/*
 * 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 {
  RuntimeHostProcessTerminationRequiredError,
  type RuntimeHostKernel,
} from './host-kernel.js';

export interface RuntimeHostProcessLifecycleOptions {
  closeOnDisconnect?: boolean;
  onReady?: () => void;
}

export type RuntimeHostProcessLifecycleEnd = 'host_closed' | 'termination_requested';

export async function runRuntimeHostProcessLifecycle(
  host: Pick<RuntimeHostKernel, 'close' | 'closed'> &
    Partial<Pick<RuntimeHostKernel, 'shutdownReason'>>,
  options: RuntimeHostProcessLifecycleOptions = {},
): Promise<RuntimeHostProcessLifecycleEnd> {
  let closing = false;
  const close = () => {
    if (closing) return;
    closing = true;
    void host.close();
  };

  process.once('SIGINT', close);
  process.once('SIGTERM', close);
  if (options.closeOnDisconnect) process.once('disconnect', close);
  try {
    options.onReady?.();
    await host.closed;
    return closing ? 'termination_requested' : 'host_closed';
  } catch (error) {
    if (error instanceof RuntimeHostProcessTerminationRequiredError) {
      process.exit(host.shutdownReason === 'retirement' ? 0 : 1);
    }
    throw error;
  } finally {
    process.off('SIGINT', close);
    process.off('SIGTERM', close);
    if (options.closeOnDisconnect) process.off('disconnect', close);
  }
}