music(chord): 拆两个 tab + 抓两种 (letters/functional)

- yopu 切 /song?title=&artist= 搜索（避免歌手词被搜糊）
- 抓的版本按搜索结果 nier-snippet svg <text> 数区分：
  >0 = 字母谱 (G/Em7/C 弹唱谱)；==0 = 功能谱 (1/4/5/6m 数字级数)
- sidecar fetch/status/state/image 都走 (id, mode) 维度，文件落 /data/chord-fetch/{id}-{mode}.png
- backend chord_fetch / chord_status 接 ?mode=letters|functional，import 时 role 分别为 chord_letters / chord_functional
- 前端 chord tab 拆「吉他谱」+「功能谱」，state/error/poll 各自独立；旧 role='chord' 显示在「吉他谱」兼容历史 import
- verified 标记探测：匿名访问 yopu HTML 里 0 hits（要登录可见），暂时只能按 svg_text 区分

apps/music/chord/yopu.py

@@ -54,16 +54,22 @@ def setup_driver(window="1920,5000"):
     return webdriver.Chrome(service=service, options=o)
 
 
-def find_first_chord_chart(driver, search_url):
-    """在搜索页找最佳的「功能谱」结果。
+def find_chart(driver, title: str, artist: str, prefer: str = 'functional'):
+    """在 /song?title=&artist= 找最佳候选 view。
 
-    yopu 现在搜索结果里同一首歌有多个版本：
-    - 字母谱（chord chart）：nier-snippet 里有 SVG <text> 渲染的 chord 字母（G/Em7/C）
-    - 功能谱（数字 / 级数）：nier-snippet 里没 SVG <text>（用 HTML/CSS 显示数字 1/4/5）
+    yopu 同一首歌一般有多个版本，按搜索结果里 nier-snippet 内的
+    SVG <text> 数量区分：
+    - svg_text > 0  → chord 字母版（G/Em7/C），民间叫弹唱谱
+    - svg_text == 0 → 功能谱 / 数字级数版
 
-    我们优先取第一个**功能谱**（svgTextCount === 0），fallback 到第一个字母谱。
+    `prefer` ∈ {'letters', 'functional'}，按需求挑第一个匹配的。
+    实在没匹配就 fallback 到第一个非空候选。
     """
-    logger.info("loading search: %s", search_url)
+    from urllib.parse import urlencode
+    base = 'https://yopu.co/song'
+    # /song 用 hash 传参（跟 yopu 前端约定一致）
+    search_url = f"{base}#title={quote(title)}&artist={quote(artist)}"
+    logger.info("loading /song: %s", search_url)
     driver.get(search_url)
     time.sleep(3)
 
@@ -77,40 +83,82 @@ def find_first_chord_chart(driver, search_url):
             var info = p.querySelector('.one-line-info');
             var snippet = p.querySelector('.nier-snippet');
             var svgTextCount = snippet ? snippet.querySelectorAll('svg text').length : 0;
+            // 任何子元素 class 含 'verified' 都算（svelte 加了 hash class）
+            var isVerified = p.querySelectorAll('[class*="verified"]').length > 0;
             out.push({
                 href: p.href,
                 title: titleEl ? (titleEl.textContent || '').trim() : '',
                 subtitle: subEl ? (subEl.textContent || '').trim() : '',
                 info: info ? (info.textContent || '').trim() : '',
-                isFunctional: svgTextCount === 0,
                 svgTextCount: svgTextCount,
+                isLetters: svgTextCount > 0,
+                isFunctional: svgTextCount === 0,
+                isVerified: isVerified,
             });
         }
         return out;
     """)
 
     if not hits:
-        logger.warning("no a.post-main found — yopu DOM changed?")
+        logger.warning("no a.post-main found at /song — fallback to /explore")
+        # fallback: yopu /song 偶尔没结果，回退到 /explore
+        from urllib.parse import quote as _q
+        q = (artist + ' ' + title).strip()
+        driver.get(f"https://yopu.co/explore#q={_q(q)}")
+        time.sleep(3)
+        hits = driver.execute_script("""
+            var out = [];
+            var posts = document.querySelectorAll('a.post-main');
+            for (var i = 0; i < posts.length; i++) {
+                var p = posts[i];
+                var titleEl = p.querySelector('.title-line .title, .title');
+                var subEl = p.querySelector('.title-line .subtitle, .subtitle');
+                var info = p.querySelector('.one-line-info');
+                var snippet = p.querySelector('.nier-snippet');
+                var svgTextCount = snippet ? snippet.querySelectorAll('svg text').length : 0;
+                out.push({
+                    href: p.href,
+                    title: titleEl ? (titleEl.textContent || '').trim() : '',
+                    subtitle: subEl ? (subEl.textContent || '').trim() : '',
+                    info: info ? (info.textContent || '').trim() : '',
+                    svgTextCount: svgTextCount,
+                    isLetters: svgTextCount > 0,
+                    isFunctional: svgTextCount === 0,
+                    isVerified: false,
+                });
+            }
+            return out;
+        """)
+    if not hits:
         return None
 
-    # 优先功能谱
-    functional = [h for h in hits if h['isFunctional']]
-    if functional:
-        chosen = functional[0]
-        kind = 'functional'
-    else:
-        chosen = hits[0]
-        kind = 'letter-chord (no functional version found)'
+    # 优先匹配 prefer；同时优先 verified（虽然匿名访问大概率全是 false）
+    def _key(h):
+        match_pref = (prefer == 'letters' and h['isLetters']) or \
+                     (prefer == 'functional' and h['isFunctional'])
+        # 数值越小越优先：first match_pref+verified, then match_pref, then verified, then all
+        return (0 if (match_pref and h['isVerified']) else
+                1 if match_pref else
+                2 if h['isVerified'] else 3)
+
+    sorted_hits = sorted(hits, key=_key)
+    chosen = sorted_hits[0]
+    matched = (prefer == 'letters' and chosen['isLetters']) or \
+              (prefer == 'functional' and chosen['isFunctional'])
+    kind = prefer if matched else f"{prefer}-fallback"
 
     href = chosen['href']
     if href.startswith('/'):
-        p = urlparse(search_url)
+        p = urlparse(driver.current_url)
         href = f"{p.scheme}://{p.netloc}{href}"
     elif not href.startswith('http'):
-        href = urljoin(search_url, href)
-    logger.info("[%s] %s — %s [%s] (%d total: %d functional, %d letter)",
+        href = urljoin(driver.current_url, href)
+    logger.info("[%s] %s — %s [%s] verified=%s (total %d, letters=%d, functional=%d, verified=%d)",
                 kind, chosen['title'], chosen['subtitle'], chosen['info'],
-                len(hits), len(functional), len(hits) - len(functional))
+                chosen['isVerified'], len(hits),
+                sum(1 for h in hits if h['isLetters']),
+                sum(1 for h in hits if h['isFunctional']),
+                sum(1 for h in hits if h['isVerified']))
     return {
         'url': href,
         'title': chosen.get('title') or '',
@@ -261,24 +309,24 @@ def _save_debug(driver, tag: str):
         logger.warning("debug snapshot failed: %s", e)
 
 
-def fetch_chord_chart(query: str, output_path: str, *,
+def fetch_chord_chart(title: str, artist: str, output_path: str, *,
+                      mode: str = 'functional',
                       sheet_style: str = '功能谱',
                       chord_style: str = '级数名',
                       verbose: bool = False) -> tuple[bool, str]:
-    """
-    搜 yopu.co、进 view 页、按 row 选样式、截图。
-    返回 (ok, msg)。msg 在失败时是错误说明。
+    """搜 yopu /song、按 mode 挑候选 view、截图。
+    mode='functional' → 数字级数版；mode='letters' → 字母版（弹唱谱）。
+    返回 (ok, msg)。
     """
     if verbose:
         logging.basicConfig(level=logging.DEBUG, format='%(asctime)s %(levelname)s %(message)s')
     else:
         logging.basicConfig(level=logging.INFO, format='%(asctime)s %(levelname)s %(message)s')
 
-    search_url = f"https://yopu.co/explore#q={quote(query)}"
     driver = None
     try:
         driver = setup_driver()
-        result = find_first_chord_chart(driver, search_url)
+        result = find_chart(driver, title, artist, prefer=mode)
         if not result:
             _save_debug(driver, 'no-search-hit')
             return False, '未找到和弦谱'