feat: add YouTube search to !play and fix NA URL fallback

Non-URL input (e.g. !play classical music) searches YouTube for 10
results and picks one randomly. Also fixes --flat-playlist returning
"NA" as the URL for single videos by falling back to the original
input URL.

plugins/music.py

@@ -4,6 +4,7 @@ from __future__ import annotations
 
 import asyncio
 import logging
+import random
 import subprocess
 from dataclasses import dataclass
 
@@ -51,6 +52,11 @@ def _truncate(text: str, max_len: int = _MAX_TITLE_LEN) -> str:
     return text[: max_len - 3].rstrip() + "..."
 
 
+def _is_url(text: str) -> bool:
+    """Check if text looks like a URL rather than a search query."""
+    return text.startswith(("http://", "https://", "ytsearch:"))
+
+
 def _resolve_tracks(url: str, max_tracks: int = _MAX_QUEUE) -> list[tuple[str, str]]:
     """Resolve URL into (url, title) pairs via yt-dlp. Blocking, run in executor.
 
@@ -73,8 +79,10 @@ def _resolve_tracks(url: str, max_tracks: int = _MAX_QUEUE) -> list[tuple[str, s
         for i in range(0, len(lines) - 1, 2):
             track_url = lines[i].strip()
             track_title = lines[i + 1].strip()
-            if track_url:
-                tracks.append((track_url, track_title or track_url))
+            # --flat-playlist prints "NA" for single videos (no extraction)
+            if not track_url or track_url == "NA":
+                track_url = url
+            tracks.append((track_url, track_title or track_url))
         return tracks if tracks else [(url, url)]
     except Exception:
         return [(url, url)]
@@ -126,12 +134,13 @@ def _ensure_loop(bot) -> None:
 # -- Commands ----------------------------------------------------------------
 
 
-@command("play", help="Music: !play <url|playlist>")
+@command("play", help="Music: !play <url|query>")
 async def cmd_play(bot, message):
     """Play a URL or add to queue if already playing.
 
     Usage:
-        !play <url>     Play audio from URL (YouTube, SoundCloud, etc.)
+        !play <url>       Play audio from URL (YouTube, SoundCloud, etc.)
+        !play <query>     Search YouTube and play the first result
 
     Playlists are expanded into individual tracks. If the queue is nearly
     full, only as many tracks as will fit are enqueued.
@@ -142,10 +151,13 @@ async def cmd_play(bot, message):
 
     parts = message.text.split(None, 1)
     if len(parts) < 2:
-        await bot.reply(message, "Usage: !play <url>")
+        await bot.reply(message, "Usage: !play <url|query>")
         return
 
     url = parts[1].strip()
+    is_search = not _is_url(url)
+    if is_search:
+        url = f"ytsearch10:{url}"
     ps = _ps(bot)
 
     if len(ps["queue"]) >= _MAX_QUEUE:
@@ -156,6 +168,10 @@ async def cmd_play(bot, message):
     loop = asyncio.get_running_loop()
     resolved = await loop.run_in_executor(None, _resolve_tracks, url, remaining)
 
+    # Search: pick one random result instead of enqueuing all
+    if is_search and len(resolved) > 1:
+        resolved = [random.choice(resolved)]
+
     was_idle = ps["current"] is None
     requester = message.nick or "?"
     added = 0