fix discord bot config restart and startup connection retry

server/src/services/discordBotService/connection.js

@@ -0,0 +1,94 @@
+// Owns connection replacement and recovery from failed initial logins.
+function createConnectionManager({ createRuntime, logger }) {
+  let desired = { enabled: false, token: '' };
+  let revision = 0;
+  let runtime = null;
+  let queue = Promise.resolve();
+  let retryTimer = null;
+  let retryDelay = 5000;
+
+  function enqueue(operation) {
+    const pending = queue.then(operation);
+    // Report failures without poisoning subsequent configuration changes.
+    queue = pending.catch((err) => logger.error('Discord connection update failed', err.message));
+    return pending;
+  }
+
+  async function stop() {
+    const previous = runtime;
+    runtime = null;
+    if (!previous) return;
+    previous.stop();
+    // discord.js cannot cancel login while gateway discovery is pending.
+    // Let that attempt settle before destroying it, otherwise it can open a
+    // socket after destroy() has already run and leave an orphan connection.
+    await previous.login;
+    await previous.client.destroy();
+  }
+
+  function scheduleRetry(version) {
+    if (version !== revision || !desired.enabled) return;
+    const delay = retryDelay;
+    retryDelay = Math.min(retryDelay * 2, 60000);
+    logger.warn('Retrying Discord login', { delayMs: delay });
+    retryTimer = setTimeout(() => {
+      retryTimer = null;
+      enqueue(() => start(version));
+    }, delay);
+    retryTimer.unref?.();
+  }
+
+  async function start(version) {
+    if (version !== revision || !desired.enabled) return;
+    await stop();
+    if (version !== revision || !desired.enabled) return;
+    const current = createRuntime();
+    runtime = current;
+    const { client } = current;
+    client.on('error', (err) => logger.error('Discord client error', err.message));
+    client.on('shardError', (err, shardId) => {
+      logger.warn('Discord connection error', { shardId, error: err.message });
+    });
+    client.on('shardDisconnect', (event, shardId) => {
+      logger.warn('Discord disconnected', { shardId, code: event.code });
+    });
+    client.on('clientReady', () => { retryDelay = 5000; });
+
+    // Login must not block configuration saves while the network is down.
+    // Each attempt has its own client, so stale login completion/cleanup cannot
+    // clear the credentials or stop the connection of its replacement.
+    current.login = client.login(desired.token).catch((err) => {
+      if (version !== revision || runtime !== current) return;
+      logger.error('Discord login failed', err.message);
+      enqueue(async () => {
+        if (version !== revision || runtime !== current) return;
+        await stop();
+        // Credentials require an operator edit; retry network/service failures.
+        if (err.code === 'TokenInvalid' || err.status === 401) return;
+        scheduleRetry(version);
+      });
+    });
+  }
+
+  function configure({ enabled, token }) {
+    const next = { enabled: Boolean(enabled), token };
+    if (next.enabled === desired.enabled && next.token === desired.token) return queue;
+    desired = next;
+    const version = ++revision;
+    clearTimeout(retryTimer);
+    retryTimer = null;
+    retryDelay = 5000;
+    return enqueue(async () => {
+      if (version !== revision) return;
+      if (desired.enabled) await start(version);
+      else await stop();
+    });
+  }
+
+  return {
+    configure,
+    refresh() { runtime?.refresh(); },
+  };
+}
+
+module.exports = { createConnectionManager };