Threads: add Slack/Discord thread sessions

src/auto-reply/reply/session.ts

@@ -1,5 +1,11 @@
 import crypto from "node:crypto";
+import fs from "node:fs";
+import path from "node:path";
 
+import {
+  CURRENT_SESSION_VERSION,
+  SessionManager,
+} from "@mariozechner/pi-coding-agent";
 import type { ClawdbotConfig } from "../../config/config.js";
 import {
   buildGroupDisplayName,
@@ -9,6 +15,7 @@ import {
   loadSessionStore,
   resolveAgentIdFromSessionKey,
   resolveGroupSessionKey,
+  resolveSessionFilePath,
   resolveSessionKey,
   resolveStorePath,
   type SessionEntry,
@@ -36,6 +43,45 @@ export type SessionInitResult = {
   triggerBodyNormalized: string;
 };
 
+function forkSessionFromParent(params: {
+  parentEntry: SessionEntry;
+}): { sessionId: string; sessionFile: string } | null {
+  const parentSessionFile = resolveSessionFilePath(
+    params.parentEntry.sessionId,
+    params.parentEntry,
+  );
+  if (!parentSessionFile || !fs.existsSync(parentSessionFile)) return null;
+  try {
+    const manager = SessionManager.open(parentSessionFile);
+    const leafId = manager.getLeafId();
+    if (leafId) {
+      const sessionFile =
+        manager.createBranchedSession(leafId) ?? manager.getSessionFile();
+      const sessionId = manager.getSessionId();
+      if (sessionFile && sessionId) return { sessionId, sessionFile };
+    }
+    const sessionId = crypto.randomUUID();
+    const timestamp = new Date().toISOString();
+    const fileTimestamp = timestamp.replace(/[:.]/g, "-");
+    const sessionFile = path.join(
+      manager.getSessionDir(),
+      `${fileTimestamp}_${sessionId}.jsonl`,
+    );
+    const header = {
+      type: "session",
+      version: CURRENT_SESSION_VERSION,
+      id: sessionId,
+      timestamp,
+      cwd: manager.getCwd(),
+      parentSession: parentSessionFile,
+    };
+    fs.writeFileSync(sessionFile, `${JSON.stringify(header)}\n`, "utf-8");
+    return { sessionId, sessionFile };
+  } catch {
+    return null;
+  }
+}
+
 export async function initSessionState(params: {
   ctx: MsgContext;
   cfg: ClawdbotConfig;
@@ -189,6 +235,26 @@ export async function initSessionState(params: {
   } else if (!sessionEntry.chatType) {
     sessionEntry.chatType = "direct";
   }
+  const threadLabel = ctx.ThreadLabel?.trim();
+  if (threadLabel) {
+    sessionEntry.displayName = threadLabel;
+  }
+  const parentSessionKey = ctx.ParentSessionKey?.trim();
+  if (
+    isNewSession &&
+    parentSessionKey &&
+    parentSessionKey !== sessionKey &&
+    sessionStore[parentSessionKey]
+  ) {
+    const forked = forkSessionFromParent({
+      parentEntry: sessionStore[parentSessionKey],
+    });
+    if (forked) {
+      sessionId = forked.sessionId;
+      sessionEntry.sessionId = forked.sessionId;
+      sessionEntry.sessionFile = forked.sessionFile;
+    }
+  }
   sessionStore[sessionKey] = sessionEntry;
   await saveSessionStore(storePath, sessionStore);