// ==UserScript==
// @name         Local Vk Downloader
// @namespace    vkDownloadAuto
// @version      1.1.0
// @description  Get Vk raw link without external service.
// @match        https://m.vk.com/mail*
// @downloadURL none
// ==/UserScript==
var peer = null;
var fetchedVideosMap = {};
var fetchedVideos = [];
var fetchStack = [];

var data = {
    videos: [],
    photos: [],
    docs: []
}
var finishState = {
    videos: false,
    photos: false,
    docs: false
}
var itemsCount = {
    videos: 0,
    photos: 0,
    docs: 0
}

function vkPlainGet(url, callback) {
    return ajax.plainpost(
        url,
        { _ajax: 1 },
        (function (e) {
            callback(e);
        }),
        (function () {
            callback(null)
        }),
        !0
    );
}

function removeImages(documentString) {
    return documentString.replace("<img", "<div").replace("</img>", "</div>");
}

function parseDocumentToHtml(documentString) {
    var htmlElement = document.createElement('html');
    if (documentString.indexOf("<body") != -1) {
        documentString = documentString.substring(documentString.indexOf("<body"), documentString.indexOf("</body>") + 7);
    }
    htmlElement.innerHTML = documentString;
    return htmlElement;
}

function isFetched(peer, href) {
    return fetchedVideosMap[peer][href];
}

function storeFetchedVideo(peer, videoItem) {
    if (isFetched(peer, videoItem.href)) {
        return;
    }
    fetchedVideosMap[peer][videoItem.href] = videoItem;
    fetchedVideos.push(videoItem);
}

function fetchVideo(peer, videoItem, callback) {
    vkPlainGet(videoItem.href, function (result) {
        videoItem.sources = getSources(result);
        storeFetchedVideo(peer, videoItem);
        callback();
    });
}

function checkFetchStack() {
    if (!fetchStack.length) {
        finishSegment("videos");
        return;
    }
    while (fetchStack.length) {
        var fetchItem = fetchStack.shift();
        var videoItem = fetchItem.item;
        if (isFetched(fetchItem.peer, videoItem.href)) {
            continue;
        }
        var callback = function () { };
        if (fetchStack.length == 0) {
            callback = function () {
                finishSegment("videos");
            }
        }
        fetchVideo(fetchItem.peer, videoItem, callback);
        return;
    }
}

function isFetchNeeded() {
    var videosCount = document.querySelectorAll(".video_item").length;
    var fetchNeeded = false;
    if (videosCount > itemsCount.videos) {
        fetchNeeded = true;
        itemsCount.videos = videosCount;
    }
    return fetchNeeded;
}

function listenFetchNeeded() {
    window.setInterval(function () {
        if (!isFetchNeeded()) {
            return;
        }
        checkFetchStack();
    }, 500);
}

function getSources(htmlString) {
    var htmlElement = parseDocumentToHtml(removeImages(htmlString));
    var sources = htmlElement.querySelectorAll("source[type='video/mp4']");
    if (!sources || !sources.length) {
        recursiveHandleVideoItem(items, ++idx, length, videos, callback);
        return;
    }
    var sourcesLinks = [];
    for (var i = 0; i < sources.length; ++i) {
        sourcesLinks.push(sources[i].src);
    }
    return sourcesLinks;
}

function getPeer() {
    var hash = window.location.search;
    var idx = hash.indexOf("peer");
    if (idx == -1) {
        return null;
    }
    var end = hash.indexOf("&", idx);
    if (end == -1) {
        end = hash.length;
    }
    return hash.substring(idx + 5, end);
}

function putVideoItemToFetchStack(itemData, peer) {
    fetchStack.push({ item: itemData, peer: peer });
}

function getVideos(peer) {
    var items = document.querySelectorAll(".video_item");
    if (!items || !items.length) {
        return;
    }
    for (var i = 0; i < items.length; ++i) {
        var item = items[i];
        var itemData = {};

        var videoTitle = item.querySelector(".vi_title_text");
        if (videoTitle) {
            itemData.title = videoTitle.innerText;
        }
        if (itemData.title.indexOf("Без названия") == -1) {
            continue;
        }

        var videoHref = item.querySelector(".video_href");
        if (!videoHref) {
            continue;
        }
        itemData.href = videoHref.href;

        var previewImg = item.querySelector("img");
        if (previewImg) {
            itemData.preview = previewImg.src;
        }

        var videoLength = item.querySelector(".thumb_label");
        if (videoLength) {
            itemData.length = videoLength.innerText;
        }

        putVideoItemToFetchStack(itemData, peer);

    }
}

function getPhotos() {
    finishSegment("photos");
}

function getDocs() {
    finishSegment("docs");
}

function getAllMedia(peer) {
    console.log("\n\n***********************************ALL_MEDIA************************************")
    data = {
        videos: [],
        photos: [],
        docs: []
    }
    finishState = {
        videos: false,
        photos: false,
        docs: false
    }
    if (!fetchedVideosMap[peer]) {
        fetchedVideosMap[peer] = {};
    }
    getVideos(peer);
    getPhotos(peer);
    getDocs(peer);
}

function start() {
    peer = getPeer();
    if (peer != null) {
        getAllMedia(peer);
    }
}

function finishSegment(segment) {
    console.log(segment + ":", data[segment]);
    finishState[segment] = true;
    if (finishState.videos && finishState.photos && finishState.docs) {
        finish(data);
    }
}

function finish(data) {
    console.log(data);
    console.log("************************************FINISH**************************************")
}

listenFetchNeeded();
start();