// Copyright (c) Microsoft Corporation. All rights reserved.
// Licensed under the MIT license. See LICENSE file in the project root for details.

import * as assert from "assert";
import * as WebSocket from "ws";
import * as path from "path";
import * as Q from "q";
import * as sinon from "sinon";
import * as child_process from "child_process";

import { MultipleLifetimesAppWorker } from "../../debugger/appWorker";
import { ForkedAppWorker } from "../../debugger/forkedAppWorker";
import * as ForkedAppWorkerModule from "../../debugger/forkedAppWorker";
import {Packager} from "../../common/packager";

suite("appWorker", function() {
    suite("debuggerContext", function() {
        const packagerPort = 8081;

        suite("SandboxedAppWorker", function() {
            const originalSpawn = child_process.spawn;
            const sourcesStoragePath = path.resolve(__dirname, "assets");

            // Inject 5 sec delay before shutting down to worker to give tests some time to execute
            const WORKER_DELAY_SHUTDOWN = `setTimeout(() => {console.log("Shutting down")}, 5000)`;

            let testWorker: ForkedAppWorker;
            let spawnStub: Sinon.SinonStub;
            let postReplyFunction = sinon.stub();

            function workerWithScript(scriptBody: string): ForkedAppWorker {
                const wrappedBody = [ MultipleLifetimesAppWorker.WORKER_BOOTSTRAP,
                    scriptBody, MultipleLifetimesAppWorker.WORKER_DONE, WORKER_DELAY_SHUTDOWN ].join("\n");

                spawnStub = sinon.stub(child_process, "spawn", () =>
                    originalSpawn("node", ["-e", wrappedBody], {stdio: ["pipe", "pipe", "pipe", "ipc"]}));

                testWorker = new ForkedAppWorker(packagerPort, sourcesStoragePath, postReplyFunction);
                return testWorker;
            }

            teardown(function() {
                // Reset everything
                spawnStub.restore();
                postReplyFunction.reset();
                if (testWorker) {
                    testWorker.stop();
                }
            });

            test("should execute scripts correctly and be able to invoke the callback", function() {
                const expectedMessageResult = { success: true };
                const startScriptContents = `var testResponse = ${JSON.stringify(expectedMessageResult)}; postMessage(testResponse);`;

                return workerWithScript(startScriptContents).start()
                .then(() =>
                    Q.delay(1000))
                .then(() =>
                    assert(postReplyFunction.calledWithExactly(expectedMessageResult)));
            });

            test("should be able to import scripts", function() {
                // NOTE: we're not able to mock reading script for import since this is performed by a
                // separate node process and is out of control so we must provide a real script file
                const scriptImportPath = path.resolve(sourcesStoragePath, "importScriptsTest.js");
                const startScriptContents = `importScripts("${scriptImportPath}"); postMessage("postImport");`;

                return workerWithScript(startScriptContents).start().then(() => {
                    // We have not yet finished importing the script, we should not have posted a response yet
                    assert(postReplyFunction.notCalled, "postReplyFuncton called before scripts imported");
                    return Q.delay(500);
                }).then(() => {
                    assert(postReplyFunction.calledWith("postImport"), "postMessage after import not handled");
                    assert(postReplyFunction.calledWith("inImport"), "postMessage not registered from within import");
                });
            });

            test("should correctly pass postMessage to the loaded script", function() {
                const startScriptContents = `onmessage = postMessage;`;
                const testMessage = { method: "test", success: true };

                const worker = workerWithScript(startScriptContents);
                return worker.start().then(() => {
                    assert(postReplyFunction.notCalled, "postRepyFunction called before message sent");
                    worker.postMessage(testMessage);
                    return Q.delay(1000);
                }).then(() => {
                    assert(postReplyFunction.calledWith({ data: testMessage }), "No echo back from app");
                });
            });

            test("should be able to require an installed node module via __debug__.require", function () {
                const expectedMessageResult = { qString: Q.toString() };
                const startScriptContents = `var Q = __debug__.require('q');
                    var testResponse = { qString: Q.toString() };
                    postMessage(testResponse);`;

                return workerWithScript(startScriptContents).start()
                .then(() => Q.delay(500))
                .then(() =>
                    assert(postReplyFunction.calledWithExactly(expectedMessageResult)));
            });
        });

        suite("MultipleLifetimesAppWorker", function() {
            const sourcesStoragePath = path.resolve(__dirname, "assets");

            let multipleLifetimesWorker: MultipleLifetimesAppWorker;
            let sandboxedAppWorkerStub: Sinon.SinonStub;
            let appWorkerModuleStub: Sinon.SinonStub;
            let webSocket: Sinon.SinonStub;
            let webSocketConstructor: Sinon.SinonStub;
            let packagerIsRunning: Sinon.SinonStub;

            let sendMessage: (message: string) => void;

            let clock: Sinon.SinonFakeTimers;

            setup(function() {
                webSocket = sinon.createStubInstance(WebSocket);

                sandboxedAppWorkerStub = sinon.createStubInstance(ForkedAppWorker);
                appWorkerModuleStub = sinon.stub(ForkedAppWorkerModule, "ForkedAppWorker").returns(sandboxedAppWorkerStub);

                const messageInvocation: Sinon.SinonStub = (<any>webSocket).on.withArgs("message");
                sendMessage = (message: string) => messageInvocation.callArgWith(1, message);

                webSocketConstructor = sinon.stub();
                webSocketConstructor.returns(webSocket);
                packagerIsRunning = sinon.stub(Packager, "isPackagerRunning");
                packagerIsRunning.returns(Q.resolve(true));

                multipleLifetimesWorker = new MultipleLifetimesAppWorker(packagerPort, sourcesStoragePath, {
                    webSocketConstructor: webSocketConstructor,
                });

                sinon.stub(multipleLifetimesWorker, "downloadAndPatchDebuggerWorker").returns(Q.resolve({}));
            });

            teardown(function() {
                // Reset everything
                multipleLifetimesWorker.stop();
                multipleLifetimesWorker = null;
                appWorkerModuleStub.restore();
                webSocket = null;
                sandboxedAppWorkerStub = null;
                webSocketConstructor = null;
                sendMessage = null;
                packagerIsRunning.restore();
                packagerIsRunning = null;

                if (clock) {
                    clock.restore();
                    clock = null;
                }
            });

            test("with packager running should construct a websocket connection to the correct endpoint and listen for events", function() {
                return multipleLifetimesWorker.start().then(() => {
                    const websocketRegex = new RegExp("ws://[^:]*:[0-9]*/debugger-proxy\\?role=debugger");
                    assert(webSocketConstructor.calledWithMatch(websocketRegex), "The web socket was not constructed to the correct url: " + webSocketConstructor.args[0][0]);

                    const expectedListeners = ["open", "close", "message", "error"];
                    expectedListeners.forEach((event) => {
                        assert((<any>webSocket).on.calledWithMatch(event), `Missing listener for ${event}`);
                    });
                });
            });

            test("with packager running should attempt to reconnect after disconnecting", function() {
                let startWorker = sinon.spy(multipleLifetimesWorker, "start");
                return multipleLifetimesWorker.start().then(() => {
                    // Forget previous invocations
                    startWorker.reset();
                    packagerIsRunning.returns(Q.resolve(true));

                    clock = sinon.useFakeTimers();

                    const closeInvocation: Sinon.SinonStub = (<any>webSocket).on.withArgs("close");
                    closeInvocation.callArg(1);

                    // Ensure that the retry is 100ms after the disconnection
                    clock.tick(99);
                    assert(startWorker.notCalled, "Attempted to reconnect too quickly");

                    clock.tick(1);
                }).then(() => {
                    assert(startWorker.called);
                });
            });

            test("with packager running should respond correctly to prepareJSRuntime messages", function() {
                return multipleLifetimesWorker.start().then(() => {
                    const messageId = 1;
                    const testMessage = JSON.stringify({ method: "prepareJSRuntime", id: messageId });
                    const expectedReply = JSON.stringify({ replyID: messageId });

                    const appWorkerDeferred = Q.defer<void>();

                    const appWorkerStart: Sinon.SinonStub = (<any>sandboxedAppWorkerStub).start;
                    const websocketSend: Sinon.SinonStub = (<any>webSocket).send;

                    appWorkerStart.returns(appWorkerDeferred.promise);

                    sendMessage(testMessage);

                    assert(appWorkerStart.called, "SandboxedAppWorker not started in respones to prepareJSRuntime");
                    assert(websocketSend.notCalled, "Response sent prior to configuring sandbox worker");

                    appWorkerDeferred.resolve(void 0);

                    return Q.delay(1).then(() => {
                        assert(websocketSend.calledWith(expectedReply), "Did not receive the expected response to prepareJSRuntime");
                    });
                });
            });

            test("with packager running should pass unknown messages to the sandboxedAppWorker", function() {
                return multipleLifetimesWorker.start().then(() => {
                    // Start up an app worker
                    const prepareJSMessage = JSON.stringify({ method: "prepareJSRuntime", id: 1 });
                    const appWorkerStart: Sinon.SinonStub = (<any>sandboxedAppWorkerStub).start;
                    appWorkerStart.returns(Q.resolve(void 0));

                    sendMessage(prepareJSMessage);

                    // Then attempt to message it

                    const testMessage = { method: "unknownMethod" };
                    const testMessageString = JSON.stringify(testMessage);

                    const postMessageStub: Sinon.SinonStub = (<any>sandboxedAppWorkerStub).postMessage;

                    assert(postMessageStub.notCalled, "sandboxedAppWorker.postMessage called prior to any message");
                    sendMessage(testMessageString);

                    assert(postMessageStub.calledWith(testMessage), "message was not passed to sandboxedAppWorker");
                });
            });

            test("with packager running should close connection if there is another debugger connected to packager", () => {
                return multipleLifetimesWorker.start().then(() => {
                    // Forget previous invocations
                    webSocketConstructor.reset();
                    clock = sinon.useFakeTimers(new Date().getTime());

                    const closeInvocation: Sinon.SinonStub = (<any>webSocket).on.withArgs("close");
                    (<any>webSocket)._closeMessage = "Another debugger is already connected";
                    closeInvocation.callArg(1);

                    // Ensure it doesn't try to reconnect
                    clock.tick(100);
                    assert(webSocketConstructor.notCalled, "socket attempted to reconnect");
                });
            });

            test("without packager running should not start if there is no packager running", () => {
                packagerIsRunning.returns(Q.resolve(false));

                return multipleLifetimesWorker.start()
                    .done(() => {
                        assert(webSocketConstructor.notCalled, "socket should not be created");
                    }, reason => {
                        assert(reason.message === `Cannot attach to packager. Are you sure there is a packager and it is running in the port ${packagerPort}? If your packager is configured to run in another port make sure to add that to the setting.json.`);
                    });
            });
        });

    });
});
