/*
 * decaffeinate suggestions:
 * DS101: Remove unnecessary use of Array.from
 * DS102: Remove unnecessary code created because of implicit returns
 * DS207: Consider shorter variations of null checks
 * Full docs: https://github.com/decaffeinate/decaffeinate/blob/master/docs/suggestions.md
 */
const sinon = require("sinon");
const chai = require("chai");
chai.should();
const {
    expect
} = chai;
const async = require("async");
const Settings = require('settings-sharelatex');
const rclient_history = require("redis-sharelatex").createClient(Settings.redis.history); // note: this is track changes, not project-history
const rclient_project_history = require("redis-sharelatex").createClient(Settings.redis.project_history);
const rclient_du = require("redis-sharelatex").createClient(Settings.redis.documentupdater);
const Keys = Settings.redis.documentupdater.key_schema;
const HistoryKeys = Settings.redis.history.key_schema;
const ProjectHistoryKeys = Settings.redis.project_history.key_schema;

const MockTrackChangesApi = require("./helpers/MockTrackChangesApi");
const MockWebApi = require("./helpers/MockWebApi");
const DocUpdaterClient = require("./helpers/DocUpdaterClient");
const DocUpdaterApp = require("./helpers/DocUpdaterApp");

describe("Applying updates to a doc", function() {
	before(function(done) {
		this.lines = ["one", "two", "three"];
		this.version = 42;
		this.update = {
			doc: this.doc_id,
			op: [{
				i: "one and a half\n",
				p: 4
			}],
			v: this.version
		};
		this.result = ["one", "one and a half", "two", "three"];
		return DocUpdaterApp.ensureRunning(done);
	});

	describe("when the document is not loaded", function() {
		before(function(done) {
			[this.project_id, this.doc_id] = Array.from([DocUpdaterClient.randomId(), DocUpdaterClient.randomId()]);
			sinon.spy(MockWebApi, "getDocument");
			this.startTime = Date.now();
			MockWebApi.insertDoc(this.project_id, this.doc_id, {lines: this.lines, version: this.version});
			DocUpdaterClient.sendUpdate(this.project_id, this.doc_id, this.update, function(error) {
				if (error != null) { throw error; }
				return setTimeout(done, 200);
			});
			return null;
		});

		after(() => MockWebApi.getDocument.restore());

		it("should load the document from the web API", function() {
			return MockWebApi.getDocument
				.calledWith(this.project_id, this.doc_id)
				.should.equal(true);
		});

		it("should update the doc", function(done) {
			DocUpdaterClient.getDoc(this.project_id, this.doc_id, (error, res, doc) => {
				doc.lines.should.deep.equal(this.result);
				return done();
			});
			return null;
		});

		it("should push the applied updates to the track changes api", function(done) {
			rclient_history.lrange(HistoryKeys.uncompressedHistoryOps({doc_id: this.doc_id}), 0, -1, (error, updates) => {
				if (error != null) { throw error; }
				JSON.parse(updates[0]).op.should.deep.equal(this.update.op);
				return rclient_history.sismember(HistoryKeys.docsWithHistoryOps({project_id: this.project_id}), this.doc_id, (error, result) => {
					if (error != null) { throw error; }
					result.should.equal(1);
					return done();
				});
			});
			return null;
		});

		it("should push the applied updates to the project history changes api", function(done) {
			rclient_project_history.lrange(ProjectHistoryKeys.projectHistoryOps({project_id: this.project_id}), 0, -1, (error, updates) => {
				if (error != null) { throw error; }
				JSON.parse(updates[0]).op.should.deep.equal(this.update.op);
				return done();
			});
			return null;
		});

		it("should set the first op timestamp", function(done) {
			rclient_project_history.get(ProjectHistoryKeys.projectHistoryFirstOpTimestamp({project_id: this.project_id}), (error, result) => {
				if (error != null) { throw error; }
				result.should.be.within(this.startTime, Date.now());
				this.firstOpTimestamp = result;
				return done();
			});
			return null;
		});

		return describe("when sending another update", function() {
			before(function(done) {
				this.timeout = 10000;
				this.second_update = Object.create(this.update);
				this.second_update.v = this.version + 1;
				DocUpdaterClient.sendUpdate(this.project_id, this.doc_id, this.second_update, function(error) {
					if (error != null) { throw error; }
					return setTimeout(done, 200);
				});
				return null;
			});

			return it("should not change the first op timestamp", function(done) {
				rclient_project_history.get(ProjectHistoryKeys.projectHistoryFirstOpTimestamp({project_id: this.project_id}), (error, result) => {
					if (error != null) { throw error; }
					result.should.equal(this.firstOpTimestamp);
					return done();
				});
				return null;
			});
		});
	});

	describe("when the document is loaded", function() {
		before(function(done) {
			[this.project_id, this.doc_id] = Array.from([DocUpdaterClient.randomId(), DocUpdaterClient.randomId()]);

			MockWebApi.insertDoc(this.project_id, this.doc_id, {lines: this.lines, version: this.version});
			DocUpdaterClient.preloadDoc(this.project_id, this.doc_id, error => {
				if (error != null) { throw error; }
				sinon.spy(MockWebApi, "getDocument");
				return DocUpdaterClient.sendUpdate(this.project_id, this.doc_id, this.update, function(error) {
					if (error != null) { throw error; }
					return setTimeout(done, 200);
				});
			});
			return null;
		});

		after(() => MockWebApi.getDocument.restore());

		it("should not need to call the web api", () => MockWebApi.getDocument.called.should.equal(false));

		it("should update the doc", function(done) {
			DocUpdaterClient.getDoc(this.project_id, this.doc_id, (error, res, doc) => {
				doc.lines.should.deep.equal(this.result);
				return done();
			});
			return null;
		});

		it("should push the applied updates to the track changes api", function(done) {
			rclient_history.lrange(HistoryKeys.uncompressedHistoryOps({doc_id: this.doc_id}), 0, -1, (error, updates) => {
				JSON.parse(updates[0]).op.should.deep.equal(this.update.op);
				return rclient_history.sismember(HistoryKeys.docsWithHistoryOps({project_id: this.project_id}), this.doc_id, (error, result) => {
					result.should.equal(1);
					return done();
				});
			});
			return null;
		});

		return it("should push the applied updates to the project history changes api", function(done) {
			rclient_project_history.lrange(ProjectHistoryKeys.projectHistoryOps({project_id: this.project_id}), 0, -1, (error, updates) => {
				JSON.parse(updates[0]).op.should.deep.equal(this.update.op);
				return done();
			});
			return null;
		});
	});

	describe("when the document is loaded and is using project-history only", function() {
		before(function(done) {
			[this.project_id, this.doc_id] = Array.from([DocUpdaterClient.randomId(), DocUpdaterClient.randomId()]);

			MockWebApi.insertDoc(this.project_id, this.doc_id, {lines: this.lines, version: this.version, projectHistoryType: 'project-history'});
			DocUpdaterClient.preloadDoc(this.project_id, this.doc_id, error => {
				if (error != null) { throw error; }
				sinon.spy(MockWebApi, "getDocument");
				return DocUpdaterClient.sendUpdate(this.project_id, this.doc_id, this.update, function(error) {
					if (error != null) { throw error; }
					return setTimeout(done, 200);
				});
			});
			return null;
		});

		after(() => MockWebApi.getDocument.restore());

		it("should update the doc", function(done) {
			DocUpdaterClient.getDoc(this.project_id, this.doc_id, (error, res, doc) => {
				doc.lines.should.deep.equal(this.result);
				return done();
			});
			return null;
		});

		it("should not push any applied updates to the track changes api", function(done) {
			rclient_history.lrange(HistoryKeys.uncompressedHistoryOps({doc_id: this.doc_id}), 0, -1, (error, updates) => {
				updates.length.should.equal(0);
				return done();
			});
			return null;
		});

		return it("should push the applied updates to the project history changes api", function(done) {
			rclient_project_history.lrange(ProjectHistoryKeys.projectHistoryOps({project_id: this.project_id}), 0, -1, (error, updates) => {
				JSON.parse(updates[0]).op.should.deep.equal(this.update.op);
				return done();
			});
			return null;
		});
	});

	describe("when the document has been deleted", function() {
		describe("when the ops come in a single linear order", function() {
			before(function(done) {
				[this.project_id, this.doc_id] = Array.from([DocUpdaterClient.randomId(), DocUpdaterClient.randomId()]);
				const lines = ["", "", ""];
				MockWebApi.insertDoc(this.project_id, this.doc_id, {lines, version: 0});
				this.updates = [
					{ doc_id: this.doc_id, v: 0,  op: [{i: "h", p: 0} ] },
					{ doc_id: this.doc_id, v: 1,  op: [{i: "e", p: 1} ] },
					{ doc_id: this.doc_id, v: 2,  op: [{i: "l", p: 2} ] },
					{ doc_id: this.doc_id, v: 3,  op: [{i: "l", p: 3} ] },
					{ doc_id: this.doc_id, v: 4,  op: [{i: "o", p: 4} ] },
					{ doc_id: this.doc_id, v: 5,  op: [{i: " ", p: 5} ] },
					{ doc_id: this.doc_id, v: 6,  op: [{i: "w", p: 6} ] },
					{ doc_id: this.doc_id, v: 7,  op: [{i: "o", p: 7} ] },
					{ doc_id: this.doc_id, v: 8,  op: [{i: "r", p: 8} ] },
					{ doc_id: this.doc_id, v: 9,  op: [{i: "l", p: 9} ] },
					{ doc_id: this.doc_id, v: 10, op: [{i: "d", p: 10}] }
				];
				this.my_result = ["hello world", "", ""];
				return done();
			});

			it("should be able to continue applying updates when the project has been deleted", function(done) {
				let update;
				const actions = [];
				for (update of Array.from(this.updates.slice(0,6))) {
					(update => {
						return actions.push(callback => DocUpdaterClient.sendUpdate(this.project_id, this.doc_id, update, callback));
					})(update);
				}
				actions.push(callback => DocUpdaterClient.deleteDoc(this.project_id, this.doc_id, callback));
				for (update of Array.from(this.updates.slice(6))) {
					(update => {
						return actions.push(callback => DocUpdaterClient.sendUpdate(this.project_id, this.doc_id, update, callback));
					})(update);
				}

				async.series(actions, error => {
					if (error != null) { throw error; }
					return DocUpdaterClient.getDoc(this.project_id, this.doc_id, (error, res, doc) => {
						doc.lines.should.deep.equal(this.my_result);
						return done();
					});
				});
				return null;
			});

			it("should push the applied updates to the track changes api", function(done) {
				rclient_history.lrange(HistoryKeys.uncompressedHistoryOps({doc_id: this.doc_id}), 0, -1, (error, updates) => {
					updates = (Array.from(updates).map((u) => JSON.parse(u)));
					for (let i = 0; i < this.updates.length; i++) {
						const appliedUpdate = this.updates[i];
						appliedUpdate.op.should.deep.equal(updates[i].op);
					}

					return rclient_history.sismember(HistoryKeys.docsWithHistoryOps({project_id: this.project_id}), this.doc_id, (error, result) => {
						result.should.equal(1);
						return done();
					});
				});
				return null;
			});

			return it("should store the doc ops in the correct order", function(done) {
				rclient_du.lrange(Keys.docOps({doc_id: this.doc_id}), 0, -1, (error, updates) => {
					updates = (Array.from(updates).map((u) => JSON.parse(u)));
					for (let i = 0; i < this.updates.length; i++) {
						const appliedUpdate = this.updates[i];
						appliedUpdate.op.should.deep.equal(updates[i].op);
					}
					return done();
				});
				return null;
			});
		});

		return describe("when older ops come in after the delete", function() {
			before(function(done) {
				[this.project_id, this.doc_id] = Array.from([DocUpdaterClient.randomId(), DocUpdaterClient.randomId()]);
				const lines = ["", "", ""];
				MockWebApi.insertDoc(this.project_id, this.doc_id, {lines, version: 0});
				this.updates = [
					{ doc_id: this.doc_id, v: 0, op: [{i: "h", p: 0} ] },
					{ doc_id: this.doc_id, v: 1, op: [{i: "e", p: 1} ] },
					{ doc_id: this.doc_id, v: 2, op: [{i: "l", p: 2} ] },
					{ doc_id: this.doc_id, v: 3, op: [{i: "l", p: 3} ] },
					{ doc_id: this.doc_id, v: 4, op: [{i: "o", p: 4} ] },
					{ doc_id: this.doc_id, v: 0, op: [{i: "world", p: 1} ] }
				];
				this.my_result = ["hello", "world", ""];
				return done();
			});

			return it("should be able to continue applying updates when the project has been deleted", function(done) {
				let update;
				const actions = [];
				for (update of Array.from(this.updates.slice(0,5))) {
					(update => {
						return actions.push(callback => DocUpdaterClient.sendUpdate(this.project_id, this.doc_id, update, callback));
					})(update);
				}
				actions.push(callback => DocUpdaterClient.deleteDoc(this.project_id, this.doc_id, callback));
				for (update of Array.from(this.updates.slice(5))) {
					(update => {
						return actions.push(callback => DocUpdaterClient.sendUpdate(this.project_id, this.doc_id, update, callback));
					})(update);
				}

				async.series(actions, error => {
					if (error != null) { throw error; }
					return DocUpdaterClient.getDoc(this.project_id, this.doc_id, (error, res, doc) => {
						doc.lines.should.deep.equal(this.my_result);
						return done();
					});
				});
				return null;
			});
		});
	});

	describe("with a broken update", function() {
		before(function(done) {
			[this.project_id, this.doc_id] = Array.from([DocUpdaterClient.randomId(), DocUpdaterClient.randomId()]);
			this.broken_update = { doc_id: this.doc_id, v: this.version, op: [{d: "not the correct content", p: 0} ] };
			MockWebApi.insertDoc(this.project_id, this.doc_id, {lines: this.lines, version: this.version});

			DocUpdaterClient.subscribeToAppliedOps(this.messageCallback = sinon.stub());

			DocUpdaterClient.sendUpdate(this.project_id, this.doc_id, this.broken_update, function(error) {
				if (error != null) { throw error; }
				return setTimeout(done, 200);
			});
			return null;
		});

		it("should not update the doc", function(done) {
			DocUpdaterClient.getDoc(this.project_id, this.doc_id, (error, res, doc) => {
				doc.lines.should.deep.equal(this.lines);
				return done();
			});
			return null;
		});

		return it("should send a message with an error", function() {
			this.messageCallback.called.should.equal(true);
			const [channel, message] = Array.from(this.messageCallback.args[0]);
			channel.should.equal("applied-ops");
			return JSON.parse(message).should.deep.include({
				project_id: this.project_id,
				doc_id: this.doc_id,
				error:'Delete component does not match'
			});
	});
});

	describe("with enough updates to flush to the track changes api", function() {
		before(function(done) {
			[this.project_id, this.doc_id] = Array.from([DocUpdaterClient.randomId(), DocUpdaterClient.randomId()]);
			const updates = [];
			for (let v = 0; v <= 199; v++) { // Should flush after 100 ops
				updates.push({
					doc_id: this.doc_id,
					op: [{i: v.toString(), p: 0}],
					v
				});
			}

			sinon.spy(MockTrackChangesApi, "flushDoc");

			MockWebApi.insertDoc(this.project_id, this.doc_id, {lines: this.lines, version: 0});

			// Send updates in chunks to causes multiple flushes
			const actions = [];
			for (let i = 0; i <= 19; i++) {
				(i => {
					return actions.push(cb => {
						return DocUpdaterClient.sendUpdates(this.project_id, this.doc_id, updates.slice(i*10, (i+1)*10), cb);
					});
				})(i);
			}
			async.series(actions, error => {
				if (error != null) { throw error; }
				return setTimeout(done, 2000);
			});
			return null;
		});

		after(() => MockTrackChangesApi.flushDoc.restore());

		return it("should flush the doc twice", () => MockTrackChangesApi.flushDoc.calledTwice.should.equal(true));
	});

	describe("when there is no version in Mongo", function() {
		before(function(done) {
			[this.project_id, this.doc_id] = Array.from([DocUpdaterClient.randomId(), DocUpdaterClient.randomId()]);
			MockWebApi.insertDoc(this.project_id, this.doc_id, {
				lines: this.lines
			});

			const update = {
				doc: this.doc_id,
				op: this.update.op,
				v: 0
			};
			DocUpdaterClient.sendUpdate(this.project_id, this.doc_id, update, function(error) {
				if (error != null) { throw error; }
				return setTimeout(done, 200);
			});
			return null;
		});

		return it("should update the doc (using version = 0)", function(done) {
			DocUpdaterClient.getDoc(this.project_id, this.doc_id, (error, res, doc) => {
				doc.lines.should.deep.equal(this.result);
				return done();
			});
			return null;
		});
	});

	return describe("when the sending duplicate ops", function() {
		before(function(done) {
			[this.project_id, this.doc_id] = Array.from([DocUpdaterClient.randomId(), DocUpdaterClient.randomId()]);
			MockWebApi.insertDoc(this.project_id, this.doc_id, {lines: this.lines, version: this.version});

			DocUpdaterClient.subscribeToAppliedOps(this.messageCallback = sinon.stub());

			// One user delete 'one', the next turns it into 'once'. The second becomes a NOP.
			DocUpdaterClient.sendUpdate(this.project_id, this.doc_id, {
				doc: this.doc_id,
				op: [{
					i: "one and a half\n",
					p: 4
				}],
				v: this.version,
				meta: {
					source: "ikHceq3yfAdQYzBo4-xZ"
				}
			}, error => {
				if (error != null) { throw error; }
				return setTimeout(() => {
					return DocUpdaterClient.sendUpdate(this.project_id, this.doc_id, {
						doc: this.doc_id,
						op: [{
							i: "one and a half\n",
							p: 4
						}],
						v: this.version,
						dupIfSource: ["ikHceq3yfAdQYzBo4-xZ"],
						meta: {
							source: "ikHceq3yfAdQYzBo4-xZ"
						}
					}, error => {
						if (error != null) { throw error; }
						return setTimeout(done, 200);
					});
				}
				, 200);
			});
			return null;
		});

		it("should update the doc", function(done) {
			DocUpdaterClient.getDoc(this.project_id, this.doc_id, (error, res, doc) => {
				doc.lines.should.deep.equal(this.result);
				return done();
			});
			return null;
		});

		return it("should return a message about duplicate ops", function() {
			this.messageCallback.calledTwice.should.equal(true);
			this.messageCallback.args[0][0].should.equal("applied-ops");
			expect(JSON.parse(this.messageCallback.args[0][1]).op.dup).to.be.undefined;
			this.messageCallback.args[1][0].should.equal("applied-ops");
			return expect(JSON.parse(this.messageCallback.args[1][1]).op.dup).to.equal(true);
		});
	});
});