#!/usr/bin/env python3
"""course-toolkit 辅助工具。

子命令:
  manifest   <rawfile>        将 index|id|title 转为 NN|id|slug|title
  clean      <outdir>         transcripts/*.txt -> clean/*.txt（去时间轴、并段）
  transcribe <wav> <out>      本地 ASR 转写（env: MODEL, LANG, THREADS）
  build      <outdir>         组装 md + README（guides/<NN>.txt 可选作中文导读）
"""
import os, re, sys

def slugify(s):
    s = s.lower()
    s = re.sub(r'[^a-z0-9]+', '-', s)
    return re.sub(r'-+', '-', s).strip('-')[:60] or 'video'

def cmd_manifest(rawfile):
    out = []
    for line in open(rawfile, encoding='utf-8'):
        line = line.strip()
        if not line: continue
        parts = line.split('|')
        if len(parts) < 3: continue
        idx, vid, title = parts[0], parts[1], '|'.join(parts[2:])
        try: nn = f"{int(idx):02d}"
        except Exception: nn = slugify(idx)[:2]
        out.append(f"{nn}|{vid}|{slugify(title)}|{title}")
    sys.stdout.write("\n".join(out) + "\n")

def cmd_clean(outdir):
    tdir = os.path.join(outdir, 'transcripts'); cdir = os.path.join(outdir, 'clean')
    os.makedirs(cdir, exist_ok=True)
    for f in sorted(os.listdir(tdir)):
        if not f.endswith('.txt'): continue
        nn = f.split('-')[0]
        lines = [l for l in open(os.path.join(tdir, f), encoding='utf-8').read().splitlines() if l.strip()]
        txt = " ".join(re.sub(r'^\[\s*[\d.]+\s*-\s*[\d.]+\s*\]\s*', '', l) for l in lines)
        open(os.path.join(cdir, f"{nn}.txt"), 'w', encoding='utf-8').write(txt)
    print(f"[clean] {len(os.listdir(cdir))} files -> {cdir}")

def cmd_transcribe(wav, out):
    os.environ.setdefault("HF_ENDPOINT", "https://hf-mirror.com")
    os.environ.setdefault("HF_HUB_DISABLE_XET", "1")
    from faster_whisper import WhisperModel
    model = os.environ.get("MODEL", "base.en")
    lang = os.environ.get("LANG", "en")
    threads = int(os.environ.get("THREADS", "1"))
    m = WhisperModel(model, device="cpu", compute_type="int8", cpu_threads=threads)
    segs, info = m.transcribe(wav, language=lang, beam_size=1, vad_filter=True)
    lines = [f"[{s.start:7.1f}-{s.end:7.1f}] {s.text.strip()}" for s in segs]
    open(out, 'w', encoding='utf-8').write("\n".join(lines))
    print(f"[transcribe] {out} segs={len(lines)} dur={info.duration:.0f}")

def cmd_build(outdir):
    import subprocess, json
    man = [l.split('|') for l in open(os.path.join(outdir, 'manifest.txt'), encoding='utf-8').read().splitlines() if l.strip()]
    gdir = os.path.join(outdir, 'guides')
    rows = []
    for p in man:
        NN, ID, SLUG = p[0], p[1], p[2]
        title = p[3] if len(p) > 3 else SLUG
        vid = f"videos/{NN}-{SLUG}.mp4"
        txt = open(os.path.join(outdir, 'clean', f'{NN}.txt'), encoding='utf-8').read().strip()
        gpath = os.path.join(gdir, f'{NN}.txt')
        guide = open(gpath, encoding='utf-8').read().strip() if os.path.exists(gpath) else "> TODO：待补充中文导读。"
        try:
            dur = float(subprocess.check_output(["ffprobe", "-v", "error", "-show_entries", "format=duration", "-of", "csv=p=0", os.path.join(outdir, vid)]).decode())
            mm, ss = int(dur // 60), int(dur % 60)
        except Exception:
            mm = ss = 0
        md = f"""# {NN} · {title}

- **原始视频**：https://youtu.be/{ID}
- **时长**：{mm} 分 {ss} 秒
- **本地视频**：[{vid}]({vid})

## 🎯 本集要点（中文导读）

{guide}

## 📝 完整文稿（自动转写）

> 由本地 ASR 转写，未人工校对，供检索/精读使用。

{txt}
"""
        open(os.path.join(outdir, f'{NN}-{SLUG}.md'), 'w', encoding='utf-8').write(md)
        rows.append((NN, title, mm, ss, SLUG))
    idx = "\n".join(f"| {n} | {t} | {m}:{s:02d} | [📄 笔记]({n}-{sl}.md) · [🎬 视频](videos/{n}-{sl}.mp4) |" for n, t, m, s, sl in rows)
    open(os.path.join(outdir, 'README.md'), 'w', encoding='utf-8').write(
        "# 课程教程\n\n> 由 course-toolkit 生成。\n\n| 集 | 标题 | 时长 | 链接 |\n|---|---|---|---|\n" + idx + "\n")
    print(f"[build] {len(rows)} 篇 + README -> {outdir}")

if __name__ == '__main__':
    if len(sys.argv) < 2:
        print(__doc__); sys.exit(1)
    cmd = sys.argv[1]
    if cmd == 'manifest': cmd_manifest(sys.argv[2])
    elif cmd == 'clean': cmd_clean(sys.argv[2])
    elif cmd == 'transcribe': cmd_transcribe(sys.argv[2], sys.argv[3])
    elif cmd == 'build': cmd_build(sys.argv[2])
    else: print(__doc__); sys.exit(1)