packages/cli/src/acp/stdio-server.ts

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

import { Readable, Writable } from 'node:stream';
import { ndJsonStream } from '@agentclientprotocol/sdk';
import {
  isRuntimeHostReconnectingConnection,
  type RuntimeHostConnection,
} from '@maka/runtime-host/client';
import { createMakaAcpAgent } from './maka-acp-agent.js';
import { AcpSessionRegistry } from './session-registry.js';
import { connectRuntimeHostCliConnection } from '../runtime-host-cli-context.js';

export interface MakaAcpStdioServerInput {
  readonly workspaceRoot: string;
  readonly clientDataRoot: string;
  readonly version: string;
}

export interface MakaAcpStdioServerDependencies {
  readonly connectRuntimeHostCliConnection?: typeof connectRuntimeHostCliConnection;
  readonly stdin?: Readable;
  readonly stdout?: Writable;
}

export async function runMakaAcpStdioServer(
  input: MakaAcpStdioServerInput,
  dependencies: MakaAcpStdioServerDependencies = {},
): Promise<number> {
  const sessionRegistry = new AcpSessionRegistry({
    connect: async (signal) => {
      const context = await (
        dependencies.connectRuntimeHostCliConnection ?? connectRuntimeHostCliConnection
      )({
        rootPath: input.workspaceRoot,
        clientDataRoot: input.clientDataRoot,
        signal,
      });
      const connection = context.connection;
      if (!isRuntimeHostReconnectingConnection(connection)) {
        await context.close().catch(() => undefined);
        throw new Error('ACP requires a reconnecting Runtime Host connection');
      }
      return {
        reconnecting: true,
        request: connection.request.bind(connection) as RuntimeHostConnection['request'],
        openSessionSubscription: connection.openSessionSubscription.bind(connection),
        openSessionSubscriptionOnce: connection.openSessionSubscriptionOnce.bind(connection),
        close: () => context.close(),
      };
    },
  });
  const stdin = dependencies.stdin ?? process.stdin;
  const stdout = dependencies.stdout ?? process.stdout;
  let stdioError: Error | undefined;
  const recordStdioError = (error: Error) => {
    stdioError ??= error;
  };
  stdin.once('error', recordStdioError);
  stdout.once('error', recordStdioError);
  try {
    const stream = ndJsonStream(
      Writable.toWeb(stdout) as WritableStream<Uint8Array>,
      Readable.toWeb(stdin) as ReadableStream<Uint8Array>,
    );
    const connection = createMakaAcpAgent({
      version: input.version,
      sessionRegistry,
    }).connect(stream);
    await connection.closed;
    if (stdioError) {
      throw stdioError;
    }
    return 0;
  } finally {
    stdin.off('error', recordStdioError);
    stdout.off('error', recordStdioError);
    await sessionRegistry.dispose();
  }
}