// needs Markdown.Converter.js at the moment

(function () {

var util = {},
    position = {},
    ui = {},
    doc = window.document,
    re = window.RegExp,
    nav = window.navigator,
    SETTINGS = { lineLength: 72 },
// Used to work around some browser bugs where we can't use feature testing.
    uaSniffed = {
        isIE: /msie/.test(nav.userAgent.toLowerCase()),
        isIE_5or6: /msie 6/.test(nav.userAgent.toLowerCase()) || /msie 5/.test(nav.userAgent.toLowerCase()),
        isOpera: /opera/.test(nav.userAgent.toLowerCase())
    };
var defaultsStrings = {
    bold: "Strong <strong> Ctrl+B",
    boldexample: "strong text",
    italic: "Emphasis <em> Ctrl+I",
    italicexample: "emphasized text",
    link: "Hyperlink <a> Ctrl+L",
    linkdescription: "enter link description here",
    linkdialog: "<p><b>Insert Hyperlink</b></p><p>http://example.com/ \"optional title\"</p>",
    quote: "Blockquote <blockquote> Ctrl+Q",
    quoteexample: "Blockquote",
    code: "Code Sample <pre><code> Ctrl+K",
    codeexample: "enter code here",
    image: "Image <img> Ctrl+G",
    imagedescription: "enter image description here",
    imagedialog: "<p><b>Insert Image</b></p><p>http://example.com/images/diagram.jpg \"optional title\"<br><br>Need <a href='http://www.google.com/search?q=free+image+hosting' target='_blank'>free image hosting?</a></p>",
    olist: "Numbered List <ol> Ctrl+O",
    ulist: "Bulleted List <ul> Ctrl+U",
    litem: "List item",
    heading: "Heading <h1>/<h2> Ctrl+H",
    headingexample: "Heading",
    hr: "Horizontal Rule <hr> Ctrl+R",
    undo: "Undo - Ctrl+Z",
    redo: "Redo - Ctrl+Y",
    redomac: "Redo - Ctrl+Shift+Z",
    help: "Markdown Editing Help"
};
// -------------------------------------------------------------------
//  YOUR CHANGES GO HERE
//
// I've tried to localize the things you are likely to change to
// this area.
// -------------------------------------------------------------------
// The default text that appears in the dialog input box when entering
// links.
var imageDefaultText = "http://";
var linkDefaultText = "http://";
// -------------------------------------------------------------------
//  END OF YOUR CHANGES
// -------------------------------------------------------------------
// options, if given, can have the following properties:
//   options.helpButton = { handler: yourEventHandler }
//   options.strings = { italicexample: "slanted text" }
// `yourEventHandler` is the click handler for the help button.
// If `options.helpButton` isn't given, not help button is created.
// `options.strings` can have any or all of the same properties as
// `defaultStrings` above, so you can just override some string displayed
// to the user on a case-by-case basis, or translate all strings to
// a different language.
//
// For backwards compatibility reasons, the `options` argument can also
// be just the `helpButton` object, and `strings.help` can also be set via
// `helpButton.title`. This should be considered legacy.
//
// The constructed editor object has the methods:
// - getConverter() returns the markdown converter object that was passed to the constructor
// - run() actually starts the editor; should be called after all necessary plugins are registered. Calling this more than once is a no-op.
// - refreshPreview() forces the preview to be updated. This method is only available after run() was called.
Markdown.Editor = function (markdownConverter, idPostfix, options) {
    options = options || {};
    if (typeof options.handler === "function") { //backwards compatible behavior
        options = { helpButton: options };
    }
    options.strings = options.strings || {};
    if (options.helpButton) {
        options.strings.help = options.strings.help || options.helpButton.title;
    }
    var getString = function (identifier) { return options.strings[identifier] || defaultsStrings[identifier]; }
    idPostfix = idPostfix || "";
    var hooks = this.hooks = new Markdown.HookCollection();
    hooks.addNoop("onPreviewRefresh");       // called with no arguments after the preview has been refreshed
    hooks.addNoop("postBlockquoteCreation"); // called with the user's selection *after* the blockquote was created; should return the actual to-be-inserted text
    hooks.addFalse("insertImageDialog");     /* called with one parameter: a callback to be called with the URL of the image. If the application creates
                                              * its own image insertion dialog, this hook should return true, and the callback should be called with the chosen
                                              * image url (or null if the user cancelled). If this hook returns false, the default dialog will be used.
                                              */
    this.getConverter = function () { return markdownConverter; }
    var that = this,
        panels;
    this.run = function () {
        if (panels)
            return; // already initialized
        panels = new PanelCollection(idPostfix);
        var commandManager = new CommandManager(hooks, getString);
        var previewManager = new PreviewManager(markdownConverter, panels, function () { hooks.onPreviewRefresh(); });
        var undoManager, uiManager;
        if (!/\?noundo/.test(doc.location.href)) {
            undoManager = new UndoManager(function () {
                previewManager.refresh();
                if (uiManager) // not available on the first call
                    uiManager.setUndoRedoButtonStates();
            }, panels);
            this.textOperation = function (f) {
                undoManager.setCommandMode();
                f();
                that.refreshPreview();
            }
        }
        uiManager = new UIManager(idPostfix, panels, undoManager, previewManager, commandManager, options.helpButton, getString);
        uiManager.setUndoRedoButtonStates();
        var forceRefresh = that.refreshPreview = function () { previewManager.refresh(true); };
        forceRefresh();
    };
}
// before: contains all the text in the input box BEFORE the selection.
// after: contains all the text in the input box AFTER the selection.
function Chunks() { }
// startRegex: a regular expression to find the start tag
// endRegex: a regular expresssion to find the end tag
Chunks.prototype.findTags = function (startRegex, endRegex) {
    var chunkObj = this;
    var regex;
    if (startRegex) {
        regex = util.extendRegExp(startRegex, "", "$");
        this.before = this.before.replace(regex,
            function (match) {
                chunkObj.startTag = chunkObj.startTag + match;
                return "";
            });
        regex = util.extendRegExp(startRegex, "^", "");
        this.selection = this.selection.replace(regex,
            function (match) {
                chunkObj.startTag = chunkObj.startTag + match;
                return "";
            });
    }
    if (endRegex) {
        regex = util.extendRegExp(endRegex, "", "$");
        this.selection = this.selection.replace(regex,
            function (match) {
                chunkObj.endTag = match + chunkObj.endTag;
                return "";
            });
        regex = util.extendRegExp(endRegex, "^", "");
        this.after = this.after.replace(regex,
            function (match) {
                chunkObj.endTag = match + chunkObj.endTag;
                return "";
            });
    }
};
// If remove is false, the whitespace is transferred
// to the before/after regions.
//
// If remove is true, the whitespace disappears.
Chunks.prototype.trimWhitespace = function (remove) {
    var beforeReplacer, afterReplacer, that = this;
    if (remove) {
        beforeReplacer = afterReplacer = "";
    } else {
        beforeReplacer = function (s) { that.before += s; return ""; }
        afterReplacer = function (s) { that.after = s + that.after; return ""; }
    }
    this.selection = this.selection.replace(/^(\s*)/, beforeReplacer).replace(/(\s*)$/, afterReplacer);
};
Chunks.prototype.skipLines = function (nLinesBefore, nLinesAfter, findExtraNewlines) {
    if (nLinesBefore === undefined) {
        nLinesBefore = 1;
    }
    if (nLinesAfter === undefined) {
        nLinesAfter = 1;
    }
    nLinesBefore++;
    nLinesAfter++;
    var regexText;
    var replacementText;
    // chrome bug ... documented at: http://meta.stackoverflow.com/questions/63307/blockquote-glitch-in-editor-in-chrome-6-and-7/65985#65985
    if (navigator.userAgent.match(/Chrome/)) {
        "X".match(/()./);
    }
    this.selection = this.selection.replace(/(^\n*)/, "");
    this.startTag = this.startTag + re.$1;
    this.selection = this.selection.replace(/(\n*$)/, "");
    this.endTag = this.endTag + re.$1;
    this.startTag = this.startTag.replace(/(^\n*)/, "");
    this.before = this.before + re.$1;
    this.endTag = this.endTag.replace(/(\n*$)/, "");
    this.after = this.after + re.$1;
    if (this.before) {
        regexText = replacementText = "";
        while (nLinesBefore--) {
            regexText += "\\n?";
            replacementText += "\n";
        }
        if (findExtraNewlines) {
            regexText = "\\n*";
        }
        this.before = this.before.replace(new re(regexText + "$", ""), replacementText);
    }
    if (this.after) {
        regexText = replacementText = "";
        while (nLinesAfter--) {
            regexText += "\\n?";
            replacementText += "\n";
        }
        if (findExtraNewlines) {
            regexText = "\\n*";
        }
        this.after = this.after.replace(new re(regexText, ""), replacementText);
    }
};
// end of Chunks
// A collection of the important regions on the page.
// Cached so we don't have to keep traversing the DOM.
// Also holds ieCachedRange and ieCachedScrollTop, where necessary; working around
// this issue:
// Internet explorer has problems with CSS sprite buttons that use HTML
// lists.  When you click on the background image "button", IE will
// select the non-existent link text and discard the selection in the
// textarea.  The solution to this is to cache the textarea selection
// on the button's mousedown event and set a flag.  In the part of the
// code where we need to grab the selection, we check for the flag
// and, if it's set, use the cached area instead of querying the
// textarea.
//
// This ONLY affects Internet Explorer (tested on versions 6, 7
// and 8) and ONLY on button clicks.  Keyboard shortcuts work
// normally since the focus never leaves the textarea.
function PanelCollection(postfix) {
    this.buttonBar = doc.getElementById("wmd-button-bar" + postfix);
    this.preview = doc.getElementById("wmd-preview" + postfix);
    this.input = doc.getElementById("wmd-input" + postfix);
};
// Returns true if the DOM element is visible, false if it's hidden.
// Checks if display is anything other than none.
util.isVisible = function (elem) {
    if (window.getComputedStyle) {
        // Most browsers
        return window.getComputedStyle(elem, null).getPropertyValue("display") !== "none";
    }
    else if (elem.currentStyle) {
        // IE
        return elem.currentStyle["display"] !== "none";
    }
};
// Adds a listener callback to a DOM element which is fired on a specified
// event.
util.addEvent = function (elem, event, listener) {
    if (elem.attachEvent) {
        // IE only.  The "on" is mandatory.
        elem.attachEvent("on" + event, listener);
    }
    else {
        // Other browsers.
        elem.addEventListener(event, listener, false);
    }
};
// Removes a listener callback from a DOM element which is fired on a specified
// event.
util.removeEvent = function (elem, event, listener) {
    if (elem.detachEvent) {
        // IE only.  The "on" is mandatory.
        elem.detachEvent("on" + event, listener);
    }
    else {
        // Other browsers.
        elem.removeEventListener(event, listener, false);
    }
};
// Converts \r\n and \r to \n.
util.fixEolChars = function (text) {
    text = text.replace(/\r\n/g, "\n");
    text = text.replace(/\r/g, "\n");
    return text;
};
// Extends a regular expression.  Returns a new RegExp
// using pre + regex + post as the expression.
// Used in a few functions where we have a base
// expression and we want to pre- or append some
// conditions to it (e.g. adding "$" to the end).
// The flags are unchanged.
//
// regex is a RegExp, pre and post are strings.
util.extendRegExp = function (regex, pre, post) {
    if (pre === null || pre === undefined) {
        pre = "";
    }
    if (post === null || post === undefined) {
        post = "";
    }
    var pattern = regex.toString();
    var flags;
    // Replace the flags with empty space and store them.
    pattern = pattern.replace(/\/([gim]*)$/, function (wholeMatch, flagsPart) {
        flags = flagsPart;
        return "";
    });
    // Remove the slash delimiters on the regular expression.
    pattern = pattern.replace(/(^\/|\/$)/g, "");
    pattern = pre + pattern + post;
    return new re(pattern, flags);
}
// UNFINISHED
// The assignment in the while loop makes jslint cranky.
// I'll change it to a better loop later.
position.getTop = function (elem, isInner) {
    var result = elem.offsetTop;
    if (!isInner) {
        while (elem = elem.offsetParent) {
            result += elem.offsetTop;
        }
    }
    return result;
};
position.getHeight = function (elem) {
    return elem.offsetHeight || elem.scrollHeight;
};
position.getWidth = function (elem) {
    return elem.offsetWidth || elem.scrollWidth;
};
position.getPageSize = function () {
    var scrollWidth, scrollHeight;
    var innerWidth, innerHeight;
    // It's not very clear which blocks work with which browsers.
    if (self.innerHeight && self.scrollMaxY) {
        scrollWidth = doc.body.scrollWidth;
        scrollHeight = self.innerHeight + self.scrollMaxY;
    }
    else if (doc.body.scrollHeight > doc.body.offsetHeight) {
        scrollWidth = doc.body.scrollWidth;
        scrollHeight = doc.body.scrollHeight;
    }
    else {
        scrollWidth = doc.body.offsetWidth;
        scrollHeight = doc.body.offsetHeight;
    }
    if (self.innerHeight) {
        // Non-IE browser
        innerWidth = self.innerWidth;
        innerHeight = self.innerHeight;
    }
    else if (doc.documentElement && doc.documentElement.clientHeight) {
        // Some versions of IE (IE 6 w/ a DOCTYPE declaration)
        innerWidth = doc.documentElement.clientWidth;
        innerHeight = doc.documentElement.clientHeight;
    }
    else if (doc.body) {
        // Other versions of IE
        innerWidth = doc.body.clientWidth;
        innerHeight = doc.body.clientHeight;
    }
    var maxWidth = Math.max(scrollWidth, innerWidth);
    var maxHeight = Math.max(scrollHeight, innerHeight);
    return [maxWidth, maxHeight, innerWidth, innerHeight];
};
// Handles pushing and popping TextareaStates for undo/redo commands.
// I should rename the stack variables to list.
function UndoManager(callback, panels) {
    var undoObj = this;
    var undoStack = []; // A stack of undo states
    var stackPtr = 0; // The index of the current state
    var mode = "none";
    var lastState; // The last state
    var timer; // The setTimeout handle for cancelling the timer
    var inputStateObj;
    // Set the mode for later logic steps.
    var setMode = function (newMode, noSave) {
        if (mode != newMode) {
            mode = newMode;
            if (!noSave) {
                saveState();
            }
        }
        if (!uaSniffed.isIE || mode != "moving") {
            timer = setTimeout(refreshState, 1);
        }
        else {
            inputStateObj = null;
        }
    };
    var refreshState = function (isInitialState) {
        inputStateObj = new TextareaState(panels, isInitialState);
        timer = undefined;
    };
    this.setCommandMode = function () {
        mode = "command";
        saveState();
        timer = setTimeout(refreshState, 0);
    };
    this.canUndo = function () {
        return stackPtr > 1;
    };
    this.canRedo = function () {
        if (undoStack[stackPtr + 1]) {
            return true;
        }
        return false;
    };
    // Removes the last state and restores it.
    this.undo = function () {
        if (undoObj.canUndo()) {
            if (lastState) {
                // What about setting state -1 to null or checking for undefined?
                lastState.restore();
                lastState = null;
            }
            else {
                undoStack[stackPtr] = new TextareaState(panels);
                undoStack[--stackPtr].restore();
                if (callback) {
                    callback();
                }
            }
        }
        mode = "none";
        panels.input.focus();
        refreshState();
    };
    // Redo an action.
    this.redo = function () {
        if (undoObj.canRedo()) {
            undoStack[++stackPtr].restore();
            if (callback) {
                callback();
            }
        }
        mode = "none";
        panels.input.focus();
        refreshState();
    };
    // Push the input area state to the stack.
    var saveState = function () {
        var currState = inputStateObj || new TextareaState(panels);
        if (!currState) {
            return false;
        }
        if (mode == "moving") {
            if (!lastState) {
                lastState = currState;
            }
            return;
        }
        if (lastState) {
            if (undoStack[stackPtr - 1].text != lastState.text) {
                undoStack[stackPtr++] = lastState;
            }
            lastState = null;
        }
        undoStack[stackPtr++] = currState;
        undoStack[stackPtr + 1] = null;
        if (callback) {
            callback();
        }
    };
    var handleCtrlYZ = function (event) {
        var handled = false;
        if ((event.ctrlKey || event.metaKey) && !event.altKey) {
            // IE and Opera do not support charCode.
            var keyCode = event.charCode || event.keyCode;
            var keyCodeChar = String.fromCharCode(keyCode);
            switch (keyCodeChar.toLowerCase()) {
                case "y":
                    undoObj.redo();
                    handled = true;
                    break;
                case "z":
                    if (!event.shiftKey) {
                        undoObj.undo();
                    }
                    else {
                        undoObj.redo();
                    }
                    handled = true;
                    break;
            }
        }
        if (handled) {
            if (event.preventDefault) {
                event.preventDefault();
            }
            if (window.event) {
                window.event.returnValue = false;
            }
            return;
        }
    };
    // Set the mode depending on what is going on in the input area.
    var handleModeChange = function (event) {
        if (!event.ctrlKey && !event.metaKey) {
            var keyCode = event.keyCode;
            if ((keyCode >= 33 && keyCode <= 40) || (keyCode >= 63232 && keyCode <= 63235)) {
                // 33 - 40: page up/dn and arrow keys
                // 63232 - 63235: page up/dn and arrow keys on safari
                setMode("moving");
            }
            else if (keyCode == 8 || keyCode == 46 || keyCode == 127) {
                // 8: backspace
                // 46: delete
                // 127: delete
                setMode("deleting");
            }
            else if (keyCode == 13) {
                // 13: Enter
                setMode("newlines");
            }
            else if (keyCode == 27) {
                // 27: escape
                setMode("escape");
            }
            else if ((keyCode < 16 || keyCode > 20) && keyCode != 91) {
                // 16-20 are shift, etc.
                // 91: left window key
                // I think this might be a little messed up since there are
                // a lot of nonprinting keys above 20.
                setMode("typing");
            }
        }
    };
    var setEventHandlers = function () {
        util.addEvent(panels.input, "keypress", function (event) {
            // keyCode 89: y
            // keyCode 90: z
            if ((event.ctrlKey || event.metaKey) && !event.altKey && (event.keyCode == 89 || event.keyCode == 90)) {
                event.preventDefault();
            }
        });
        var handlePaste = function () {
            if (uaSniffed.isIE || (inputStateObj && inputStateObj.text != panels.input.value)) {
                if (timer == undefined) {
                    mode = "paste";
                    saveState();
                    refreshState();
                }
            }
        };
        util.addEvent(panels.input, "keydown", handleCtrlYZ);
        util.addEvent(panels.input, "keydown", handleModeChange);
        util.addEvent(panels.input, "mousedown", function () {
            setMode("moving");
        });
        panels.input.onpaste = handlePaste;
        panels.input.ondrop = handlePaste;
    };
    var init = function () {
        setEventHandlers();
        refreshState(true);
        saveState();
    };
    init();
}
// end of UndoManager
// The input textarea state/contents.
// This is used to implement undo/redo by the undo manager.
function TextareaState(panels, isInitialState) {
    // Aliases
    var stateObj = this;
    var inputArea = panels.input;
    this.init = function () {
        if (!util.isVisible(inputArea)) {
            return;
        }
        if (!isInitialState && doc.activeElement && doc.activeElement !== inputArea) { // this happens when tabbing out of the input box
            return;
        }
        this.setInputAreaSelectionStartEnd();
        this.scrollTop = inputArea.scrollTop;
        if (!this.text && inputArea.selectionStart || inputArea.selectionStart === 0) {
            this.text = inputArea.value;
        }
    }
    // Sets the selected text in the input box after we've performed an
    // operation.
    this.setInputAreaSelection = function () {
        if (!util.isVisible(inputArea)) {
            return;
        }
        if (inputArea.selectionStart !== undefined && !uaSniffed.isOpera) {
            inputArea.focus();
            inputArea.selectionStart = stateObj.start;
            inputArea.selectionEnd = stateObj.end;
            inputArea.scrollTop = stateObj.scrollTop;
        }
        else if (doc.selection) {
            if (doc.activeElement && doc.activeElement !== inputArea) {
                return;
            }
            inputArea.focus();
            var range = inputArea.createTextRange();
            range.moveStart("character", -inputArea.value.length);
            range.moveEnd("character", -inputArea.value.length);
            range.moveEnd("character", stateObj.end);
            range.moveStart("character", stateObj.start);
            range.select();
        }
    };
    this.setInputAreaSelectionStartEnd = function () {
        if (!panels.ieCachedRange && (inputArea.selectionStart || inputArea.selectionStart === 0)) {
            stateObj.start = inputArea.selectionStart;
            stateObj.end = inputArea.selectionEnd;
        }
        else if (doc.selection) {
            stateObj.text = util.fixEolChars(inputArea.value);
            // IE loses the selection in the textarea when buttons are
            // clicked.  On IE we cache the selection. Here, if something is cached,
            // we take it.
            var range = panels.ieCachedRange || doc.selection.createRange();
            var fixedRange = util.fixEolChars(range.text);
            var marker = "\x07";
            var markedRange = marker + fixedRange + marker;
            range.text = markedRange;
            var inputText = util.fixEolChars(inputArea.value);
            range.moveStart("character", -markedRange.length);
            range.text = fixedRange;
            stateObj.start = inputText.indexOf(marker);
            stateObj.end = inputText.lastIndexOf(marker) - marker.length;
            var len = stateObj.text.length - util.fixEolChars(inputArea.value).length;
            if (len) {
                range.moveStart("character", -fixedRange.length);
                while (len--) {
                    fixedRange += "\n";
                    stateObj.end += 1;
                }
                range.text = fixedRange;
            }
            if (panels.ieCachedRange)
                stateObj.scrollTop = panels.ieCachedScrollTop; // this is set alongside with ieCachedRange
            panels.ieCachedRange = null;
            this.setInputAreaSelection();
        }
    };
    // Restore this state into the input area.
    this.restore = function () {
        if (stateObj.text != undefined && stateObj.text != inputArea.value) {
            inputArea.value = stateObj.text;
        }
        this.setInputAreaSelection();
        inputArea.scrollTop = stateObj.scrollTop;
    };
    // Gets a collection of HTML chunks from the inptut textarea.
    this.getChunks = function () {
        var chunk = new Chunks();
        chunk.before = util.fixEolChars(stateObj.text.substring(0, stateObj.start));
        chunk.startTag = "";
        chunk.selection = util.fixEolChars(stateObj.text.substring(stateObj.start, stateObj.end));
        chunk.endTag = "";
        chunk.after = util.fixEolChars(stateObj.text.substring(stateObj.end));
        chunk.scrollTop = stateObj.scrollTop;
        return chunk;
    };
    // Sets the TextareaState properties given a chunk of markdown.
    this.setChunks = function (chunk) {
        chunk.before = chunk.before + chunk.startTag;
        chunk.after = chunk.endTag + chunk.after;
        this.start = chunk.before.length;
        this.end = chunk.before.length + chunk.selection.length;
        this.text = chunk.before + chunk.selection + chunk.after;
        this.scrollTop = chunk.scrollTop;
    };
    this.init();
};
function PreviewManager(converter, panels, previewRefreshCallback) {
    var managerObj = this;
    var timeout;
    var elapsedTime;
    var oldInputText;
    var maxDelay = 3000;
    var startType = "delayed"; // The other legal value is "manual"
    // Adds event listeners to elements
    var setupEvents = function (inputElem, listener) {
        util.addEvent(inputElem, "input", listener);
        inputElem.onpaste = listener;
        inputElem.ondrop = listener;
        util.addEvent(inputElem, "keypress", listener);
        util.addEvent(inputElem, "keydown", listener);
    };
    var getDocScrollTop = function () {
        var result = 0;
        if (window.innerHeight) {
            result = window.pageYOffset;
        }
        else
            if (doc.documentElement && doc.documentElement.scrollTop) {
                result = doc.documentElement.scrollTop;
            }
            else
                if (doc.body) {
                    result = doc.body.scrollTop;
                }
        return result;
    };
    var makePreviewHtml = function () {
        // If there is no registered preview panel
        // there is nothing to do.
        if (!panels.preview)
            return;
        var text = panels.input.value;
        if (text && text == oldInputText) {
            return; // Input text hasn't changed.
        }
        else {
            oldInputText = text;
        }
        var prevTime = new Date().getTime();
        text = converter.makeHtml(text);
        // Calculate the processing time of the HTML creation.
        // It's used as the delay time in the event listener.
        var currTime = new Date().getTime();
        elapsedTime = currTime - prevTime;
        pushPreviewHtml(text);
    };
    // setTimeout is already used.  Used as an event listener.
    var applyTimeout = function () {
        if (timeout) {
            clearTimeout(timeout);
            timeout = undefined;
        }
        if (startType !== "manual") {
            var delay = 0;
            if (startType === "delayed") {
                delay = elapsedTime;
            }
            if (delay > maxDelay) {
                delay = maxDelay;
            }
            timeout = setTimeout(makePreviewHtml, delay);
        }
    };
    var getScaleFactor = function (panel) {
        if (panel.scrollHeight <= panel.clientHeight) {
            return 1;
        }
        return panel.scrollTop / (panel.scrollHeight - panel.clientHeight);
    };
    var setPanelScrollTops = function () {
        if (panels.preview) {
            panels.preview.scrollTop = (panels.preview.scrollHeight - panels.preview.clientHeight) * getScaleFactor(panels.preview);
        }
    };
    this.refresh = function (requiresRefresh) {
        if (requiresRefresh) {
            oldInputText = "";
            makePreviewHtml();
        }
        else {
            applyTimeout();
        }
    };
    this.processingTime = function () {
        return elapsedTime;
    };
    var isFirstTimeFilled = true;
    // IE doesn't let you use innerHTML if the element is contained somewhere in a table
    // (which is the case for inline editing) -- in that case, detach the element, set the
    // value, and reattach. Yes, that *is* ridiculous.
    var ieSafePreviewSet = function (text) {
        var preview = panels.preview;
        var parent = preview.parentNode;
        var sibling = preview.nextSibling;
        parent.removeChild(preview);
        preview.innerHTML = text;
        if (!sibling)
            parent.appendChild(preview);
        else
            parent.insertBefore(preview, sibling);
    }
    var nonSuckyBrowserPreviewSet = function (text) {
        panels.preview.innerHTML = text;
    }
    var previewSetter;
    var previewSet = function (text) {
        if (previewSetter)
            return previewSetter(text);
        try {
            nonSuckyBrowserPreviewSet(text);
            previewSetter = nonSuckyBrowserPreviewSet;
        } catch (e) {
            previewSetter = ieSafePreviewSet;
            previewSetter(text);
        }
    };
    var pushPreviewHtml = function (text) {
        var emptyTop = position.getTop(panels.input) - getDocScrollTop();
        if (panels.preview) {
            previewSet(text);
            previewRefreshCallback();
        }
        setPanelScrollTops();
        if (isFirstTimeFilled) {
            isFirstTimeFilled = false;
            return;
        }
        var fullTop = position.getTop(panels.input) - getDocScrollTop();
        if (uaSniffed.isIE) {
            setTimeout(function () {
                window.scrollBy(0, fullTop - emptyTop);
            }, 0);
        }
        else {
            window.scrollBy(0, fullTop - emptyTop);
        }
    };
    var init = function () {
        setupEvents(panels.input, applyTimeout);
        makePreviewHtml();
        if (panels.preview) {
            panels.preview.scrollTop = 0;
        }
    };
    init();
};
// Creates the background behind the hyperlink text entry box.
// And download dialog
// Most of this has been moved to CSS but the div creation and
// browser-specific hacks remain here.
ui.createBackground = function () {
    var background = doc.createElement("div"),
        style = background.style;
    background.className = "wmd-prompt-background";
    style.position = "absolute";
    style.top = "0";
    style.zIndex = "1000";
    if (uaSniffed.isIE) {
        style.filter = "alpha(opacity=50)";
    }
    else {
        style.opacity = "0.5";
    }
    var pageSize = position.getPageSize();
    style.height = pageSize[1] + "px";
    if (uaSniffed.isIE) {
        style.left = doc.documentElement.scrollLeft;
        style.width = doc.documentElement.clientWidth;
    }
    else {
        style.left = "0";
        style.width = "100%";
    }
    doc.body.appendChild(background);
    return background;
};
// This simulates a modal dialog box and asks for the URL when you
// click the hyperlink or image buttons.
//
// text: The html for the input box.
// defaultInputText: The default value that appears in the input box.
// callback: The function which is executed when the prompt is dismissed, either via OK or Cancel.
//      It receives a single argument; either the entered text (if OK was chosen) or null (if Cancel
//      was chosen).
ui.prompt = function (text, defaultInputText, callback) {
    // These variables need to be declared at this level since they are used
    // in multiple functions.
    var dialog;         // The dialog box.
    var input;         // The text box where you enter the hyperlink.
    if (defaultInputText === undefined) {
        defaultInputText = "";
    }
    // Used as a keydown event handler. Esc dismisses the prompt.
    // Key code 27 is ESC.
    var checkEscape = function (key) {
        var code = (key.charCode || key.keyCode);
        if (code === 27) {
            close(true);
        }
    };
    // Dismisses the hyperlink input box.
    // isCancel is true if we don't care about the input text.
    // isCancel is false if we are going to keep the text.
    var close = function (isCancel) {
        util.removeEvent(doc.body, "keydown", checkEscape);
        var text = input.value;
        if (isCancel) {
            text = null;
        }
        else {
            // Fixes common pasting errors.
            text = text.replace(/^http:\/\/(https?|ftp):\/\//, '$1://');
            if (!/^(?:https?|ftp):\/\//.test(text))
                text = 'http://' + text;
        }
        dialog.parentNode.removeChild(dialog);
        callback(text);
        return false;
    };
    // Create the text input box form/window.
    var createDialog = function () {
        // The main dialog box.
        dialog = doc.createElement("div");
        dialog.className = "wmd-prompt-dialog";
        dialog.style.padding = "10px;";
        dialog.style.position = "fixed";
        dialog.style.width = "400px";
        dialog.style.zIndex = "1001";
        // The dialog text.
        var question = doc.createElement("div");
        question.innerHTML = text;
        question.style.padding = "5px";
        dialog.appendChild(question);
        // The web form container for the text box and buttons.
        var form = doc.createElement("form"),
            style = form.style;
        form.onsubmit = function () { return close(false); };
        style.padding = "0";
        style.margin = "0";
        style.cssFloat = "left";
        style.width = "100%";
        style.textAlign = "center";
        style.position = "relative";
        dialog.appendChild(form);
        // The input text box
        input = doc.createElement("input");
        input.type = "text";
        input.value = defaultInputText;
        style = input.style;
        style.display = "block";
        style.width = "80%";
        style.marginLeft = style.marginRight = "auto";
        form.appendChild(input);
        // The ok button
        var okButton = doc.createElement("input");
        okButton.type = "button";
        okButton.onclick = function () { return close(false); };
        okButton.value = "OK";
        style = okButton.style;
        style.margin = "10px";
        style.display = "inline";
        style.width = "7em";
        // The cancel button
        var cancelButton = doc.createElement("input");
        cancelButton.type = "button";
        cancelButton.onclick = function () { return close(true); };
        cancelButton.value = "Cancel";
        style = cancelButton.style;
        style.margin = "10px";
        style.display = "inline";
        style.width = "7em";
        form.appendChild(okButton);
        form.appendChild(cancelButton);
        util.addEvent(doc.body, "keydown", checkEscape);
        dialog.style.top = "50%";
        dialog.style.left = "50%";
        dialog.style.display = "block";
        if (uaSniffed.isIE_5or6) {
            dialog.style.position = "absolute";
            dialog.style.top = doc.documentElement.scrollTop + 200 + "px";
            dialog.style.left = "50%";
        }
        doc.body.appendChild(dialog);
        // This has to be done AFTER adding the dialog to the form if you
        // want it to be centered.
        dialog.style.marginTop = -(position.getHeight(dialog) / 2) + "px";
        dialog.style.marginLeft = -(position.getWidth(dialog) / 2) + "px";
    };
    // Why is this in a zero-length timeout?
    // Is it working around a browser bug?
    setTimeout(function () {
        createDialog();
        var defTextLen = defaultInputText.length;
        if (input.selectionStart !== undefined) {
            input.selectionStart = 0;
            input.selectionEnd = defTextLen;
        }
        else if (input.createTextRange) {
            var range = input.createTextRange();
            range.collapse(false);
            range.moveStart("character", -defTextLen);
            range.moveEnd("character", defTextLen);
            range.select();
        }
        input.focus();
    }, 0);
};
function UIManager(postfix, panels, undoManager, previewManager, commandManager, helpOptions, getString) {
    var inputBox = panels.input,
        buttons = {}; // buttons.undo, buttons.link, etc. The actual DOM elements.
    makeSpritedButtonRow();
    var keyEvent = "keydown";
    if (uaSniffed.isOpera) {
        keyEvent = "keypress";
    }
    util.addEvent(inputBox, keyEvent, function (key) {
        // Check to see if we have a button key and, if so execute the callback.
        if ((key.ctrlKey || key.metaKey) && !key.altKey && !key.shiftKey) {
            var keyCode = key.charCode || key.keyCode;
            var keyCodeStr = String.fromCharCode(keyCode).toLowerCase();
            switch (keyCodeStr) {
                case "b":
                    doClick(buttons.bold);
                    break;
                case "i":
                    doClick(buttons.italic);
                    break;
                case "l":
                    doClick(buttons.link);
                    break;
                case "q":
                    doClick(buttons.quote);
                    break;
                case "k":
                    doClick(buttons.code);
                    break;
                case "g":
                    doClick(buttons.image);
                    break;
                case "o":
                    doClick(buttons.olist);
                    break;
                case "u":
                    doClick(buttons.ulist);
                    break;
                case "h":
                    doClick(buttons.heading);
                    break;
                case "r":
                    doClick(buttons.hr);
                    break;
                case "y":
                    doClick(buttons.redo);
                    break;
                case "z":
                    if (key.shiftKey) {
                        doClick(buttons.redo);
                    }
                    else {
                        doClick(buttons.undo);
                    }
                    break;
                default:
                    return;
            }
            if (key.preventDefault) {
                key.preventDefault();
            }
            if (window.event) {
                window.event.returnValue = false;
            }
        }
    });
    // Auto-indent on shift-enter
    util.addEvent(inputBox, "keyup", function (key) {
        if (key.shiftKey && !key.ctrlKey && !key.metaKey) {
            var keyCode = key.charCode || key.keyCode;
            // Character 13 is Enter
            if (keyCode === 13) {
                var fakeButton = {};
                fakeButton.textOp = bindCommand("doAutoindent");
                doClick(fakeButton);
            }
        }
    });
    // special handler because IE clears the context of the textbox on ESC
    if (uaSniffed.isIE) {
        util.addEvent(inputBox, "keydown", function (key) {
            var code = key.keyCode;
            if (code === 27) {
                return false;
            }
        });
    }
    // Perform the button's action.
    function doClick(button) {
        inputBox.focus();
        if (button.textOp) {
            if (undoManager) {
                undoManager.setCommandMode();
            }
            var state = new TextareaState(panels);
            if (!state) {
                return;
            }
            var chunks = state.getChunks();
            // Some commands launch a "modal" prompt dialog.  Javascript
            // can't really make a modal dialog box and the WMD code
            // will continue to execute while the dialog is displayed.
            // This prevents the dialog pattern I'm used to and means
            // I can't do something like this:
            //
            // var link = CreateLinkDialog();
            // makeMarkdownLink(link);
            //
            // Instead of this straightforward method of handling a
            // dialog I have to pass any code which would execute
            // after the dialog is dismissed (e.g. link creation)
            // in a function parameter.
            //
            // Yes this is awkward and I think it sucks, but there's
            // no real workaround.  Only the image and link code
            // create dialogs and require the function pointers.
            var fixupInputArea = function () {
                inputBox.focus();
                if (chunks) {
                    state.setChunks(chunks);
                }
                state.restore();
                previewManager.refresh();
            };
            var noCleanup = button.textOp(chunks, fixupInputArea);
            if (!noCleanup) {
                fixupInputArea();
            }
        }
        if (button.execute) {
            button.execute(undoManager);
        }
    };
    function setupButton(button, isEnabled) {
        var normalYShift = "0px";
        var disabledYShift = "-20px";
        var highlightYShift = "-40px";
        var image = button.getElementsByTagName("span")[0];
        if (isEnabled) {
            image.style.backgroundPosition = button.XShift + " " + normalYShift;
            button.onmouseover = function () {
                image.style.backgroundPosition = this.XShift + " " + highlightYShift;
            };
            button.onmouseout = function () {
                image.style.backgroundPosition = this.XShift + " " + normalYShift;
            };
            // IE tries to select the background image "button" text (it's
            // implemented in a list item) so we have to cache the selection
            // on mousedown.
            if (uaSniffed.isIE) {
                button.onmousedown = function () {
                    if (doc.activeElement && doc.activeElement !== panels.input) { // we're not even in the input box, so there's no selection
                        return;
                    }
                    panels.ieCachedRange = document.selection.createRange();
                    panels.ieCachedScrollTop = panels.input.scrollTop;
                };
            }
            if (!button.isHelp) {
                button.onclick = function () {
                    if (this.onmouseout) {
                        this.onmouseout();
                    }
                    doClick(this);
                    return false;
                }
            }
        }
        else {
            image.style.backgroundPosition = button.XShift + " " + disabledYShift;
            button.onmouseover = button.onmouseout = button.onclick = function () { };
        }
    }
    function bindCommand(method) {
        if (typeof method === "string")
            method = commandManager[method];
        return function () { method.apply(commandManager, arguments); }
    }
    function makeSpritedButtonRow() {
        var buttonBar = panels.buttonBar;
        var normalYShift = "0px";
        var disabledYShift = "-20px";
        var highlightYShift = "-40px";
        var buttonRow = document.createElement("ul");
        buttonRow.id = "wmd-button-row" + postfix;
        buttonRow.className = 'wmd-button-row';
        buttonRow = buttonBar.appendChild(buttonRow);
        var xPosition = 0;
        var makeButton = function (id, title, XShift, textOp) {
            var button = document.createElement("li");
            button.className = "wmd-button";
            button.style.left = xPosition + "px";
            xPosition += 25;
            var buttonImage = document.createElement("span");
            button.id = id + postfix;
            button.appendChild(buttonImage);
            button.title = title;
            button.XShift = XShift;
            if (textOp)
                button.textOp = textOp;
            setupButton(button, true);
            buttonRow.appendChild(button);
            return button;
        };
        var makeSpacer = function (num) {
            var spacer = document.createElement("li");
            spacer.className = "wmd-spacer wmd-spacer" + num;
            spacer.id = "wmd-spacer" + num + postfix;
            buttonRow.appendChild(spacer);
            xPosition += 25;
        }
        buttons.bold = makeButton("wmd-bold-button", getString("bold"), "0px", bindCommand("doBold"));
        buttons.italic = makeButton("wmd-italic-button", getString("italic"), "-20px", bindCommand("doItalic"));
        makeSpacer(1);
        buttons.link = makeButton("wmd-link-button", getString("link"), "-40px", bindCommand(function (chunk, postProcessing) {
            return this.doLinkOrImage(chunk, postProcessing, false);
        }));
        buttons.quote = makeButton("wmd-quote-button", getString("quote"), "-60px", bindCommand("doBlockquote"));
        buttons.code = makeButton("wmd-code-button", getString("code"), "-80px", bindCommand("doCode"));
        buttons.image = makeButton("wmd-image-button", getString("image"), "-100px", bindCommand(function (chunk, postProcessing) {
            return this.doLinkOrImage(chunk, postProcessing, true);
        }));
        makeSpacer(2);
        buttons.olist = makeButton("wmd-olist-button", getString("olist"), "-120px", bindCommand(function (chunk, postProcessing) {
            this.doList(chunk, postProcessing, true);
        }));
        buttons.ulist = makeButton("wmd-ulist-button", getString("ulist"), "-140px", bindCommand(function (chunk, postProcessing) {
            this.doList(chunk, postProcessing, false);
        }));
        buttons.heading = makeButton("wmd-heading-button", getString("heading"), "-160px", bindCommand("doHeading"));
        buttons.hr = makeButton("wmd-hr-button", getString("hr"), "-180px", bindCommand("doHorizontalRule"));
        makeSpacer(3);
        buttons.undo = makeButton("wmd-undo-button", getString("undo"), "-200px", null);
        buttons.undo.execute = function (manager) { if (manager) manager.undo(); };
        var redoTitle = /win/.test(nav.platform.toLowerCase()) ?
            getString("redo") :
            getString("redomac"); // mac and other non-Windows platforms
        buttons.redo = makeButton("wmd-redo-button", redoTitle, "-220px", null);
        buttons.redo.execute = function (manager) { if (manager) manager.redo(); };
        if (helpOptions) {
            var helpButton = document.createElement("li");
            var helpButtonImage = document.createElement("span");
            helpButton.appendChild(helpButtonImage);
            helpButton.className = "wmd-button wmd-help-button";
            helpButton.id = "wmd-help-button" + postfix;
            helpButton.XShift = "-240px";
            helpButton.isHelp = true;
            helpButton.style.right = "0px";
            helpButton.title = getString("help");
            helpButton.onclick = helpOptions.handler;
            setupButton(helpButton, true);
            buttonRow.appendChild(helpButton);
            buttons.help = helpButton;
        }
        setUndoRedoButtonStates();
    }
    function setUndoRedoButtonStates() {
        if (undoManager) {
            setupButton(buttons.undo, undoManager.canUndo());
            setupButton(buttons.redo, undoManager.canRedo());
        }
    };
    this.setUndoRedoButtonStates = setUndoRedoButtonStates;
}
function CommandManager(pluginHooks, getString) {
    this.hooks = pluginHooks;
    this.getString = getString;
}
var commandProto = CommandManager.prototype;
// The markdown symbols - 4 spaces = code, > = blockquote, etc.
commandProto.prefixes = "(?:\\s{4,}|\\s*>|\\s*-\\s+|\\s*\\d+\\.|=|\\+|-|_|\\*|#|\\s*\\[[^\n]]+\\]:)";
// Remove markdown symbols from the chunk selection.
commandProto.unwrap = function (chunk) {
    var txt = new re("([^\\n])\\n(?!(\\n|" + this.prefixes + "))", "g");
    chunk.selection = chunk.selection.replace(txt, "$1 $2");
};
commandProto.wrap = function (chunk, len) {
    this.unwrap(chunk);
    var regex = new re("(.{1," + len + "})( +|$\\n?)", "gm"),
        that = this;
    chunk.selection = chunk.selection.replace(regex, function (line, marked) {
        if (new re("^" + that.prefixes, "").test(line)) {
            return line;
        }
        return marked + "\n";
    });
    chunk.selection = chunk.selection.replace(/\s+$/, "");
};
commandProto.doBold = function (chunk, postProcessing) {
    return this.doBorI(chunk, postProcessing, 2, this.getString("boldexample"));
};
commandProto.doItalic = function (chunk, postProcessing) {
    return this.doBorI(chunk, postProcessing, 1, this.getString("italicexample"));
};
// chunk: The selected region that will be enclosed with */**
// nStars: 1 for italics, 2 for bold
// insertText: If you just click the button without highlighting text, this gets inserted
commandProto.doBorI = function (chunk, postProcessing, nStars, insertText) {
    // Get rid of whitespace and fixup newlines.
    chunk.trimWhitespace();
    chunk.selection = chunk.selection.replace(/\n{2,}/g, "\n");
    // Look for stars before and after.  Is the chunk already marked up?
    // note that these regex matches cannot fail
    var starsBefore = /(\**$)/.exec(chunk.before)[0];
    var starsAfter = /(^\**)/.exec(chunk.after)[0];
    var prevStars = Math.min(starsBefore.length, starsAfter.length);
    // Remove stars if we have to since the button acts as a toggle.
    if ((prevStars >= nStars) && (prevStars != 2 || nStars != 1)) {
        chunk.before = chunk.before.replace(re("[*]{" + nStars + "}$", ""), "");
        chunk.after = chunk.after.replace(re("^[*]{" + nStars + "}", ""), "");
    }
    else if (!chunk.selection && starsAfter) {
        // It's not really clear why this code is necessary.  It just moves
        // some arbitrary stuff around.
        chunk.after = chunk.after.replace(/^([*_]*)/, "");
        chunk.before = chunk.before.replace(/(\s?)$/, "");
        var whitespace = re.$1;
        chunk.before = chunk.before + starsAfter + whitespace;
    }
    else {
        // In most cases, if you don't have any selected text and click the button
        // you'll get a selected, marked up region with the default text inserted.
        if (!chunk.selection && !starsAfter) {
            chunk.selection = insertText;
        }
        // Add the true markup.
        var markup = nStars <= 1 ? "*" : "**"; // shouldn't the test be = ?
        chunk.before = chunk.before + markup;
        chunk.after = markup + chunk.after;
    }
    return;
};
commandProto.stripLinkDefs = function (text, defsToAdd) {
    text = text.replace(/^[ ]{0,3}\[(\d+)\]:[ \t]*\n?[ \t]*<?(\S+?)>?[ \t]*\n?[ \t]*(?:(\n*)["(](.+?)[")][ \t]*)?(?:\n+|$)/gm,
        function (totalMatch, id, link, newlines, title) {
            defsToAdd[id] = totalMatch.replace(/\s*$/, "");
            if (newlines) {
                // Strip the title and return that separately.
                defsToAdd[id] = totalMatch.replace(/["(](.+?)[")]$/, "");
                return newlines + title;
            }
            return "";
        });
    return text;
};
commandProto.addLinkDef = function (chunk, linkDef) {
    var refNumber = 0; // The current reference number
    var defsToAdd = {}; //
    // Start with a clean slate by removing all previous link definitions.
    chunk.before = this.stripLinkDefs(chunk.before, defsToAdd);
    chunk.selection = this.stripLinkDefs(chunk.selection, defsToAdd);
    chunk.after = this.stripLinkDefs(chunk.after, defsToAdd);
    var defs = "";
    var regex = /(\[)((?:\[[^\]]*\]|[^\[\]])*)(\][ ]?(?:\n[ ]*)?\[)(\d+)(\])/g;
    var addDefNumber = function (def) {
        refNumber++;
        def = def.replace(/^[ ]{0,3}\[(\d+)\]:/, "  [" + refNumber + "]:");
        defs += "\n" + def;
    };
    // note that
    // a) the recursive call to getLink cannot go infinite, because by definition
    //    of regex, inner is always a proper substring of wholeMatch, and
    // b) more than one level of nesting is neither supported by the regex
    //    nor making a lot of sense (the only use case for nesting is a linked image)
    var getLink = function (wholeMatch, before, inner, afterInner, id, end) {
        inner = inner.replace(regex, getLink);
        if (defsToAdd[id]) {
            addDefNumber(defsToAdd[id]);
            return before + inner + afterInner + refNumber + end;
        }
        return wholeMatch;
    };
    chunk.before = chunk.before.replace(regex, getLink);
    if (linkDef) {
        addDefNumber(linkDef);
    }
    else {
        chunk.selection = chunk.selection.replace(regex, getLink);
    }
    var refOut = refNumber;
    chunk.after = chunk.after.replace(regex, getLink);
    if (chunk.after) {
        chunk.after = chunk.after.replace(/\n*$/, "");
    }
    if (!chunk.after) {
        chunk.selection = chunk.selection.replace(/\n*$/, "");
    }
    chunk.after += "\n\n" + defs;
    return refOut;
};
// takes the line as entered into the add link/as image dialog and makes
// sure the URL and the optinal title are "nice".
function properlyEncoded(linkdef) {
    return linkdef.replace(/^\s*(.*?)(?:\s+"(.+)")?\s*$/, function (wholematch, link, title) {
        link = link.replace(/\?.*$/, function (querypart) {
            return querypart.replace(/\+/g, " "); // in the query string, a plus and a space are identical
        });
        link = decodeURIComponent(link); // unencode first, to prevent double encoding
        link = encodeURI(link).replace(/'/g, '%27').replace(/\(/g, '%28').replace(/\)/g, '%29');
        link = link.replace(/\?.*$/, function (querypart) {
            return querypart.replace(/\+/g, "%2b"); // since we replaced plus with spaces in the query part, all pluses that now appear where originally encoded
        });
        if (title) {
            title = title.trim ? title.trim() : title.replace(/^\s*/, "").replace(/\s*$/, "");
            title = title.replace(/"/g, "quot;").replace(/\(/g, "&#40;").replace(/\)/g, "&#41;").replace(/</g, "&lt;").replace(/>/g, "&gt;");
        }
        return title ? link + ' "' + title + '"' : link;
    });
}
commandProto.doLinkOrImage = function (chunk, postProcessing, isImage) {
    chunk.trimWhitespace();
    chunk.findTags(/\s*!?\[/, /\][ ]?(?:\n[ ]*)?(\[.*?\])?/);
    var background;
    if (chunk.endTag.length > 1 && chunk.startTag.length > 0) {
        chunk.startTag = chunk.startTag.replace(/!?\[/, "");
        chunk.endTag = "";
        this.addLinkDef(chunk, null);
    }
    else {
        // We're moving start and end tag back into the selection, since (as we're in the else block) we're not
        // *removing* a link, but *adding* one, so whatever findTags() found is now back to being part of the
        // link text. linkEnteredCallback takes care of escaping any brackets.
        chunk.selection = chunk.startTag + chunk.selection + chunk.endTag;
        chunk.startTag = chunk.endTag = "";
        if (/\n\n/.test(chunk.selection)) {
            this.addLinkDef(chunk, null);
            return;
        }
        var that = this;
        // The function to be executed when you enter a link and press OK or Cancel.
        // Marks up the link and adds the ref.
        var linkEnteredCallback = function (link) {
            background.parentNode.removeChild(background);
            if (link !== null) {
                // (                          $1
                //     [^\\]                  anything that's not a backslash
                //     (?:\\\\)*              an even number (this includes zero) of backslashes
                // )
                // (?=                        followed by
                //     [[\]]                  an opening or closing bracket
                // )
                //
                // In other words, a non-escaped bracket. These have to be escaped now to make sure they
                // don't count as the end of the link or similar.
                // Note that the actual bracket has to be a lookahead, because (in case of to subsequent brackets),
                // the bracket in one match may be the "not a backslash" character in the next match, so it
                // should not be consumed by the first match.
                // The "prepend a space and finally remove it" steps makes sure there is a "not a backslash" at the
                // start of the string, so this also works if the selection begins with a bracket. We cannot solve
                // this by anchoring with ^, because in the case that the selection starts with two brackets, this
                // would mean a zero-width match at the start. Since zero-width matches advance the string position,
                // the first bracket could then not act as the "not a backslash" for the second.
                chunk.selection = (" " + chunk.selection).replace(/([^\\](?:\\\\)*)(?=[[\]])/g, "$1\\").substr(1);
                var linkDef = " [999]: " + properlyEncoded(link);
                var num = that.addLinkDef(chunk, linkDef);
                chunk.startTag = isImage ? "![" : "[";
                chunk.endTag = "][" + num + "]";
                if (!chunk.selection) {
                    if (isImage) {
                        chunk.selection = that.getString("imagedescription");
                    }
                    else {
                        chunk.selection = that.getString("linkdescription");
                    }
                }
            }
            postProcessing();
        };
        background = ui.createBackground();
        if (isImage) {
            if (!this.hooks.insertImageDialog(linkEnteredCallback))
                ui.prompt(this.getString("imagedialog"), imageDefaultText, linkEnteredCallback);
        }
        else {
            ui.prompt(this.getString("linkdialog"), linkDefaultText, linkEnteredCallback);
        }
        return true;
    }
};
// When making a list, hitting shift-enter will put your cursor on the next line
// at the current indent level.
commandProto.doAutoindent = function (chunk, postProcessing) {
    var commandMgr = this,
        fakeSelection = false;
    chunk.before = chunk.before.replace(/(\n|^)[ ]{0,3}([*+-]|\d+[.])[ \t]*\n$/, "\n\n");
    chunk.before = chunk.before.replace(/(\n|^)[ ]{0,3}>[ \t]*\n$/, "\n\n");
    chunk.before = chunk.before.replace(/(\n|^)[ \t]+\n$/, "\n\n");
    // There's no selection, end the cursor wasn't at the end of the line:
    // The user wants to split the current list item / code line / blockquote line
    // (for the latter it doesn't really matter) in two. Temporarily select the
    // (rest of the) line to achieve this.
    if (!chunk.selection && !/^[ \t]*(?:\n|$)/.test(chunk.after)) {
        chunk.after = chunk.after.replace(/^[^\n]*/, function (wholeMatch) {
            chunk.selection = wholeMatch;
            return "";
        });
        fakeSelection = true;
    }
    if (/(\n|^)[ ]{0,3}([*+-]|\d+[.])[ \t]+.*\n$/.test(chunk.before)) {
        if (commandMgr.doList) {
            commandMgr.doList(chunk);
        }
    }
    if (/(\n|^)[ ]{0,3}>[ \t]+.*\n$/.test(chunk.before)) {
        if (commandMgr.doBlockquote) {
            commandMgr.doBlockquote(chunk);
        }
    }
    if (/(\n|^)(\t|[ ]{4,}).*\n$/.test(chunk.before)) {
        if (commandMgr.doCode) {
            commandMgr.doCode(chunk);
        }
    }
    if (fakeSelection) {
        chunk.after = chunk.selection + chunk.after;
        chunk.selection = "";
    }
};
commandProto.doBlockquote = function (chunk, postProcessing) {
    chunk.selection = chunk.selection.replace(/^(\n*)([^\r]+?)(\n*)$/,
        function (totalMatch, newlinesBefore, text, newlinesAfter) {
            chunk.before += newlinesBefore;
            chunk.after = newlinesAfter + chunk.after;
            return text;
        });
    chunk.before = chunk.before.replace(/(>[ \t]*)$/,
        function (totalMatch, blankLine) {
            chunk.selection = blankLine + chunk.selection;
            return "";
        });
    chunk.selection = chunk.selection.replace(/^(\s|>)+$/, "");
    chunk.selection = chunk.selection || this.getString("quoteexample");
    // The original code uses a regular expression to find out how much of the
    // text *directly before* the selection already was a blockquote:
    /*
    if (chunk.before) {
    chunk.before = chunk.before.replace(/\n?$/, "\n");
    }
    chunk.before = chunk.before.replace(/(((\n|^)(\n[ \t]*)*>(.+\n)*.*)+(\n[ \t]*)*$)/,
    function (totalMatch) {
    chunk.startTag = totalMatch;
    return "";
    });
    */
    // This comes down to:
    // Go backwards as many lines a possible, such that each line
    //  a) starts with ">", or
    //  b) is almost empty, except for whitespace, or
    //  c) is preceeded by an unbroken chain of non-empty lines
    //     leading up to a line that starts with ">" and at least one more character
    // and in addition
    //  d) at least one line fulfills a)
    //
    // Since this is essentially a backwards-moving regex, it's susceptible to
    // catstrophic backtracking and can cause the browser to hang;
    // see e.g. http://meta.stackoverflow.com/questions/9807.
    //
    // Hence we replaced this by a simple state machine that just goes through the
    // lines and checks for a), b), and c).
    var match = "",
        leftOver = "",
        line;
    if (chunk.before) {
        var lines = chunk.before.replace(/\n$/, "").split("\n");
        var inChain = false;
        for (var i = 0; i < lines.length; i++) {
            var good = false;
            line = lines[i];
            inChain = inChain && line.length > 0; // c) any non-empty line continues the chain
            if (/^>/.test(line)) {                // a)
                good = true;
                if (!inChain && line.length > 1)  // c) any line that starts with ">" and has at least one more character starts the chain
                    inChain = true;
            } else if (/^[ \t]*$/.test(line)) {   // b)
                good = true;
            } else {
                good = inChain;                   // c) the line is not empty and does not start with ">", so it matches if and only if we're in the chain
            }
            if (good) {
                match += line + "\n";
            } else {
                leftOver += match + line;
                match = "\n";
            }
        }
        if (!/(^|\n)>/.test(match)) {             // d)
            leftOver += match;
            match = "";
        }
    }
    chunk.startTag = match;
    chunk.before = leftOver;
    // end of change
    if (chunk.after) {
        chunk.after = chunk.after.replace(/^\n?/, "\n");
    }
    chunk.after = chunk.after.replace(/^(((\n|^)(\n[ \t]*)*>(.+\n)*.*)+(\n[ \t]*)*)/,
        function (totalMatch) {
            chunk.endTag = totalMatch;
            return "";
        }
    );
    var replaceBlanksInTags = function (useBracket) {
        var replacement = useBracket ? "> " : "";
        if (chunk.startTag) {
            chunk.startTag = chunk.startTag.replace(/\n((>|\s)*)\n$/,
                function (totalMatch, markdown) {
                    return "\n" + markdown.replace(/^[ ]{0,3}>?[ \t]*$/gm, replacement) + "\n";
                });
        }
        if (chunk.endTag) {
            chunk.endTag = chunk.endTag.replace(/^\n((>|\s)*)\n/,
                function (totalMatch, markdown) {
                    return "\n" + markdown.replace(/^[ ]{0,3}>?[ \t]*$/gm, replacement) + "\n";
                });
        }
    };
    if (/^(?![ ]{0,3}>)/m.test(chunk.selection)) {
        this.wrap(chunk, SETTINGS.lineLength - 2);
        chunk.selection = chunk.selection.replace(/^/gm, "> ");
        replaceBlanksInTags(true);
        chunk.skipLines();
    } else {
        chunk.selection = chunk.selection.replace(/^[ ]{0,3}> ?/gm, "");
        this.unwrap(chunk);
        replaceBlanksInTags(false);
        if (!/^(\n|^)[ ]{0,3}>/.test(chunk.selection) && chunk.startTag) {
            chunk.startTag = chunk.startTag.replace(/\n{0,2}$/, "\n\n");
        }
        if (!/(\n|^)[ ]{0,3}>.*$/.test(chunk.selection) && chunk.endTag) {
            chunk.endTag = chunk.endTag.replace(/^\n{0,2}/, "\n\n");
        }
    }
    chunk.selection = this.hooks.postBlockquoteCreation(chunk.selection);
    if (!/\n/.test(chunk.selection)) {
        chunk.selection = chunk.selection.replace(/^(> *)/,
        function (wholeMatch, blanks) {
            chunk.startTag += blanks;
            return "";
        });
    }
};
commandProto.doCode = function (chunk, postProcessing) {
    var hasTextBefore = /\S[ ]*$/.test(chunk.before);
    var hasTextAfter = /^[ ]*\S/.test(chunk.after);
    // Use 'four space' markdown if the selection is on its own
    // line or is multiline.
    if ((!hasTextAfter && !hasTextBefore) || /\n/.test(chunk.selection)) {
        chunk.before = chunk.before.replace(/[ ]{4}$/,
            function (totalMatch) {
                chunk.selection = totalMatch + chunk.selection;
                return "";
            });
        var nLinesBack = 1;
        var nLinesForward = 1;
        if (/(\n|^)(\t|[ ]{4,}).*\n$/.test(chunk.before)) {
            nLinesBack = 0;
        }
        if (/^\n(\t|[ ]{4,})/.test(chunk.after)) {
            nLinesForward = 0;
        }
        chunk.skipLines(nLinesBack, nLinesForward);
        if (!chunk.selection) {
            chunk.startTag = "    ";
            chunk.selection = this.getString("codeexample");
        }
        else {
            if (/^[ ]{0,3}\S/m.test(chunk.selection)) {
                if (/\n/.test(chunk.selection))
                    chunk.selection = chunk.selection.replace(/^/gm, "    ");
                else // if it's not multiline, do not select the four added spaces; this is more consistent with the doList behavior
                    chunk.before += "    ";
            }
            else {
                chunk.selection = chunk.selection.replace(/^(?:[ ]{4}|[ ]{0,3}\t)/gm, "");
            }
        }
    }
    else {
        // Use backticks (`) to delimit the code block.
        chunk.trimWhitespace();
        chunk.findTags(/`/, /`/);
        if (!chunk.startTag && !chunk.endTag) {
            chunk.startTag = chunk.endTag = "`";
            if (!chunk.selection) {
                chunk.selection = this.getString("codeexample");
            }
        }
        else if (chunk.endTag && !chunk.startTag) {
            chunk.before += chunk.endTag;
            chunk.endTag = "";
        }
        else {
            chunk.startTag = chunk.endTag = "";
        }
    }
};
commandProto.doList = function (chunk, postProcessing, isNumberedList) {
    // These are identical except at the very beginning and end.
    // Should probably use the regex extension function to make this clearer.
    var previousItemsRegex = /(\n|^)(([ ]{0,3}([*+-]|\d+[.])[ \t]+.*)(\n.+|\n{2,}([*+-].*|\d+[.])[ \t]+.*|\n{2,}[ \t]+\S.*)*)\n*$/;
    var nextItemsRegex = /^\n*(([ ]{0,3}([*+-]|\d+[.])[ \t]+.*)(\n.+|\n{2,}([*+-].*|\d+[.])[ \t]+.*|\n{2,}[ \t]+\S.*)*)\n*/;
    // The default bullet is a dash but others are possible.
    // This has nothing to do with the particular HTML bullet,
    // it's just a markdown bullet.
    var bullet = "-";
    // The number in a numbered list.
    var num = 1;
    // Get the item prefix - e.g. " 1. " for a numbered list, " - " for a bulleted list.
    var getItemPrefix = function () {
        var prefix;
        if (isNumberedList) {
            prefix = " " + num + ". ";
            num++;
        }
        else {
            prefix = " " + bullet + " ";
        }
        return prefix;
    };
    // Fixes the prefixes of the other list items.
    var getPrefixedItem = function (itemText) {
        // The numbering flag is unset when called by autoindent.
        if (isNumberedList === undefined) {
            isNumberedList = /^\s*\d/.test(itemText);
        }
        // Renumber/bullet the list element.
        itemText = itemText.replace(/^[ ]{0,3}([*+-]|\d+[.])\s/gm,
            function (_) {
                return getItemPrefix();
            });
        return itemText;
    };
    chunk.findTags(/(\n|^)*[ ]{0,3}([*+-]|\d+[.])\s+/, null);
    if (chunk.before && !/\n$/.test(chunk.before) && !/^\n/.test(chunk.startTag)) {
        chunk.before += chunk.startTag;
        chunk.startTag = "";
    }
    if (chunk.startTag) {
        var hasDigits = /\d+[.]/.test(chunk.startTag);
        chunk.startTag = "";
        chunk.selection = chunk.selection.replace(/\n[ ]{4}/g, "\n");
        this.unwrap(chunk);
        chunk.skipLines();
        if (hasDigits) {
            // Have to renumber the bullet points if this is a numbered list.
            chunk.after = chunk.after.replace(nextItemsRegex, getPrefixedItem);
        }
        if (isNumberedList == hasDigits) {
            return;
        }
    }
    var nLinesUp = 1;
    chunk.before = chunk.before.replace(previousItemsRegex,
        function (itemText) {
            if (/^\s*([*+-])/.test(itemText)) {
                bullet = re.$1;
            }
            nLinesUp = /[^\n]\n\n[^\n]/.test(itemText) ? 1 : 0;
            return getPrefixedItem(itemText);
        });
    if (!chunk.selection) {
        chunk.selection = this.getString("litem");
    }
    var prefix = getItemPrefix();
    var nLinesDown = 1;
    chunk.after = chunk.after.replace(nextItemsRegex,
        function (itemText) {
            nLinesDown = /[^\n]\n\n[^\n]/.test(itemText) ? 1 : 0;
            return getPrefixedItem(itemText);
        });
    chunk.trimWhitespace(true);
    chunk.skipLines(nLinesUp, nLinesDown, true);
    chunk.startTag = prefix;
    var spaces = prefix.replace(/./g, " ");
    this.wrap(chunk, SETTINGS.lineLength - spaces.length);
    chunk.selection = chunk.selection.replace(/\n/g, "\n" + spaces);
};
commandProto.doHeading = function (chunk, postProcessing) {
    // Remove leading/trailing whitespace and reduce internal spaces to single spaces.
    chunk.selection = chunk.selection.replace(/\s+/g, " ");
    chunk.selection = chunk.selection.replace(/(^\s+|\s+$)/g, "");
    // If we clicked the button with no selected text, we just
    // make a level 2 hash header around some default text.
    if (!chunk.selection) {
        chunk.startTag = "## ";
        chunk.selection = this.getString("headingexample");
        chunk.endTag = " ##";
        return;
    }
    var headerLevel = 0;     // The existing header level of the selected text.
    // Remove any existing hash heading markdown and save the header level.
    chunk.findTags(/#+[ ]*/, /[ ]*#+/);
    if (/#+/.test(chunk.startTag)) {
        headerLevel = re.lastMatch.length;
    }
    chunk.startTag = chunk.endTag = "";
    // Try to get the current header level by looking for - and = in the line
    // below the selection.
    chunk.findTags(null, /\s?(-+|=+)/);
    if (/=+/.test(chunk.endTag)) {
        headerLevel = 1;
    }
    if (/-+/.test(chunk.endTag)) {
        headerLevel = 2;
    }
    // Skip to the next line so we can create the header markdown.
    chunk.startTag = chunk.endTag = "";
    chunk.skipLines(1, 1);
    // We make a level 2 header if there is no current header.
    // If there is a header level, we substract one from the header level.
    // If it's already a level 1 header, it's removed.
    var headerLevelToCreate = headerLevel == 0 ? 2 : headerLevel - 1;
    if (headerLevelToCreate > 0) {
        // The button only creates level 1 and 2 underline headers.
        // Why not have it iterate over hash header levels?  Wouldn't that be easier and cleaner?
        var headerChar = headerLevelToCreate >= 2 ? "-" : "=";
        var len = chunk.selection.length;
        if (len > SETTINGS.lineLength) {
            len = SETTINGS.lineLength;
        }
        chunk.endTag = "\n";
        while (len--) {
            chunk.endTag += headerChar;
        }
    }
};
commandProto.doHorizontalRule = function (chunk, postProcessing) {
    chunk.startTag = "----------\n";
    chunk.selection = "";
    chunk.skipLines(2, 1, true);
}

})();