// See COPYING for copyright and license details
(function () {
    var prefixMessage     = "\n==> DEBUG [MESSAGE]    : ";
    var prefixFile        = "\n==> DEBUG [FILE]       : ";
    var prefixError       = "\n==> DEBUG [ERROR]      : ";
    var prefixStack       = "\n==> DEBUG [STACK]      : ";
    var prefixArguments   = "\n==> DEBUG [ARGUMENTS]  : ";
    var prefixCaller      = "\n==> DEBUG [CALLER]";
    var prefixSource      = "\n==> DEBUG [SOURCE]\n";
    var prefixFunction = "\n------>";
    var regHasDwb = new RegExp("[^]*/\\*<dwb\\*/([^]*)/\\*dwb>\\*/[^]*");
    var prefixEditor    = "    ";
    var prefixHighlight = "--> ";
    var _formatLine = function(max, line) 
    {
            var size = max - Math.ceil(Math.log(line+1)/Math.log(10)) + 1; 
            return Array(size).join(" ") + line + " > ";
    };

    Object.defineProperties(io, {
        "debug" : 
        {
            value : function (params) 
            {
                if (typeof params == "function" && this._arguments)
                    return params.bind(this);
                var outMessage = new String();
                params = params || {};
                var offset = params.offset || 0;
                var error, message;
                var line = -1;
                var showLine;
                var caller, source;
                var stack;

                if (typeof params == "string")
                    message = params;
                else if (params instanceof Error)
                    error = params;
                else 
                {
                    if (params.message) 
                        message = params.message;
                    if (params.error instanceof Error)
                        error = params.error;
                }

                if (this.path) 
                    outMessage += prefixFile + this.path;
                if (message)
                    outMessage += prefixMessage + message;

                if (error)
                {
                    if (error.line || error.line === 0)
                        line = showLine = error.line;
                    else 
                        showLine = "?";
                    if (!error.stack) 
                    {
                        try 
                        {
                            throw new Error(error.message);
                        }
                        catch(e) 
                        { 
                            error = e;
                        }
                        offset += 1;
                    }
                    outMessage += prefixError + "Error in line " + showLine + ": " + error.message;
                    stack = "[" + error.stack.match(/[^\n]+/g).slice(offset).join("] [")+"]"; 
                }
                else 
                {
                    try 
                    {
                        throw new Error();
                    }
                    catch(e) 
                    {
                        stack =  "[" + e.stack.match(/[^\n]+/g).slice(offset + 2).join("] [")+"]"; 
                    }
                }
                if (stack) 
                {
                    outMessage += prefixStack + stack;
                }

                if (this._arguments && line >= 0)
                {
                    caller = String(this._arguments.callee).replace(regHasDwb, "$1", "");
                    source = caller.split("\n");
                    var length = source.length;
                    var formatLine = _formatLine.bind(null, Math.ceil(Math.log(source.length+1)/Math.log(10)));

                    outMessage += prefixSource;
                    if (length >= line-2 && line-2 >= 0)
                    {
                        if (line > 2)
                            outMessage += prefixEditor + "...\n";
                        else 
                            outMessage += prefixEditor + "BOF\n";
                        outMessage += prefixEditor + formatLine(line-1) +  source[line-2] + "\n";
                    }
                    else 
                        outMessage += prefixEditor + "BOF\n";
                    if (length > line-1)
                        outMessage += prefixHighlight + formatLine(line) + source[line-1] + "\n";
                    if (length > line && length != line+1) 
                    {
                        outMessage += prefixEditor + formatLine(line+1) + source[line];
                        if (length > line + 2)
                            outMessage += "\n" + prefixEditor + "...";
                        else 
                            outMessage += "\n" + prefixEditor + "EOF";
                    }
                    else 
                        outMessage += prefixEditor + "EOF";
                }
                else if (params.arguments) 
                {
                    outMessage += prefixArguments + JSON.stringify(params.arguments);
                    caller = String(params.arguments.callee.caller);
                    outMessage += prefixCaller;
                    outMessage += prefixFunction + "\n";
                    outMessage += caller.replace(regHasDwb, "$1").replace(/\n/gm, "\n  ");
                    outMessage += prefixFunction;
                }
                io.print(outMessage + "\n", "stderr");
                return undefined;
            }

        }
    });
})();
Object.freeze(io);
