)
    suffix = Path(upload.filename or "audio").suffix or ".mp3"
    temp_path = tmp_dir / f"upload_{uuid.uuid4().hex}{suffix}"

    with temp_path.open("wb") as buffer:
        shutil.copyfileobj(upload.file, buffer)

    return temp_path


def store_audio_file(audio_path: Path, prefix: str | None = None) -> Tuple[Path, str]:
    """Copy an audio file to the public static folder and return the new path and URL."""
    cleanup_old_audio_files()

    prefix = prefix or "audio"
    suffix = audio_path.suffix or ".mp3"
    dest_filename = f"{prefix}_{uuid.uuid4().hex}{suffix}"
    dest_path = settings.audio_dir / dest_filename

    shutil.copy2(audio_path, dest_path)

    url = f"/media/{dest_filename}"
    return dest_path, url