"""
本地配音历史：扫描 outputs/ 下已生成的 wav，供 Gradio 下拉试听与下载。
文件不会被自动删除，重启服务后仍可访问。
"""

from __future__ import annotations

import logging
from datetime import datetime
from pathlib import Path
from typing import List, Tuple

from config import OUTPUT_DIR

logger = logging.getLogger(__name__)

HISTORY_MAX_ITEMS = 50
VOICEOVER_GLOB = "voiceover_*.wav"


def list_voice_history(limit: int = HISTORY_MAX_ITEMS) -> List[Tuple[str, str]]:
    """
    返回 Gradio Dropdown 选项：(显示名, 文件绝对路径)，按时间倒序。
    """
    if not OUTPUT_DIR.is_dir():
        return []

    files = sorted(
        OUTPUT_DIR.glob(VOICEOVER_GLOB),
        key=lambda p: p.stat().st_mtime,
        reverse=True,
    )[:limit]

    choices: List[Tuple[str, str]] = []
    for path in files:
        try:
            st = path.stat()
        except OSError:
            logger.debug("跳过不可读历史文件: %s", path)
            continue
        ts = datetime.fromtimestamp(st.st_mtime).strftime("%Y-%m-%d %H:%M")
        size_mb = st.st_size / (1024 * 1024)
        label = f"{ts} · {path.name} ({size_mb:.1f} MB)"
        choices.append((label, str(path.resolve())))
    return choices


def latest_voice_path() -> str | None:
    """最新一条配音路径，无历史时返回 None。"""
    items = list_voice_history(limit=1)
    return items[0][1] if items else None