// ==UserScript==
// @name          Expand code blocks on Stack Exchange sites
// @namespace     stackapps
// @version		  1.1
// @description   Click a code block with scroll bars and it automatically expands
// @icon		  http://i.stack.imgur.com/EmeVj.png
// @match         *://*.serverfault.com/questions*
// @match         *://*.serverfault.com/review*
// @match         *://*.stackapps.com/questions*
// @match         *://*.stackapps.com/review*
// @match         *://*.stackoverflow.com/questions*
// @match         *://*.stackoverflow.com/review*
// @match         *://*.superuser.com/questions*
// @match         *://*.superuser.com/review*
// @match         *://*.wordpress.stackexchange.com/questions*
// @match         *://*.wordpress.stackexchange.com/review*
// @grant		  none
// @author        Alconja
// @contributor   brasofilo
// ==/UserScript==

/**
 * Adapted from http://stackoverflow.com/a/8971716/1287812
 */
$.fn.has_scrollbar = function() {
    var divnode = this.get(0);
    if(divnode.scrollHeight > divnode.clientHeight || divnode.scrollWidth > divnode.clientWidth )
        return true;
};

/**
 * Expand <pre>
 */
function expando( pre ) {
	var maxHeight = null;
	pre.css("z-index", 1000);
    var code = pre.children("code");
    if (maxHeight === null) {
        maxHeight = pre.css("max-height");
        if( pre.attr('max-height') === undefined )
	        pre.attr('max-height',maxHeight);
    }
    var oldWidth = pre.width();
    var codeWidth = Math.max(code.width(), oldWidth);
    var maxWidth = $(window).width() - 20;
    var width = Math.min(maxWidth, codeWidth);
    
    var maxLeft = (-1 * pre.offset().left) + 5;
    var idealLeft = (oldWidth - width) / 4.5;
    var left = Math.max(maxLeft, idealLeft);
    pre.css({width: width + "px", position: "relative", left: left + "px", maxHeight: "inherit"});
    if (width < codeWidth) {                //last ditch attempt to fit...
        var pc = 100 * width / codeWidth;
        pc = Math.max(pc, 70);              //any smaller & you can't read it...
        pre.css("font-size", pc + "%");
    }
}

/**
 * Contract <pre>
 */
function contracto( pre ) {
    pre.css({width: "auto", position: "static", maxHeight: pre.attr('max-height'), fontSize: "100%"});
}

/**
 * Check page and add arrows
 */
function addArrows() {
    var count_pre = 1;
    $('pre').each(function(){ 
        if( $(this).has_scrollbar() ) {
            $(this).before('<span class="expander-arrow-small-hide" id="expander-id-' + count_pre + '" style="float:right"></span>'); 
            $('#expander-id-'+count_pre).click(function(){
                if( $(this).hasClass('expander-arrow-small-hide') ){
                    expando( $(this).next() );
                    if( location.host.indexOf('wordpress.stackexchange') > -1 ) {
                        $('#content').css('overflow','visible');
                    }
                    $(this).removeClass('expander-arrow-small-hide').addClass('expander-arrow-small-show');
                }
                else {
                    if( location.host.indexOf('wordpress.stackexchange') > -1 ) {
                        $('#content').css('overflow','auto');
                    }
                    contracto( $(this).next() );
                    $(this).removeClass('expander-arrow-small-show').addClass('expander-arrow-small-hide');
                }
            }).css('cursor','pointer');
            count_pre++;
        }
    });
}

/**
 * Run when reviewing
 */
if( StackExchange.options.routeName === 'Review/Task' ) {
    $(document).ajaxComplete(function( event, xhr, settings ){
        if( settings.url.indexOf('review/task-reviewed') !== -1 || settings.url.indexOf('review/next-task') !== -1 ) {
            addArrows();
        }
    });
}

/**
 * Run when viewing a question
 */
if( StackExchange.options.routeName == "Questions/Show" ) {
    // Only SO has this property as visible, which is needed to fully expand the blocks 
    if( location.host.indexOf('stackoverflow.com') === -1 && location.host.indexOf('wordpress.stackexchange') === -1  ) {
        if( $('#content').css('overflow') === 'auto' )
            $('#content').css('overflow','visible');
    }
    addArrows();
}