/*
Script Name: Wordpress keyboad navigation
Author: Mateus Reis
Author URI: http://laboratorio72.com/
Description: Adds keyboard navigation to index and single post pages.
Version: 1.0                                                              
*/
function checkKey(e){
		// next prev post
		var f=false, b=false;
		// next prev nav
		var next=false, prev=false, target=false;
		
		if (e.target.tagName.match(/input|textarea/i)) return;
		
		switch (e.keyCode) {
			case 37:
				prev = true;
				target = jQuery('.nav-previous').find('a').attr('href');
				break;
			case 39:
				next = true;
				target = jQuery('.nav-next').find('a').attr('href');
				break;	
			case 75:
			case 107:
				b=true;
				break;
			case 74:
			case 106:
				f=true;
				break;
	}
	
	// alert(e.keyCode);
	
	// if nav == true, go!
    if ((next || prev) && target) {
    	window.location.href = target;    	
    };
    
    // if single post, return before next/prev post
    if (jQuery('.post').length < 2) return;
    
	if (!f && !b) return;
		jQuery('.post').each( function(i,el) {
			if(f && parseInt(jQuery(el).offset().top,10) > parseInt(jQuery(document).scrollTop(),10)) {
				if(jQuery(document).scrollTop() + jQuery(window).height() >= jQuery(document).height()){
					pnkeynavPage(1);
				}			
				jQuery(document).scrollTop(jQuery(el).offset().top);
				f = false;
			}
			if(b && parseInt(jQuery(el).offset().top,10) >= parseInt(jQuery(document).scrollTop(),10)) {
				var d=jQuery('.post').get(i-1);
				if (i > 0) {
					jQuery(document).scrollTop(jQuery(d).offset().top);
					b = false;
				} else {
					pnkeynavPage(-1);
				}
			}
		});
		if (f) {
			pnkeynavPage(1);
		}
}

function pnkeynavPage (inc) {
	var path = window.location.pathname;
	if (p=path.match(/\/page\/(\d+)\/?$/)) {
		var p = parseInt(p[1], 10) + inc;
		var s = p > 1 ? '/page/'+p+'/' : '';
		window.location.pathname = path.replace(/\/page\/(\d+)\/?$/, s);
	} else if (inc > 0)
		window.location.pathname = path + '/page/2/';
}

jQuery(document).keydown(checkKey);