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 *       notice, this list of conditions and the following disclaimer.
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 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
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define(function(require, exports, module) {
"use strict";

var oop = require("../../lib/oop");
var BaseFoldMode = require("./fold_mode").FoldMode;
var Range = require("../../range").Range;

var FoldMode = exports.FoldMode = function() {};
oop.inherits(FoldMode, BaseFoldMode);

(function() {
    this.foldingStartMarker = /^(?:[=-]+\s*$|#{1,6} |`{3})/;

    this.getFoldWidget = function(session, foldStyle, row) {
        var line = session.getLine(row);
        if (!this.foldingStartMarker.test(line))
            return "";

        if (line[0] == "`") {
            if (session.bgTokenizer.getState(row) == "start")
                return "end";
            return "start";
        }

        return "start";
    };

    this.getFoldWidgetRange = function(session, foldStyle, row) {
        var line = session.getLine(row);
        var startColumn = line.length;
        var maxRow = session.getLength();
        var startRow = row;
        var endRow = row;
        if (!line.match(this.foldingStartMarker))
            return;

        if (line[0] == "`") {
            if (session.bgTokenizer.getState(row) !== "start") {
                while (++row < maxRow) {
                    line = session.getLine(row);
                    if (line[0] == "`" & line.substring(0, 3) == "```")
                        break;
                }
                return new Range(startRow, startColumn, row, 0);
            } else {
                while (row -- > 0) {
                    line = session.getLine(row);
                    if (line[0] == "`" & line.substring(0, 3) == "```")
                        break;
                }
                return new Range(row, line.length, startRow, 0);
            }
        }

        var token;
        function isHeading(row) {
            token = session.getTokens(row)[0];
            return token && token.type.lastIndexOf(heading, 0) === 0;
        }

        var heading = "markup.heading";
        function getLevel() {
            var ch = token.value[0];
            if (ch == "=") return 6;
            if (ch == "-") return 5;
            return 7 - token.value.search(/[^#]/);
        }

        if (isHeading(row)) {
            var startHeadingLevel = getLevel();
            while (++row < maxRow) {
                if (!isHeading(row))
                    continue;
                var level = getLevel();
                if (level >= startHeadingLevel)
                    break;
            }

            endRow = row - (!token || ["=", "-"].indexOf(token.value[0]) == -1 ? 1 : 2);

            if (endRow > startRow) {
                while (endRow > startRow && /^\s*$/.test(session.getLine(endRow)))
                    endRow--;
            }

            if (endRow > startRow) {
                var endColumn = session.getLine(endRow).length;
                return new Range(startRow, startColumn, endRow, endColumn);
            }
        }
    };

}).call(FoldMode.prototype);

});
