var global = this;
var widgets = global.widgets = new function() {
    function debug(msg) {
        if (window.console && console.log) {
            console.log(msg);
        } else {
            if (!window.debugmessages) {
                window.debugmessages = [];
            };
            window.debugmessages.push(msg);
        };
    };

    var add_event_handler = function add_event_handler(
            el, evtname, handler, context, preventdefault) {
        /* register an event handler for event evtname on el

            use handler as the event handler, the handler is called with
            the TimeWidget instance as 'this'
        */
        var args = [];
        for (var i=4; i < arguments.length; i++) {
            args.push(arguments[i]);
        };
        var _wrapped_handler = function _wrapped_handler(e) {
            var currargs = args.concat(arguments);
            handler.apply(context, currargs);
            if (preventdefault) {
                if (e.preventDefault) {
                    e.preventDefault();
                };
                if (e.stopPropagation) {
                    e.stopPropagation();
                };
                e.cancelBubble = true;
                e.returnValue = false;
            };
        };
        if (el.addEventListener) {
            el.addEventListener(evtname, _wrapped_handler, false);
        } else if (el.attachEvent) {
            el.attachEvent('on' + evtname, _wrapped_handler);
        } else {
            debug('error attaching event handler - unrecognized browser');
        };

        return _wrapped_handler;
    };

    var remove_event_handler =
            function remove_event_handler(el, evtname, handler) {
        if (el.removeEventListener) {
            el.removeEventListener(evtname, handler, false);
        } else if (el.detachEvent) {
            el.detachEvent('on' + evtname, handler);
        };
    };

    var schedule = function schedule(handler, msecs) {
        var id = this._last_handler_id ? this._last_handler_id + 1 : 0;
        this._last_handler_id = id;
        var args = [];
        for (var i=2; i < arguments.length; i++) {
            args.push(arguments[i]);
        };
        var self = this;
        var wrappedhandler = window['_scheduled_' + id] = function() {
            handler.apply(self, args);
        };
        return window.setTimeout('window._scheduled_' + id + '()', msecs);
    };

    function TimeWidget(widgetinput) {
        if (arguments.length) {
            if (typeof widgetinput == 'string') {
                widgetinput = document.getElementById(widgetinput);
            };
            this._initialize(widgetinput);
        };
    };

    this.TimeWidget = TimeWidget;

    TimeWidget.prototype._initialize = function _initialize(input) {
        this.orginput = input;
        var value = input.value;
        if (!/^\d{1,2}\:\d{2}$/.exec(value)) {
            debug('unexpected time value ("' + value + '") on widget ' +
                  'initialization');
            value = '0:00';
        };

        this._submit_handler = add_event_handler(
            input.form, 'submit', this.deinit, this);
        this._unload_handler = add_event_handler(
            window, 'unload', this.deinit, this);
        this._build_widget(input, value);
    };

    TimeWidget.prototype.deinit = function deinit() {
        /* deinitialize for form submit and page reload
        
            serialize the value, write to the (now hiddden) text input
            and remove the widget
        */
        remove_event_handler(
            this.orginput.form, 'submit', this._submit_handler);
        remove_event_handler(
            window, 'unload', this._unload_handler);
        this.widgetdiv.parentNode.removeChild(this.widgetdiv);
        var value = this.get_value();
        this.orginput.value = value;
        this.orginput.style.display = 'inline';
    };

    TimeWidget.prototype.get_value = function get_value() {
        var value = this.timeinput.value;
        if (!/^\d{1,2}\:\d{2}$/.exec(value)) {
            debug('incorrect value in form field: ' + value);
            value = '0:00';
        };
        return value;
    };

    TimeWidget.prototype._change_value = function _change_value(intensity) {
        var value = this.get_value();
        var hourminute = value.split(':');
        var hour = parseInt(hourminute[0]);
        var minute = parseInt(hourminute[1], 10);
        var d = new Date(1970, 1, 2, hour, minute);
        var hourplus = 0;
        var minuteplus = 0;
        switch (intensity) {
            case -2:
                hourplus = -1;
                break;
            case -1:
                minuteplus = -1;
                break;
            case 1:
                minuteplus = 1;
                break;
            case 2:
                hourplus = 1;
                break;
        };
        var toadd = (hourplus * 60 * 60000) + (minuteplus * 60000);
        var d2 = new Date(d.getTime() + toadd);
        var hours = d2.getHours().toString();
        var minutes = d2.getMinutes().toString();
        if (minutes.length == 1) {
            minutes = '0' + minutes;
        };
        var newvalue = hours + ':' + minutes;
        this.timeinput.value = newvalue;
    };

    TimeWidget.prototype._build_widget =
            function _build_widget(placeholder, value) {
        placeholder.style.display = 'none';
        var doc = placeholder.ownerDocument;
        var div = this.widgetdiv = doc.createElement('div');
        div.className = 'timewidget';
        var timeinput = this.timeinput = doc.createElement('input');
        timeinput.value = value;
        timeinput.type = 'text';
        timeinput.size = 5;
        timeinput.maxlength = 5;
        //timeinput.disabled = 'disabled';
        div.appendChild(timeinput);
        var self = this;
        this.updowncontrol = new UpDownControl(
            div, timeinput, function(x) {self._change_value(x)});
        placeholder.parentNode.insertBefore(div, placeholder);
    };

    function FloatWidget(widgetinput, stepsize, precision, disallownegative) {
        if (arguments.length) {
            if (typeof widgetinput == 'string') {
                widgetinput = document.getElementById(widgetinput);
            };
            this._initialize(
                widgetinput, stepsize, precision, disallownegative);
        };
    };

    this.FloatWidget = FloatWidget;

    FloatWidget.prototype._initialize =
            function _initialize(input, stepsize, precision,
                                 disallownegative) {
        this.orginput = input;
        this.stepsize = stepsize || 0.1;
        this.precision = precision || 1;
        this.disallownegative = !!disallownegative;
        var value = input.value;
        if (!/^[-]?\d+(\.\d+)?$/.exec(value)) {
            debug('unexpected float value ("' + value + '") on widget ' +
                  'initialization');
            value = 0.0;
        } else {
            value = parseFloat(value);
        };

        this._submit_handler = add_event_handler(
            input.form, 'submit', this.deinit, this);
        this._unload_handler = add_event_handler(
            window, 'unload', this.deinit, this);
        this._build_widget(input, value);
    };

    FloatWidget.prototype.deinit = function deinit() {
        /* deinitialize for form submit and page reload
        
            serialize the value, write to the (now hiddden) text input
            and remove the widget
        */
        remove_event_handler(
            this.orginput.form, 'submit', this._submit_handler);
        remove_event_handler(
            window, 'unload', this._unload_handler);
        this.widgetdiv.parentNode.removeChild(this.widgetdiv);
        var value = this.get_value();
        this.orginput.value = value;
        this.orginput.style.display = 'inline';
    };

    FloatWidget.prototype.get_value = function get_value() {
        var value = this.floatinput.value;
        if (!/^[-]?\d+(\.\d+)?$/.exec(value)) {
            debug('incorrect value in form field: ' + value);
            value = 0.0;
        } else {
            value = parseFloat(value);
        };
        if (this.disallownegative && value < 0) {
            value = 0.0;
        };
        return value;
    };

    FloatWidget.prototype._change_value = function _change_value(intensity) {
        var value = this.get_value();
        var toadd;
        switch (intensity) {
            case -2:
                toadd = -1;
                break;
            case -1:
                toadd = -this.stepsize;
                break;
            case 1:
                toadd = this.stepsize;
                break;
            case 2:
                toadd = 1;
                break;
        };
        var newvalue = value + toadd;
        if (this.disallownegative && newvalue < 0) {
            newvalue = 0.0;
        };
        this.floatinput.value = newvalue.toFixed(this.precision);
    };

    FloatWidget.prototype._build_widget =
            function _build_widget(placeholder, value) {
        placeholder.style.display = 'none';
        var doc = placeholder.ownerDocument;
        var div = this.widgetdiv = doc.createElement('div');
        div.className = 'floatwidget';
        var floatinput = this.floatinput = doc.createElement('input');
        alert(value);
        floatinput.value = value;
        floatinput.type = 'text';
        floatinput.size = 5;
        floatinput.maxlength = 5;
        //timeinput.disabled = 'disabled';
        div.appendChild(floatinput);
        var self = this;
        this.updowncontrol = new UpDownControl(
            div, floatinput, function(x) {self._change_value(x)});
        placeholder.parentNode.insertBefore(div, placeholder);
    };

    function UpDownControl() {
        if (arguments.length) {
            this._initialize.apply(this, arguments);
        };
    };

    this.UpDownControl = UpDownControl;

    UpDownControl.prototype._initialize =
            function _initialize(placeholder, input, handler) {
        this.placeholder = placeholder;
        this.input = input;
        this.handler = handler;

        var doc = placeholder.ownerDocument;
        var plusicon = doc.createElement('a');
        plusicon.className = 'up';
        plusicon.appendChild(doc.createTextNode('\xa0'));
        add_event_handler(
            plusicon, 'mousedown', this.plus_down, this, true);
        add_event_handler(
            plusicon, 'mouseup', this.cancel, this, true);
        add_event_handler(
            plusicon, 'mouseout', this.cancel, this, true);
        placeholder.appendChild(plusicon);
        var minusicon = doc.createElement('a');
        minusicon.className = 'down';
        minusicon.appendChild(doc.createTextNode('\xa0'));
        add_event_handler(
            minusicon, 'mousedown', this.minus_down, this, true);
        add_event_handler(
            minusicon, 'mouseup', this.cancel, this, true);
        add_event_handler(
            minusicon, 'mouseout', this.cancel, this, true);
        placeholder.appendChild(minusicon);
    };

    UpDownControl.prototype.minus_down = function minus_down() {
        this._start_loop(-1);
    };

    UpDownControl.prototype.plus_down = function plus_down() {
        this._start_loop(1);
    };

    UpDownControl.prototype._start_loop = function _start_loop(direction) {
        var i = 0;
        var self = this;
        var handler = function() {
            var intensity = i < 15 ? 1 : 2;
            self.handler(direction * intensity);
            var interval = (i < 3) ? 400 : 200;
            self._scheduled = schedule(handler, interval);
            i++;
        };
        handler();
    };

    UpDownControl.prototype.cancel = function cancel() {
        if (this._scheduled) {
            window.clearTimeout(this._scheduled);
            this._scheduled = null;
        };
    };
}();