var highlighter
var util = rangy.util
var doc = document
var body = util.getBody(doc)
var reviewClassNames = ['review', 'friend-review']

// 在DOM加载完成后应用字体设置
document.addEventListener('DOMContentLoaded', function() {
    if (window.wrInitialFontScale) {
        changeFontSizeWithScale(window.wrInitialFontScale);
    }
});

rangy.ready(function () {
    rangy.init();
    rangy.config.preferTextRange = true;

    highlighter = rangy.createHighlighter(window.document, 'TextRange');

    highlighter.addClassApplier(rangy.createClassApplier("highlight", {
        ignoreWhiteSpace: true,
        tagNames: ["span"],
        elementProperties: {
            onclick: function (event) {
                return click(this, event)
            }
        }
    }));

    util.forEach(reviewClassNames, function (cls) {
        highlighter.addClassApplier(rangy.createClassApplier(cls, {
            ignoreWhiteSpace: true,
            tagNames: ["span"],
            elementProperties: {
                onclick: function (event) {
                    return click(this, event)
                }
            }
        }));
    })

    highlighter.addClassApplier(rangy.createClassApplier("reference", {
        ignoreWhiteSpace: true,
        tagNames: ["span"]
    }));

    highlighter.addClassApplier(rangy.createClassApplier("tts", {
        ignoreWhiteSpace: true,
        tagNames: ["span"]
    }));

    rangy.util.addListener(document, 'selectionchange', debounce(function () {
        var rectInfo = getRectInfoInSelection()
        var result = {
            cmd: 'selectionChange',
            hasSelection: rectInfo != null && rectInfo.end > rectInfo.start,
            hasSelectionRange: rectInfo != null
        }
        if (rectInfo != null) {
            result = rangy.util.extend(result, rectInfo)
        }
        wereadBridge.execMPReaderMethod('MPReader', result);
    }))

    // 通知音频的播放、暂停
    var switches = document.getElementsByClassName('icon_share_audio_switch');
    for (var i = 0; i < switches.length; i++) {
        switches[i].addEventListener('touchstart', function () {
            wereadBridge.execMPReaderMethod('MPReader', {
                cmd: 'audioWillToggle'
            });
        }, true);
    }

    addClickEventToImage()
    transferH5Link()
    mediaPlatform.getAuthor();
});

/**
 * @startP 开始查询的段落， 如果未负数，则是从倒数第 startP 段往前检索
 * @minDetectLength 最小检测长度，如果段落长度小于它，则跳过，查看下一段是否匹配，
 *                  如果没有匹配 minDetectLength 的段落，则返回最长的一段
 * @collectLength 收集长度，如果大于minDetectLength 而小于collectLength，则返回整个段落
 *                否则截取到 collectLength 之后句子结束的位置
 *
 * @return string
 */
function getShareAbstractText(startP, minDetectLength, collectLength) {
    var jsContent = document.getElementById("js_content");
    if (jsContent == null) {
        return "";
    }
    var pList = jsContent.getElementsByTagName("p");
    if (pList == null) {
        return "";
    }
    var length = pList.length;
    minDetectLength = minDetectLength || 50
    collectLength = collectLength || 100
    var dir = 1;
    if (startP < 0) {
        startP = Math.max(0, length + startP);
        dir = -1;
    } else if (startP >= length) {
        startP = length - 1;
        dir = -1;
    }
    var i = startP, text, failedFindText = "", failedFindTextLength = 0;
    while (i >= 0 && i < length) {
        text = pList[i].innerText;
        text = text && text.replace(/(\s|\t){2,}/g, ' ').trim();
        if (text && text.length > minDetectLength) {
            if (text.length < collectLength) {
                return text;
            }
            var endSequenceIndex = text.indexOf("。", collectLength - 1);
            if (endSequenceIndex < collectLength) {
                return text;
            }
            return text.substring(0, endSequenceIndex + 1)
        } else {
            if (text && text.length > failedFindTextLength) {
                failedFindText = text;
                failedFindTextLength = text.length
            }
            i += dir;
        }
    }
    return failedFindText;
}

/**
  * 从最开始获取接近 collectLength 的字数。末尾加三个点
  */
function getBeginAbstractText(collectLength) {
    var jsContent = document.getElementById("js_content");
        if (jsContent == null) {
            return "";
        }
        var children = jsContent.children
        if (children == null || children.length == 0) {
            return "";
        }
        var length = children.length;
        collectLength = collectLength || 100
        var i = 0, text, ret = "";
        while (collectLength > 0 && i < length) {
            text = children[i].innerText;
            text = text && text.replace(/(\s|\t){2,}/g, ' ').trim();
            if(text.length > 0){
                if(text.length < collectLength){
                    if(ret){
                        ret += '\n'
                    }
                    ret += text
                    collectLength -= text.length
                }else{
                    if(ret){
                         ret += '\n'
                    }
                    ret += text.substring(0, collectLength) + "..."
                    return ret
                }
            }
            i++
        }
        return ret;
}

function addClickEventToImage() {
//    if (rangy.Recognizer.isAndroid) {
        util.addListener(body, 'click', function (event) {
            var target = event.target
            if (target.tagName.toLowerCase() === 'img') {
                var images = getAllImagesAndTargetIndex(target)
                if (images.targetIndex >= 0) {
                    wereadBridge.execMPReaderMethod('MPReader', {
                        cmd: 'didTapImage',
                        images: images.allImages,
                        index: images.targetIndex
                    });
                }
            }
        })
//    } else {
//        // click delegate 在 ios 11.4.1 会造成滚动延迟和菜单弹出延迟
//        // 且 click delegate 无法在 ios 的 document 或者 body 上生效
//        // 如果直接绑定点击事件，则无法选择图片
//        var imgs = document.getElementsByTagName('img')
//        for (var i = 0; i < imgs.length; i++) {
//            if (!isHidden(imgs[i])) {
//                // 如果mp 支持了tap事件，就不需要我们自定义的了。否则需要自定义。
//                rangy.attachTouch(document, 'tap')
//                util.addListener(imgs[i], 'tap', function (e) {
//                    var images = getAllImagesAndTargetIndex(e.target)
//                    if (images.targetIndex >= 0) {
//                        wereadBridge.execMPReaderMethod('MPReader', {
//                            cmd: 'didTapImage',
//                            images: images.allImages,
//                            index: images.targetIndex
//                        });
//                    }
//                    return false
//                })
//            }
//        }
//    }
}


function click(el, event) {
    var classNameStr = rangy.ClassApplier.util.getClass(el)
    var classNames = ['highlight']

    for (var i = 0; i < reviewClassNames.length; i++) {
        if (classNameStr.indexOf(reviewClassNames[i]) >= 0) {
            // 重叠部分，以 review 为主
            classNames = reviewClassNames
            break
        }
    }
    event.preventDefault();
    event.stopPropagation();
    var range = rangy.createRange(doc);
    range.selectNodeContents(el);
    var characterRange = highlighter.converter.rangeToCharacterRange(range, body)
    var mergedCharacterRange = highlighter.getMergedCharacterRange(characterRange, reviewClassNames, classNames === reviewClassNames)
    var isClickReview = false
    if (mergedCharacterRange != null) {
        isClickReview = true
    } else {
        mergedCharacterRange = highlighter.getMergedCharacterRange(characterRange, ['highlight'], true)
    }
    if (mergedCharacterRange == null) {
        return false
    }
    var rect = getCharacterRangeRectInfo(mergedCharacterRange)
    if (rect == null) {
        return false
    }
    var result = rangy.util.extend({
        cmd: !isClickReview ? 'didTapHighlight' : 'didTapReview',
        start: mergedCharacterRange.start,
        end: mergedCharacterRange.end,
        content: getContentByPos(mergedCharacterRange.start, mergedCharacterRange.end)
    }, rect);
    wereadBridge.execMPReaderMethod('MPReader', result);
    return true
}

function getRectInfoByPos(start, end) {
    return getInfoByPos(start, end, getCharacterRangeRectInfo)
}

function getTopByPos(start, end) {
    return getInfoByPos(start, end, getCharacterRangeTop)
}

function getInfoByPos(start, end, func) {
    if (start === end) {
        return null
    }
    if (start > end) {
        var tmp = start
        start = end
        end = tmp
    }
    var chapterType = highlighter.createCharacterRange(start, end)
    return func.call(null, chapterType)
}


function getCharacterRangeTop(chapterRange) {
    if (!chapterRange || chapterRange.end <= chapterRange.start) {
        return -1
    }
    return highlighter.converter.characterRangeToRange(document, chapterRange, body).nativeRange.getBoundingClientRect().top
}

function getCharacterRangeRectInfo(chapterRange) {
    if (!chapterRange || chapterRange.end <= chapterRange.start) {
        return null
    }
    var testRange = rangy.createRange(doc);
    testRange.selectCharacters(body, chapterRange.start, chapterRange.start + 1);
    var firstRect = testRange.nativeRange.getBoundingClientRect()
    var lastRect = firstRect
    if (chapterRange.end > chapterRange.start + 1) {
        testRange.selectCharacters(body, chapterRange.end - 1, chapterRange.end)
        lastRect = testRange.nativeRange.getBoundingClientRect()
    }
    var rangeRect = highlighter.converter.characterRangeToRange(document, chapterRange, body).nativeRange.getBoundingClientRect()
    return {
        startX: firstRect.left,
        startY: firstRect.top,
        endX: lastRect.right,
        endY: lastRect.bottom,
        minLeft: rangeRect.left,
        maxRight: rangeRect.right,
        singleLine: firstRect.top === lastRect.top
    }
}

function getSelectionRectInfo() {
    var selection = rangy.getSelection()
    var nativeSelection = window.getSelection()
    var ranges = selection.getAllRanges()
    if (nativeSelection.rangeCount && !nativeSelection.isCollapsed) {
        var doc = document
        var body = rangy.util.getBody(doc)
        var result = {
            startX: 0,
            startY: 0,
            endX: 0,
            endY: 0,
            minLeft: Number.MAX_VALUE,
            maxRight: 0,
            singleLine: true
        }
        var firstTextPos = Number.MAX_VALUE, lastTextPos = 0
        rangy.util.forEach(ranges, function (range) {
            var chapterRange = highlighter.converter.rangeToCharacterRange(range, body)
            firstTextPos = Math.min(chapterRange.start, firstTextPos)
            lastTextPos = Math.max(lastTextPos, chapterRange.end)
            var rect = range.nativeRange.getBoundingClientRect()
            result.minLeft = Math.min(result.minLeft, rect.left)
            result.maxRight = Math.max(result.maxRight, rect.right)
            result.startY = result.startY === 0 ? rect.top : Math.min(result.startY, rect.top)
            result.endY = result.endY === 0 ? rect.bottom : Math.max(result.endY, rect.bottom)
        })
        if (lastTextPos < firstTextPos) {
            return null
        } else if (lastTextPos === firstTextPos) {
            var text = getSelectedText(false, true)
            if (text.length > 0) {
                // image
                result.startX = result.minLeft
                result.endX = result.maxRight
                return result
            }
            return null
        }
        var testRange = rangy.createRange(doc);
        testRange.selectCharacters(body, firstTextPos, firstTextPos + 1);
        var firstRect = testRange.nativeRange.getBoundingClientRect()
        var lastRect = firstRect
        if (lastTextPos > firstTextPos + 1) {
            testRange.selectCharacters(body, lastTextPos - 1, lastTextPos)
            lastRect = testRange.nativeRange.getBoundingClientRect()
        }
        result.startX = firstRect.left
        result.startY = firstRect.top
        result.endX = lastRect.right
        result.endY = lastRect.bottom
        result.singleLine = firstRect.top === lastRect.top
        return result
    }
    return null
}

// 初始化划线及高亮方法
function initAnnotations(items) {
    rangy.load(function () {
        var scrollTop = -1
        removeAllAnnotations();
        var serializedHighlights = "type:TextRange";
        items = JSON.parse(items);
        for (var i = 0; i < items.length; i++) {

            var className
            if (items[i].type === 'highlight') {
                if (items[i].isReference) {
                    className = 'reference'

                    items.push({
                        type: 'highlight',
                        isReference: false,
                        isMySelf: items[i].isMySelf,
                        start: items[i].start,
                        end: items[i].end
                    })
                } else {
                    className = 'highlight'
                }

                if (items[i].needScrollTo) {
                    scrollTop = getTopByPos(items[i].start, items[i].end)
                }
            } else if (items[i].type === 'review') {
                if (items[i].isReference) {
                    className = 'reference'
                    scrollTop = getTopByPos(items[i].start, items[i].end)
                    items.push({
                        type: 'review',
                        isReference: false,
                        isMySelf: items[i].isMySelf,
                        start: items[i].start,
                        end: items[i].end
                    })
                } else if (items[i].isMySelf) {
                    className = 'review'
                } else {
                    className = 'friend-review'
                }

                if (items[i].needScrollTo) {
                    scrollTop = getTopByPos(items[i].start, items[i].end)
                }
            } else {
                if (items[i].isReference) {
                    className = 'reference'
                }
                if (items[i].needScrollTo) {
                    scrollTop = getTopByPos(items[i].start, items[i].end)
                }
            }

            if (className) {
                serializedHighlights = serializedHighlights + '|' + items[i].start + '$' + items[i].end + '$' + (i + 1) + '$' + className;
            }
        }
        if (scrollTop > 0) {
            wereadBridge.execMPReaderMethod('MPReader', {
                cmd: 'scrollToOffsetTop',
                top: scrollTop
            });
            setTimeout(function () {
                highlighter.deserialize(serializedHighlights);
            }, 100)
        } else {
            highlighter.deserialize(serializedHighlights);
        }
    })
}

// 新增划线
function didTapCreateHighlightButton() {
    var newHighlights = highlighter.highlightSelection("highlight", {
        exclusive: false
    });
    if (newHighlights.length === 0) {
        return null
    }
    var highlight = newHighlights[newHighlights.length - 1]
    var result = getStartEndContentFromHighlight(highlight)
    // 去除聚焦
    removeSelection();
    return result;
}

// 对指定位置新增划线
function addNewUnderLineByPosition(start, end) {
    var result = null;
    if (start >= 0 && end >= 0) {
        var range = rangy.createRange(doc)
        range.selectCharacters(body, start, end)
        highlighter.highlightRanges("highlight", [range], {
            exclusive: false
        })
        var characterRange = highlighter.converter.rangeToCharacterRange(range, body)
        result = {
            start: characterRange.start,
            end: characterRange.end,
            content: range.text()
        }
    }
    return result;
}

// 新增想法
function didTapCreateReviewButton(start, end) {
    var selection = rangy.getSelection()
    var hasSelection = selection.toString().length > 0
    var result = null
    if (hasSelection) {
        highlighter.highlightSelection("review", {
            exclusive: false
        })
        result = getStartEndContentFromRanges(selection.getAllRanges())
    } else if (start >= 0 && end >= 0) {
        var range = rangy.createRange(doc)
        range.selectCharacters(body, start, end)
        highlighter.highlightRanges("review", [range], {
            exclusive: false
        })
        var characterRange = highlighter.converter.rangeToCharacterRange(range, body)
        result = {
            start: characterRange.start,
            end: characterRange.end,
            content: range.text()
        }
    } else {
        return null
    }
    // 去除聚焦
    removeSelection();
    return result;
}

function getStartEndContentFromHighlight(highlight, includeImages) {
    var characterRange = highlight.characterRange
    return {
        start: characterRange.start,
        end: characterRange.end,
        content: highlighter.converter.characterRangeToRange(doc, characterRange, body).text({
            includeImages: includeImages
        })
    };
}

function getStartEndContentFromRanges(ranges, includeImages) {
    var start = -1, end = -1, text = "", characterRange
    util.forEach(ranges, function (range) {
        characterRange = highlighter.converter.rangeToCharacterRange(range, body)
        if (start < 0) {
            start = characterRange.start
        } else {
            start = Math.min(start, characterRange.start)
        }
        end = Math.max(start, end, characterRange.end)
        text += range.text({
            includeImages: includeImages
        })
    })
    return {
        start: start,
        end: end,
        content: text
    };
}

// 需要判断是否是删除划线
function getRectInfoInSelection() {
    var rectInfo = getSelectionRectInfo(), characterRange
    if (rectInfo == null) {
        return null
    }
    var classNames = ['highlight']
    var highlight = highlighter.highghtWhichContainSelection(classNames)
    var start = -1, end = -1, isRemove = false
    if (highlight != null) {
        isRemove = true
        characterRange = highlighter.getMergedCharacterRange(highlight.characterRange, classNames, true)
        start = characterRange.start
        end = characterRange.end
    } else {
        var selection = rangy.getSelection()
        var ranges = selection.getAllRanges()
        for (var i = 0; i < ranges.length; i++) {
            characterRange = highlighter.converter.rangeToCharacterRange(ranges[i], body)
            if (start < 0) {
                start = characterRange.start
            } else {
                start = Math.min(characterRange.start, start)
            }
            end = Math.max(start, end, characterRange.end)
        }
    }

    return rangy.util.extend({
        start: start,
        end: end,
        isRemove: isRemove,
        content: getSelectedText(false)
    }, rectInfo);
}

// 删除所有想法 / 划线
function removeAllAnnotations() {
    highlighter.removeAllHighlights();
}

// 删除选中的划线
function removeAnnotationFromSelectedText() {
    highlighter.unhighlightSelection();
}

// 删除划线 / 想法
function didTapDeleteAnnotationButton(start, end, type) {
    var allHighlights = highlighter.highlights, highlight
    var removeHighlights = []

    for (var i = 0; i < allHighlights.length; i++) {
        highlight = allHighlights[i]
        if (type === 'highlight') {
            if (highlight.classApplier.className !== 'highlight') {
                continue
            }
        } else if (type === 'review') {
            if (highlight.classApplier.className !== 'review') {
                continue
            }
            if (reviewClassNames.indexOf(highlight.classApplier.className) < 0) {
                continue
            }
        }
        if (highlight.characterRange.start >= start && highlight.characterRange.end <= end) {
            removeHighlights.push(highlight)

        }
    }
    if (removeHighlights.length > 0) {
        highlighter.removeHighlights(removeHighlights)
        return true
    }
    return false
}

// 重新加载页面
function reloadPage(button) {
    button.form.elements["serializedHighlights"].value = highlighter.serialize();
    button.form.submit();
}

function removeSelection() {
    rangy.getSelection().removeAllRanges()
}

function getAllForwardLinks() {
    var arr = [], l = document.links;
    for (var i = 0; i < l.length; i++) {
        /*
        某些公众号的链接通过 data-url 复制，href 是 javascript:; 的。而 iOS
        的拦截是通过捕捉所有 link 跳转，所以需要下面这一句
        */
        if (l[i].getAttribute('data-url')) {
            l[i].href = l[i].getAttribute("data-url");
        }
        var href = l[i].href;
        if (href && (href.startsWith('http://') || href.startsWith('https://'))) {
            var ampRegEx = /&amp;/g;
            href = href.replace(ampRegEx, '&');
            arr.push(href);
        }
    }
    return arr;
}

function getAllImagesAndTargetIndex(target) {
    var images = document.getElementsByTagName('img')
    var result = [], targetIndex = -1
    for (var i = 0; i < images.length; i++) {
        
        var parent = images[i].parentNode
        while (parent.nodeName != "A" && parent.nodeName != "BODY" && parent.nodeName != "HTML") {
            parent = parent.parentNode;
        }
            
        // 小程序、跳转链接的图片不受响应
        var invalid = parent.nodeName == "A" &&
        (parent.className.indexOf('h5_image_link') > -1 ||
         parent.className.indexOf('weapp_image_link') > -1 ||
         parent.getAttribute('data-weread-bookid') != null ||
         parent.getAttribute('data-weread-reviewid') != null);
        
        var info = getImageInfo(images[i])
        if (info != null && !invalid) {
            if (target === images[i]) {
                targetIndex = result.length
            }
            result.push(info)
        }
    }
    return {
        allImages: result,
        targetIndex: targetIndex
    }
}

function getAllImages() {
    var images = document.getElementsByTagName('img')
    var result = []
    for (var i = 0; i < images.length; i++) {
        var info = getImageInfo(images[i])
        if (info) {
            result.push(info)
        }
    }
    return result
}

function getImageInfo(image) {
    if (!isHidden(image)) {
        var src = image.getAttribute("data-src")
        if (!src || !src.startsWith("http")) {
            src = image.getAttribute("src")
            if (!src || !src.startsWith("http")) {
                src = image.src
            }
        }
        if (src) {
            var rect = image.getBoundingClientRect()
            return {
                src: src,
                x: rect.left,
                y: rect.top,
                width: rect.width,
                height: rect.height
            }
        }
    }
    return null
}

function getContentByPos(start, end, shouldRemoveSelection, includeImages) {
    if (start >= 0 && end >= 0) {
        var range = rangy.createRange(doc)
        range.selectCharacters(body, start, end)
        return range.text({
            includeImages: includeImages
        })
    } else {
        return getSelectedText(shouldRemoveSelection, includeImages)
    }
}

function getSelectedText(shouldRemoveSelection, includeImages) {
    var selection = rangy.getSelection()
    var ranges = selection.getAllRanges()
    var text = ""
    if (ranges.length > 0) {
        util.forEach(ranges, function (range) {
            text += range.text({
                includeImages: includeImages
            })
        })
    }
    if (shouldRemoveSelection) {
        selection.removeAllRanges()
    }
    return text
}

// sample:https://weread.qq.com/web/appreader/6bb324405e15d46bb6d43d0?wtype=mpArticle
// 将以上的 link 在客户端转化为 data-weread-bookId 和 data-weread-chapterUid
function transferH5Link() {
    var detectReader = 'weread.qq.com/web/appreader'
    var detectLecture = 'weread.qq.com/wrpage/book/lecture'
    var links = document.getElementsByTagName('a')
    
    for (var i = 0; i < links.length; i++) {
        var link = links[i]
        if (link.href.indexOf(detectReader) > -1 || link.href.indexOf(detectLecture) > -1) {
            var encryptString = link.href.split('/').slice(-1)[0]
            if (encryptString) {
                // remove params
                encryptString = encryptString.split('?')[0]
                
                // rule：web_encrypt(bookId) + 'k' + web_encrypt(chapterUid)
                var encryptAry = encryptString.split('k')
                var bookId, chapterUid, reviewId;
                
                if (encryptAry[0]) {
                    bookId = WRLink_decrypt(encryptAry[0])
                    link.setAttribute('data-weread-bookid', bookId)
                }
                
                if (encryptAry[1]) {
                    chapterUid = WRLink_decrypt(encryptAry[1])
                    link.setAttribute('data-weread-chapteruid', chapterUid)
                }
                
                if (link.href.indexOf(detectLecture) > -1) {
                    reviewId = encryptString;
                    link.setAttribute('data-weread-reviewid', reviewId)
                }
                
                if (bookId.length || reviewId.length) {
                    // 删掉 href 以致于让 App 不显示微信自带的”即将打开新页面“
                    link.removeAttribute('href');
                    
                    link.addEventListener('touchend', function (e) {
                        var bookId = this.getAttribute('data-weread-bookid') ? this.getAttribute('data-weread-bookid') : '';
                        var chapterUid = this.getAttribute('data-weread-chapteruid') ? this.getAttribute('data-weread-chapteruid') : '';
                        var reviewId = this.getAttribute('data-weread-reviewid') ? this.getAttribute('data-weread-reviewid') : '';
                        if (bookId.length || reviewId.length) {
                            wereadBridge.execMPReaderMethod('MPReader', {
                            cmd: 'didTapBook',
                            bookId: bookId,
                            chapterUid: chapterUid,
                            reviewId: reviewId,
                            });
                        }
                    }, true);
                }
            }
        }
    }
}

// copy by https://git.code.oa.com/WeRead/wrencryption/blob/master/src/index.js
// need check update
function WRLink_decrypt (str) {
    var md5Length = 3;
    if (typeof str !== 'string' || str.length <= md5Length) return '';
    var type = str.charAt(3);
    var randomLen = parseInt(str.charAt(4));
    var firstContentPartIdx = 5 + randomLen;
    var contentMaxIdx = str.length - 3; // 后面3位是 md5
    var s = '';
    var idx = firstContentPartIdx;
    while (idx < contentMaxIdx && (idx === firstContentPartIdx || str.charAt(idx) === 'g')) {
        if (idx !== firstContentPartIdx) {
            idx++; // 跳过 'g'
        }
        if (idx + 2 > contentMaxIdx) {
            return '';
        }
        var contentLength = parseInt(str.substr(idx, 2), 16);
        if (idx + 2 + contentLength > contentMaxIdx) {
            return '';
        }
        var substring = str.substr(idx + 2, contentLength);
        var decodeResult = '';
        if (type === '3') {
            var number = parseInt(substring, 16);
            if (isNaN(number)) {
                return '';
            }
            decodeResult = '' + number;
        } else {
            for (var i = 0, iLen = substring.length; i < iLen; i += 2) {
                var charCode = parseInt(substring.substr(i, 2), 16);
                decodeResult += String.fromCharCode(charCode);
            }
        }
        s += decodeResult;

        idx = idx + 2 + contentLength;
    }
    return s;
}

// ================================  TTS  ===================================================

var lastTTSInfo = {
    lastTTSRange: null,
    lastTTSHighlightInfo: null,
    lastIndex: -1,
    lastText: "",
    lastTop: -1,
    lastBottom: -1
}
var passTags = ['body', 'html', 'code', 'pre']
var filterTags = ['style', 'script', 'mpvoice', 'iframe', 'br']
var filterClass = ['js_audio_frame']
var mergeTags = ['p', 'li', 'a', 'h1', 'h2', 'h3', 'h4', 'h5']

function TTSRange() {
    this.range = new rangy.DomRange(document)
    this.matchedString = ""
    this.start = false
    this.lastInfo = null
}

function TTSText() {
    this.result = []
    this.stack = []
    this.restoreIndex = -1
    this.needHandleStart = true
    this.tmpRange = null
    this.getForCurrentIndex = -1
    this.getForCurrentIndexHandled = false
}

/**
 * 获取 TTS 文本内容
 * @param startY
 * @returns {string}
 */
function getTTSText(startY) {
    var start = new Date - 0
    var util = rangy.util
    var body = util.getBody(document)
    var ttsText = new TTSText()
    handleTTSTextGet(body, startY, ttsText)
    var handleResult = []
    var startPos = 0
    for (var i = 0; i < ttsText.result.length; i++) {
        if (ttsText.result[i]) {
            handleResult.push({index: i, text: ttsText.result[i], startPos: startPos})
            startPos += ttsText.result[i].length
        }
    }
    console.log("getTTSText speed: " + (new Date - start))
    return handleResult
}

/**
 * 获取 currentY 位置文本的 index 以及 pos
 * @param startY
 * @param currentY
 * @returns {*}
 */
function getCurrentIndex(startY, currentY) {
    if(currentY <= startY){
        return {
            index: 0,
            pos: 0
        }
    }

    var util = rangy.util
    var body = util.getBody(document)
    var ttsText = new TTSText()
    ttsText.getForCurrentIndex = currentY
    handleTTSTextGet(body, startY, ttsText)
    var result = ttsText.result
    if (result.length > 0) {
        return {
            index: result.length - 1,
            pos: result[result.length - 1].length
        }
    } else {
        return {
            index: 0,
            pos: 0
        }
    }

}

/**
 * 恢复 TTS 播放的上下文记录
 * @param startY
 * @param restoreIndex
 */
function restoreTTSContext(startY, restoreIndex) {
    var ttsText = new TTSText()
    ttsText.restoreIndex = restoreIndex
    handleTTSTextGet(body, startY, ttsText)
}

/**
 * el 过滤
 * @param el
 * @returns {boolean}
 */
function filter(el) {
    var tagName = el.nodeName.toLowerCase()
    if (passTags.indexOf(tagName) >= 0) {
        return false
    }
    if (filterTags.indexOf(tagName) >= 0) {
        return true
    }

    if (el.getAttribute('wr-ignore-no-content')) {
        return true
    }

    if (isNodeHidden(el)) {
        return true
    }

    var parent = el.parentNode
    if (parent == null) {
        return true
    }

    if (tagName === 'p' && (parseInt(getStyle(el, 'text-indent'), 10) || 0) < -3000) {
        el.setAttribute('wr-ignore-no-content', true)
        return true
    }

    var offsetParent = el.offsetParent
    var offsetWidth = el.offsetWidth
    var offsetLeft = el.offsetLeft
    var parentOffsetWidth = parent.offsetWidth
    if (offsetParent == null) {
        return true
    }
    if (parentOffsetWidth <= 0 || offsetWidth == 0) {
        // offsetWidth 为 0，可能是离线 Webview, 如果检测？
        // 如果 display 为 inline， 然后包裹其它元素，offsetWidth 可能会出错
        return false
    }
    
    if ((offsetWidth != 0 && offsetLeft + offsetWidth < 0) || (offsetParent.offsetWidth != 0 && offsetLeft > offsetParent.offsetWidth)) {
        el.setAttribute('wr-ignore-no-content', true)
        return true
    }

    var classUtil = rangy.ClassApplier.util
    for (var i = 0; i < filterClass.length; i++) {
        if (classUtil.hasClass(el, filterClass[i])) {
            return true
        }
    }
    return false
}

function handleTTSTextGet(el, startY, ttsText) {
    if (el.nodeType === 1) {
        var tagName = el.nodeName.toLowerCase()
        if (ttsText.needHandleStart) {
            var rect = el.getBoundingClientRect()
            if (rect.bottom <= startY && tagName !== 'body') {
                // ignore
                return
            }
            if (rect.top >= startY) {
                ttsText.needHandleStart = false
            }
        }

        if (filter(el)) {
            return
        }

        var child, lastIndex;
        if (mergeTags.indexOf(tagName) >= 0) {
            var isInMergeTag = false
            if (!ttsText.stack.length) {
                ttsText.stack.push(tagName)
                ttsText.result.push('')
            }else{
                isInMergeTag = true
            }
            child = el.firstChild
            while (child) {
                handleTTSTextGet(child, startY, ttsText)
                if (ttsText.getForCurrentIndexHandled) {
                    break
                }
                child = child.nextSibling
            }
            if(!isInMergeTag){
                ttsText.stack.pop()
                lastIndex = ttsText.result.length - 1
                ttsText.result[lastIndex] = ttsText.result[lastIndex].trim()
                if (ttsText.getForCurrentIndexHandled) {
                    return
                }
                if (ttsText.result[lastIndex] === '') {
                    ttsText.result.pop()
                    el.setAttribute('wr-ignore-no-content', true)
                } else {
                    if (ttsText.result.length === ttsText.restoreIndex) {
                        lastTTSInfo.lastTTSRange = rangy.createRange(doc)
                        lastTTSInfo.lastTTSRange.selectNodeContents(el)
                        lastTTSInfo.lastTTSRange = highlighter.converter.rangeToCharacterRange(lastTTSInfo.lastTTSRange, body)
                    }
                }
            }

        } else {
            child = el.firstChild
            while (child) {
                handleTTSTextGet(child, startY, ttsText)
                if (ttsText.getForCurrentIndexHandled) {
                    return
                }
                child = child.nextSibling
            }
        }
    } else if (el.nodeType === 3) {
        if (!emptyTextNode(el)) {
            if (!ttsText.needHandleStart) {
                if(ttsText.getForCurrentIndex > startY && !ttsText.getForCurrentIndexHandled){
                    var range = ttsText.tmpRange
                    if (!range) {
                        range = ttsText.tmpRange = document.createRange()
                    }
                    range.selectNodeContents(el)
                    rect = range.getBoundingClientRect()
                    handleGetForCurrentIndex(ttsText, rect, el, range)
                    if(ttsText.getForCurrentIndexHandled){
                        return
                    }
                }
                collectText(el, ttsText, 0)
            } else {
                var range = ttsText.tmpRange
                if (!range) {
                    range = ttsText.tmpRange = document.createRange()
                }
                range.selectNodeContents(el)
                rect = range.getBoundingClientRect()
                if (rect.bottom <= startY) {
                    // ignore
                    return
                }
                if (rect.top >= startY) {
                    ttsText.needHandleStart = false
                    collectText(el, ttsText, 0)
                    handleGetForCurrentIndex(ttsText, rect, el, range)
                    if(ttsText.getForCurrentIndexHandled){
                        return
                    }
                } else {
                    handleGetForCurrentIndex(ttsText, rect, el, range)
                    if(ttsText.getForCurrentIndexHandled){
                        return
                    }
                    var start = 0, end = el.data.length - 1
                    var sliceIndex = sliceTextNode(el, range, startY, start, end, rect.top, rect.bottom)
                    if (sliceIndex + 1 <= end) {
                        ttsText.needHandleStart = false
                        collectText(el, ttsText, sliceIndex + 1)
                    }
                }
            }
        }
    }
}

function handleGetForCurrentIndex(ttsText, rect, el, range) {
    if (ttsText.getForCurrentIndex > 0) {
        if (rect.top > ttsText.getForCurrentIndex) {
            if (!ttsText.stack.length) {
                ttsText.result.push("")
            }
            ttsText.getForCurrentIndexHandled = true
        } else if (rect.bottom > ttsText.getForCurrentIndex) {
            var start = 0, end = el.data.length - 1
            var slice = sliceTextNode(el, range, ttsText.getForCurrentIndex, start, end, rect.top, rect.bottom)
            var data = slice > 0 ? el.data.substring(0, slice) : el.data
            if (!ttsText.stack.length) {
                ttsText.result.push(data)
            } else {
                var lastI = ttsText.result.length - 1
                ttsText.result[lastI] = ttsText.result[lastI] + data
            }
            ttsText.getForCurrentIndexHandled = true
        }
    }
}

function sliceTextNode(el, range, startY, start, end) {
    if (end - start <= 1) {
        return end
    }
    var half = Math.floor((end + start) / 2), rect
    range.setStart(el, half)
    range.setEnd(el, half + 1)
    rect = range.getBoundingClientRect()
    if (rect.top >= startY) {
        return sliceTextNode(el, range, startY, 0, half - 1)
    } else {
        return sliceTextNode(el, range, startY, half, end)
    }
}

function collectText(el, ttsText, sliceIndex) {
    var data = sliceIndex > 0 ? el.data.substring(sliceIndex) : el.data
    if (ttsText.stack.length) {
        var lastIndex = ttsText.result.length - 1
        ttsText.result[lastIndex] = ttsText.result[lastIndex] + data
    } else {
        ttsText.result.push(data.trim())
        if (ttsText.result.length === ttsText.restoreIndex) {
            lastTTSInfo.lastTTSRange = rangy.createRange(doc)
            lastTTSInfo.lastTTSRange.selectNodeContents(el)
            lastTTSInfo.lastTTSRange = highlighter.converter.rangeToCharacterRange(lastTTSInfo.lastTTSRange, body)
        }
    }
}

function highlightTTSText(text, index, startY) {
    var start = new Date - 0
    var range = new TTSRange()
    if (lastTTSInfo.lastTTSHighlightInfo != null) {
        // 如果与上次信息相同，直接返回
        if (lastTTSInfo.lastIndex === index && lastTTSInfo.lastText === text) {
            return {
                top: lastTTSInfo.lastTop,
                bottom: lastTTSInfo.lastBottom
            }
        }
        highlighter.removeHighlights(lastTTSInfo.lastTTSHighlightInfo)
        lastTTSInfo.lastTTSHighlightInfo = null
    }
    lastTTSInfo.lastIndex = index
    lastTTSInfo.lastText = text
    if (lastTTSInfo.lastTTSRange == null && index > 0) {
        restoreTTSContext(startY, index)
    }

    if (lastTTSInfo.lastTTSRange != null) {
        range.lastInfo = highlighter.converter.characterRangeToRange(doc, lastTTSInfo.lastTTSRange, body)
    }
    var remain = handleTTSHighlight(text, body, range)
    if (remain && remain.length) {
        // there no matched text in dom
        return {
            reason: "there no matched text in dom",
            top: -1,
            bottom: -1
        }
    } else {
        // 必须在 highlightRanges 前转换成 ChapterRange,
        // highlightRanges 可能会造成 DOM 更改，使得之前所保存到 dom 节点失效
        lastTTSInfo.lastTTSRange = highlighter.converter.rangeToCharacterRange(range.range, body)
        lastTTSInfo.lastTTSHighlightInfo = highlighter.highlightRanges("tts", [range.range], {
            exclusive: false
        });
        if (!lastTTSInfo.lastTTSHighlightInfo || !lastTTSInfo.lastTTSHighlightInfo.length) {
            return {
                reason: "no lastTTSHighlightInfo",
                top: -1,
                bottom: -1
            }
        }
        var highlightRange = highlighter.converter.characterRangeToRange(doc, lastTTSInfo.lastTTSHighlightInfo[0].characterRange, body)
        var rect = highlightRange.nativeRange.getBoundingClientRect()
        console.log("highlightTTSText speed: " + (new Date - start))
        lastTTSInfo.lastTop = rect.top
        lastTTSInfo.lastBottom = rect.bottom
        return {
            top: rect.top,
            bottom: rect.bottom
        }
    }
}

function handleTTSHighlight(text, el, range) {
    if (text == null || text.length === 0) {
        return null
    }

    var offset = 0

    // 快速方案： 从上次匹配位置开始向后匹配高亮区域
    // if (range.lastInfo != null) {
    //     var isOrIsAncestorOf = rangy.dom.isOrIsAncestorOf
    //     if (!isOrIsAncestorOf(el, range.lastInfo.endContainer)) {
    //         return text
    //     } else if (el === range.lastInfo.endContainer) {
    //         offset = range.lastInfo.endOffset
    //         range.lastInfo = null
    //     }
    // }
    var remain, index
    if (el.nodeType === 1) {
        if (filter(el)) {
            return text
        }
        var child
        if (offset > 0) {
            if (el.children && el.children.length > offset + 1) {
                child = el.children[offset + 1]
            } else {
                return text
            }
        } else {
            child = el.firstChild
        }
        while (child) {
            text = handleTTSHighlight(text, child, range)
            if (text == null || text.length === 0) {
                return null
            }
            child = child.nextSibling
        }
        return text
    } else if (el.nodeType === 3) {
        var elData = el.data
        if (range.start) {
            if (emptyTextNode(el)) {
                return text
            } else if (text.indexOf(elData) === 0) {
                range.matchedString += elData
                remain = text.substring(elData.length)
                if (remain.length === 0) {
                    range.range.setEnd(el, text.length)
                }
                return remain
            } else if (elData.indexOf(text) === 0) {
                range.matchedString += text
                range.range.setEnd(el, text.length)
                return null
            } else {
                // 匹配错误, 重新匹配
                console.log("matchedString = " + range.matchedString + "; remain = " + text)
                range.start = false
                text = range.matchedString + text
                range.matchedString = ""
                // TODO 从错误节点重新处理？
                return handleTTSHighlight(text, el, range)
            }
        } else {
            if (emptyTextNode(el)) {
                return text
            } else if (text.indexOf(elData) === offset) {
                range.matchedString += elData
                range.start = true
                range.range.setStart(el, offset)
                remain = text.substring(elData.length)
                if (remain.length === 0) {
                    range.range.setEnd(el, text.length)
                }
                return remain
            } else if ((index = elData.indexOf(text, offset)) >= 0) {
                range.start = true
                range.matchedString += text
                range.range.setStart(el, index)
                range.range.setEnd(el, index + text.length)
                return null
            }
            var matchStart, matchIndex
            matchStart = matchIndex = elData.indexOf(text[0], offset)
            if (matchIndex === -1) {
                return text
            } else {
                var textIndex = 0
                while (true) {
                    matchIndex++
                    textIndex++
                    if (elData.length <= matchIndex || text.length <= textIndex) {
                        range.start = true
                        range.matchedString += elData.substring(matchStart, matchIndex)
                        range.range.setStart(el, matchStart)
                        text = text.substring(textIndex)
                        if (text.length === 0) {
                            range.range.setEnd(el, matchIndex + text.length)
                        }
                        return text
                    } else if (elData[matchIndex] !== text[textIndex]) {
                        matchStart = elData.indexOf(text[0], matchStart + 1)
                        if (matchStart === -1) {
                            return text
                        } else {
                            matchIndex = matchStart
                            textIndex = 0
                        }
                    }
                }
            }
        }
    }
    return text;
}

function emptyTextNode(el) {
    return !el.data || /^(\s|\t)+$/g.test(el.data)
}

function isNodeHidden(node) {
    if (node.sourceIndex === 0) {
        return true
    }
    // 故事流之后不显示标题，但是为了与之前版本划线兼容，并不能隐藏标题
    return getStyle(node, 'display') === 'none' || rangy.ClassApplier.util.hasClass(node, 'rich_media_title')
}

function isHidden(node) {
    var ancestors = [node];
    while (node.parentNode) {
        ancestors.unshift(node.parentNode);
        node = node.parentNode;
    }
    for (var i = 0, len = ancestors.length; i < len; ++i) {
        if (ancestors[i].nodeType === 1 && isNodeHidden(ancestors[i])) {
            return true;
        }
    }
    return false;
}


function getStyle(node, name) {
    if (window.getComputedStyle) {
        return window.getComputedStyle(node, null)[name]
    } else {
        return node.currentStyle[name]
    }
}

function finishTTSPlay() {
    if (lastTTSInfo.lastTTSHighlightInfo != null) {
        highlighter.removeHighlights(lastTTSInfo.lastTTSHighlightInfo)
        lastTTSInfo.lastTTSHighlightInfo = null
    }
    lastTTSInfo.lastTTSRange = null
    lastTTSInfo.lastIndex = -1
    lastTTSInfo.lastText = ""
}

function debounce(callback, timeout) {
    var timerId = null
    timeout = timeout || 250
    return function () {
        var args = arguments
        var self = this
        if (timerId) {
            clearTimeout(timerId);

            timerId = null;
        }
        timerId = setTimeout(function () {
            callback.apply(self, args)
        }, timeout)
    }
}
                          
function changeFontSizeWithScale(scale) {
    // iPad iOS13 不支持 -weikit-text-size-adjust，改用自定义方法
    // 注意：传入的 scale 是 0.80 这样的值
    var root = document.getElementById('js_content');
    var setQueue = [];
    var textWalker = document.createTreeWalker(root, 4); // 4 === NodeFilter.SHOW_TEXT
    while (textWalker.nextNode()) {
        var textContainer = textWalker.currentNode.parentNode;
        var oriFontSize = textContainer.getAttribute('data-weread-fontsize');
        var oriLineHeight = textContainer.getAttribute('data-weread-lineheight');
        if (!oriFontSize) {
            oriFontSize = getComputedStyle(textContainer).fontSize;
            textContainer.setAttribute('data-weread-fontsize', oriFontSize);
        }
        if (!oriLineHeight) {
            oriLineHeight = getComputedStyle(textContainer).lineHeight;
            textContainer.setAttribute('data-weread-lineheight', oriLineHeight);
        } 
        // 先不要马上设置fontSize，会影响子节点的fontSize，存起来最后统一设置
        setQueue.push([textContainer, oriFontSize, oriLineHeight]);
    }
    setQueue.forEach(function (setPair) {
        setPair[0].style.fontSize = parseFloat(setPair[1]) * scale + 'px';
        setPair[0].style.lineHeight = parseFloat(setPair[2]) * scale + 'px';
    });
}

function findAllBookTitles() {
    var container = document.getElementById("js_content");
    if (!container) return [];
    
    var walker = document.createTreeWalker(
      container,
      NodeFilter.SHOW_TEXT,
      null,
      false
    );
    var node;
    var regex = /《[^《》]{1,30}》/g;
    var results = [];
    while ((node = walker.nextNode())) {
      var text = node.nodeValue;
      var match;
      while ((match = regex.exec(text)) !== null) {
        results.push({
          text: match[0],
        });
      }
    }
    return results;
}

function highlightSelectedBookTitles(indexArray) {
    // indexArray: [{nodeIndex, start, end}, ...]
    var container = document.getElementById("js_content");
    if (!container) return;

    // 清除上一次的高亮
    var prevSpans = document.querySelectorAll('span.blue-clickable');
    prevSpans.forEach(function(span) {
        var parent = span.parentNode;
        while (span.firstChild) {
            parent.insertBefore(span.firstChild, span);
        }
        parent.removeChild(span);
    });
  
    // 重新遍历一遍，找到所有文本节点
    var walker = document.createTreeWalker(
      container,
      NodeFilter.SHOW_TEXT,
      null,
      false
    );
    var nodes = [];
    var node;
    while ((node = walker.nextNode())) {
      nodes.push(node);
    }

    var highlighter = rangy.createHighlighter();
    var applier = rangy.createClassApplier("blue-clickable", { 
        tagNames: ["span"],
        elementProperties: {
            onclick: function (event) {
                return clickHighlightBookTitle(this, event)
            }
        },
        normalize: false,
    });
    highlighter.addClassApplier(applier);
  
    var regex = /《[^《》]{1,30}》/g;
    const textSet = new Set(indexArray);

    // 1. 先收集每个 node 里所有需要高亮的区间
    nodes.forEach(function(node) {
        var text = node.nodeValue;
        var match;
        var ranges = [];
        while ((match = regex.exec(text)) !== null) {
            if (textSet.has(match[0])) {
                ranges.push({
                    start: match.index,
                    end: match.index + match[0].length,
                    text: match[0]
                });
            }
        }
        // 2. 按 start 降序排序
        ranges.sort((a, b) => b.start - a.start);
        // 3. 倒序高亮
        ranges.forEach(function(item) {
            var range = rangy.createRange();
            range.setStart(node, item.start);
            range.setEnd(node, item.end);
            highlighter.highlightRanges("blue-clickable", [range]);
        });
    });
  }

  function clickHighlightBookTitle(el, event) {
    console.log('clickHighlightBookTitle', el, event);
    event.preventDefault();
    event.stopPropagation();
    
    var result = {
        cmd: 'didTapHighlightBookTitle',
        content: el.textContent,
    }
    wereadBridge.execMPReaderMethod('MPReader', result);
    return true
}