import { spawn } from 'node:child_process';

export function createDevProcessSpecs({
  nodeCommand = process.execPath,
  env = process.env,
} = {}) {
  return {
    roda: {
      command: nodeCommand,
      args: ['groups/RODA/server.js'],
      options: {
        env: {
          ...env,
          HOST: env.RODA_HOST || '127.0.0.1',
          PORT: env.RODA_PORT || '3000',
        },
        stdio: ['ignore', 'ignore', 'pipe'],
      },
    },
    vite: {
      command: nodeCommand,
      args: ['node_modules/vite/bin/vite.js'],
      options: {
        env: { ...env },
        stdio: 'inherit',
      },
    },
  };
}

export function startDevServers({
  spawnProcess = spawn,
  specs = createDevProcessSpecs(),
} = {}) {
  const roda = spawnProcess(specs.roda.command, specs.roda.args, specs.roda.options);
  const vite = spawnProcess(specs.vite.command, specs.vite.args, specs.vite.options);
  let shuttingDown = false;
  let rodaErrorOutput = '';

  roda.stderr?.on('data', (chunk) => {
    const message = String(chunk);
    rodaErrorOutput += message;
    if (!message.includes('EADDRINUSE')) {
      process.stderr.write(`[roda] ${message}`);
    }
  });

  function stopChildren() {
    shuttingDown = true;
    if (!roda.killed) {
      roda.kill();
    }
    if (!vite.killed) {
      vite.kill();
    }
  }

  vite.on('exit', (code, signal) => {
    shuttingDown = true;
    if (!roda.killed) {
      roda.kill();
    }

    if (signal) {
      process.exitCode = 1;
      return;
    }

    process.exitCode = code ?? 0;
  });

  roda.on('exit', (code, signal) => {
    if (shuttingDown) {
      return;
    }

    if (rodaErrorOutput.includes('EADDRINUSE')) {
      process.stderr.write('[roda] Port 3000 is already in use; continuing with the existing RODA server.\n');
      return;
    }

    const reason = signal ? `signal ${signal}` : `exit code ${code}`;
    process.stderr.write(`[roda] server stopped unexpectedly (${reason})\n`);
    if (!vite.killed) {
      vite.kill();
    }
    process.exitCode = code || 1;
  });

  process.once('SIGINT', stopChildren);
  process.once('SIGTERM', stopChildren);

  return { roda, vite };
}