/* Copyright 2016 Mozilla Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

"use strict";

if (!pdfjsLib.getDocument || !pdfjsViewer.PDFViewer) {
    alert("Please build the pdfjs-dist library using\n `gulp dist-install`");
}

var USE_ONLY_CSS_ZOOM = true;
var TEXT_LAYER_MODE = 0; // DISABLE
var MAX_IMAGE_SIZE = 1024 * 1024;
var CMAP_URL = "../../node_modules/pdfjs-dist/cmaps/";
var CMAP_PACKED = true;

pdfjsLib.GlobalWorkerOptions.workerSrc =
    "./js/pdfjs/mobile/js/pdf.worker.js";

// var DEFAULT_URL = "./js/pdfjs/web/compressed.tracemonkey-pldi-09.pdf";
var DEFAULT_SCALE_DELTA = 1.1;
var MIN_SCALE = 0.25;
var MAX_SCALE = 10.0;
var DEFAULT_SCALE_VALUE = "auto";

var PDFViewerApplication = {
    pdfLoadingTask: null,
    pdfDocument: null,
    pdfViewer: null,
    pdfHistory: null,
    pdfLinkService: null,
    eventBus: null,

    /**
     * Opens PDF document specified by URL.
     * @returns {Promise} - Returns the promise, which is resolved when document
     *                      is opened.
     */
    open: function (params) {
        if (this.pdfLoadingTask) {
            // We need to destroy already opened document
            return this.close().then(
                function () {
                    // ... and repeat the open() call.
                    return this.open(params);
                }.bind(this)
            );
        }

        var url = params.url;
        var self = this;
        this.setTitleUsingUrl(url);

        // Loading document.
        var loadingTask = pdfjsLib.getDocument({
            url: url,
            maxImageSize: MAX_IMAGE_SIZE,
            cMapUrl: CMAP_URL,
            cMapPacked: CMAP_PACKED,
        });
        this.pdfLoadingTask = loadingTask;

        loadingTask.onProgress = function (progressData) {
            self.progress(progressData.loaded / progressData.total);
        };

        return loadingTask.promise.then(
            function (pdfDocument) {
                // Document loaded, specifying document for the viewer.
                self.pdfDocument = pdfDocument;
                self.pdfViewer.setDocument(pdfDocument);
                self.pdfLinkService.setDocument(pdfDocument);
                self.pdfHistory.initialize({ fingerprint: pdfDocument.fingerprint });

                self.loadingBar.hide();
                self.setTitleUsingMetadata(pdfDocument);
            },
            function (exception) {
                var message = exception && exception.message;
                var l10n = self.l10n;
                var loadingErrorMessage;

                if (exception instanceof pdfjsLib.InvalidPDFException) {
                    // change error message also for other builds
                    loadingErrorMessage = l10n.get(
                        "invalid_file_error",
                        null,
                        "Invalid or corrupted PDF file."
                    );
                } else if (exception instanceof pdfjsLib.MissingPDFException) {
                    // special message for missing PDFs
                    loadingErrorMessage = l10n.get(
                        "missing_file_error",
                        null,
                        "Missing PDF file."
                    );
                } else if (exception instanceof pdfjsLib.UnexpectedResponseException) {
                    loadingErrorMessage = l10n.get(
                        "unexpected_response_error",
                        null,
                        "Unexpected server response."
                    );
                } else {
                    loadingErrorMessage = l10n.get(
                        "loading_error",
                        null,
                        "An error occurred while loading the PDF."
                    );
                }

                loadingErrorMessage.then(function (msg) {
                    self.error(msg, { message: message });
                });
                self.loadingBar.hide();
            }
        );
    },

    /**
     * Closes opened PDF document.
     * @returns {Promise} - Returns the promise, which is resolved when all
     *                      destruction is completed.
     */
    close: function () {
        var errorWrapper = document.getElementById("errorWrapper");
        errorWrapper.setAttribute("hidden", "true");

        if (!this.pdfLoadingTask) {
            return Promise.resolve();
        }

        var promise = this.pdfLoadingTask.destroy();
        this.pdfLoadingTask = null;

        if (this.pdfDocument) {
            this.pdfDocument = null;

            this.pdfViewer.setDocument(null);
            this.pdfLinkService.setDocument(null, null);

            if (this.pdfHistory) {
                this.pdfHistory.reset();
            }
        }

        return promise;
    },

    get loadingBar() {
        var bar = new pdfjsViewer.ProgressBar("#loadingBar", {});

        return pdfjsLib.shadow(this, "loadingBar", bar);
    },

    setTitleUsingUrl: function pdfViewSetTitleUsingUrl(url) {
        this.url = url;
        var title = pdfjsLib.getFilenameFromUrl(url) || url;
        try {
            title = decodeURIComponent(title);
        } catch (e) {
            // decodeURIComponent may throw URIError,
            // fall back to using the unprocessed url in that case
        }
        this.setTitle(title);
    },

    setTitleUsingMetadata: function (pdfDocument) {
        var self = this;
        pdfDocument.getMetadata().then(function (data) {
            var info = data.info,
                metadata = data.metadata;
            self.documentInfo = info;
            self.metadata = metadata;

            // Provides some basic debug information
            console.log(
                "PDF " +
                pdfDocument.fingerprint +
                " [" +
                info.PDFFormatVersion +
                " " +
                (info.Producer || "-").trim() +
                " / " +
                (info.Creator || "-").trim() +
                "]" +
                " (PDF.js: " +
                (pdfjsLib.version || "-") +
                ")"
            );

            var pdfTitle;
            if (metadata && metadata.has("dc:title")) {
                var title = metadata.get("dc:title");
                // Ghostscript sometimes returns 'Untitled', so prevent setting the
                // title to 'Untitled.
                if (title !== "Untitled") {
                    pdfTitle = title;
                }
            }

            if (!pdfTitle && info && info.Title) {
                pdfTitle = info.Title;
            }

            if (pdfTitle) {
                self.setTitle(pdfTitle + " - " + document.title);
            }
        });
    },

    setTitle: function pdfViewSetTitle(title) {
        document.title = title;
        document.getElementById("title").textContent = title;
    },

    error: function pdfViewError(message, moreInfo) {
        var l10n = this.l10n;
        var moreInfoText = [
            l10n.get(
                "error_version_info",
                { version: pdfjsLib.version || "?", build: pdfjsLib.build || "?" },
                "PDF.js v{{version}} (build: {{build}})"
            ),
        ];

        if (moreInfo) {
            moreInfoText.push(
                l10n.get(
                    "error_message",
                    { message: moreInfo.message },
                    "Message: {{message}}"
                )
            );
            if (moreInfo.stack) {
                moreInfoText.push(
                    l10n.get("error_stack", { stack: moreInfo.stack }, "Stack: {{stack}}")
                );
            } else {
                if (moreInfo.filename) {
                    moreInfoText.push(
                        l10n.get(
                            "error_file",
                            { file: moreInfo.filename },
                            "File: {{file}}"
                        )
                    );
                }
                if (moreInfo.lineNumber) {
                    moreInfoText.push(
                        l10n.get(
                            "error_line",
                            { line: moreInfo.lineNumber },
                            "Line: {{line}}"
                        )
                    );
                }
            }
        }

        var errorWrapper = document.getElementById("errorWrapper");
        errorWrapper.removeAttribute("hidden");

        var errorMessage = document.getElementById("errorMessage");
        errorMessage.textContent = message;

        var closeButton = document.getElementById("errorClose");
        closeButton.onclick = function () {
            errorWrapper.setAttribute("hidden", "true");
        };

        var errorMoreInfo = document.getElementById("errorMoreInfo");
        var moreInfoButton = document.getElementById("errorShowMore");
        var lessInfoButton = document.getElementById("errorShowLess");
        moreInfoButton.onclick = function () {
            errorMoreInfo.removeAttribute("hidden");
            moreInfoButton.setAttribute("hidden", "true");
            lessInfoButton.removeAttribute("hidden");
            errorMoreInfo.style.height = errorMoreInfo.scrollHeight + "px";
        };
        lessInfoButton.onclick = function () {
            errorMoreInfo.setAttribute("hidden", "true");
            moreInfoButton.removeAttribute("hidden");
            lessInfoButton.setAttribute("hidden", "true");
        };
        moreInfoButton.removeAttribute("hidden");
        lessInfoButton.setAttribute("hidden", "true");
        Promise.all(moreInfoText).then(function (parts) {
            errorMoreInfo.value = parts.join("\n");
        });
    },

    progress: function pdfViewProgress(level) {
        var percent = Math.round(level * 100);
        // Updating the bar if value increases.
        if (percent > this.loadingBar.percent || isNaN(percent)) {
            this.loadingBar.percent = percent;
        }
    },

    get pagesCount() {
        return this.pdfDocument.numPages;
    },

    get page() {
        return this.pdfViewer.currentPageNumber;
    },

    set page(val) {
        this.pdfViewer.currentPageNumber = val;
    },

    zoomIn: function pdfViewZoomIn(ticks) {
        var newScale = this.pdfViewer.currentScale;
        do {
            newScale = (newScale * DEFAULT_SCALE_DELTA).toFixed(2);
            newScale = Math.ceil(newScale * 10) / 10;
            newScale = Math.min(MAX_SCALE, newScale);
        } while (--ticks && newScale < MAX_SCALE);
        this.pdfViewer.currentScaleValue = newScale;
    },

    zoomOut: function pdfViewZoomOut(ticks) {
        var newScale = this.pdfViewer.currentScale;
        do {
            newScale = (newScale / DEFAULT_SCALE_DELTA).toFixed(2);
            newScale = Math.floor(newScale * 10) / 10;
            newScale = Math.max(MIN_SCALE, newScale);
        } while (--ticks && newScale > MIN_SCALE);
        this.pdfViewer.currentScaleValue = newScale;
    },

    initUI: function pdfViewInitUI() {
        var eventBus = new pdfjsViewer.EventBus();
        this.eventBus = eventBus;

        var linkService = new pdfjsViewer.PDFLinkService({
            eventBus: eventBus,
        });
        this.pdfLinkService = linkService;

        this.l10n = pdfjsViewer.NullL10n;

        var container = document.getElementById("viewerContainer");
        var pdfViewer = new pdfjsViewer.PDFViewer({
            container: container,
            eventBus: eventBus,
            linkService: linkService,
            l10n: this.l10n,
            useOnlyCssZoom: USE_ONLY_CSS_ZOOM,
            textLayerMode: TEXT_LAYER_MODE,
        });
        this.pdfViewer = pdfViewer;
        linkService.setViewer(pdfViewer);

        this.pdfHistory = new pdfjsViewer.PDFHistory({
            eventBus: eventBus,
            linkService: linkService,
        });
        linkService.setHistory(this.pdfHistory);

        document.getElementById("previous").addEventListener("click", function () {
            PDFViewerApplication.page--;
        });

        document.getElementById("next").addEventListener("click", function () {
            PDFViewerApplication.page++;
        });

        document.getElementById("zoomIn").addEventListener("click", function () {
            PDFViewerApplication.zoomIn();
        });

        document.getElementById("zoomOut").addEventListener("click", function () {
            PDFViewerApplication.zoomOut();
        });

        document
            .getElementById("pageNumber")
            .addEventListener("click", function () {
                this.select();
            });

        document
            .getElementById("pageNumber")
            .addEventListener("change", function () {
                PDFViewerApplication.page = this.value | 0;

                // Ensure that the page number input displays the correct value,
                // even if the value entered by the user was invalid
                // (e.g. a floating point number).
                if (this.value !== PDFViewerApplication.page.toString()) {
                    this.value = PDFViewerApplication.page;
                }
            });

        eventBus.on("pagesinit", function () {
            // We can use pdfViewer now, e.g. let's change default scale.
            pdfViewer.currentScaleValue = DEFAULT_SCALE_VALUE;
        });

        eventBus.on(
            "pagechanging",
            function (evt) {
                var page = evt.pageNumber;
                var numPages = PDFViewerApplication.pagesCount;

                document.getElementById("pageNumber").value = page;
                document.getElementById("previous").disabled = page <= 1;
                document.getElementById("next").disabled = page >= numPages;
            },
            true
        );
    },
};

document.addEventListener(
    "DOMContentLoaded",
    function () {
        PDFViewerApplication.initUI();
    },
    true
);

(function animationStartedClosure() {
    // The offsetParent is not set until the PDF.js iframe or object is visible.
    // Waiting for first animation.
    PDFViewerApplication.animationStartedPromise = new Promise(function (
        resolve
    ) {
        window.requestAnimationFrame(resolve);
    });
})();

// We need to delay opening until all HTML is loaded.
PDFViewerApplication.animationStartedPromise.then(function () {
    PDFViewerApplication.open({
        url: DEFAULT_URL,
    });
});

// =======================================
// Smart scroll
// =======================================
let navbar = document.getElementById('top-navbar');
let viewerContainer = document.getElementById('viewerContainer');

if (document.getElementsByClassName('smart-scroll').length > 0) {
    let lastScrollTop = 0;
    viewerContainer.onscroll = (e) => {
        let scrollTop = e.target.scrollTop

        if (scrollTop < lastScrollTop) {
            navbar.classList.remove('scrolled-down');
            navbar.classList.add('scrolled-up');
            if (scrollTop <= navbar.offsetHeight ) e.target.style.top = navbar.offsetHeight+'px';
        } else {
            navbar.classList.remove('scrolled-up');
            navbar.classList.add('scrolled-down');
            e.target.style.top = 0;
        }
        lastScrollTop = scrollTop
    }
}