$(function() {

    var calculator = {
        // key styles
        primaryStyles: ['fontFamily', 'fontSize', 'fontWeight', 'fontVariant', 'fontStyle',
			'paddingLeft', 'paddingTop', 'paddingBottom', 'paddingRight',
			'marginLeft', 'marginTop', 'marginBottom', 'marginRight',
			'borderLeftColor', 'borderTopColor', 'borderBottomColor', 'borderRightColor',
			'borderLeftStyle', 'borderTopStyle', 'borderBottomStyle', 'borderRightStyle',
			'borderLeftWidth', 'borderTopWidth', 'borderBottomWidth', 'borderRightWidth',
			'line-height', 'outline'],

        specificStyle: {
            'word-wrap': 'break-word',
            'overflow-x': 'hidden',
            'overflow-y': 'auto'
        },

        simulator: $('<div id="textarea_simulator"/>').css({
            position: 'absolute',
            top: 0,
            left: 0,
            visibility: 'hidden'
        }).appendTo(document.body),

        toHtml: function(text) {
            return text.replace(/\n/g, '<br>')
				.split(' ').join('<span style="white-space:prev-wrap">&nbsp;</span>');
        },
        // calculate position
        getCaretPosition: function(cursorPosition) {
            var cal = calculator, self = this, element = self[0], elementOffset = self.offset();

            // IE has easy way to get caret offset position
            if ($.browser.msie) {
                // must get focus first
                element.focus();
                var range = document.selection.createRange();
                $('#hskeywords').val(element.scrollTop);
                return {
                    left: range.boundingLeft - elementOffset.left,
                    top: parseInt(range.boundingTop) - elementOffset.top + element.scrollTop
						+ document.documentElement.scrollTop + parseInt(self.getComputedStyle("fontSize"))
                };
            }
            cal.simulator.empty();
            // clone primary styles to imitate textarea
            $.each(cal.primaryStyles, function(index, styleName) {
                self.cloneStyle(cal.simulator, styleName);
            });

            // caculate width and height
            cal.simulator.css($.extend({
                'width': self.width(),
                'height': self.height()
            }, cal.specificStyle));

            var value = self.val();
            var beforeText = value.substring(0, cursorPosition),
				afterText = value.substring(cursorPosition);

            var before = $('<span class="before"/>').html(cal.toHtml(beforeText)),
				focus = $('<span class="focus"/>'),
				after = $('<span class="after"/>').html(cal.toHtml(afterText));

            cal.simulator.append(before).append(focus).append(after);
            var focusOffset = focus.offset(), simulatorOffset = cal.simulator.offset();
            // alert(focusOffset.left  + ',' +  simulatorOffset.left + ',' + element.scrollLeft);
            return {
                top: focusOffset.top - simulatorOffset.top - element.scrollTop
                // calculate and add the font height except Firefox
					+ ($.browser.mozilla ? 0 : parseInt(self.getComputedStyle("fontSize"))),
                left: focus[0].offsetLeft - cal.simulator[0].offsetLeft - element.scrollLeft
            };
        }
    };

    $.fn.extend({
        getComputedStyle: function(styleName) {
            if (this.length == 0) return;
            var thiz = this[0];
            var result = this.css(styleName);
            result = result || ($.browser.msie ?
				thiz.currentStyle[styleName] :
				document.defaultView.getComputedStyle(thiz, null)[styleName]);
            return result;
        },
        // easy clone method 
        cloneStyle: function(target, styleName) {
            var styleVal = this.getComputedStyle(styleName);
            if (!!styleVal) {
                $(target).css(styleName, styleVal);
            }
        },
        cloneAllStyle: function(target, style) {
            var thiz = this[0];
            for (var styleName in thiz.style) {
                var val = thiz.style[styleName];
                typeof val == 'string' || typeof val == 'number'
					? this.cloneStyle(target, styleName)
					: NaN;
            }
        },
        getCursorPosition: function() {
            var thiz = this[0], result = 0;
            if ('selectionStart' in thiz) {
                result = thiz.selectionStart;
            } else if ('selection' in document) {
                var range = document.selection.createRange();
                if (parseInt($.browser.version) > 6) {
                    thiz.focus();
                    var length = document.selection.createRange().text.length;
                    range.moveStart('character', -thiz.value.length);
                    result = range.text.length - length;
                } else {
                    var bodyRange = document.body.createTextRange();
                    bodyRange.moveToElementText(thiz);
                    for (; bodyRange.compareEndPoints("StartToStart", range) < 0; result++)
                        bodyRange.moveStart('character', 1);
                    for (var i = 0; i <= result; i++) {
                        if (thiz.value.charAt(i) == '\n')
                            result++;
                    }
                    var enterCount = thiz.value.split('\n').length - 1;
                    result -= enterCount;
                    return result;
                }
            }
            return result;
        },
        getCaretPosition: calculator.getCaretPosition
    });
});
TextareaUtils = (function() {
    var it = {};
    var ds = document.selection;
    var atTime = null;
    var reg = new RegExp("@[0-9(请输入网校号)]{0,12}$");

    it.init = function(obj, numbObj) {
        it.check(obj, numbObj);
        $(obj).bind('click keyup input propertychange', function(event) {
            $('#atTip').remove();
            //$('<div id="atTip"  class="tipDIV" style="position:absolute;"><ul><li alt="@001">天才</li></ul></div>').appendTo($(obj).parent()).hide();
            it.check(obj, numbObj);
            window.clearTimeout(atTime);
            atTime = window.setTimeout(function() {
                var pos = it.getTextPos(obj).start;
                var pretext = obj.value.substr(0, pos);
                if (reg.test(pretext)) {
                    var m = pretext.match(reg).toString();
                    var reg2 = new RegExp("^[0-9]+[ ]{0,}");
                    var m2 = (obj.value.substr(pos).match(reg2) || "").toString();

                    var position = $(obj).getCaretPosition(pos - m.length + 2);
                    showAtContent(obj, obj);
                    $('#showAtContent').css({ left: ($(obj).offset().left + position.left), top: ($(obj).offset().top + position.top + 10) });
                    $('#showAtContent input').val(m.substring(1, m.length) + m2.substring(0, m2.length - 1)).change();
                    $('#showAtContent li').unbind('click').click(function() {
                        var usernumb = $(this).attr('usernumb');
                        it.selectText(obj, pos - m.length + 1, pos + m2.length + 1);
                        it.rangeText(obj, usernumb + " ");
                        it.selectText(obj, pos - m.length + usernumb.length + 1, pos - m.length + usernumb.length + 1);
                        $('#showAtContent').hide();
                        it.selectText(obj, pos - m.length, pos - m.length + usernumb.length + 1);
                    });

                } else {
                    $('#showAtContent').hide();
                }
            }, 100);
        });
    };

    it.check = function(obj, numbObj) {
        var text = $(obj).val();
        text = text.replace(/@请输入网校号/g, "");
        text = text.replace(/#请输入话题#/g, "");
        text = text.replace(/^[ \r\n]+$/g, "");
        text = text.replace(/[ \r\n]+/g, " ");
        var n = 140 - text.length;
        if (n == 140) { $(numbObj).html("请输入内容"); return false; }
        else if (n >= 0) { $(numbObj).html("还可输入<strong>" + n + "</strong>字"); return true; }
        else {
            $(numbObj).html("已经超出<strong>" + (-n) + "</strong>字");
            return false;
        }
    }

    //@人
    it.inAt = function(obj, str) {
        var str = str || "@请输入网校号";
        var reg = new RegExp(str),
	                    oValue = obj.value,
	                    val_index = 0,
	                    val_match,
                        val_pos;
        if (reg.test(oValue)) {
            val_match = oValue.match(reg);
            val_index = val_match.index;

        }
        else {
            val_pos = it.getTextPos(obj);
            val_index = val_pos.start;
            it.rangeText(obj, str);
        }
        it.selectText(obj, val_index + str.length, val_index + str.length);
    };

    //插入话题
    it.inTopic = function(obj, str) {
        var str = str || "请输入话题";
        str = "#" + str + "#";
        var reg = new RegExp(str),
	            oValue = obj.value,
	            val_index = 0,
	            val_match,
                val_pos;
        if (reg.test(oValue)) {
            val_match = oValue.match(reg);
            val_index = val_match.index;
        }
        else {
            val_pos = it.getTextPos(obj);
            val_index = val_pos.start;
            it.rangeText(obj, str);
        }
        it.selectText(obj, val_index + 1, val_index + str.length - 1);
    };

    //插入文本
    it.inText = function(obj, str) {
        val_pos = it.getTextPos(obj);
        val_index = val_pos.start;
        it.rangeText(obj, str);
        it.selectText(obj, val_index, val_index + str.length);
    };

    //插入文本 不选
    it.inText1 = function (obj, str) {
        val_pos = it.getTextPos(obj);
        val_index = val_pos.start;
        it.rangeText(obj, str);
        it.selectText(obj, val_index + str.length, val_index + str.length);
    };

    /*获取光标位置*/
    it.getTextPos = function(obj) {
        if (!obj || obj.offsetWidth == 0) { return false; }
        var t = obj, start = 0, end = 0, value = '', range, range_all;
        value = t.value;
        if (typeof (t.selectionStart) == "number") {
            start = t.selectionStart;
            end = t.selectionEnd;
        }
        else if (document.selection && t.offsetWidth > 0) {
            t.focus();
            range = document.selection.createRange();
            if (range.parentElement() == t) {
                range_all = document.body.createTextRange();
                range_all.moveToElementText(t);
                for (start = 0; range_all.compareEndPoints("StartToStart", range) < 0; start++) {
                    range_all.moveStart('character', 1);
                }
                for (var i = 0; i <= start; i++) {
                    if (t.value.charAt(i) == '\n') {
                        start++;
                    }
                }
                range_all.moveToElementText(t);
                for (end = 0; range_all.compareEndPoints('StartToEnd', range) < 0; end++) {
                    range_all.moveStart('character', 1);
                }
                for (var i = 0; i <= end; i++) {
                    if (t.value.charAt(i) == '\n') {
                        end++;
                    }
                }
            }
        }
        else {
            start = value.length;
            end = value.length;
        }
        return {
            start: start,
            end: end
        }
    };

    //光标处替换的文本
    it.rangeText = function(obj, val, num) {
        if (!obj || obj.offsetWidth == 0) { return false; }
        var t = obj, start = 0, end = 0, value = '', val_start = '', val_end = '', pos;
        var userAgent = navigator.userAgent.toLowerCase(), ie = /msie/.test(userAgent) && !/opera/.test(userAgent);
        if (ie && t.nodeName.toLocaleLowerCase() != 'textarea') {
            t.value = val;
            t.focus;
            return;
        }
        value = t.value;
        pos = it.getTextPos(t);
        start = pos.start;
        end = pos.end;
        if (typeof num == 'number') {
            start = start - num;
        }
        val_start = value.substring(0, start);
        val_end = value.substring(end);
        t.value = val_start + val + val_end;
        if (typeof num == 'number') {
            end = end - num;
        }
        it.selectText(t, end + val.length, end + val.length);
    };

    //光标定位到指定文本
    it.selectText = function(obj, start, stop) {
        if (!obj || obj.offsetWidth == 0) { return false; }
        var range;
        if (obj.setSelectionRange) {
            obj.setSelectionRange(start, stop);
        }
        else {
            range = obj.createTextRange();
            range.collapse(true);
            range.moveStart("character", start);
            range.moveEnd("character", stop - start);
            range.select();
        }
        obj.focus();
    };

    it.shownormal = function(obj, times) {
        $(obj).css("background-color", "#FFF");
        if (times < 0) return;
        times = times - 1;
        setTimeout(function() { TextareaUtils.showerror(obj, times) }, 150);
    }

    it.showerror = function(obj, times) {
        $(obj).css("background-color", "#F6CECE");
        times = times - 1;
        setTimeout(function() { TextareaUtils.shownormal(obj, times) }, 150);
    }

    return it;
})();

if ($('#weibo_textarea').length > 0)
    TextareaUtils.init($('#weibo_textarea')[0], $('#weibo_num')[0]);