feat(acp): add experimental ACP support

Co-authored-by: Jonathan Taylor <visionik@pobox.com>

src/acp/session-mapper.ts

@@ -0,0 +1,95 @@
+import type { GatewayClient } from "../gateway/client.js";
+
+import type { AcpServerOptions } from "./types.js";
+import { readBool, readString } from "./meta.js";
+
+export type AcpSessionMeta = {
+  sessionKey?: string;
+  sessionLabel?: string;
+  resetSession?: boolean;
+  requireExisting?: boolean;
+  prefixCwd?: boolean;
+};
+
+export function parseSessionMeta(meta: unknown): AcpSessionMeta {
+  if (!meta || typeof meta !== "object") return {};
+  const record = meta as Record<string, unknown>;
+  return {
+    sessionKey: readString(record, ["sessionKey", "session", "key"]),
+    sessionLabel: readString(record, ["sessionLabel", "label"]),
+    resetSession: readBool(record, ["resetSession", "reset"]),
+    requireExisting: readBool(record, ["requireExistingSession", "requireExisting"]),
+    prefixCwd: readBool(record, ["prefixCwd"]),
+  };
+}
+
+export async function resolveSessionKey(params: {
+  meta: AcpSessionMeta;
+  fallbackKey: string;
+  gateway: GatewayClient;
+  opts: AcpServerOptions;
+}): Promise<string> {
+  const requestedLabel = params.meta.sessionLabel ?? params.opts.defaultSessionLabel;
+  const requestedKey = params.meta.sessionKey ?? params.opts.defaultSessionKey;
+  const requireExisting =
+    params.meta.requireExisting ?? params.opts.requireExistingSession ?? false;
+
+  if (params.meta.sessionLabel) {
+    const resolved = await params.gateway.request<{ ok: true; key: string }>(
+      "sessions.resolve",
+      { label: params.meta.sessionLabel },
+    );
+    if (!resolved?.key) {
+      throw new Error(`Unable to resolve session label: ${params.meta.sessionLabel}`);
+    }
+    return resolved.key;
+  }
+
+  if (params.meta.sessionKey) {
+    if (!requireExisting) return params.meta.sessionKey;
+    const resolved = await params.gateway.request<{ ok: true; key: string }>(
+      "sessions.resolve",
+      { key: params.meta.sessionKey },
+    );
+    if (!resolved?.key) {
+      throw new Error(`Session key not found: ${params.meta.sessionKey}`);
+    }
+    return resolved.key;
+  }
+
+  if (requestedLabel) {
+    const resolved = await params.gateway.request<{ ok: true; key: string }>(
+      "sessions.resolve",
+      { label: requestedLabel },
+    );
+    if (!resolved?.key) {
+      throw new Error(`Unable to resolve session label: ${requestedLabel}`);
+    }
+    return resolved.key;
+  }
+
+  if (requestedKey) {
+    if (!requireExisting) return requestedKey;
+    const resolved = await params.gateway.request<{ ok: true; key: string }>(
+      "sessions.resolve",
+      { key: requestedKey },
+    );
+    if (!resolved?.key) {
+      throw new Error(`Session key not found: ${requestedKey}`);
+    }
+    return resolved.key;
+  }
+
+  return params.fallbackKey;
+}
+
+export async function resetSessionIfNeeded(params: {
+  meta: AcpSessionMeta;
+  sessionKey: string;
+  gateway: GatewayClient;
+  opts: AcpServerOptions;
+}): Promise<void> {
+  const resetSession = params.meta.resetSession ?? params.opts.resetSession ?? false;
+  if (!resetSession) return;
+  await params.gateway.request("sessions.reset", { key: params.sessionKey });
+}