import { resolve } from 'node:path';
import { fileURLToPath } from 'node:url';

import {
  readAgcDevEndpoint,
  resolveAgcDevEndpoint,
  withAgcDevEndpointEnv,
} from './dev-port.mjs';
import {
  isAiGameCreatorServer,
  preflightExistingVite,
  readChildFailure,
  readExistingViteServer,
  spawnChild,
  stopChild,
  terminateChildTree,
  waitForChildTermination,
} from './start-dev-stack.mjs';

const appRoot = fileURLToPath(new URL('..', import.meta.url));
const repoRoot = resolve(appRoot, '../..');
const tauriCliPath = resolve(repoRoot, 'node_modules/@tauri-apps/cli/tauri.js');

function buildTauriArguments(argv, devUrl = readAgcDevEndpoint().url) {
  const args = [...argv];
  const configOverride = JSON.stringify({
    build: { devUrl, beforeDevCommand: '' },
  });
  const separatorIndex = args.indexOf('--');
  if (separatorIndex < 0) {
    return ['dev', ...args, '--config', configOverride];
  }
  const separatedArguments = args.slice(separatorIndex);
  if (separatedArguments[1] !== '--') {
    separatedArguments.unshift('--');
  }
  return [
    'dev',
    ...args.slice(0, separatorIndex),
    '--config',
    configOverride,
    ...separatedArguments,
  ];
}

function spawnTauriCli(argv, { env = process.env } = {}) {
  return spawnChild(process.execPath, [tauriCliPath, ...argv], {
    cwd: appRoot,
    env,
    shell: false,
  });
}

async function runTauriDev(
  argv = process.argv.slice(2),
  {
    resolveDevEndpoint = resolveAgcDevEndpoint,
    preflight = preflightExistingVite,
    prepareFrontend = prepareFrontendDev,
    spawnCli = spawnTauriCli,
    waitForCli = waitForChildTermination,
    terminateTree = terminateChildTree,
  } = {},
) {
  const endpoint = await resolveDevEndpoint();
  await preflight({ endpoint });

  let child = null;
  let frontendChild = null;
  const preparationAbort = new AbortController();
  let resolveShutdown;
  let shutdownSignal = '';
  let repeatedSignal = false;
  const shutdownRequested = new Promise((resolveRequest) => {
    resolveShutdown = resolveRequest;
  });
  const signalHandlers = new Map();

  for (const signal of ['SIGINT', 'SIGTERM']) {
    const handler = () => {
      if (!shutdownSignal) {
        shutdownSignal = signal;
        stopChild(child, 'SIGTERM');
        stopChild(frontendChild, 'SIGTERM');
        preparationAbort.abort();
        resolveShutdown(signal);
        return;
      }
      repeatedSignal = true;
      stopChild(child, 'SIGKILL');
      stopChild(frontendChild, 'SIGKILL');
    };
    signalHandlers.set(signal, handler);
    process.on(signal, handler);
  }

  try {
    const preparation = prepareFrontend(endpoint, {
      signal: preparationAbort.signal,
      onChild(frontend) {
        frontendChild = frontend;
      },
    });
    const prepared = await Promise.race([
      preparation.then(() => true),
      shutdownRequested.then(() => false),
    ]);
    if (!prepared || shutdownSignal) return 1;
    const tauriArguments = buildTauriArguments(argv, endpoint.url);
    child = spawnCli(tauriArguments, {
      env: withAgcDevEndpointEnv(endpoint),
    });
    const childResult = waitForCli(child);
    const outcome = await Promise.race([
      childResult.then((failure) => ({ type: 'exit', failure })),
      shutdownRequested.then((signal) => ({ type: 'signal', signal })),
      ...(frontendChild
        ? [
            waitForChildTermination(frontendChild).then((failure) => ({
              type: 'frontend-exit',
              failure,
            })),
          ]
        : []),
    ]);
    const cleanup = await terminateTree(child, {
      gracefulTimeoutMs: repeatedSignal ? 0 : 2500,
    });
    if (!cleanup.stopped) {
      console.error(
        '[ai-game-creator-shell] Tauri dev exited, but its process tree could not be fully stopped.',
      );
      return 1;
    }

    if (outcome.type === 'signal') {
      return 1;
    }
    if (outcome.type === 'frontend-exit') return 1;
    const { failure } = outcome;
    return failure.type === 'error' || failure.signal ? 1 : (failure.code ?? 0);
  } finally {
    for (const [signal, handler] of signalHandlers) {
      process.off(signal, handler);
    }
    preparationAbort.abort();
    if (frontendChild) {
      const cleanup = await terminateTree(frontendChild);
      if (!cleanup.stopped) {
        console.error('[ai-game-creator-shell] 配套开发服务未能完全停止。');
      }
    }
  }
}

async function prepareFrontendDev(endpoint, { onChild, signal }) {
  const frontend = spawnChild(
    process.platform === 'win32' ? 'npm.cmd' : 'npm',
    ['run', 'agc:serve'],
    { cwd: repoRoot, env: withAgcDevEndpointEnv(endpoint) },
  );
  onChild(frontend);
  console.log(
    '[ai-game-creator-shell] 正在准备前端与配套后端，完成后启动 Tauri',
  );
  const deadline = Date.now() + 660_000;
  while (Date.now() < deadline) {
    signal.throwIfAborted();
    const failure = readChildFailure(frontend);
    if (failure) {
      throw new Error(
        `配套开发服务退出，前端未就绪：${failure.error?.message ?? failure.signal ?? failure.code}`,
      );
    }
    if (isAiGameCreatorServer(await readExistingViteServer(endpoint))) return;
    await Promise.race([
      new Promise((resolveWait) => setTimeout(resolveWait, 1000)),
      waitForChildTermination(frontend),
    ]);
  }
  throw new Error(`等待前端与配套后端就绪超时：${endpoint.url}`);
}

function isDirectModuleExecution() {
  return Boolean(
    process.argv[1] &&
      resolve(process.argv[1]) === fileURLToPath(import.meta.url),
  );
}

export {
  buildTauriArguments,
  isDirectModuleExecution,
  runTauriDev,
  spawnTauriCli,
};

if (isDirectModuleExecution()) {
  try {
    process.exitCode = await runTauriDev();
  } catch (error) {
    console.error(
      `[ai-game-creator-shell] ${error instanceof Error ? error.message : String(error)}`,
    );
    process.exitCode = 1;
  }
}