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 * Distributed under the BSD license:
 *
 * Copyright (c) 2010, Ajax.org B.V.
 * All rights reserved.
 * 
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 * modification, are permitted provided that the following conditions are met:
 *     * 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
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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define(function(require, exports, module) {
"use strict";

var oop = require("../lib/oop");
var TextMode = require("./text").Mode;
var Tokenizer = require("../tokenizer").Tokenizer;
var LuaHighlightRules = require("./lua_highlight_rules").LuaHighlightRules;
var LuaFoldMode = require("./folding/lua").FoldMode;
var Range = require("../range").Range;

var Mode = function() {
    this.$tokenizer = new Tokenizer(new LuaHighlightRules().getRules());
    this.foldingRules = new LuaFoldMode();
};
oop.inherits(Mode, TextMode);

(function() {
    var indentKeywords = {
        "function": 1,
        "then": 1,
        "do": 1,
        "else": 1,
        "elseif": 1,
        "repeat": 1,
        "end": -1,
        "until": -1
    };
    var outdentKeywords = [
        "else",
        "elseif",
        "end",
        "until"
    ];

    function getNetIndentLevel(tokens) {
        var level = 0;
        // Support single-line blocks by decrementing the indent level if
        // an ending token is found
        for (var i in tokens){
            var token = tokens[i];
            if (token.type == "keyword") {
                if (token.value in indentKeywords) {
                    level += indentKeywords[token.value];
                }
            } else if (token.type == "paren.lparen") {
                level ++;
            } else if (token.type == "paren.rparen") {
                level --;
            }
        }
        // Limit the level to +/- 1 since usually users only indent one level
        // at a time regardless of the logical nesting level
        if (level < 0) {
            return -1;
        } else if (level > 0) {
            return 1;
        } else {
            return 0;
        }
    }

    this.getNextLineIndent = function(state, line, tab) {
        var indent = this.$getIndent(line);
        var level = 0;

        var tokenizedLine = this.$tokenizer.getLineTokens(line, state);
        var tokens = tokenizedLine.tokens;

        if (state == "start") {
            level = getNetIndentLevel(tokens);
        }
        if (level > 0) {
            return indent + tab;
        } else if (level < 0 && indent.substr(indent.length - tab.length) == tab) {
            // Don't do a next-line outdent if we're going to do a real outdent of this line
            if (!this.checkOutdent(state, line, "\n")) {
                return indent.substr(0, indent.length - tab.length);
            }
        }
        return indent;
    };

    this.checkOutdent = function(state, line, input) {
        if (input != "\n" && input != "\r" && input != "\r\n")
            return false;

        if (line.match(/^\s*[\)\}\]]$/))
            return true;

        var tokens = this.$tokenizer.getLineTokens(line.trim(), state).tokens;

        if (!tokens || !tokens.length)
            return false;

        return (tokens[0].type == "keyword" && outdentKeywords.indexOf(tokens[0].value) != -1);
    };

    this.autoOutdent = function(state, session, row) {
        var prevLine = session.getLine(row - 1);
        var prevIndent = this.$getIndent(prevLine).length;
        var prevTokens = this.$tokenizer.getLineTokens(prevLine, "start").tokens;
        var tabLength = session.getTabString().length;
        var expectedIndent = prevIndent + tabLength * getNetIndentLevel(prevTokens);
        var curIndent = this.$getIndent(session.getLine(row)).length;
        if (curIndent < expectedIndent) {
            // User already outdented //
            return;
        }
        session.outdentRows(new Range(row, 0, row + 2, 0));
    };

}).call(Mode.prototype);

exports.Mode = Mode;
});