import {
  createLightship
} from 'lightship';

const configuration: ConfigurationInput = {};

const lightship: Lightship = await createLightship(configuration);

/**
 * A teardown function called when shutdown is initialized.
 */
type ShutdownHandler = () => Promise<void> | void;

/**
 * @property detectKubernetes Run Lightship in local mode when Kubernetes is not detected. Default: true.
 * @property gracefulShutdownTimeout A number of milliseconds before forcefull termination if process does not gracefully exit. The timer starts when `lightship.shutdown()` is called. This includes the time allowed to live beacons. Default: 30000.
 * @property port The port on which the Lightship service listens. This port must be different than your main service port, if any. The default port is 9000. The default can be overwritten using LIGHTSHIP_PORT environment variable.
 * @property shutdownDelay Delays the shutdown handler by X milliseconds. This value should match `readinessProbe.periodSeconds`. Default 5000.
 * @property shutdownHandlerTimeout A number of milliseconds before forcefull termination if shutdown handlers do not complete. The timer starts when the first shutdown handler is called. Default: 5000.
 * @property signals An a array of [signal events]{@link https://nodejs.org/api/process.html#process_signal_events}. Default: [SIGTERM].
 * @property terminate Method used to terminate Node.js process. Default: `() => { process.exit(1) };`.
 */
export type ConfigurationInput = {|
  +detectKubernetes?: boolean,
  +gracefulShutdownTimeout?: number,
  +port?: number,
  +shutdownDelay?: number,
  +shutdownHandlerTimeout?: number,
  +signals?: $ReadOnlyArray<string>,
  +terminate?: () => void,
|};

/**
 * @property queueBlockingTask Forces service state to SERVER_IS_NOT_READY until all promises are resolved.
 * @property registerShutdownHandler Registers teardown functions that are called when shutdown is initialized. All registered shutdown handlers are executed in the order they have been registered. After all shutdown handlers have been executed, Lightship asks `process.exit()` to terminate the process synchronously.
 * @property shutdown Changes server state to SERVER_IS_SHUTTING_DOWN and initialises the shutdown of the application.
 * @property signalNotReady Changes server state to SERVER_IS_NOT_READY.
 * @property signalReady Changes server state to SERVER_IS_READY.
 * @property whenFirstReady Resolves the first time the service goes from `SERVER_IS_NOT_READY` to `SERVER_IS_READY` state.
 */
type Lightship = {|
  +createBeacon: (context?: BeaconContext) => BeaconController,
  +isServerReady: () => boolean,
  +isServerShuttingDown: () => boolean,
  +queueBlockingTask: (blockingTask: Promise<any>) => void,
  +registerShutdownHandler: (shutdownHandler: ShutdownHandler) => void,
  +server: http$Server,
  +shutdown: () => Promise<void>,
  +signalNotReady: () => void,
  +signalReady: () => void,
  +whenFirstReady: () => Promise<void>,
|};

import express from 'express';
import {
  createLightship
} from 'lightship';

const lightship = await createLightship();

lightship.queueBlockingTask(new Promise((resolve) => {
  setTimeout(() => {
    // Lightship service status will be `SERVER_IS_NOT_READY` until all promises
    // submitted to `queueBlockingTask` are resolved.
    resolve();
  }, 1000);
}));

const app = express();

app.get('/', (req, res) => {
  res.send('Hello, World!');
});

const server = app.listen(8080, () => {
  // All signals will be queued until after all blocking tasks are resolved.
  lightship.signalReady();
});

import express from 'express';
import {
  createLightship
} from 'lightship';

const lightship = await createLightship();

const app = express();

app.get('/', (req, res) => {
  res.send('Hello, World!');
});

const server = app.listen(8080, () => {
  lightship.signalReady();
});

(async () => {
  // `whenFirstReady` returns a promise that is resolved the first time that
  // the service goes from `SERVER_IS_NOT_READY` to `SERVER_IS_READY` state.
  await lightship.whenFirstReady();

  await runIntegrationTests();
})();

import express from 'express';

const app = express();

app.get('/', (req, res) => {
  res.send('Hello, World!');
});

app.listen(8080);

import express from 'express';
import {
  createLightship
} from 'lightship';

const app = express();

app.get('/', (req, res) => {
  res.send('Hello, World!');
});

const server = app
  .listen(8080, () => {
    // Lightship default state is "SERVER_IS_NOT_READY". Therefore, you must signal
    // that the server is now ready to accept connections.
    lightship.signalReady();
  })
  .on('error', () => {
    lightship.shutdown();
  });;

const lightship = await createLightship();

lightship.registerShutdownHandler(() => {
  server.close();
});

import express from 'express';
import {
  createLightship
} from 'lightship';

const app = express();

const minute = 60 * 1000;

let runningTotal = 0;

app.get('/', (req, res) => {
  runningTotal++;

  setTimeout(() => {
    runningTotal--;

    if (runningTotal < 100) {
      lightship.signalReady();
    } else {
      lightship.signalNotReady();
    }
  }, minute);

  res.send('Hello, World!');
});

const server = app.listen(8080);

const lightship = await createLightship();

lightship.registerShutdownHandler(() => {
  server.close();
});

// Lightship default state is "SERVER_IS_NOT_READY". Therefore, you must signal
// that the server is now ready to accept connections.
lightship.signalReady();

import express from 'express';
import delay from 'delay';
import {
  createLightship
} from 'lightship';

const app = express();

const minute = 60 * 1000;

let total = 0;
let runningTotal = 0;

app.get('/', (req, res) => {
  total++;
  runningTotal++;

  if (total === 1000) {
    lightship.shutdown();
  }

  setTimeout(() => {
    runningTotal--;

    if (runningTotal < 100) {
      lightship.signalReady();
    } else {
      lightship.signalNotReady();
    }
  }, minute);

  res.send('Hello, World!');
});

const server = app.listen(8080);

const lightship = await createLightship();

lightship.registerShutdownHandler(async () => {
  // Allow sufficient amount of time to allow all of the existing
  // HTTP requests to finish before terminating the service.
  await delay(minute);

  server.close();
});

// Lightship default state is "SERVER_IS_NOT_READY". Therefore, you must signal
// that the server is now ready to accept connections.
lightship.signalReady();

const lightship = await createLightship();

const beacon = lightship.createBeacon();

beacon.die();
// This beacon is now dead.

for (const job of jobs) {
  if (lightship.isServerShuttingDown()) {
    log.info('detected that the service is shutting down; terminating the event loop');

    break;
  }

  const beacon = lightship.createBeacon();

  // Do the job.

  await beacon.die();
}

for (const job of jobs) {
  if (lightship.isServerShuttingDown()) {
    log.info('detected that the service is shutting down; terminating the event loop');

    break;
  }

  const beacon = lightship.createBeacon({
    jobId: job.id
  });

  // Do the job.

  await beacon.die();
}

const startTime = Date.now();

let index0 = 1000;

while (index0--) {
  let index1 = 1000;

  while (index1--) {
    console.log(index0 + ':' + index1);
  }
}

console.log(Date.now() - startTime);

import whyIsNodeRunning from 'why-is-node-running';
import express from 'express';
import {
  createLightship
} from 'lightship';

const app = express();

app.get('/', (req, res) => {
  res.send('Hello, World!');
});

const server = app.listen(8080);

const lightship = await createLightship();

lightship.registerShutdownHandler(() => {
  server.close();

  whyIsNodeRunning();
});

lightship.signalReady();