/**
 * @author n1474335 [n1474335@gmail.com]
 * @author j433866 [j433866@gmail.com]
 * @copyright Crown Copyright 2016
 * @license Apache-2.0
 */

import Utils from "../core/Utils";
import FileSaver from "file-saver";
import zip from "zlibjs/bin/zip.min";
import ZipWorker from "worker-loader?inline&fallback=false!./ZipWorker";

const Zlib = zip.Zlib;

/**
  * Waiter to handle events related to the output
  */
class OutputWaiter {

    /**
     * OutputWaiter constructor.
     *
     * @param {App} app - The main view object for CyberChef.
     * @param {Manager} manager - The CyberChef event manager
     */
    constructor(app, manager) {
        this.app = app;
        this.manager = manager;

        this.outputs = {};
        this.activeTab = -1;

        this.zipWorker = null;

        this.maxTabs = 4; // Calculate this
    }

    /**
     * Calculates the maximum number of tabs to display
     */
    calcMaxTabs() {
        const numTabs = Math.floor((document.getElementById("IO").offsetWidth - 75)  / 120);
        this.maxTabs = numTabs;
    }

    /**
     * Gets the output for the specified input number
     *
     * @param {number} inputNum
     * @returns {string | ArrayBuffer}
     */
    getOutput(inputNum) {
        if (this.outputs[inputNum] === undefined || this.outputs[inputNum] === null) return -1;

        if (this.outputs[inputNum].data === null) return "";

        if (typeof this.outputs[inputNum].data.result === "string") {
            return this.outputs[inputNum].data.result;
        } else {
            return this.outputs[inputNum].data.result || "";
        }
    }

    /**
     * Gets the output string or FileBuffer for the active input
     *
     * @returns {string | ArrayBuffer}
     */
    getActive() {
        return this.getOutput(this.getActiveTab());
    }

    /**
     * Adds a new output to the output array.
     * Creates a new tab if we have less than maxtabs tabs open
     *
     * @param {number} inputNum
     * @param {boolean} [changeTab=true]
     */
    addOutput(inputNum, changeTab = true) {
        const output = this.getOutput(inputNum);
        if (output !== -1) {
            // Remove the output if it already exists
            delete this.outputs[inputNum];
        }
        const newOutput = {
            data: null,
            inputNum: inputNum,
            statusMessage: `Input ${inputNum} has not been baked yet.`,
            error: null,
            status: "inactive",
            bakeId: -1
        };

        this.outputs[inputNum] = newOutput;

        // add new tab
        this.addTab(inputNum, changeTab);
    }

    /**
     * Updates the value for the output in the output array.
     * If this is the active output tab, updates the output textarea
     *
     * @param {Object} data
     * @param {number} inputNum
     */
    updateOutputValue(data, inputNum) {
        if (this.getOutput(inputNum) === -1) {
            this.addOutput(inputNum);
        }

        this.outputs[inputNum].data = data;

        // set output here
        this.set(inputNum);
    }

    /**
     * Updates the status message for the output in the output array.
     * If this is the active output tab, updates the output textarea
     *
     * @param {string} statusMessage
     * @param {number} inputNum
     */
    updateOutputMessage(statusMessage, inputNum) {
        if (this.getOutput(inputNum) === -1) return;
        this.outputs[inputNum].statusMessage = statusMessage;
        this.set(inputNum);
    }

    /**
     * Updates the error value for the output in the output array.
     * If this is the active output tab, calls app.handleError.
     * Otherwise, the error will be handled when the output is switched to
     *
     * @param {Error} error
     * @param {number} inputNum
     * @param {number} [progress=0]
     */
    updateOutputError(error, inputNum, progress=0) {
        if (this.getOutput(inputNum) === -1) return;

        this.outputs[inputNum].error = error;
        this.outputs[inputNum].progress = progress;
        this.updateOutputStatus("error", inputNum);

        // call handle error here
        // or make the error handling part of set()
    }

    /**
     * Updates the status value for the output in the output array
     *
     * @param {string} status
     * @param {number} inputNum
     */
    updateOutputStatus(status, inputNum) {
        if (this.getOutput(inputNum) === -1) return;
        this.outputs[inputNum].status = status;

        if (status !== "error") {
            delete this.outputs[inputNum].error;
            delete this.outputs[inputNum].progress;
        }

        this.set(inputNum);
    }

    /**
     * Updates the stored bake ID for the output in the ouptut array
     *
     * @param {number} bakeId
     * @param {number} inputNum
     */
    updateOutputBakeId(bakeId, inputNum) {
        if (this.getOutput(inputNum) === -1) return;
        this.outputs[inputNum].bakeId = bakeId;
    }

    /**
     * Removes an output from the output array.
     *
     * @param {number} inputNum
     */
    removeOutput(inputNum) {
        if (this.getOutput(inputNum) === -1) return;

        delete (this.outputs[inputNum]);
    }

    /**
     * Removes all output tabs
     */
    removeAllOutputs() {
        this.outputs = {};
        const tabs = document.getElementById("output-tabs").children;
        for (let i = tabs.length - 1; i >= 0; i--) {
            tabs.item(i).remove();
        }
    }

    /**
     * Sets the output in the output textarea.
     *
     * @param {number} inputNum
     */
    set(inputNum) {
        const output = this.outputs[inputNum];
        if (output === undefined || output === null) return;
        if (typeof inputNum !== "number") inputNum = parseInt(inputNum, 10);

        if (inputNum !== this.getActiveTab()) return;

        const outputText = document.getElementById("output-text");
        const outputHtml = document.getElementById("output-html");
        const outputFile = document.getElementById("output-file");
        const outputHighlighter = document.getElementById("output-highlighter");
        const inputHighlighter = document.getElementById("input-highlighter");
        // If pending or baking, show loader and status message
        // If error, style the tab and handle the error
        // If done, display the output if it's the active tab
        // If inactive, show the last bake value (or blank)
        if (output.status === "inactive" ||
            output.status === "stale" ||
            (output.status === "baked" && output.bakeId < this.manager.worker.bakeId)) {
            this.manager.controls.showStaleIndicator();
        } else {
            this.manager.controls.hideStaleIndicator();
        }

        this.manager.recipe.updateBreakpointIndicator(false);

        if (output.status === "pending" || output.status === "baking") {
            // show the loader and the status message if it's being shown
            // otherwise don't do anything
            this.toggleLoader(true);
            document.querySelector("#output-loader .loading-msg").textContent = output.statusMessage;

        } else if (output.status === "error") {
            // style the tab if it's being shown
            // run app.handleError()
            this.toggleLoader(false);
            outputText.style.display = "block";
            outputHtml.style.display = "none";
            outputFile.style.display = "none";
            outputHighlighter.display = "none";
            inputHighlighter.display = "none";

            outputText.value = output.error;
            outputHtml.innerHTML = "";

            this.manager.recipe.updateBreakpointIndicator(output.progress);
        } else if (output.status === "baked" || output.status === "inactive") {
            this.displayTabInfo(inputNum);
            this.toggleLoader(false);
            this.closeFile();
            let scriptElements, lines, length;

            if (output.data === null) {
                outputText.style.display = "block";
                outputHtml.style.display = "none";
                outputFile.style.display = "none";
                outputHighlighter.display = "block";
                inputHighlighter.display = "block";

                outputText.value = "";
                outputHtml.innerHTML = "";

                lines = 0;
                length = 0;
                return;
            }

            switch (output.data.type) {
                case "html":
                    outputText.style.display = "none";
                    outputHtml.style.display = "block";
                    outputFile.style.display = "none";
                    outputHighlighter.style.display = "none";
                    inputHighlighter.style.display = "none";

                    outputText.value = "";
                    outputHtml.innerHTML = output.data.result;

                    // Execute script sections
                    scriptElements = outputHtml.querySelectorAll("script");
                    for (let i = 0; i < scriptElements.length; i++) {
                        try {
                            eval(scriptElements[i].innerHTML); // eslint-disable-line no-eval
                        } catch (err) {
                            log.error(err);
                        }
                    }
                    length = output.data.dish.value.length;

                    break;
                case "ArrayBuffer":
                    outputText.style.display = "block";
                    outputHtml.style.display = "none";
                    outputHighlighter.display = "none";
                    inputHighlighter.display = "none";

                    outputText.value = "";
                    outputHtml.innerHTML = "";

                    length = output.data.result.length;
                    this.setFile(output.data.result);
                    break;
                case "string":
                default:
                    outputText.style.display = "block";
                    outputHtml.style.display = "none";
                    outputFile.style.display = "none";
                    outputHighlighter.display = "block";
                    inputHighlighter.display = "block";

                    outputText.value = Utils.printable(output.data.result, true);
                    outputHtml.innerHTML = "";

                    lines = output.data.result.count("\n") + 1;
                    length = output.data.result.length;
                    break;
            }
            this.setOutputInfo(length, lines, output.data.duration);
            this.backgroundMagic();
        }
    }

    /**
     * Shows file details
     *
     * @param {ArrayBuffer} buf
     */
    setFile(buf) {
        const file = new File([buf], "output.dat");

        // Display file overlay in output area with details
        const fileOverlay = document.getElementById("output-file"),
            fileSize = document.getElementById("output-file-size"),
            outputText = document.getElementById("output-text"),
            fileSlice = buf.slice(0, 4096);

        fileOverlay.style.display = "block";
        fileSize.textContent = file.size.toLocaleString() + " bytes";

        outputText.classList.add("blur");
        outputText.value = Utils.printable(Utils.arrayBufferToStr(fileSlice));
    }

    /**
     * Clears output file details
     */
    closeFile() {
        document.getElementById("output-file").style.display = "none";
        document.getElementById("output-text").classList.remove("blur");
    }

    /**
     * Save bombe object then remove it from the DOM so that it does not cause performance issues.
     */
    saveBombe() {
        this.bombeEl = document.getElementById("bombe");
        this.bombeEl.parentNode.removeChild(this.bombeEl);
    }

    /**
     * Shows or hides the output loading screen.
     * The animated Bombe SVG, whilst quite aesthetically pleasing, is reasonably CPU
     * intensive, so we remove it from the DOM when not in use. We only show it if the
     * recipe is taking longer than 200ms. We add it to the DOM just before that so that
     * it is ready to fade in without stuttering.
     *
     * @param {boolean} value - true == show loader
     */
    toggleLoader(value) {
        clearTimeout(this.appendBombeTimeout);
        clearTimeout(this.outputLoaderTimeout);

        const outputLoader = document.getElementById("output-loader"),
            outputElement = document.getElementById("output-text"),
            animation = document.getElementById("output-loader-animation");

        if (value) {
            this.manager.controls.hideStaleIndicator();

            // Don't add the bombe if it's already there!
            if (animation.children.length > 0) return;

            // Start a timer to add the Bombe to the DOM just before we make it
            // visible so that there is no stuttering
            this.appendBombeTimeout = setTimeout(function() {
                animation.appendChild(this.bombeEl);
            }.bind(this), 150);

            // Show the loading screen
            this.outputLoaderTimeout = setTimeout(function() {
                outputElement.disabled = true;
                outputLoader.style.visibility = "visible";
                outputLoader.style.opacity = 1;
            }, 200);
        } else {
            // Remove the Bombe from the DOM to save resources
            this.outputLoaderTimeout = setTimeout(function () {
                try {
                    animation.removeChild(this.bombeEl);
                } catch (err) {}
            }.bind(this), 500);
            outputElement.disabled = false;
            outputLoader.style.opacity = 0;
            outputLoader.style.visibility = "hidden";
            // this.setStatusMsg("");
        }
    }

    /**
     * Handler for save click events.
     * Saves the current output to a file.
     */
    saveClick() {
        this.downloadFile();
    }

    /**
     * Handler for file download events.
     */
    async downloadFile() {
        const fileName = window.prompt("Please enter a filename: ", "download.dat");
        const file = new File([this.getActive()], fileName);
        FileSaver.saveAs(file, fileName, false);
    }

    /**
     * Handler for save all click event
     * Saves all outputs to a single archvie file
     */
    saveAllClick() {
        const downloadButton = document.getElementById("save-all-to-file");
        if (downloadButton.firstElementChild.innerHTML === "archive") {
            this.downloadAllFiles();
        } else if (window.confirm("Cancel zipping of outputs?")) {
            this.terminateZipWorker();
        }
    }


    /**
     * Spawns a new ZipWorker and sends it the outputs so that they can
     * be zipped for download
     */
    downloadAllFiles() {

        const inputNums = Object.keys(this.outputs);
        for (let i = 0; i < inputNums.length; i++) {
            const iNum = inputNums[i];
            log.error(this.outputs[iNum]);
            if (this.outputs[iNum].status !== "baked" ||
            this.outputs[iNum].bakeId !== this.manager.worker.bakeId) {
                if (window.confirm("Not all outputs have been baked yet. Continue downloading outputs?")) {
                    break;
                } else {
                    return;
                }
            }
        }

        let fileName = window.prompt("Please enter a filename: ", "download.zip");

        if (fileName === null || fileName === "") {
            // Don't zip the files if there isn't a filename
            this.app.alert("No filename was specified.", 3000);
            return;
        }

        if (!fileName.match(/.zip$/)) {
            fileName += ".zip";
        }

        let fileExt = window.prompt("Please enter a file extension for the files: ", ".txt");

        if (fileExt === null) {
            // Use .dat as the default file extension
            fileExt = ".dat";
        }

        if (this.zipWorker !== null) {
            this.terminateZipWorker();
        }

        const downloadButton = document.getElementById("save-all-to-file");

        downloadButton.classList.add("spin");
        downloadButton.title = `Downloading ${inputNums.length} files...`;
        downloadButton.setAttribute("data-original-title", `Downloading ${inputNums.length} files...`);

        downloadButton.firstElementChild.innerHTML = "autorenew";

        log.debug("Creating ZipWorker");
        this.zipWorker = new ZipWorker();
        this.zipWorker.postMessage({
            outputs: this.outputs,
            filename: fileName,
            fileExtension: fileExt
        });
        this.zipWorker.addEventListener("message", this.handleZipWorkerMessage.bind(this));

    }

    /**
     * Terminate the ZipWorker
     */
    terminateZipWorker() {
        if (this.zipWorker === null) return; // Already terminated

        log.debug("Terminating ZipWorker.");

        this.zipWorker.terminate();
        this.zipWorker = null;

        const downloadButton = document.getElementById("save-all-to-file");

        downloadButton.classList.remove("spin");
        downloadButton.title = "Save all outputs to a zip file";
        downloadButton.setAttribute("data-original-title", "Save all outputs to a zip file");

        downloadButton.firstElementChild.innerHTML = "archive";

    }


    /**
     * Handle messages sent back by the ZipWorker
     */
    handleZipWorkerMessage(e) {
        const r = e.data;
        if (!r.hasOwnProperty("zippedFile")) {
            log.error("No zipped file was sent in the message.");
            this.terminateZipWorker();
            return;
        }
        if (!r.hasOwnProperty("filename")) {
            log.error("No filename was sent in the message.");
            this.terminateZipWorker();
            return;
        }

        const file = new File([r.zippedFile], r.filename);
        FileSaver.saveAs(file, r.filename, false);

        this.terminateZipWorker();
    }


    /**
     * Handler for download all files events.
     */
    async downloadAllFilesOld() {
        const fileName = window.prompt("Please enter a filename: ", "download.zip");
        const fileExt = window.prompt("Please enter a file extension for the files: ", ".txt");
        const zip = new Zlib.Zip();
        const inputNums = Object.keys(this.outputs);
        for (let i = 0; i < inputNums.length; i++) {
            const name = Utils.strToByteArray(inputNums[i] + fileExt);
            let out = this.getOutput(inputNums[i]);
            if (typeof out === "string") {
                out = Utils.strToUtf8ByteArray(out);
            }
            out = new Uint8Array(out);
            // options.filename = Utils.strToByteArray(this.outputs[i].inputNum + ".dat");
            zip.addFile(out, {filename: name});
        }
        const file = new File([zip.compress()], fileName);
        FileSaver.saveAs(file, fileName, false);
    }

    /**
     * Adds a new output tab.
     *
     * @param {number} inputNum
     * @param {boolean} [changeTab=true]
     */
    addTab(inputNum, changeTab = true) {
        const tabsWrapper = document.getElementById("output-tabs");
        const numTabs = tabsWrapper.children.length;

        if (this.getTabItem(inputNum) === undefined && numTabs < this.maxTabs) {
            // Create a new tab element
            const newTab = this.createTabElement(inputNum);

            tabsWrapper.appendChild(newTab);

            if (numTabs > 0) {
                tabsWrapper.parentElement.style.display = "block";

                document.getElementById("output-wrapper").style.height = "calc(100% - var(--tab-height) - var(--title-height))";
                document.getElementById("output-highlighter").style.height = "calc(100% - var(--tab-height) - var(--title-height))";
                document.getElementById("output-file").style.height = "calc(100% - var(--tab-height) - var(--title-height))";
                document.getElementById("output-loader").style.height = "calc(100% - var(--tab-height) - var(--title-height))";

                document.getElementById("save-all-to-file").style.display = "inline-block";
            } else {
                tabsWrapper.parentElement.style.display = "none";

                document.getElementById("output-wrapper").style.height = "calc(100% - var(--title-height))";
                document.getElementById("output-highlighter").style.height = "calc(100% - var(--title-height))";
                document.getElementById("output-file").style.height = "calc(100% - var(--title-height))";
                document.getElementById("output-loader").style.height = "calc(100% - var(--title-height))";

                document.getElementById("save-all-to-file").style.display = "none";
            }
        }

        if (changeTab) {
            this.changeTab(inputNum, false);
        }
    }

    /**
     * Changes the active tab
     *
     * @param {number} inputNum
     * @param {boolean} [changeInput = false]
     */
    changeTab(inputNum, changeInput = false) {
        const currentNum = this.getActiveTab();
        if (this.getOutput(inputNum) === -1) return;
        this.hideMagicButton();

        const tabsWrapper = document.getElementById("output-tabs");
        const tabs = tabsWrapper.children;

        let found = false;
        for (let i = 0; i < tabs.length; i++) {
            if (tabs.item(i).getAttribute("inputNum") === inputNum.toString()) {
                tabs.item(i).classList.add("active-output-tab");
                this.activeTab = inputNum;
                found = true;
            } else {
                tabs.item(i).classList.remove("active-output-tab");
            }
        }
        if (!found) {
            let direction = "right";
            if (currentNum > inputNum) {
                direction = "left";
            }

            const newOutputs = this.getNearbyNums(inputNum, direction);
            for (let i = 0; i < newOutputs.length; i++) {
                tabs.item(i).setAttribute("inputNum", newOutputs[i].toString());
                this.displayTabInfo(newOutputs[i]);
                if (newOutputs[i] === inputNum) {
                    this.activeTab = inputNum;
                    tabs.item(i).classList.add("active-output-tab");
                }
            }
        }

        this.set(inputNum);

        if (changeInput) {
            this.manager.input.changeTab(inputNum, false);
        }
    }

    /**
     * Handler for changing tabs event
     *
     * @param {event} mouseEvent
     */
    changeTabClick(mouseEvent) {
        if (!mouseEvent.target) return;
        const tabNum = mouseEvent.target.parentElement.getAttribute("inputNum");
        if (tabNum) {
            this.changeTab(parseInt(tabNum, 10), this.app.options.syncTabs);
        }
    }

    /**
     * Handler for changing to the left tab
     */
    changeTabLeft() {
        const currentTab = this.getActiveTab();
        this.changeTab(this.getPreviousInputNum(currentTab), this.app.options.syncTabs);
    }

    /**
     * Handler for changing to the right tab
     */
    changeTabRight() {
        const currentTab = this.getActiveTab();
        this.changeTab(this.getNextInputNum(currentTab), this.app.options.syncTabs);
    }

    /**
     * Handler for go to tab button clicked
     */
    goToTab() {
        const tabNum = parseInt(window.prompt("Enter tab number:", this.getActiveTab().toString()), 10);
        if (this.getOutput(tabNum) !== undefined) {
            this.changeTab(tabNum, this.app.options.syncTabs);
        }
    }

    /**
     * Generates a list of the nearby inputNums
     * @param inputNum
     * @param direction
     */
    getNearbyNums(inputNum, direction) {
        const nums = [];
        for (let i = 0; i < this.maxTabs; i++) {
            let newNum;
            if (i === 0) {
                newNum = inputNum;
            } else {
                switch (direction) {
                    case "left":
                        newNum = this.getNextInputNum(nums[i - 1]);
                        if (newNum === nums[i - 1]) {
                            direction = "right";
                            newNum = this.getPreviousInputNum(nums[i - 1]);
                        }
                        break;
                    case "right":
                        newNum = this.getPreviousInputNum(nums[i - 1]);
                        if (newNum === nums[i - 1]) {
                            direction = "left";
                            newNum = this.getNextInputNum(nums[i - 1]);
                        }
                }
            }
            if (!nums.includes(newNum) && (newNum > 0)) {
                nums.push(newNum);
            }
        }
        nums.sort(function(a, b) {
            return a - b;
        });
        return nums;
    }

    /**
     * Gets the largest inputNum
     *
     * @returns {number}
     */
    getLargestInputNum() {
        let largest = 0;
        const inputNums = Object.keys(this.outputs);
        for (let i = 0; i < inputNums.length; i++) {
            const iNum = parseInt(inputNums[i], 10);
            if (iNum > largest) {
                largest = iNum;
            }
        }
        return largest;
    }

    /**
     * Gets the smallest inputNum
     *
     * @returns {number}
     */
    getSmallestInputNum() {
        let smallest = this.getLargestInputNum();
        const inputNums = Object.keys(this.outputs);
        for (let i = 0; i < inputNums.length; i++) {
            const iNum = parseInt(inputNums[i], 10);
            if (iNum < smallest) {
                smallest = iNum;
            }
        }
        return smallest;
    }

    /**
     * Gets the previous inputNum
     *
     * @param {number} inputNum - The current input number
     * @returns {number}
     */
    getPreviousInputNum(inputNum) {
        let num = this.getSmallestInputNum();
        const inputNums = Object.keys(this.outputs);
        for (let i = 0; i < inputNums.length; i++) {
            const iNum = parseInt(inputNums[i], 10);
            if (iNum < inputNum) {
                if (iNum > num) {
                    num = iNum;
                }
            }
        }
        return num;
    }

    /**
     * Gets the next inputNum
     *
     * @param {number} inputNum - The current input number
     * @returns {number}
     */
    getNextInputNum(inputNum) {
        let num = this.getLargestInputNum();
        const inputNums = Object.keys(this.outputs);
        for (let i = 0; i < inputNums.length; i++) {
            const iNum = parseInt(inputNums[i], 10);
            if (iNum > inputNum) {
                if (iNum < num) {
                    num = iNum;
                }
            }
        }
        return num;
    }

    /**
     * Removes a tab and it's corresponding output
     *
     * @param {number} inputNum
     */
    removeTab(inputNum) {
        let activeTab = this.getActiveTab();
        if (this.getOutput(inputNum) === -1) return;

        const tabElement = this.getTabItem(inputNum);

        this.removeOutput(inputNum);

        if (tabElement !== null) {
            // find new tab number?
            if (inputNum === activeTab) {
                activeTab = this.getPreviousInputNum(activeTab);
                if (activeTab === this.getActiveTab()) {
                    activeTab = this.getNextInputNum(activeTab);
                }
            }
            this.refreshTabs(activeTab);
        }
    }

    /**
     * Redraw the entire tab bar to remove any outdated tabs
     * @param {number} activeTab
     */
    refreshTabs(activeTab) {
        const tabsList = document.getElementById("output-tabs");
        let newInputs = this.getNearbyNums(activeTab, "right");
        if (newInputs.length < this.maxTabs) {
            newInputs = this.getNearbyNums(activeTab, "left");
        }

        for (let i = tabsList.children.length - 1; i >= 0; i--) {
            tabsList.children.item(i).remove();
        }

        for (let i = 0; i < newInputs.length; i++) {
            tabsList.appendChild(this.createTabElement(newInputs[i]));
            this.displayTabInfo(newInputs[i]);
        }

        if (newInputs.length > 1) {
            tabsList.parentElement.style.display = "block";

            document.getElementById("output-wrapper").style.height = "calc(100% - var(--tab-height) - var(--title-height))";
            document.getElementById("output-highlighter").style.height = "calc(100% - var(--tab-height) - var(--title-height))";
            document.getElementById("output-file").style.height = "calc(100% - var(--tab-height) - var(--title-height))";
            document.getElementById("output-loader").style.height = "calc(100% - var(--tab-height) - var(--title-height))";

            document.getElementById("save-all-to-file").style.display = "inline-block";

        } else {
            tabsList.parentElement.style.display = "none";

            document.getElementById("output-wrapper").style.height = "calc(100% - var(--title-height))";
            document.getElementById("output-highlighter").style.height = "calc(100% - var(--title-height))";
            document.getElementById("output-file").style.height = "calc(100% - var(--title-height))";
            document.getElementById("output-loader").style.height = "calc(100% - var(--title-height))";

            document.getElementById("save-all-to-file").style.display = "none";
        }

        this.changeTab(activeTab);

    }

    /**
     * Creates a new tab element to be added to the tab bar
     *
     * @param {number} inputNum
     */
    createTabElement(inputNum) {
        const newTab = document.createElement("li");
        newTab.setAttribute("inputNum", inputNum.toString());

        const newTabContent = document.createElement("div");
        newTabContent.classList.add("output-tab-content");
        newTabContent.innerText = `Tab ${inputNum.toString()}`;

        // Do we want remove tab button on output?
        newTab.appendChild(newTabContent);

        return newTab;
    }

    /**
     * Gets the number of the current active tab
     *
     * @returns {number}
     */
    getActiveTab() {
        return this.activeTab;
    }

    /**
     * Gets the li element for a tab
     *
     * @param {number} inputNum
     */
    getTabItem(inputNum) {
        const tabs = document.getElementById("output-tabs").children;
        for (let i = 0; i < tabs.length; i++) {
            if (parseInt(tabs.item(i).getAttribute("inputNum"), 10) === inputNum) {
                return tabs.item(i);
            }
        }
    }

    /**
     * Display output information in the tab header
     *
     * @param {number} inputNum
     */
    displayTabInfo(inputNum) {
        const tabItem = this.getTabItem(inputNum);

        if (!tabItem) return;

        const tabContent = tabItem.firstElementChild;

        tabContent.innerText = `Tab ${inputNum}`;

    }

    /**
     * Displays information about the output.
     *
     * @param {number} length - The length of the current output string
     * @param {number} lines - The number of the lines in the current output string
     * @param {number} duration - The length of time (ms) it took to generate the output
     */
    setOutputInfo(length, lines, duration) {
        if (!length) return;
        let width = length.toString().length;
        width = width < 4 ? 4 : width;

        const lengthStr = length.toString().padStart(width, " ").replace(/ /g, "&nbsp;");
        const timeStr = (duration.toString() + "ms").padStart(width, " ").replace(/ /g, "&nbsp;");

        let msg = "time: " + timeStr + "<br>length: " + lengthStr;

        if (typeof lines === "number") {
            const linesStr = lines.toString().padStart(width, " ").replace(/ /g, "&nbsp;");
            msg += "<br>lines: " + linesStr;
        }

        document.getElementById("output-info").innerHTML = msg;
        document.getElementById("input-selection-info").innerHTML = "";
        document.getElementById("output-selection-info").innerHTML = "";
    }

    /**
     * Triggers the BackgroundWorker to attempt Magic on the current output.
     */
    backgroundMagic() {
        this.hideMagicButton();
        if (!this.app.options.autoMagic || !this.getActive()) return;
        const sample = this.getActive().slice(0, 1000) || "";
        if (sample.length || sample.byteLength) {
            this.manager.background.magic(sample);
        }
    }

    /**
     * Handles the results of a background Magic call.
     *
     * @param {Object[]} options
     */
    backgroundMagicResult(options) {
        if (!options.length ||
            !options[0].recipe.length)
            return;

        const currentRecipeConfig = this.app.getRecipeConfig();
        const newRecipeConfig = currentRecipeConfig.concat(options[0].recipe);
        const opSequence = options[0].recipe.map(o => o.op).join(", ");

        this.showMagicButton(opSequence, options[0].data, newRecipeConfig);
    }

    /**
     * Handler for Magic click events.
     *
     * Loads the Magic recipe.
     *
     * @fires Manager#statechange
     */
    magicClick() {
        const magicButton = document.getElementById("magic");
        this.app.setRecipeConfig(JSON.parse(magicButton.getAttribute("data-recipe")));
        window.dispatchEvent(this.manager.statechange);
        this.hideMagicButton();
    }

    /**
     * Displays the Magic button with a title and adds a link to a complete recipe.
     *
     * @param {string} opSequence
     * @param {string} result
     * @param {Object[]} recipeConfig
     */
    showMagicButton(opSequence, result, recipeConfig) {
        const magicButton = document.getElementById("magic");
        magicButton.setAttribute("data-original-title", `<i>${opSequence}</i> will produce <span class="data-text">"${Utils.escapeHtml(Utils.truncate(result), 30)}"</span>`);
        magicButton.setAttribute("data-recipe", JSON.stringify(recipeConfig), null, "");
        magicButton.classList.remove("hidden");
    }


    /**
     * Hides the Magic button and resets its values.
     */
    hideMagicButton() {
        const magicButton = document.getElementById("magic");
        magicButton.classList.add("hidden");
        magicButton.setAttribute("data-recipe", "");
        magicButton.setAttribute("data-original-title", "Magic!");
    }


    /**
     * Handler for file slice display events.
     */
    displayFileSlice() {
        const startTime = new Date().getTime(),
            showFileOverlay = document.getElementById("show-file-overlay"),
            sliceFromEl = document.getElementById("output-file-slice-from"),
            sliceToEl = document.getElementById("output-file-slice-to"),
            sliceFrom = parseInt(sliceFromEl.value, 10),
            sliceTo = parseInt(sliceToEl.value, 10),
            str = Utils.arrayBufferToStr(this.getActive().slice(sliceFrom, sliceTo));

        document.getElementById("output-text").classList.remove("blur");
        showFileOverlay.style.display = "block";

    }


    /**
     * Handler for copy click events.
     * Copies the output to the clipboard
     */
    copyClick() {
        let output = this.getActive();

        if (typeof output !== "string") {
            output = Utils.arrayBufferToStr(output);
        }

        // Create invisible textarea to populate with the raw dish string (not the printable version that
        // contains dots instead of the actual bytes)
        const textarea = document.createElement("textarea");
        textarea.style.position = "fixed";
        textarea.style.top = 0;
        textarea.style.left = 0;
        textarea.style.width = 0;
        textarea.style.height = 0;
        textarea.style.border = "none";

        textarea.value = output;
        document.body.appendChild(textarea);

        let success = false;
        try {
            textarea.select();
            success = output && document.execCommand("copy");
        } catch (err) {
            success = false;
        }

        if (success) {
            this.app.alert("Copied raw output successfully.", 2000);
        } else {
            this.app.alert("Sorry, the output could not be copied.", 3000);
        }

        // Clean up
        document.body.removeChild(textarea);
    }
}

export default OutputWaiter;