// Switch these lines once there are useful utils
// const testUtils = require('./utils');
require('./utils');
const path = require('path');
const sinon = require('sinon');
const delay = require('delay');
const FakeTimers = require('@sinonjs/fake-timers');

const JobManager = require('../index');

describe('Job Manager', function () {
    let logging;

    beforeEach(function () {
        logging = {
            info: sinon.stub(),
            warn: sinon.stub(),
            error: sinon.stub()
        };
    });

    it('public interface', function () {
        const jobManager = new JobManager({logging});

        should.exist(jobManager.addJob);
    });

    describe('Add a job', function () {
        describe('Inline jobs', function () {
            it('adds a job to a queue', async function () {
                const spy = sinon.spy();
                const jobManager = new JobManager({logging});

                jobManager.addJob({
                    job: spy,
                    data: 'test data',
                    offloaded: false
                });
                should(jobManager.queue.idle()).be.false();

                // give time to execute the job
                await delay(1);

                should(jobManager.queue.idle()).be.true();
                should(spy.called).be.true();
                should(spy.args[0][0]).equal('test data');
            });

            it('handles failed job gracefully', async function () {
                const spy = sinon.stub().throws();
                const jobManager = new JobManager({logging});

                jobManager.addJob({
                    job: spy,
                    data: 'test data',
                    offloaded: false
                });
                should(jobManager.queue.idle()).be.false();

                // give time to execute the job
                await delay(1);

                should(jobManager.queue.idle()).be.true();
                should(spy.called).be.true();
                should(spy.args[0][0]).equal('test data');
                should(logging.error.called).be.true();
            });
        });

        describe('Offloaded jobs', function () {
            it('fails to schedule for invalid scheduling expression', function () {
                const jobManager = new JobManager({logging});

                try {
                    jobManager.addJob({
                        at: 'invalid expression',
                        name: 'jobName'
                    });
                } catch (err) {
                    err.message.should.equal('Invalid schedule format');
                }
            });

            it('fails to schedule for no job name', function () {
                const jobManager = new JobManager({logging});

                try {
                    jobManager.addJob({
                        at: 'invalid expression',
                        job: () => {}
                    });
                } catch (err) {
                    err.message.should.equal('Name parameter should be present if job is a function');
                }
            });

            it('schedules a job using date format', async function () {
                const jobManager = new JobManager({logging});
                const timeInTenSeconds = new Date(Date.now() + 10);
                const jobPath = path.resolve(__dirname, './jobs/simple.js');

                const clock = FakeTimers.install({now: Date.now()});
                jobManager.addJob({
                    at: timeInTenSeconds,
                    job: jobPath,
                    name: 'job-in-ten'
                });

                should(jobManager.bree.timeouts['job-in-ten']).type('object');
                should(jobManager.bree.workers['job-in-ten']).type('undefined');

                // allow to run the job and start the worker
                await clock.nextAsync();

                should(jobManager.bree.workers['job-in-ten']).type('object');

                const promise = new Promise((resolve, reject) => {
                    jobManager.bree.workers['job-in-ten'].on('error', reject);
                    jobManager.bree.workers['job-in-ten'].on('exit', (code) => {
                        should(code).equal(0);
                        resolve();
                    });
                });

                // allow job to finish execution and exit
                clock.next();

                await promise;

                should(jobManager.bree.workers['job-in-ten']).type('undefined');

                clock.uninstall();
            });

            it('schedules a job to run immediately', async function () {
                const jobManager = new JobManager({logging});
                const clock = FakeTimers.install({now: Date.now()});

                const jobPath = path.resolve(__dirname, './jobs/simple.js');
                jobManager.addJob({
                    job: jobPath,
                    name: 'job-now'
                });

                should(jobManager.bree.timeouts['job-now']).type('object');

                // allow scheduler to pick up the job
                clock.tick(1);

                should(jobManager.bree.workers['job-now']).type('object');

                const promise = new Promise((resolve, reject) => {
                    jobManager.bree.workers['job-now'].on('error', reject);
                    jobManager.bree.workers['job-now'].on('exit', (code) => {
                        should(code).equal(0);
                        resolve();
                    });
                });

                await promise;

                should(jobManager.bree.workers['job-now']).type('undefined');

                clock.uninstall();
            });

            it('fails to schedule a job with the same name to run immediately one after another', async function () {
                const jobManager = new JobManager({logging});
                const clock = FakeTimers.install({now: Date.now()});

                const jobPath = path.resolve(__dirname, './jobs/simple.js');
                jobManager.addJob({
                    job: jobPath,
                    name: 'job-now'
                });

                should(jobManager.bree.timeouts['job-now']).type('object');

                // allow scheduler to pick up the job
                clock.tick(1);

                should(jobManager.bree.workers['job-now']).type('object');

                const promise = new Promise((resolve, reject) => {
                    jobManager.bree.workers['job-now'].on('error', reject);
                    jobManager.bree.workers['job-now'].on('exit', (code) => {
                        should(code).equal(0);
                        resolve();
                    });
                });

                await promise;

                should(jobManager.bree.workers['job-now']).type('undefined');

                (() => {
                    jobManager.addJob({
                        job: jobPath,
                        name: 'job-now'
                    });
                }).should.throw('Job #1 has a duplicate job name of job-now');

                clock.uninstall();
            });

            it('uses custom error handler when job fails', async function (){
                let job = function namedJob() {
                    throw new Error('job error');
                };
                const spyHandler = sinon.spy();
                const jobManager = new JobManager({logging, errorHandler: spyHandler});

                jobManager.addJob({
                    job,
                    name: 'will-fail'
                });

                // give time to execute the job
                // has to be this long because in Node v10 the communication is
                // done through processes, which takes longer comparing to worker_threads
                // can be reduced to 100 when Node v10 support is dropped
                await delay(600);

                should(spyHandler.called).be.true();
                should(spyHandler.args[0][0].message).equal('job error');
                should(spyHandler.args[0][1].name).equal('will-fail');
            });

            it('uses worker message handler when job sends a message', async function (){
                const workerMessageHandlerSpy = sinon.spy();
                const jobManager = new JobManager({logging, workerMessageHandler: workerMessageHandlerSpy});

                jobManager.addJob({
                    job: path.resolve(__dirname, './jobs/message.js'),
                    name: 'will-send-msg'
                });
                jobManager.bree.run('will-send-msg');

                jobManager.bree.workers['will-send-msg'].postMessage('hello from Ghost!');

                // Give time for worker (worker thread) <-> parent process (job manager) communication
                await delay(1000);

                should(workerMessageHandlerSpy.called).be.true();
                should(workerMessageHandlerSpy.args[0][0].name).equal('will-send-msg');
                should(workerMessageHandlerSpy.args[0][0].message).equal('hello from Ghost!');
            });
        });
    });

    describe('Remove a job', function () {
        it('removes a scheduled job from the queue', async function () {
            const jobManager = new JobManager({logging});

            const timeInTenSeconds = new Date(Date.now() + 10);
            const jobPath = path.resolve(__dirname, './jobs/simple.js');

            jobManager.addJob({
                at: timeInTenSeconds,
                job: jobPath,
                name: 'job-in-ten'
            });
            jobManager.bree.config.jobs[0].name.should.equal('job-in-ten');

            await jobManager.removeJob('job-in-ten');

            should(jobManager.bree.config.jobs[0]).be.undefined;
        });
    });

    describe('Shutdown', function () {
        it('gracefully shuts down an inline jobs', async function () {
            const jobManager = new JobManager({logging});

            jobManager.addJob({
                job: require('./jobs/timed-job'),
                data: 200,
                offloaded: false
            });

            should(jobManager.queue.idle()).be.false();

            await jobManager.shutdown();

            should(jobManager.queue.idle()).be.true();
        });

        it('gracefully shuts down an interval job', async function () {
            const jobManager = new JobManager({logging});

            jobManager.addJob({
                at: 'every 5 seconds',
                job: path.resolve(__dirname, './jobs/graceful.js')
            });

            await delay(1); // let the job execution kick in

            should(Object.keys(jobManager.bree.workers).length).equal(0);
            should(Object.keys(jobManager.bree.timeouts).length).equal(0);
            should(Object.keys(jobManager.bree.intervals).length).equal(1);

            await jobManager.shutdown();

            should(Object.keys(jobManager.bree.intervals).length).equal(0);
        });
    });
});