// Minimal framing needed to use CodeMirror-style parsers to highlight
// code. Load this along with tokenize.js, stringstream.js, and your
// parser. Then call highlightText, passing a string as the first
// argument, and as the second argument either a callback function
// that will be called with an array of SPAN nodes for every line in
// the code, or a DOM node to which to append these spans, and
// optionally (not needed if you only loaded one parser) a parser
// object.

// Stuff from util.js that the parsers are using.
var StopIteration = {toString: function() {return "StopIteration"}};

var Editor = {};
var indentUnit = 2;

(function(){
    function normaliseString(string) {
        var tab = "";
        for (var i = 0; i < indentUnit; i++) tab += " ";

        string = string.replace(/\t/g, tab).replace(/\u00a0/g, " ").replace(/\r\n?/g, "\n");
        var pos = 0, parts = [], lines = string.split("\n");
        for (var line = 0; line < lines.length; line++) {
            if (line != 0) parts.push("\n");
            parts.push(lines[line]);
        }

        return {
            next: function() {
                if (pos < parts.length) return parts[pos++];
                else throw StopIteration;
            }
        };
    }

    window.highlightText = function(string, callback, parser) {
        parser = (parser || Editor.Parser).make(stringStream(normaliseString(string)));
        var line = [];
        if (callback.nodeType == 1) {
            var node = callback;
            callback = function(line) {
                for (var i = 0; i < line.length; i++)
                    node.appendChild(line[i]);
                node.appendChild(document.createElement("br"));
            };
        }

        try {
            while (true) {
                var token = parser.next();
                if (token.value == "\n") {
                    callback(line);
                    line = [];
                }
                else {
                    var span = document.createElement("span");
                    span.className = token.style;
                    span.appendChild(document.createTextNode(token.value));
                    line.push(span);
                }
            }
        }
        catch (e) {
            if (e != StopIteration) throw e;
        }
        if (line.length) callback(line);
    }
})();
