var GSFN;
if (GSFN == undefined) {
    GSFN = {};

    GSFN.gId = function(id) {
        return document.getElementById(id);
    };

    GSFN.hasClassName = function(element, className) {
        var elementClassName = element.className;

        return (elementClassName.length > 0 && (elementClassName == className ||
      new RegExp("(^|\\s)" + className + "(\\s|$)").test(elementClassName)));
    };

    GSFN.addClassName = function(element, className) {
        if (!GSFN.hasClassName(element, className))
            element.className += (element.className ? ' ' : '') + className;
        return element;
    };

    GSFN.removeClassName = function(element, className) {
        var newClass = GSFN.strip(element.className.replace(new RegExp("(^|\\s+)" + className + "(\\s+|$)"), ' '));
        element.className = newClass;
        return element;
    };

    GSFN.strip = function(string) {
        return string.replace(/^\s+/, '').replace(/\s+$/, '');
    };
}

GSFN.feedback = function(url, tab_options) {
    this.empty_url = "https://s3.amazonaws.com/getsatisfaction.com/feedback/transparent.gif";
    this.feedback_url = url;
    this.tab_options = tab_options ? tab_options : {};
    this.tab_options.placement = this.tab_options.placement ? this.tab_options.placement : 'left';
    this.tab_options.color = this.tab_options.color ? this.tab_options.color : '#222';


    this.tab_html = '<a href="#" id="fdbk_tab" class="fdbk_tab_' + this.tab_options.placement + '" style="background-color:' + this.tab_options.color + '">FEEDBACK</a>';
    this.overlay_html = '<div id="fdbk_overlay" style="display:none">' +
                        '<div id="fdbk_container">' +
                          '<a href="#" onclick="GSFN.hide();return false" id="fdbk_close"></a>' +
                          '<iframe src="' + this.empty_url + '" id="fdbk_iframe" allowTransparency="true" scrolling="no" frameborder="0" class="loading"></iframe>' +
                        '</div>' +
                        '<div id="fdbk_screen"></div>' +
                      '</div>';

    if (this.tab_options.container) {
        var container_el = this.gId(this.tab_options.container);
        container_el.innerHTML = this.tab_html + this.overlay_html;
    } else {
        document.write(this.tab_html);
        document.write(this.overlay_html);
    }

    this.gId('fdbk_tab').onclick = function() { GSFN.show(); return false; }
    this.gId('fdbk_iframe').setAttribute("src", this.empty_url);
};

GSFN.set_position = function() {
    this.scroll_top = document.documentElement.scrollTop || document.body.scrollTop;
    this.scroll_height = document.documentElement.scrollHeight;
    this.client_height = window.innerHeight || document.documentElement.clientHeight;
    this.gId('fdbk_screen').style.height = this.scroll_height + "px";
    this.gId('fdbk_container').style.top = this.scroll_top + (this.client_height * 0.1) + "px";
};

GSFN.show = function() {
    this.gId('fdbk_iframe').setAttribute("src", this.feedback_url);
    if (this.gId('fdbk_iframe').addEventListener) {
        this.gId('fdbk_iframe').addEventListener("load", GSFN.loaded, false);
    } else if (this.gId('fdbk_iframe').attachEvent) {
        this.gId('fdbk_iframe').attachEvent("onload", GSFN.loaded);
    }
    this.set_position();

    GSFN.addClassName(document.getElementsByTagName('html')[0], 'feedback_tab_on');
    this.gId('fdbk_overlay').style.display = "block";
};

GSFN.hide = function() {
    if (GSFN.gId('fdbk_iframe').addEventListener) {
        GSFN.gId('fdbk_iframe').removeEventListener("load", GSFN.loaded, false);
    } else if (GSFN.gId('fdbk_iframe').attachEvent) {
        GSFN.gId('fdbk_iframe').detachEvent("onload", GSFN.loaded);
    }
    this.gId('fdbk_overlay').style.display = "none";
    this.gId('fdbk_iframe').setAttribute("src", this.empty_url);
    GSFN.gId('fdbk_iframe').className = "loading";

    GSFN.removeClassName(document.getElementsByTagName('html')[0], 'feedback_tab_on');
};

GSFN.loaded = function() {
    GSFN.gId('fdbk_iframe').className = "loaded";
};