(function($) {

    var testTimeout = false;
    var hintTimeout = false;

    $.fn.is_input = function(options) {

        var args = arguments;

        return this.each(function(){

            var obj = this;
            var $obj = $(this);

            switch (options) {
                case 'test':
                    return test(obj);
                case 'setRegExp':
                    return setRegExp(obj, args[1]);
                case 'setHint':
                    return setHint(obj, args[1]);
            }

            var defaults = {
                is_input: true,
                old_value: '',
                hint: false,
                regexp: false,
                filterRegexp: false,
                onchange: false,
                onerror: false
            }

            if (this.params && this.params.is_input) return true;
            if (obj.tagName != 'TEXTAREA' && (obj.tagName != 'INPUT' || obj.type.toUpperCase() != 'TEXT')) return true;
            this.params = $.extend(defaults, options, this.params);

            $obj.keydown(function(e) {
                if (e.keyCode == 17) return true;
                if (obj.params.time == new Date().getTime()) return true;
                obj.params.time = new Date().getTime();
                if (testTimeout) return false;
                if (!obj.params.regexp && !obj.params.filterRegexp) return true;
                obj.params.old_value = $obj.val();
                testTimeout = window.setTimeout(function() {
                    testTimeout = false;
                    test(obj);
                }, 10);
                return true;
            });

            $obj.bind("input paste", function(e) {
                if (testTimeout) return true;
                if (!obj.params.regexp && !obj.params.filterRegexp) return true;
                obj.params.old_value = $obj.val();
                testTimeout = window.setTimeout(function() {
                    testTimeout = false;
                    test(obj);
                }, 10);
                return true;
            });

            $obj.bind("blur", function(e) {
                hideHint(obj);
            });

            test(obj);

        });

    }

    function test(obj) {
        var $obj = $(obj);
        obj = $obj[0];
        if (!obj.params) return true;
        var result = true;
        if (obj.params.filterRegexp) {
            var oldVal = $obj.val();
            var newVal = oldVal.replace(obj.params.filterRegexp, '');
            if (newVal != oldVal) {
                result = false;
                $obj.val(newVal);
            }
        }
        if (obj.params.regexp && !obj.params.regexp.test($obj.val())) {
            result = false;
            var val = obj.params.old_value;
            for (var i = val.length - 1; i >= 0; i--) {
                if (obj.params.regexp.test(val)) break;
                val = val.substr(0, i) + val.substr(i + 1);
            }
            $obj.val(val);
        }
        if (result && obj.params.onchange && obj.params.old_value != $obj.val()) obj.params.onchange(obj);
        if (!result && obj.params.onerror) obj.params.onerror(obj);
        if (!result && obj.params.hint) showHint(obj, obj.params.hint);
        if (result && obj.params.hint) hideHint(obj);
        obj.params.old_value = '';
        return result;
    }

    function showHint(obj, hint) {

        var $obj = $(obj);
        obj = $obj[0];

        var $element = $('#is_input_hint');
        if (!$element.length) {
            var html =
            '<div id="is_input_hint"></div>';
            $('body').append(html);
            $element = $('#is_input_hint');
        }

        hideHint(obj);

        var top = $obj.offset().top + $obj.outerHeight() + 1;
        var left = $obj.offset().left;
        $element.html(htmlEncode(hint, true));

        if (top + $element.outerHeight() - $(window).scrollTop() > $(window).height()) {
            top -= $obj.outerHeight() + $element.outerHeight() + 2;
        }
        $element.css('top', top).css('left', left).show();
        hintTimeout = window.setTimeout(function() {
            hintTimeout = false;
            $('#is_input_hint').hide();
        }, 5000);

    }

    function hideHint(obj) {
        if (hintTimeout) {
            window.clearTimeout(hintTimeout);
            hintTimeout = false;
            $('#is_input_hint').hide();
        }
    }

    function setRegExp(obj, regexp) {

        var $obj = $(obj);
        obj = $obj[0];

        if (!obj.params) return;
        obj.params.regexp = regexp;
        test(obj);

    }

    function setHint(obj, hint) {

        var $obj = $(obj);
        obj = $obj[0];

        if (!obj.params) return;
        obj.params.hint = hint;

    }

    function htmlEncode(s, lineBreaks) {
        var result = s
        .replace(/&/g, "&amp;")
        .replace(/</g, "&lt;")
        .replace(/>/g, "&gt;")
        .replace(/\"/g, "&quot;");
        if (lineBreaks) result = result.replace(/\n/g, '<br>');
        return result;
    }

    function htmlDecode(s) {
        return s
        .replace(/&quot;/g, "\"")
        .replace(/&gt;/g, ">")
        .replace(/&lt;/g, "<")
        .replace(/&amp;/g, "&");
    }

})(jQuery);