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 * Distributed under the BSD license:
 *
 * Copyright (c) 2010, Ajax.org B.V.
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 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
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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 Tokenizer = require("../tokenizer").Tokenizer;
var TextHighlightRules = require("./text_highlight_rules").TextHighlightRules;
var Behaviour = require("./behaviour").Behaviour;
var unicode = require("../unicode");
var lang = require("../lib/lang");
var TokenIterator = require("../token_iterator").TokenIterator;
var Range = require("../range").Range;

var Mode = function() {
    this.HighlightRules = TextHighlightRules;
    this.$behaviour = new Behaviour();
};

(function() {

    this.tokenRe = new RegExp("^["
        + unicode.packages.L
        + unicode.packages.Mn + unicode.packages.Mc
        + unicode.packages.Nd
        + unicode.packages.Pc + "\\$_]+", "g"
    );

    this.nonTokenRe = new RegExp("^(?:[^"
        + unicode.packages.L
        + unicode.packages.Mn + unicode.packages.Mc
        + unicode.packages.Nd
        + unicode.packages.Pc + "\\$_]|\s])+", "g"
    );

    this.getTokenizer = function() {
        if (!this.$tokenizer) {
            this.$highlightRules = new this.HighlightRules();
            this.$tokenizer = new Tokenizer(this.$highlightRules.getRules());
        }
        return this.$tokenizer;
    };

    this.lineCommentStart = "";
    this.blockComment = "";

    this.toggleCommentLines = function(state, session, startRow, endRow) {
        var doc = session.doc;

        var ignoreBlankLines = true;
        var shouldRemove = true;
        var minIndent = Infinity;
        var tabSize = session.getTabSize();
        var insertAtTabStop = false;

        if (!this.lineCommentStart) {
            if (!this.blockComment)
                return false;
            var lineCommentStart = this.blockComment.start;
            var lineCommentEnd = this.blockComment.end;
            var regexpStart = new RegExp("^(\\s*)(?:" + lang.escapeRegExp(lineCommentStart) + ")");
            var regexpEnd = new RegExp("(?:" + lang.escapeRegExp(lineCommentEnd) + ")\\s*$");

            var comment = function(line, i) {
                if (testRemove(line, i))
                    return;
                if (!ignoreBlankLines || /\S/.test(line)) {
                    doc.insertInLine({row: i, column: line.length}, lineCommentEnd);
                    doc.insertInLine({row: i, column: minIndent}, lineCommentStart);
                }
            };

            var uncomment = function(line, i) {
                var m;
                if (m = line.match(regexpEnd))
                    doc.removeInLine(i, line.length - m[0].length, line.length);
                if (m = line.match(regexpStart))
                    doc.removeInLine(i, m[1].length, m[0].length);
            };

            var testRemove = function(line, row) {
                if (regexpStart.test(line))
                    return true;
                var tokens = session.getTokens(row);
                for (var i = 0; i < tokens.length; i++) {
                    if (tokens[i].type === 'comment')
                        return true;
                }
            };
        } else {
            if (Array.isArray(this.lineCommentStart)) {
                var regexpStart = this.lineCommentStart.map(lang.escapeRegExp).join("|");
                var lineCommentStart = this.lineCommentStart[0];
            } else {
                var regexpStart = lang.escapeRegExp(this.lineCommentStart);
                var lineCommentStart = this.lineCommentStart;
            }
            regexpStart = new RegExp("^(\\s*)(?:" + regexpStart + ") ?");
            
            insertAtTabStop = session.getUseSoftTabs();

            var uncomment = function(line, i) {
                var m = line.match(regexpStart);
                if (!m) return;
                var start = m[1].length, end = m[0].length;
                if (!shouldInsertSpace(line, start, end) && m[0][end - 1] == " ")
                    end--;
                doc.removeInLine(i, start, end);
            };
            var commentWithSpace = lineCommentStart + " ";
            var comment = function(line, i) {
                if (!ignoreBlankLines || /\S/.test(line)) {
                    if (shouldInsertSpace(line, minIndent, minIndent))
                        doc.insertInLine({row: i, column: minIndent}, commentWithSpace);
                    else
                        doc.insertInLine({row: i, column: minIndent}, lineCommentStart);
                }
            };
            var testRemove = function(line, i) {
                return regexpStart.test(line);
            };
            
            var shouldInsertSpace = function(line, before, after) {
                var spaces = 0;
                while (before-- && line.charAt(before) == " ")
                    spaces++;
                if (spaces % tabSize != 0)
                    return false;
                var spaces = 0;
                while (line.charAt(after++) == " ")
                    spaces++;
                if (tabSize > 2)
                    return spaces % tabSize != tabSize - 1;
                else
                    return spaces % tabSize == 0;
                return true;
            };
        }

        function iter(fun) {
            for (var i = startRow; i <= endRow; i++)
                fun(doc.getLine(i), i);
        }


        var minEmptyLength = Infinity;
        iter(function(line, i) {
            var indent = line.search(/\S/);
            if (indent !== -1) {
                if (indent < minIndent)
                    minIndent = indent;
                if (shouldRemove && !testRemove(line, i))
                    shouldRemove = false;
            } else if (minEmptyLength > line.length) {
                minEmptyLength = line.length;
            }
        });

        if (minIndent == Infinity) {
            minIndent = minEmptyLength;
            ignoreBlankLines = false;
            shouldRemove = false;
        }

        if (insertAtTabStop && minIndent % tabSize != 0)
            minIndent = Math.floor(minIndent / tabSize) * tabSize;

        iter(shouldRemove ? uncomment : comment);
    };

    this.toggleBlockComment = function(state, session, range, cursor) {
        var comment = this.blockComment;
        if (!comment)
            return;
        if (!comment.start && comment[0])
            comment = comment[0];

        var iterator = new TokenIterator(session, cursor.row, cursor.column);
        var token = iterator.getCurrentToken();

        var sel = session.selection;
        var initialRange = session.selection.toOrientedRange();
        var startRow, colDiff;

        if (token && /comment/.test(token.type)) {
            var startRange, endRange;
            while (token && /comment/.test(token.type)) {
                var i = token.value.indexOf(comment.start);
                if (i != -1) {
                    var row = iterator.getCurrentTokenRow();
                    var column = iterator.getCurrentTokenColumn() + i;
                    startRange = new Range(row, column, row, column + comment.start.length);
                    break
                }
                token = iterator.stepBackward();
            };

            var iterator = new TokenIterator(session, cursor.row, cursor.column);
            var token = iterator.getCurrentToken();
            while (token && /comment/.test(token.type)) {
                var i = token.value.indexOf(comment.end);
                if (i != -1) {
                    var row = iterator.getCurrentTokenRow();
                    var column = iterator.getCurrentTokenColumn() + i;
                    endRange = new Range(row, column, row, column + comment.end.length);
                    break;
                }
                token = iterator.stepForward();
            }
            if (endRange)
                session.remove(endRange);
            if (startRange) {
                session.remove(startRange);
                startRow = startRange.start.row;
                colDiff = -comment.start.length
            }
        } else {
            colDiff = comment.start.length
            startRow = range.start.row;
            session.insert(range.end, comment.end);
            session.insert(range.start, comment.start);
        }
        // todo: selection should have ended up in the right place automatically!
        if (initialRange.start.row == startRow)
            initialRange.start.column += colDiff;
        if (initialRange.end.row == startRow)
            initialRange.end.column += colDiff;
        session.selection.fromOrientedRange(initialRange);
    };

    this.getNextLineIndent = function(state, line, tab) {
        return this.$getIndent(line);
    };

    this.checkOutdent = function(state, line, input) {
        return false;
    };

    this.autoOutdent = function(state, doc, row) {
    };

    this.$getIndent = function(line) {
        return line.match(/^\s*/)[0];
    };

    this.createWorker = function(session) {
        return null;
    };

    this.createModeDelegates = function (mapping) {
        this.$embeds = [];
        this.$modes = {};
        for (var i in mapping) {
            if (mapping[i]) {
                this.$embeds.push(i);
                this.$modes[i] = new mapping[i]();
            }
        }

        var delegations = ['toggleCommentLines', 'getNextLineIndent', 'checkOutdent', 'autoOutdent', 'transformAction', 'getCompletions'];

        for (var i = 0; i < delegations.length; i++) {
            (function(scope) {
              var functionName = delegations[i];
              var defaultHandler = scope[functionName];
              scope[delegations[i]] = function() {
                  return this.$delegator(functionName, arguments, defaultHandler);
              }
            } (this));
        }
    };

    this.$delegator = function(method, args, defaultHandler) {
        var state = args[0];
        if (typeof state != "string")
            state = state[0];
        for (var i = 0; i < this.$embeds.length; i++) {
            if (!this.$modes[this.$embeds[i]]) continue;

            var split = state.split(this.$embeds[i]);
            if (!split[0] && split[1]) {
                args[0] = split[1];
                var mode = this.$modes[this.$embeds[i]];
                return mode[method].apply(mode, args);
            }
        }
        var ret = defaultHandler.apply(this, args);
        return defaultHandler ? ret : undefined;
    };

    this.transformAction = function(state, action, editor, session, param) {
        if (this.$behaviour) {
            var behaviours = this.$behaviour.getBehaviours();
            for (var key in behaviours) {
                if (behaviours[key][action]) {
                    var ret = behaviours[key][action].apply(this, arguments);
                    if (ret) {
                        return ret;
                    }
                }
            }
        }
    };
    
    this.getKeywords = function(append) {
        // this is for autocompletion to pick up regexp'ed keywords
        if (!this.completionKeywords) {
            var rules = this.$tokenizer.rules;
            var completionKeywords = [];
            for (var rule in rules) {
                var ruleItr = rules[rule];
                for (var r = 0, l = ruleItr.length; r < l; r++) {
                    if (typeof ruleItr[r].token === "string") {
                        if (/keyword|support|storage/.test(ruleItr[r].token))
                            completionKeywords.push(ruleItr[r].regex);
                    }
                    else if (typeof ruleItr[r].token === "object") {
                        for (var a = 0, aLength = ruleItr[r].token.length; a < aLength; a++) {    
                            if (/keyword|support|storage/.test(ruleItr[r].token[a])) {
                                // drop surrounding parens
                                var rule = ruleItr[r].regex.match(/\(.+?\)/g)[a];
                                completionKeywords.push(rule.substr(1, rule.length - 2));
                            }
                        }
                    }
                }
            }
            this.completionKeywords = completionKeywords;
        }
        // this is for highlighting embed rules, like HAML/Ruby or Obj-C/C
        if (!append)
            return this.$keywordList;
        return completionKeywords.concat(this.$keywordList || []);
    };
    
    this.$createKeywordList = function() {
        if (!this.$highlightRules)
            this.getTokenizer();
        return this.$keywordList = this.$highlightRules.$keywordList || [];
    }

    this.getCompletions = function(state, session, pos, prefix) {
        var keywords = this.$keywordList || this.$createKeywordList();
        return keywords.map(function(word) {
            return {
                name: word,
                value: word,
                score: 0,
                meta: "keyword"
            };
        });
    };

}).call(Mode.prototype);

exports.Mode = Mode;
});