fix(player): WinHTTP fallback for /jdymusic/ CDN that drops Node TCP

The old jdymusic CDN (e.g. m701/m801.music.126.net/.../jdymusic/obj/...)
intermittently drops connections from Node's HTTP stack — even with a
browser UA — while the same URL fetched via WinHTTP works. Newer paths
(/jd-musicrep-ts/, /ymusic/) do not have this restriction.

On Windows, dispatch /jdymusic/ URLs through `System.Net.WebClient` in
PowerShell into a temp file, then run ffmpeg against the file. Other
URLs and non-Windows platforms keep the direct ffmpeg + browser-UA path
from the previous commit. Also fix buildFfmpegArgs to omit HTTP-only
flags (-reconnect_*, -headers) when the input is a local file path —
new ffmpeg builds reject these as "Option not found".

stop() now also kills any in-flight PowerShell downloader and removes
the temp dir, so cancellation is clean.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/audio/player.ts

@@ -1,7 +1,9 @@
 import { spawn, execSync, type ChildProcess } from "node:child_process";
 import { EventEmitter } from "node:events";
 import { createRequire } from "node:module";
-import { accessSync, chmodSync, constants } from "node:fs";
+import { accessSync, chmodSync, constants, mkdtempSync, rmSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
 import { createOpusEncoder, PCM_FRAME_BYTES, type Encoder } from "./encoder.js";
 import type { Logger } from "../logger.js";
 
@@ -52,28 +54,49 @@ function getFfmpegCommand(): string {
 const BROWSER_UA =
   "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36";
 
+// Old jdymusic CDN paths (e.g. /jdymusic/obj/...) RST direct Node-stack
+// requests on Windows; same URL works when fetched via WinHTTP. Empirically,
+// /jd-musicrep-ts/ and /ymusic/ paths do not have this restriction.
+export function shouldUsePowerShellDownload(
+  url: string,
+  platform: string = process.platform,
+): boolean {
+  return platform === "win32" && url.includes("/jdymusic/");
+}
+
+export function cleanupTempDir(dir: string): void {
+  try {
+    rmSync(dir, { recursive: true, force: true });
+  } catch {
+    // best-effort
+  }
+}
+
 export function buildFfmpegArgs(url: string, seekSeconds: number): string[] {
   const args: string[] = [];
+  const isHttp = /^https?:\/\//i.test(url);
 
-  if (url.includes("bilivideo") || url.includes("bilibili")) {
+  if (isHttp && (url.includes("bilivideo") || url.includes("bilibili"))) {
     args.push(
       "-headers",
       `Referer: https://www.bilibili.com\r\nUser-Agent: ${BROWSER_UA}\r\n`,
     );
-  } else if (url.includes("music.126.net") || url.includes("music.163.com")) {
+  } else if (isHttp && (url.includes("music.126.net") || url.includes("music.163.com"))) {
     args.push(
       "-headers",
       `Referer: https://music.163.com/\r\nUser-Agent: ${BROWSER_UA}\r\n`,
     );
   }
 
-  args.push(
-    "-reconnect", "1",
-    "-reconnect_streamed", "1",
-    "-reconnect_delay_max", "30",
-    "-reconnect_on_network_error", "1",
-    "-reconnect_on_http_error", "4xx,5xx",
-  );
+  if (isHttp) {
+    args.push(
+      "-reconnect", "1",
+      "-reconnect_streamed", "1",
+      "-reconnect_delay_max", "30",
+      "-reconnect_on_network_error", "1",
+      "-reconnect_on_http_error", "4xx,5xx",
+    );
+  }
   if (seekSeconds > 0) args.push("-ss", String(seekSeconds));
   args.push("-i", url, "-f", "s16le", "-ar", "48000", "-ac", "2", "-acodec", "pcm_s16le", "-");
 
@@ -111,6 +134,8 @@ export class AudioPlayer extends EventEmitter {
   private static readonly MAX_CONSECUTIVE_FAILURES = 3;
   private healthyFrames = 0;
   private static readonly HEALTHY_FRAME_RESET = 50; // ~1 second of audio
+  private downloader: ChildProcess | null = null;
+  private currentTempDir: string | null = null;
 
   constructor(logger: Logger) {
     super();
@@ -137,6 +162,11 @@ export class AudioPlayer extends EventEmitter {
       return;
     }
 
+    if (shouldUsePowerShellDownload(url)) {
+      this.playViaPowerShellDownload(url, seekSeconds, currentSessionId);
+      return;
+    }
+
     const args = buildFfmpegArgs(url, seekSeconds);
 
     const ffmpegBin = getFfmpegCommand();
@@ -183,6 +213,124 @@ export class AudioPlayer extends EventEmitter {
     this.startFrameLoop();
   }
 
+  private playViaPowerShellDownload(url: string, seekSeconds: number, sessionId: number): void {
+    const tempDir = mkdtempSync(join(tmpdir(), "tsbot-jdymusic-"));
+    const tempFile = join(tempDir, "song.audio");
+    this.currentTempDir = tempDir;
+
+    const psScript = [
+      "$ErrorActionPreference = 'Stop'",
+      "$ProgressPreference = 'SilentlyContinue'",
+      "$wc = New-Object System.Net.WebClient",
+      "$wc.Headers.Add('User-Agent', $env:DL_UA)",
+      "$wc.Headers.Add('Referer', $env:DL_REFERER)",
+      "$wc.DownloadFile($env:DL_URL, $env:DL_OUT)",
+    ].join("; ");
+
+    this.logger.debug({ sessionId, tempFile }, "Downloading via PowerShell (jdymusic CDN)");
+
+    const ps = spawn(
+      "powershell",
+      ["-NoProfile", "-ExecutionPolicy", "Bypass", "-Command", psScript],
+      {
+        env: {
+          ...process.env,
+          DL_URL: url,
+          DL_OUT: tempFile,
+          DL_UA: BROWSER_UA,
+          DL_REFERER: "https://music.163.com/",
+        },
+        stdio: ["ignore", "pipe", "pipe"],
+      },
+    );
+    this.downloader = ps;
+
+    let stderrTail = "";
+    ps.stderr!.on("data", (chunk: Buffer) => {
+      stderrTail = (stderrTail + chunk.toString()).slice(-500);
+    });
+
+    ps.on("exit", (code, signal) => {
+      if (this.sessionId !== sessionId) {
+        cleanupTempDir(tempDir);
+        return;
+      }
+      this.downloader = null;
+      if (code !== 0) {
+        this.logger.warn({ code, signal, stderr: stderrTail }, "PowerShell download failed");
+        this.spawnFailed = true;
+        this.consecutiveFailures++;
+        this.state = "idle";
+        cleanupTempDir(tempDir);
+        this.currentTempDir = null;
+        this.emit("error", new Error(`PowerShell download exited ${code}`));
+        return;
+      }
+      this.spawnFfmpegFromFile(tempFile, seekSeconds, sessionId);
+    });
+
+    ps.on("error", (err) => {
+      if (this.sessionId !== sessionId) return;
+      this.downloader = null;
+      this.spawnFailed = true;
+      this.consecutiveFailures++;
+      cleanupTempDir(tempDir);
+      this.currentTempDir = null;
+      this.emit("error", err);
+    });
+
+    this.state = "playing";
+    this.startFrameLoop();
+  }
+
+  private spawnFfmpegFromFile(tempFile: string, seekSeconds: number, sessionId: number): void {
+    if (this.sessionId !== sessionId) {
+      if (this.currentTempDir) {
+        cleanupTempDir(this.currentTempDir);
+        this.currentTempDir = null;
+      }
+      return;
+    }
+
+    const args = buildFfmpegArgs(tempFile, seekSeconds);
+    const ffmpegBin = getFfmpegCommand();
+    this.ffmpeg = spawn(ffmpegBin, args, { stdio: ["ignore", "pipe", "pipe"] });
+
+    const currentPid = this.ffmpeg.pid;
+    if (currentPid) {
+      globalActivePids.add(currentPid);
+      this.logger.debug({ pid: currentPid, sessionId }, "FFmpeg spawned (from temp file)");
+    }
+    const tempDirToCleanup = this.currentTempDir;
+
+    this.ffmpeg.stdout!.on("data", (chunk: Buffer) => {
+      if (this.sessionId !== sessionId) return;
+      this.pcmBuffer = Buffer.concat([this.pcmBuffer, chunk]);
+      if (this.pcmBuffer.length > AudioPlayer.BUFFER_HIGH_WATER && !this.ffmpegPaused && this.ffmpeg?.stdout) {
+        this.ffmpeg.stdout.pause();
+        this.ffmpegPaused = true;
+      }
+    });
+
+    this.ffmpeg.on("exit", (code, signal) => {
+      if (currentPid) globalActivePids.delete(currentPid);
+      this.logger.info({ pid: currentPid, code, signal }, "FFmpeg exited");
+      if (this.sessionId === sessionId) {
+        this.ffmpeg = null;
+        if (this.currentTempDir === tempDirToCleanup) this.currentTempDir = null;
+      }
+      if (tempDirToCleanup) cleanupTempDir(tempDirToCleanup);
+    });
+
+    this.ffmpeg.on("error", (err) => {
+      if (this.sessionId === sessionId) {
+        this.spawnFailed = true;
+        this.consecutiveFailures++;
+        this.emit("error", err);
+      }
+    });
+  }
+
   stop(): void {
     // 3. 递增 ID 是最有效的逻辑“隔离墙”
     this.sessionId++; 
@@ -194,13 +342,24 @@ export class AudioPlayer extends EventEmitter {
     if (this.ffmpeg) {
       const procToKill = this.ffmpeg;
       const pidToKill = procToKill.pid;
-      this.ffmpeg = null; 
+      this.ffmpeg = null;
 
       if (pidToKill) {
         this.forceCleanup(procToKill, pidToKill);
       }
     }
 
+    if (this.downloader) {
+      const ps = this.downloader;
+      this.downloader = null;
+      try { ps.kill("SIGTERM"); } catch { /* already gone */ }
+    }
+
+    if (this.currentTempDir) {
+      cleanupTempDir(this.currentTempDir);
+      this.currentTempDir = null;
+    }
+
     this.ffmpegPaused = false;
     this.spawnFailed = false;
     this.state = "idle";