/* ***** BEGIN LICENSE BLOCK *****
 * Distributed under the BSD license:
 *
 * Copyright (c) 2012, Ajax.org B.V.
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
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 *       notice, this list of conditions and the following disclaimer.
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 *       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
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 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *
 * Contributor(s):
 * 
 * NalaGinrut@gmail.com
 *
 * ***** END LICENSE BLOCK ***** */

define(function (require, exports, module) {
    "use strict";

    var oop = require("../lib/oop");
    var TextMode = require("./text").Mode;
    var SchemeHighlightRules = require("./scheme_highlight_rules").SchemeHighlightRules;
    var MatchingParensOutdent = require("./matching_parens_outdent").MatchingParensOutdent;

    var Mode = function () {
        this.HighlightRules = SchemeHighlightRules;
        this.$outdent = new MatchingParensOutdent();
        this.$behaviour = this.$defaultBehaviour;
    };
    oop.inherits(Mode, TextMode);

    (function () {

        this.lineCommentStart = ";";
        this.minorIndentFunctions = ["define", "lambda", "define-macro", "define-syntax", "syntax-rules", "define-record-type", "define-structure"];

        this.$toIndent = function (str) {
            return str.split('').map(function (ch) {
                if (/\s/.exec(ch)) {
                    return ch;
                } else {
                    return ' ';
                }
            }).join('');
        };

        this.$calculateIndent = function (line, tab) {
            var baseIndent = this.$getIndent(line);
            var delta = 0;
            var isParen, ch;
            // Walk back from end of line, find matching braces
            for (var i = line.length - 1; i >= 0; i--) {
                ch = line[i];
                if (ch === '(') {
                    delta--;
                    isParen = true;
                } else if (ch === '(' || ch === '[' || ch === '{') {
                    delta--;
                    isParen = false;
                } else if (ch === ')' || ch === ']' || ch === '}') {
                    delta++;
                }
                if (delta < 0) {
                    break;
                }
            }
            if (delta < 0 && isParen) {
                // Were more brackets opened than closed and was a ( left open?
                i += 1;
                var iBefore = i;
                var fn = '';
                while (true) {
                    ch = line[i];
                    if (ch === ' ' || ch === '\t') {
                        if (this.minorIndentFunctions.indexOf(fn) !== -1) {
                            return this.$toIndent(line.substring(0, iBefore - 1) + tab);
                        } else {
                            return this.$toIndent(line.substring(0, i + 1));
                        }
                    } else if (ch === undefined) {
                        return this.$toIndent(line.substring(0, iBefore - 1) + tab);
                    }
                    fn += line[i];
                    i++;
                }
            } else if (delta < 0 && !isParen) {
                // Were more brackets openend than closed and was it not a (?
                return this.$toIndent(line.substring(0, i + 1));
            } else if (delta > 0) {
                // Mere more brackets closed than opened? Outdent.
                baseIndent = baseIndent.substring(0, baseIndent.length - tab.length);
                return baseIndent;
            } else {
                // Were they nicely matched? Just indent like line before.
                return baseIndent;
            }
        };

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

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

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

        this.$id = "ace/mode/scheme";
    }).call(Mode.prototype);

    exports.Mode = Mode;
});
