/*
 * decaffeinate suggestions:
 * DS102: Remove unnecessary code created because of implicit returns
 * Full docs: https://github.com/decaffeinate/decaffeinate/blob/master/docs/suggestions.md
 */
const chai = require('chai');
const should = chai.should();
const {
    expect
} = chai;
const sinon = require("sinon");
const modulePath = "../../../app/js/ChannelManager.js";
const SandboxedModule = require('sandboxed-module');

describe('ChannelManager', function() {
	beforeEach(function() {
		this.rclient = {};
		this.other_rclient = {};
		return this.ChannelManager = SandboxedModule.require(modulePath, { requires: {
			"settings-sharelatex": (this.settings = {}),
			"metrics-sharelatex": (this.metrics = {inc: sinon.stub(), summary: sinon.stub()}),
			"logger-sharelatex": (this.logger = { log: sinon.stub(), warn: sinon.stub(), error: sinon.stub() })
		}
	});});

	describe("subscribe", function() {

		describe("when there is no existing subscription for this redis client", function() {
			beforeEach(function(done) {
				this.rclient.subscribe = sinon.stub().resolves();
				this.ChannelManager.subscribe(this.rclient, "applied-ops", "1234567890abcdef");
				return setTimeout(done);
			});

			return it("should subscribe to the redis channel", function() {
				return this.rclient.subscribe.calledWithExactly("applied-ops:1234567890abcdef").should.equal(true);
			});
		});

		describe("when there is an existing subscription for this redis client", function() {
			beforeEach(function(done) {
				this.rclient.subscribe = sinon.stub().resolves();
				this.ChannelManager.subscribe(this.rclient, "applied-ops", "1234567890abcdef");
				this.ChannelManager.subscribe(this.rclient, "applied-ops", "1234567890abcdef");
				return setTimeout(done);
			});

			return it("should subscribe to the redis channel again", function() {
				return this.rclient.subscribe.callCount.should.equal(2);
			});
		});

		describe("when subscribe errors", function() {
			beforeEach(function(done) {
				this.rclient.subscribe = sinon.stub()
					.onFirstCall().rejects(new Error("some redis error"))
					.onSecondCall().resolves();
				const p = this.ChannelManager.subscribe(this.rclient, "applied-ops", "1234567890abcdef");
				p.then(() => done(new Error('should not subscribe but fail'))).catch(err => {
					err.message.should.equal("some redis error");
					this.ChannelManager.getClientMapEntry(this.rclient).has("applied-ops:1234567890abcdef").should.equal(false);
					this.ChannelManager.subscribe(this.rclient, "applied-ops", "1234567890abcdef");
					// subscribe is wrapped in Promise, delay other assertions
					return setTimeout(done);
				});
				return null;
			});

			it("should have recorded the error", function() {
				return expect(this.metrics.inc.calledWithExactly("subscribe.failed.applied-ops")).to.equal(true);
			});

			it("should subscribe again", function() {
				return this.rclient.subscribe.callCount.should.equal(2);
			});

			return it("should cleanup", function() {
				return this.ChannelManager.getClientMapEntry(this.rclient).has("applied-ops:1234567890abcdef").should.equal(false);
			});
		});

		describe("when subscribe errors and the clientChannelMap entry was replaced", function() {
			beforeEach(function(done) {
				this.rclient.subscribe = sinon.stub()
					.onFirstCall().rejects(new Error("some redis error"))
					.onSecondCall().resolves();
				this.first = this.ChannelManager.subscribe(this.rclient, "applied-ops", "1234567890abcdef");
				// ignore error
				this.first.catch((function(){}));
				expect(this.ChannelManager.getClientMapEntry(this.rclient).get("applied-ops:1234567890abcdef")).to.equal(this.first);

				this.rclient.unsubscribe = sinon.stub().resolves();
				this.ChannelManager.unsubscribe(this.rclient, "applied-ops", "1234567890abcdef");
				this.second = this.ChannelManager.subscribe(this.rclient, "applied-ops", "1234567890abcdef");
				// should get replaced immediately
				expect(this.ChannelManager.getClientMapEntry(this.rclient).get("applied-ops:1234567890abcdef")).to.equal(this.second);

				// let the first subscribe error -> unsubscribe -> subscribe
				return setTimeout(done);
			});

			return it("should cleanup the second subscribePromise", function() {
				return expect(this.ChannelManager.getClientMapEntry(this.rclient).has("applied-ops:1234567890abcdef")).to.equal(false);
			});
		});

		return describe("when there is an existing subscription for another redis client but not this one", function() {
			beforeEach(function(done) {
				this.other_rclient.subscribe = sinon.stub().resolves();
				this.ChannelManager.subscribe(this.other_rclient, "applied-ops", "1234567890abcdef");
				this.rclient.subscribe = sinon.stub().resolves();  // discard the original stub
				this.ChannelManager.subscribe(this.rclient, "applied-ops", "1234567890abcdef");
				return setTimeout(done);
			});

			return it("should subscribe to the redis channel on this redis client", function() {
				return this.rclient.subscribe.calledWithExactly("applied-ops:1234567890abcdef").should.equal(true);
			});
		});
	});

	describe("unsubscribe", function() {

		describe("when there is no existing subscription for this redis client", function() {
			beforeEach(function(done) {
				this.rclient.unsubscribe = sinon.stub().resolves();
				this.ChannelManager.unsubscribe(this.rclient, "applied-ops", "1234567890abcdef");
				return setTimeout(done);
			});

			return it("should unsubscribe from the redis channel", function() {
				return this.rclient.unsubscribe.called.should.equal(true);
			});
		});


		describe("when there is an existing subscription for this another redis client but not this one", function() {
			beforeEach(function(done) {
				this.other_rclient.subscribe = sinon.stub().resolves();
				this.rclient.unsubscribe = sinon.stub().resolves();
				this.ChannelManager.subscribe(this.other_rclient, "applied-ops", "1234567890abcdef");
				this.ChannelManager.unsubscribe(this.rclient, "applied-ops", "1234567890abcdef");
				return setTimeout(done);
			});

			return it("should still unsubscribe from the redis channel on this client", function() {
				return this.rclient.unsubscribe.called.should.equal(true);
			});
		});

		describe("when unsubscribe errors and completes", function() {
			beforeEach(function(done) {
				this.rclient.subscribe = sinon.stub().resolves();
				this.ChannelManager.subscribe(this.rclient, "applied-ops", "1234567890abcdef");
				this.rclient.unsubscribe = sinon.stub().rejects(new Error("some redis error"));
				this.ChannelManager.unsubscribe(this.rclient, "applied-ops", "1234567890abcdef");
				setTimeout(done);
				return null;
			});

			it("should have cleaned up", function() {
				return this.ChannelManager.getClientMapEntry(this.rclient).has("applied-ops:1234567890abcdef").should.equal(false);
			});

			return it("should not error out when subscribing again", function(done) {
				const p = this.ChannelManager.subscribe(this.rclient, "applied-ops", "1234567890abcdef");
				p.then(() => done()).catch(done);
				return null;
			});
		});

		describe("when unsubscribe errors and another client subscribes at the same time", function() {
			beforeEach(function(done) {
				this.rclient.subscribe = sinon.stub().resolves();
				this.ChannelManager.subscribe(this.rclient, "applied-ops", "1234567890abcdef");
				let rejectSubscribe = undefined;
				this.rclient.unsubscribe = () => new Promise((resolve, reject) => rejectSubscribe = reject);
				this.ChannelManager.unsubscribe(this.rclient, "applied-ops", "1234567890abcdef");

				setTimeout(() => {
					// delay, actualUnsubscribe should not see the new subscribe request
					this.ChannelManager.subscribe(this.rclient, "applied-ops", "1234567890abcdef")
					.then(() => setTimeout(done)).catch(done);
					return setTimeout(() => // delay, rejectSubscribe is not defined immediately
                    rejectSubscribe(new Error("redis error")));
				});
				return null;
			});

			it("should have recorded the error", function() {
				return expect(this.metrics.inc.calledWithExactly("unsubscribe.failed.applied-ops")).to.equal(true);
			});

			it("should have subscribed", function() {
				return this.rclient.subscribe.called.should.equal(true);
			});

			return it("should have discarded the finished Promise", function() {
				return this.ChannelManager.getClientMapEntry(this.rclient).has("applied-ops:1234567890abcdef").should.equal(false);
			});
		});

		return describe("when there is an existing subscription for this redis client", function() {
			beforeEach(function(done) {
				this.rclient.subscribe = sinon.stub().resolves();
				this.rclient.unsubscribe = sinon.stub().resolves();
				this.ChannelManager.subscribe(this.rclient, "applied-ops", "1234567890abcdef");
				this.ChannelManager.unsubscribe(this.rclient, "applied-ops", "1234567890abcdef");
				return setTimeout(done);
			});

			return it("should unsubscribe from the redis channel", function() {
				return this.rclient.unsubscribe.calledWithExactly("applied-ops:1234567890abcdef").should.equal(true);
			});
		});
	});

	return describe("publish", function() {

		describe("when the channel is 'all'", function() {
			beforeEach(function() {
				this.rclient.publish = sinon.stub();
				return this.ChannelManager.publish(this.rclient, "applied-ops", "all", "random-message");
			});

			return it("should publish on the base channel", function() {
				return this.rclient.publish.calledWithExactly("applied-ops", "random-message").should.equal(true);
			});
		});

		describe("when the channel has an specific id", function() {

			describe("when the individual channel setting is false", function() {
				beforeEach(function() {
					this.rclient.publish = sinon.stub();
					this.settings.publishOnIndividualChannels = false;
					return this.ChannelManager.publish(this.rclient, "applied-ops", "1234567890abcdef", "random-message");
				});

				return it("should publish on the per-id channel", function() {
					this.rclient.publish.calledWithExactly("applied-ops", "random-message").should.equal(true);
					return this.rclient.publish.calledOnce.should.equal(true);
				});
			});

			return describe("when the individual channel setting is true", function() {
				beforeEach(function() {
					this.rclient.publish = sinon.stub();
					this.settings.publishOnIndividualChannels = true;
					return this.ChannelManager.publish(this.rclient, "applied-ops", "1234567890abcdef", "random-message");
				});

				return it("should publish on the per-id channel", function() {
					this.rclient.publish.calledWithExactly("applied-ops:1234567890abcdef", "random-message").should.equal(true);
					return this.rclient.publish.calledOnce.should.equal(true);
				});
			});
		});

		return describe("metrics", function() {
			beforeEach(function() {
				this.rclient.publish = sinon.stub();
				return this.ChannelManager.publish(this.rclient, "applied-ops", "all", "random-message");
			});

			return it("should track the payload size", function() {
				return this.metrics.summary.calledWithExactly(
					"redis.publish.applied-ops",
					"random-message".length
				).should.equal(true);
			});
		});
	});
});