/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Ajax.org Code Editor (ACE).
 *
 * The Initial Developer of the Original Code is
 * Ajax.org B.V.
 * Portions created by the Initial Developer are Copyright (C) 2010
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *      Fabian Jakobs <fabian AT ajax DOT org>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

define(function(require, exports, module) {

var Tokenizer = function(rules) {
    this.rules = rules;

    this.regExps = {};
    this.matchMappings = {};
    for ( var key in this.rules) {
        var rule = this.rules[key];
        var state = rule;
        var ruleRegExps = [];
        var matchTotal = 0;
        var mapping = this.matchMappings[key] = {};
        
        for ( var i = 0; i < state.length; i++) {
            // Count number of matching groups. 2 extra groups from the full match
            // And the catch-all on the end (used to force a match);
            var matchcount = new RegExp("(?:(" + state[i].regex + ")|(.))").exec("a").length - 2;
        
            // Replace any backreferences and offset appropriately.
            var adjustedregex = state[i].regex.replace(/\\([0-9]+)/g, function (match, digit) {
                return "\\" + (parseInt(digit, 10) + matchTotal + 1);
            });
            
            mapping[matchTotal] = {
                rule: i,
                len: matchcount
            };
            matchTotal += matchcount;
            
            ruleRegExps.push(adjustedregex);
        }

        this.regExps[key] = new RegExp("(?:(" + ruleRegExps.join(")|(") + ")|(.))", "g");
    }
};

(function() {

    this.getLineTokens = function(line, startState) {
        var currentState = startState;
        var state = this.rules[currentState];
        var mapping = this.matchMappings[currentState];
        var re = this.regExps[currentState];
        re.lastIndex = 0;
        
        var match, tokens = [];
        
        var lastIndex = 0;
        
        var token = {
            type: null,
            value: ""
        };
        
        while (match = re.exec(line)) {
            var type = "text";
            var rule = null;
            var value = [match[0]];

            for (var i = 0; i < match.length-2; i++) {
                if (match[i + 1] !== undefined) {
                    rule = state[mapping[i].rule];
                    
                    if (mapping[i].len > 1) {
                        value = match.slice(i+2, i+1+mapping[i].len);
                    }
                    
                    // compute token type
                    if (typeof rule.token == "function")
                        type = rule.token.apply(this, value);
                    else
                        type = rule.token;

                    var next = rule.next;                    
                    if (next && next !== currentState) {
                        currentState = next;
                        state = this.rules[currentState];
                        mapping = this.matchMappings[currentState];
                        lastIndex = re.lastIndex;

                        re = this.regExps[currentState];
                        re.lastIndex = lastIndex;
                    }
                    break;
                }
            };

            if (value[0]) {
                if (typeof type == "string") {
                    value = [value.join("")];
                    type = [type];
                }
                for (var i = 0; i < value.length; i++) {
                    if ((!rule || rule.merge || type[i] === "text") && token.type === type[i]) {
                        token.value += value[i];
                    } else {
                        if (token.type) {
                            tokens.push(token);
                        }
                    
                        token = {
                            type: type[i],
                            value: value[i]
                        }
                    }
                }
            }
            
            if (lastIndex == line.length)
                break;
            
            lastIndex = re.lastIndex;
        };

        if (token.type)
            tokens.push(token);

        return {
            tokens : tokens,
            state : currentState
        };
    };

}).call(Tokenizer.prototype);

exports.Tokenizer = Tokenizer;
});