(function($) {

// static constructs
$.tools = $.tools || {version: '@VERSION'};

var tool;

tool = $.tools.expose = {

conf: {
maskId: 'exposeMask',
loadSpeed: 'slow',
closeSpeed: 'fast',
closeOnClick: true,
closeOnEsc: true,

// css settings
zIndex: 9998,
opacity: 0.8,
startOpacity: 0,
color: '#fff',

// callbacks
onLoad: null,
onClose: null
}
};

/* one of the greatest headaches in the tool. finally made it */
function viewport() {

// the horror case
if ($.browser.msie) {

// if there are no scrollbars then use window.height
var d = $(document).height(), w = $(window).height();

return [
window.innerWidth || // ie7+
document.documentElement.clientWidth || // ie6
document.body.clientWidth, // ie6 quirks mode
d - w < 20 ? w : d
];
}

// other well behaving browsers
return [$(document).width(), $(document).height()];
}

function call(fn) {
if (fn) { return fn.call($.mask); }
}

var mask, exposed, loaded, config, overlayIndex;


$.mask = {

load: function(conf, els) {

// already loaded ?
if (loaded) { return this; }

// configuration
if (typeof conf == 'string') {
conf = {color: conf};
}

// use latest config
conf = conf || config;

config = conf = $.extend($.extend({}, tool.conf), conf);

// get the mask
mask = $("#" + conf.maskId);

// or create it
if (!mask.length) {
mask = $('<div/>').attr("id", conf.maskId);
$("body").append(mask);
}

// set position and dimensions
var size = viewport();

mask.css({
position:'absolute',
top: 0,
left: 0,
width: size[0],
height: size[1],
display: 'none',
opacity: conf.startOpacity,
zIndex: conf.zIndex
});

if (conf.color) {
mask.css("backgroundColor", conf.color);
}

// onBeforeLoad
if (call(conf.onBeforeLoad) === false) {
return this;
}

// esc button
if (conf.closeOnEsc) {
$(document).bind("keydown.mask", function(e) {
if (e.keyCode == 27) {
$.mask.close(e);
}
});
}

// mask click closes
if (conf.closeOnClick) {
mask.bind("click.mask", function(e) {
$.mask.close(e);
});
}

// resize mask when window is resized
$(window).bind("resize.mask", function() {
$.mask.fit();
});

// exposed elements
if (els && els.length) {

overlayIndex = els.eq(0).css("zIndex");

// make sure element is positioned absolutely or relatively
$.each(els, function() {
var el = $(this);
if (!/relative|absolute|fixed/i.test(el.css("position"))) {
el.css("position", "relative");
}
});

// make elements sit on top of the mask
exposed = els.css({ zIndex: Math.max(conf.zIndex + 1, overlayIndex == 'auto' ? 0 : overlayIndex)});
}

// reveal mask
mask.css({display: 'block'}).fadeTo(conf.loadSpeed, conf.opacity, function() {
$.mask.fit();
call(conf.onLoad);
loaded = "full";
});

loaded = true;
return this;
},

close: function() {
if (loaded) {

// onBeforeClose
if (call(config.onBeforeClose) === false) { return this; }

mask.fadeOut(config.closeSpeed, function() {
call(config.onClose);
if (exposed) {
exposed.css({zIndex: overlayIndex});
}
loaded = false;
});

// unbind various event listeners
$(document).unbind("keydown.mask");
mask.unbind("click.mask");
$(window).unbind("resize.mask");
}

return this;
},

fit: function() {
if (loaded) {
var size = viewport();
mask.css({width: size[0], height: size[1]});
}
},

getMask: function() {
return mask;
},

isLoaded: function(fully) {
return fully ? loaded == 'full' : loaded;
},

getConf: function() {
return config;
},

getExposed: function() {
return exposed;
}
};

$.fn.mask = function(conf) {
$.mask.load(conf);
return this;
};

$.fn.expose = function(conf) {
$.mask.load(conf, this);
return this;
};


})(jQuery);