/* CodeMirror main module
 *
 * Implements the CodeMirror constructor and prototype, which take care
 * of initializing the editor frame, and providing the outside interface.
 */

// The CodeMirrorConfig object is used to specify a default
// configuration. If you specify such an object before loading this
// file, the values you put into it will override the defaults given
// below. You can also assign to it after loading.
var CodeMirrorConfig = window.CodeMirrorConfig || {};

var CodeMirror = (function() {
    function setDefaults(object, defaults) {
        for (var option in defaults) {
            if (!object.hasOwnProperty(option))
                object[option] = defaults[option];
        }
    }
    function forEach(array, action) {
        for (var i = 0; i < array.length; i++)
            action(array[i]);
    }

    // These default options can be overridden by passing a set of
    // options to a specific CodeMirror constructor. See manual.html for
    // their meaning.
    setDefaults(CodeMirrorConfig, {
        stylesheet: "",
        path: "",
        parserfile: [],
        basefiles: ["util.js", "stringstream.js", "select.js", "undo.js", "editor.js", "tokenize.js"],
        iframeClass: null,
        passDelay: 200,
        passTime: 50,
        continuousScanning: false,
        saveFunction: null,
        onChange: null,
        undoDepth: 50,
        undoDelay: 800,
        disableSpellcheck: true,
        textWrapping: true,
        readOnly: false,
        width: "100%",
        height: "300px",
        autoMatchParens: false,
        parserConfig: null,
        tabMode: "indent", // or "spaces", "default", "shift"
        reindentOnLoad: false,
        activeTokens: null,
        cursorActivity: null,
        lineNumbers: false,
        indentUnit: 2
    });

    function wrapLineNumberDiv(place) {
        return function(node, conID) {
            var container = document.createElement("DIV"),
            nums = document.createElement("DIV"),
            scroller = document.createElement("DIV");
          
            if(conID) container.id = conID;
            container.style.position = "relative";
            nums.style.position = "absolute";
            nums.style.height = "100%";
            if (nums.style.setExpression) {
                try { nums.style.setExpression("height", "this.previousSibling.offsetHeight + 'px'"); }
                catch (e) { } // Seems to throw 'Not Implemented' on some IE8 versions
            }
            nums.style.top = "0px";
            nums.style.overflow = "hidden";
            place(container);
            container.appendChild(node);
            container.appendChild(nums);
            scroller.className = "CodeMirror-line-numbers";
            nums.appendChild(scroller);
        }
    }

    function applyLineNumbers(frame) {
        var win = frame.contentWindow, doc = win.document,
        nums = frame.nextSibling, scroller = nums.firstChild;

        var nextNum = 1, barWidth = null;
        function sizeBar() {
            if (nums.offsetWidth != barWidth) {
                barWidth = nums.offsetWidth;
                nums.style.left = "-" + (frame.parentNode.style.marginLeft = barWidth + "px");
            }
        }
        function update() {
            var diff = 20 + Math.max(doc.body.offsetHeight, frame.offsetHeight) - scroller.offsetHeight;
            for (var n = Math.ceil(diff / 10); n > 0; n--) {
                var div = document.createElement("DIV");
                div.appendChild(document.createTextNode(nextNum++));
                scroller.appendChild(div);
            }
            nums.scrollTop = doc.body.scrollTop || doc.documentElement.scrollTop || 0;
        }
        sizeBar();
        update();
        win.addEventHandler(win, "scroll", update);
        setInterval(sizeBar, 500);
    }

    function CodeMirror(place, options) {
        // Backward compatibility for deprecated options.
        if (options.dumbTabs) options.tabMode = "spaces";
        else if (options.normalTab) options.tabMode = "default";

        // Use passed options, if any, to override defaults.
        this.options = options = options || {};
        setDefaults(options, CodeMirrorConfig);

        var frame = this.frame = document.createElement("IFRAME");
        if (options.iframeClass) frame.className = options.iframeClass;
        frame.frameBorder = 0;
        frame.src = "javascript:false;";
        frame.style.border = "0";
        frame.style.width = options.width;
        frame.style.height = options.height;
        // display: block occasionally suppresses some Firefox bugs, so we
        // always add it, redundant as it sounds.
        frame.style.display = "block";

        if (place.appendChild) {
            var node = place;
            place = function(n) { node.appendChild(n); };
        }
        if (options.lineNumbers) place = wrapLineNumberDiv(place);
        place(frame, options.containerID);

        // Link back to this object, so that the editor can fetch options
        // and add a reference to itself.
        frame.CodeMirror = this;
        this.win = frame.contentWindow;

        if (typeof options.parserfile == "string")
            options.parserfile = [options.parserfile];
        if (typeof options.stylesheet == "string")
            options.stylesheet = [options.stylesheet];

        var html = ["<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.0 Transitional//EN\" \"http://www.w3.org/TR/html4/loose.dtd\"><html><head>"];
        forEach(options.stylesheet, function(file) {
            html.push("<link rel=\"stylesheet\" type=\"text/css\" href=\"" + file + "\"/>");
        });
        forEach(options.basefiles.concat(options.parserfile), function(file) {
            html.push("<script type=\"text/javascript\" src=\"" + options.path + file + "\"></script>");
        });
        html.push("</head><body style=\"border-width: 0;\" class=\"editbox\" spellcheck=\"" +
              (options.disableSpellcheck ? "false" : "true") + "\"></body></html>");

        var doc = this.win.document;
        doc.open();
        doc.write(html.join(""));
        doc.close();
    }

    CodeMirror.prototype = {
        init: function() {
            if (this.options.initCallback) this.options.initCallback(this);
            if (this.options.lineNumbers) applyLineNumbers(this.frame);
            if (this.options.reindentOnLoad) this.reindent();
        },
        toggleWrapping: function() { this.editor.toggleWrapping(); },
        getCode: function() { return this.editor.getCode(); },
        setCode: function(code) { this.editor.importCode(code); },
        selection: function() { return this.editor.selectedText(); },
        reindent: function() { this.editor.reindent(); },
        reindentSelection: function() { this.editor.reindentSelection(null); },

        focus: function() {
            this.win.focus();
            if (this.editor.selectionSnapshot) // IE hack
                this.win.select.selectCoords(this.win, this.editor.selectionSnapshot);
        },
        replaceSelection: function(text) {
            this.focus();
            this.editor.replaceSelection(text);
            return true;
        },
        replaceChars: function(text, start, end) {
            this.editor.replaceChars(text, start, end);
        },
        getSearchCursor: function(string, fromCursor) {
            return this.editor.getSearchCursor(string, fromCursor);
        },

        undo: function() { this.editor.history.undo(); },
        redo: function() { this.editor.history.redo(); },
        historySize: function() { return this.editor.history.historySize(); },
        clearHistory: function() { this.editor.history.clear(); },

        grabKeys: function(callback, filter) { this.editor.grabKeys(callback, filter); },
        ungrabKeys: function() { this.editor.ungrabKeys(); },

        setParser: function(name) { this.editor.setParser(name); },

        cursorPosition: function(start) {
            if (this.win.select.ie_selection) this.focus();
            return this.editor.cursorPosition(start);
        },
        firstLine: function() { return this.editor.firstLine(); },
        lastLine: function() { return this.editor.lastLine(); },
        nextLine: function(line) { return this.editor.nextLine(line); },
        prevLine: function(line) { return this.editor.prevLine(line); },
        lineContent: function(line) { return this.editor.lineContent(line); },
        setLineContent: function(line, content) { this.editor.setLineContent(line, content); },
        insertIntoLine: function(line, position, content) { this.editor.insertIntoLine(line, position, content); },
        selectLines: function(startLine, startOffset, endLine, endOffset) {
            this.win.focus();
            this.editor.selectLines(startLine, startOffset, endLine, endOffset);
        },
        nthLine: function(n) {
            var line = this.firstLine();
            for (; n > 1 && line !== false; n--)
                line = this.nextLine(line);
            return line;
        },
        lineNumber: function(line) {
            var num = 0;
            while (line !== false) {
                num++;
                line = this.prevLine(line);
            }
            return num;
        },

        // Old number-based line interface
        jumpToLine: function(n) {
            this.selectLines(this.nthLine(n), 0);
            this.win.focus();
        },
        currentLine: function() {
            return this.lineNumber(this.cursorPosition().line);
        }
    };

    CodeMirror.InvalidLineHandle = { toString: function() { return "CodeMirror.InvalidLineHandle"; } };

    CodeMirror.replace = function(element) {
        if (typeof element == "string")
            element = document.getElementById(element);
        return function(newElement) {
            element.parentNode.replaceChild(newElement, element);
        };
    };

    CodeMirror.fromTextArea = function(area, options) {
        if (typeof area == "string")
            area = document.getElementById(area);

        options = options || {};
        if (area.style.width && options.width == null)
            options.width = area.style.width;
        if (area.style.height && options.height == null)
            options.height = area.style.height;
        if (options.content == null) options.content = area.value;

        if (area.form) {
            function updateField() {
                area.value = mirror.getCode();
            }
            if (typeof area.form.addEventListener == "function")
                area.form.addEventListener("submit", updateField, false);
            else
                area.form.attachEvent("onsubmit", updateField);
        }

        function insert(frame) {
            if (area.nextSibling)
                area.parentNode.insertBefore(frame, area.nextSibling);
            else
                area.parentNode.appendChild(frame);
        }

        area.style.display = "none";
        var mirror = new CodeMirror(insert, options);
        return mirror;
    };

    CodeMirror.isProbablySupported = function() {
        // This is rather awful, but can be useful.
        var match;
        if (window.opera)
            return Number(window.opera.version()) >= 9.52;
        else if (/Apple Computers, Inc/.test(navigator.vendor) && (match = navigator.userAgent.match(/Version\/(\d+(?:\.\d+)?)\./)))
            return Number(match[1]) >= 3;
        else if (document.selection && window.ActiveXObject && (match = navigator.userAgent.match(/MSIE (\d+(?:\.\d*)?)\b/)))
            return Number(match[1]) >= 6;
        else if (match = navigator.userAgent.match(/gecko\/(\d{8})/i))
            return Number(match[1]) >= 20050901;
        else if (match = navigator.userAgent.match(/AppleWebKit\/(\d+)/))
            return Number(match[1]) >= 525;
        else
            return null;
    };

    return CodeMirror;
})();
