'use strict';

// A worker may own both a fixture and a production server. Signal cleanup must
// finish all server shutdowns before removing the fixture directory or exiting.
const resources = [];
let installed = false;
let exiting;

function registerResource(stop, emergencyStop, phase = 0) {
  const resource = { stop, emergencyStop, phase };
  resources.push(resource);
  if (!installed) {
    process.on('exit', emergencyCleanup);
    process.on('SIGINT', interrupted);
    process.on('SIGTERM', interrupted);
    installed = true;
  }
  return () => {
    const index = resources.indexOf(resource);
    if (index !== -1) resources.splice(index, 1);
    if (resources.length === 0 && installed) {
      process.removeListener('exit', emergencyCleanup);
      process.removeListener('SIGINT', interrupted);
      process.removeListener('SIGTERM', interrupted);
      installed = false;
    }
  };
}

function emergencyCleanup() {
  for (const resource of [...resources].sort((a, b) => b.phase - a.phase)) {
    resource.emergencyStop();
  }
}

function interrupted() {
  if (exiting) return;
  exiting = (async () => {
    // Production children have higher phase and stop before fixture cleanup.
    for (const phase of [...new Set(resources.map((resource) => resource.phase))].sort((a, b) => b - a)) {
      await Promise.allSettled(resources.filter((resource) => resource.phase === phase).map((resource) => resource.stop()));
    }
    process.exit(130);
  })();
}

module.exports = { registerResource };