import expect from 'expect.js';
import sinon from 'sinon';
import moment from 'moment';
import { noop, random, get, find } from 'lodash';
import Worker from '../../lib/worker';
import elasticsearchMock from '../fixtures/elasticsearch';
import constants from '../../lib/helpers/constants';

const anchor = '2016-04-02T01:02:03.456'; // saturday
const defaults = {
  timeout: 10000,
  interval: 1500,
  size: 10,
  unknownMime: false,
  contentBody: null,
};

describe('Worker class', function () {
  let anchorMoment;
  let clock;
  let client;
  let mockQueue;

  beforeEach(function () {
    client = new elasticsearchMock.Client();
    mockQueue = {
      client: client
    };
  });

  describe('invalid construction', function () {
    it('should throw without a type', function () {
      const init = () => new Worker(mockQueue);
      expect(init).to.throwException(/type.+string/i);
    });

    it('should throw without an invalid type', function () {
      const init = () => new Worker(mockQueue, { string: false });
      expect(init).to.throwException(/type.+string/i);
    });

    it('should throw without a worker', function () {
      const init = () => new Worker(mockQueue, 'test');
      expect(init).to.throwException(/worker.+function/i);
    });

    it('should throw with an invalid worker', function () {
      const init = () => new Worker(mockQueue, 'test', { function: false });
      expect(init).to.throwException(/worker.+function/i);
    });
  });

  describe('construction', function () {
    it('should have a unique ID', function () {
      const worker = new Worker(mockQueue, 'test', noop);
      expect(worker.id).to.be.a('string');

      const worker2 = new Worker(mockQueue, 'test', noop);
      expect(worker2.id).to.be.a('string');

      expect(worker.id).to.not.equal(worker2.id);
    });
  });

  describe('output formatting', function () {
    let worker;
    let f;

    beforeEach(function () {
      worker = new Worker(mockQueue, 'test', noop);
      f = (output) => worker._formatOutput(output);
    });

    it('should handle primitives', function () {
      const primitives = ['test', true, 1234, { one: 1}, [5, 6, 7, 8]];

      primitives.forEach((val) => {
        expect(f(val)).to.have.property('content_type', defaults.unknownMime);
        expect(f(val)).to.have.property('content', val);
      });
    });

    it('should accept content object without type', function () {
      const output = {
        content: 'test output'
      };

      expect(f(output)).to.have.property('content_type', defaults.unknownMime);
      expect(f(output)).to.have.property('content', output.content);
    });

    it('should accept a content type', function () {
      const output = {
        content_type: 'test type',
        content: 'test output'
      };

      expect(f(output)).to.have.property('content_type', output.content_type);
      expect(f(output)).to.have.property('content', output.content);
    });

    it('should work with no input', function () {
      expect(f()).to.have.property('content_type', defaults.unknownMime);
      expect(f()).to.have.property('content', defaults.contentBody);
    });
  });

  describe('searching for jobs', function () {
    let searchSpy;

    function getSearchParams(jobtype, params = {}) {
      new Worker(mockQueue, jobtype, noop, params);
      clock.tick(defaults.interval);
      return searchSpy.firstCall.args[0];
    }

    beforeEach(() => {
      anchorMoment = moment(anchor);
      clock = sinon.useFakeTimers(anchorMoment.valueOf());
      searchSpy = sinon.spy(mockQueue.client, 'search');
    });

    afterEach(() => {
      clock.restore();
    });

    describe('polling interval', function () {
      it('should start polling for jobs after interval', function () {
        new Worker(mockQueue, 'test', noop);
        sinon.assert.notCalled(searchSpy);
        clock.tick(defaults.interval);
        sinon.assert.calledOnce(searchSpy);
      });

      it('should use interval option to control polling', function () {
        const interval = 567;
        new Worker(mockQueue, 'test', noop, { interval });
        sinon.assert.notCalled(searchSpy);
        clock.tick(interval);
        sinon.assert.calledOnce(searchSpy);
      });
    });

    describe('query parameters', function () {
      it('should query with version', function () {
        const params = getSearchParams('test');
        expect(params).to.have.property('version', true);
      });

      it('should query by default doctype', function () {
        const params = getSearchParams('test');
        expect(params).to.have.property('type', constants.DEFAULT_SETTING_DOCTYPE);
      });

      it('should query by custom doctype', function () {
        const doctype = 'custom_test';
        const params = getSearchParams('test', { doctype });
        expect(params).to.have.property('type', doctype);
      });
    });

    describe('query body', function () {
      const conditionPath = 'query.constant_score.filter.bool';
      const jobtype = 'test_jobtype';

      it('should search by job type', function () {
        const { body } = getSearchParams(jobtype);
        const conditions = get(body, conditionPath);
        expect(conditions).to.have.property('must');
        expect(conditions.must).to.eql({ term: { jobtype: jobtype } });
      });

      it('should search for pending or expired jobs', function () {
        const { body } = getSearchParams(jobtype);
        const conditions = get(body, conditionPath);
        expect(conditions).to.have.property('should');

        // this works because we are stopping the clock, so all times match
        const nowTime = moment().toISOString();
        const pending = { term: { status: 'pending'} };
        const expired = { bool: { must: [
          { term: { status: 'processing' } },
          { range: { process_expiration: { lte: nowTime } } }
        ] } };

        const pendingMatch = find(conditions.should, pending);
        expect(pendingMatch).to.not.be(undefined);

        const expiredMatch = find(conditions.should, expired);
        expect(expiredMatch).to.not.be(undefined);
      });

      it('should use default size', function () {
        const { body } = getSearchParams(jobtype);
        expect(body).to.have.property('size', defaults.size);
      });

      it('should observe the size option', function () {
        const size = 25;
        const { body } = getSearchParams(jobtype, { size });
        expect(body).to.have.property('size', size);
      });
    });

  });

  describe('claiming a job', function () {
    let params;
    let job;
    let worker;
    let updateSpy;

    beforeEach(function () {
      anchorMoment = moment(anchor);
      clock = sinon.useFakeTimers(anchorMoment.valueOf());

      params = {
        index: 'myIndex',
        type: 'test',
        id: 12345,
        version: 3
      };
      job = mockQueue.client.get(params);
      worker = new Worker(mockQueue, 'test', noop);
      updateSpy = sinon.spy(mockQueue.client, 'update');
    });

    afterEach(() => {
      clock.restore();
    });

    it('should use version on update', function () {
      worker._claimJob(job);
      const query = updateSpy.firstCall.args[0];
      expect(query).to.have.property('index', job._index);
      expect(query).to.have.property('type', job._type);
      expect(query).to.have.property('id', job._id);
      expect(query).to.have.property('version', job._version);
    });

    it('should increment the job attempts', function () {
      worker._claimJob(job);
      const doc = updateSpy.firstCall.args[0].body.doc;
      expect(doc).to.have.property('attempts', job._source.attempts + 1);
    });

    it('should update the job status', function () {
      worker._claimJob(job);
      const doc = updateSpy.firstCall.args[0].body.doc;
      expect(doc).to.have.property('status', constants.JOB_STATUS_PROCESSING);
    });

    it('should set job expiration time', function () {
      worker._claimJob(job);
      const doc = updateSpy.firstCall.args[0].body.doc;
      const expiration = anchorMoment.add(defaults.timeout).toISOString();
      expect(doc).to.have.property('process_expiration', expiration);
    });

    it('should fail job if max_attempts are hit', function () {
      const failSpy = sinon.spy(worker, '_failJob');
      job._source.attempts = job._source.max_attempts;
      worker._claimJob(job);
      sinon.assert.calledOnce(failSpy);
    });

    it('should append error message if no existing content', function () {
      const failSpy = sinon.spy(worker, '_failJob');
      job._source.attempts = job._source.max_attempts;
      expect(job._source.output).to.be(undefined);
      worker._claimJob(job);
      const msg = failSpy.firstCall.args[1];
      expect(msg).to.contain('Max attempts reached');
      expect(msg).to.contain(job._source.max_attempts);
    });

    it('should not append message if existing output', function () {
      const failSpy = sinon.spy(worker, '_failJob');
      job._source.attempts = job._source.max_attempts;
      job._source.output = 'i have some output';
      worker._claimJob(job);
      const msg = failSpy.firstCall.args[1];
      expect(msg).to.equal(false);
    });

    it('should swallow version mismatch errors', function () {
      mockQueue.client.update.restore();
      sinon.stub(mockQueue.client, 'update').returns(Promise.reject({ statusCode: 409 }));
      return worker._claimJob(job);
    });
  });

  describe('failing a job', function () {
    let job;
    let worker;
    let updateSpy;

    beforeEach(function () {
      anchorMoment = moment(anchor);
      clock = sinon.useFakeTimers(anchorMoment.valueOf());

      job = mockQueue.client.get();
      worker = new Worker(mockQueue, 'test', noop);
      updateSpy = sinon.spy(mockQueue.client, 'update');
    });

    afterEach(() => {
      clock.restore();
    });


    it('should use version on update', function () {
      worker._failJob(job);
      const query = updateSpy.firstCall.args[0];
      expect(query).to.have.property('index', job._index);
      expect(query).to.have.property('type', job._type);
      expect(query).to.have.property('id', job._id);
      expect(query).to.have.property('version', job._version);
    });

    it('should set status to failed', function () {
      worker._failJob(job);
      const doc = updateSpy.firstCall.args[0].body.doc;
      expect(doc).to.have.property('status', constants.JOB_STATUS_FAILED);
    });

    it('should append error message if supplied', function () {
      const msg = 'test message';
      worker._failJob(job, msg);
      const doc = updateSpy.firstCall.args[0].body.doc;
      expect(doc).to.have.property('output');
      expect(doc.output).to.have.property('content', msg);
    });

    it('should swallow version mismatch errors', function () {
      mockQueue.client.update.restore();
      sinon.stub(mockQueue.client, 'update').returns(Promise.reject({ statusCode: 409 }));
      return worker._failJob(job);
    });

    it('should set completed time and status to failed', function () {
      const startTime = moment().valueOf();
      const msg = 'test message';
      clock.tick(100);

      worker._failJob(job, msg);
      const doc = updateSpy.firstCall.args[0].body.doc;
      expect(doc).to.have.property('output');
      expect(doc).to.have.property('status', constants.JOB_STATUS_FAILED);
      expect(doc).to.have.property('completed_at');
      const completedTimestamp = moment(doc.completed_at).valueOf();
      expect(completedTimestamp).to.be.greaterThan(startTime);
    });
  });

  describe('performing a job', function () {
    let job;
    let payload;
    let updateSpy;

    beforeEach(function () {
      payload = {
        value: random(0, 100, true)
      };
      job = mockQueue.client.get({}, { payload });
      updateSpy = sinon.spy(mockQueue.client, 'update');
    });

    it('should call the workerFn with the payload', function (done) {
      const workerFn = function (jobPayload) {
        expect(jobPayload).to.eql(payload);
      };
      const worker = new Worker(mockQueue, 'test', workerFn);

      worker._performJob(job)
      .then(() => done());
    });

    it('should update the job with the workerFn output', function () {
      const workerFn = function (jobPayload) {
        expect(jobPayload).to.eql(payload);
        return payload;
      };
      const worker = new Worker(mockQueue, 'test', workerFn);

      return worker._performJob(job)
      .then(() => {
        sinon.assert.calledOnce(updateSpy);
        const query = updateSpy.firstCall.args[0];
        expect(query).to.have.property('index', job._index);
        expect(query).to.have.property('type', job._type);
        expect(query).to.have.property('id', job._id);
        expect(query).to.have.property('version', job._version);
        expect(query.body.doc).to.have.property('output');
        expect(query.body.doc.output).to.have.property('content_type', false);
        expect(query.body.doc.output).to.have.property('content', payload);
      });
    });

    it('should update the job status and completed time', function () {
      const startTime = moment().valueOf();
      const workerFn = function (jobPayload) {
        expect(jobPayload).to.eql(payload);
        return new Promise(function (resolve) {
          setTimeout(() => resolve(payload), 10);
        });
      };
      const worker = new Worker(mockQueue, 'test', workerFn);

      worker._performJob(job)
      .then(() => {
        sinon.assert.calledOnce(updateSpy);
        const doc = updateSpy.firstCall.args[0].body.doc;
        expect(doc).to.have.property('status', constants.JOB_STATUS_COMPLETED);
        expect(doc).to.have.property('completed_at');
        const completedTimestamp = moment(doc.completed_at).valueOf();
        expect(completedTimestamp).to.be.greaterThan(startTime);
      });
    });

    it('should append error output to job', function () {
      const workerFn = function () {
        throw new Error('test error');
      };
      const worker = new Worker(mockQueue, 'test', workerFn);
      const failStub = sinon.stub(worker, '_failJob');

      return worker._performJob(job)
      .then(() => {
        sinon.assert.calledOnce(failStub);
        sinon.assert.calledWith(failStub, job, 'Error: test error');
      });
    });
  });

  describe('job timeouts', function () {
    let job;
    let failStub;
    let worker;
    const timeout = 20;
    const timeoutPadding = 10;

    beforeEach(function () {
      const workerFn = function () {
        return new Promise(function (resolve) {
          setTimeout(() => {
            resolve();
          }, timeout + timeoutPadding);
        });
      };
      worker = new Worker(mockQueue, 'test', workerFn);
      job = {
        _id: 'testJob1',
        _source: {
          timeout: timeout,
          payload: 'test'
        }
      };
      failStub = sinon.stub(worker, '_failJob').returns(Promise.resolve());
    });

    it('should fail if not complete within allotted time', function () {
      return worker._performJob(job)
      .then(() => {
        sinon.assert.notCalled(failStub);
      });
    });
  });

});