YUI.add('ui-code-editor', function (Y) {

    CodeMirror.defineMode("oberon07", function () {
        function words(str) {
            var obj = {}, words = str.split(" ");
        
            for (var i = 0; i < words.length; ++i) obj[words[i]] = true;
            return obj;
        }
      
        var keywords = words("ARRAY IMPORT THEN BEGIN IN TO BY IS TRUE CASE MOD TYPE " +
                           "CONST MODULE UNTIL DIV NIL VAR DO OF WHILE ELSE OR " +
                           "ELSIF POINTER END PROCEDURE FALSE RECORD FOR REPEAT IF RETURN");
                                                 
        var atoms = {'null': true};

        var isOperatorChar = /[+\-*&%=<>^~#!?\|\/]/;

        function tokenBase(stream, state) {
            var ch = stream.next();
        
            if (ch == "#" && state.startOfLine) {
                stream.skipToEnd();
                return "meta";
            }
        
            if (ch == '"' || ch == "'") {
                state.tokenize = tokenString(ch);
                return state.tokenize(stream, state);
            }
        
            if (ch == "(" && stream.eat("*")) {
                state.tokenize = tokenComment;
                return tokenComment(stream, state);
            }
        
            if (/[\[\]{}\(\),;\:\.]/.test(ch)) {
                return null;
            }
        
            if (/\d/.test(ch)) {
                stream.eatWhile(/[\w\.]/);
                return "number";
            }
        
            if (ch == "/") {
                if (stream.eat("/")) {
                    stream.skipToEnd();
                    return "comment";
                }
            }
        
            if (isOperatorChar.test(ch)) {
                stream.eatWhile(isOperatorChar);
                return "operator";
            }

            stream.eatWhile(/[\w\$_]/);
            
            var cur = stream.current();
        
            if (keywords.propertyIsEnumerable(cur)) return "keyword";
            if (atoms.propertyIsEnumerable(cur)) return "atom";
            return "variable";
        }

        function tokenString(quote) {
            return function(stream, state) {
                var escaped = false, next, end = false;
                
                while ((next = stream.next()) != null) {
                    if (next == quote && !escaped) {end = true; break;}
                    escaped = !escaped && next == "\\";
                }
                
                if (end || !escaped) state.tokenize = null;
                return "string";
            };
        }

        function tokenComment(stream, state) {
            var maybeEnd = false, ch;
            
            while (ch = stream.next()) {
                if (ch == ")" && maybeEnd) {
                    state.tokenize = null;
                    break;
                }
                maybeEnd = (ch == "*");
            }
            return "comment";
        }

      // Interface

        return {
            startState: function() {
                return {tokenize: null};
            },

            token: function(stream, state) {
                if (stream.eatSpace()) return null;
                
                var style = (state.tokenize || tokenBase)(stream, state);
                
                if (style == "comment" || style == "meta") return style;
                
                return style;
            },

            electricChars: "{}"
        };
    });

    CodeMirror.defineMIME("text/x-oberon07", "oberon07");

    /** Wrapper for CodeMirror Editor */
    Y.namespace('UI.Code').Editor = Y.Base.create('editorCodeUI', Y.View, {
        render: function (srcNode) {
            var editor,
                node = srcNode instanceof Y.Node ? srcNode : Y.one(srcNode);

            if (node) {
                editor = CodeMirror.fromTextArea(node._node, {
                    lineNumbers: true,
                    mode: 'text/x-oberon07'
                });
            }
        }
    }, {});

}, '1.0', {
    requires: [
        'view'
    ]
});