Initial release

src/herdr.ts

@@ -0,0 +1,92 @@
+import net from "node:net";
+import type { Task } from "./types.ts";
+import { orderedTreeRows } from "./ui.ts";
+
+const SOURCE = "pi-todo-herdr";
+const TOKEN = "task";
+let reportSeq = Date.now() * 1000;
+
+function nextSeq(): number {
+  reportSeq += 1;
+  return reportSeq;
+}
+
+export function isHerdrEnvironment(): boolean {
+  return process.env.HERDR_ENV === "1" && !!process.env.HERDR_SOCKET_PATH && !!process.env.HERDR_PANE_ID;
+}
+
+function hasDescendantWithStatus(task: Task, status: Task["status"], byId: Map<number, Task>): boolean {
+  for (const childId of task.childrenIds) {
+    const child = byId.get(childId);
+    if (!child) continue;
+    if (child.status === status || hasDescendantWithStatus(child, status, byId)) return true;
+  }
+  return false;
+}
+
+export function currentTaskLabel(tasks: Task[]): string | null {
+  const byId = new Map(tasks.map((task) => [task.id, task]));
+  const ordered = orderedTreeRows(tasks).map(({ task }) => task);
+  const inProgress = ordered.filter(
+    (task) => task.status === "in-progress" && !hasDescendantWithStatus(task, "in-progress", byId),
+  );
+  const candidates =
+    inProgress.length > 0
+      ? inProgress
+      : ordered.filter((task) => task.status === "blocked" && !hasDescendantWithStatus(task, "blocked", byId));
+  if (candidates.length === 0) return null;
+  const suffix = candidates.length > 1 ? ` +${candidates.length - 1}` : "";
+  return `#${candidates[0]!.id} ${candidates[0]!.name}${suffix}`;
+}
+
+function sendAttempt(request: unknown, timeoutMs: number): Promise<boolean> {
+  if (!isHerdrEnvironment()) return Promise.resolve(true);
+  const socketPath = process.env.HERDR_SOCKET_PATH!;
+  const endpoint = process.platform === "win32" ? `\\\\.\\pipe\\${socketPath}` : socketPath;
+
+  return new Promise((resolve) => {
+    let settled = false;
+    let timer: ReturnType<typeof setTimeout> | undefined;
+    const socket = net.createConnection(endpoint);
+    const finish = (delivered: boolean) => {
+      if (settled) return;
+      settled = true;
+      if (timer) clearTimeout(timer);
+      socket.destroy();
+      resolve(delivered);
+    };
+    socket.on("error", () => finish(false));
+    socket.on("connect", () => socket.write(`${JSON.stringify(request)}\n`));
+    socket.on("data", () => finish(true));
+    socket.on("end", () => finish(false));
+    timer = setTimeout(() => finish(false), timeoutMs);
+    timer.unref?.();
+  });
+}
+
+async function send(request: unknown): Promise<void> {
+  if (await sendAttempt(request, 500)) return;
+  await sendAttempt(request, 1500);
+}
+
+async function reportToken(value: string | null): Promise<void> {
+  if (!isHerdrEnvironment()) return;
+  await send({
+    id: `${SOURCE}:${Date.now()}:${Math.random().toString(36).slice(2)}`,
+    method: "pane.report_metadata",
+    params: {
+      pane_id: process.env.HERDR_PANE_ID,
+      source: SOURCE,
+      tokens: { [TOKEN]: value },
+      seq: nextSeq(),
+    },
+  });
+}
+
+export function reportCurrentTask(tasks: Task[]): Promise<void> {
+  return reportToken(currentTaskLabel(tasks));
+}
+
+export function clearCurrentTask(): Promise<void> {
+  return reportToken(null);
+}