var EPUBJS = EPUBJS || {}; 
EPUBJS.core = {}

//-- Get a element for an id
EPUBJS.core.getEl = function(elem) {
  return document.getElementById(elem);
}

//-- Get all elements for a class
EPUBJS.core.getEls = function(classes) {
  return document.getElementsByClassName(classes);
}


EPUBJS.core.request = function(url, type) {
	var promise = new RSVP.Promise();
	
	var xhr = new XMLHttpRequest();
	
	xhr.open("GET", url);
	xhr.onreadystatechange = handler;
	
	if(type == 'blob'){
		xhr.responseType = type;
	}
	
	if(type == "json") {
		xhr.setRequestHeader("Accept", "application/json");
	}
	
	if(type == 'xml') {
		xhr.overrideMimeType('text/xml');
	}
	
	xhr.send();
	
	function handler() {
	  if (this.readyState === this.DONE) {
		if (this.status === 200 || this.responseXML ) { //-- Firefox is reporting 0 for blob urls
			var r;
			
			if(type == 'xml'){
				r = this.responseXML;
			}else 
			if(type == 'json'){
				r = JSON.parse(this.response);
			}else{
				r = this.response;
			}
			
			promise.resolve(r);			
		}
		else { promise.reject(this); }
	  }
	};
  

  return promise;
};

// EPUBJS.core.loadXML = function(url, callback){
// 	var xhr = new XMLHttpRequest();
// 	xhr.open('GET', url, true);
// 	xhr.overrideMimeType('text/xml');
// 
// 	xhr.onload = function(e) {
// 		if (this.status == 200) {
// 			callback(this.responseXML);
// 		}
// 	};
// 
// 	xhr.send();
// }

// EPUBJS.core.loadFile = function(url){
// 	var xhr = new XMLHttpRequest(),
// 		succeeded,
// 		failed;
// 
// 	function _loaded(response){
// 		console.log("response")
// 	}
// 	
// 	function _error(err){
// 		console.log("Error:", err);
// 	}
// 	
// 	function start(){
// 		//xhr.open('GET', url, true);
// 		//xhr.responseType = 'blob';
// 		
// 		xhr.onload = function(e) {
// 			if (this.status == 200) {
// 				succeeded(this.response);
// 			}
// 		};
// 		
// 		xhr.onerror = function(e) {
// 			_error(this.status); //-- TODO: better error message
// 		};
// 		
// 		//xhr.send();
// 		console.log(succeeded)
// 	}
// 	
// 	return {
// 		"start": start,
// 		"loaded" : succeeded,
// 		"error" : failed
// 	}
// }
// 
// EPUBJS.core.loadFile = function(url, callback){
// 	var xhr = new XMLHttpRequest();
// 	
// 	this.succeeded = function(response){
// 		if(callback){
// 			callback(response);
// 		}
// 	}
// 
// 	this.failed = function(err){
// 		console.log("Error:", err);
// 	}
// 
// 	this.start = function(){
// 		var that = this;
// 		
// 		xhr.open('GET', url, true);
// 		xhr.responseType = 'blob';
// 
// 		xhr.onload = function(e) {
// 			if (this.status == 200) {
// 				that.succeeded(this.response);
// 			}
// 		};
// 
// 		xhr.onerror = function(e) {
// 			that.failed(this.status); //-- TODO: better error message
// 		};
// 
// 		xhr.send();
// 	}
// 
// 	return {
// 		"start": this.start,
// 		"succeeded" : this.succeeded,
// 		"failed" : this.failed
// 	}
// }



EPUBJS.core.toArray = function(obj) {
  var arr = [];

  for (member in obj) {
	var newitm;
	if ( obj.hasOwnProperty(member) ) {
	  newitm = obj[member];
	  newitm.ident = member;
	  arr.push(newitm);
	}
  }

  return arr;
};

//-- Parse out the folder
EPUBJS.core.folder = function(url){
	
	var slash = url.lastIndexOf('/'),
		folder = url.slice(0, slash + 1);

	return folder;

};

//-- https://github.com/ebidel/filer.js/blob/master/src/filer.js#L128
EPUBJS.core.dataURLToBlob = function(dataURL) {
	var BASE64_MARKER = ';base64,';
	if (dataURL.indexOf(BASE64_MARKER) == -1) {
	  var parts = dataURL.split(',');
	  var contentType = parts[0].split(':')[1];
	  var raw = parts[1];

	  return new Blob([raw], {type: contentType});
	}

	var parts = dataURL.split(BASE64_MARKER);
	var contentType = parts[0].split(':')[1];
	var raw = window.atob(parts[1]);
	var rawLength = raw.length;

	var uInt8Array = new Uint8Array(rawLength);

	for (var i = 0; i < rawLength; ++i) {
	  uInt8Array[i] = raw.charCodeAt(i);
	}

	return new Blob([uInt8Array], {type: contentType});
 }
 
//-- Load scripts async: http://stackoverflow.com/questions/7718935/load-scripts-asynchronously 
EPUBJS.core.addScript = function(src, callback, target) {
   var s, r;
   r = false;
   s = document.createElement('script');
   s.type = 'text/javascript';
   s.async = false;
   s.src = src;
   s.onload = s.onreadystatechange = function() {
 	//console.log( this.readyState ); //uncomment this line to see which ready states are called.
 	if ( !r && (!this.readyState || this.readyState == 'complete') )
 	{
 	  r = true;
 	  if(callback) callback();
 	}
   },
   target = target || document.body;
   target.appendChild(s);
 }
 
 EPUBJS.core.addScripts = function(srcArr, callback, target) {
	var total = srcArr.length,
		curr = 0,
		cb = function(){
			curr++;
			if(total == curr){
				if(callback) callback();
			}else{
				EPUBJS.core.loadScript(srcArr[curr], cb, target);
			}
		};
		
    // srcArr.forEach(function(src){
    // EPUBJS.core.loadScript(src, cb, target);
    // });
    EPUBJS.core.addScript(srcArr[curr], cb, target);
    
 }
 
 EPUBJS.core.addCss = function(src, callback, target) {
    var s, r;
    r = false;
    s = document.createElement('link');
    s.type = 'text/css';
    s.rel = "stylesheet";
    s.href = src;
    s.onload = s.onreadystatechange = function() {
  	if ( !r && (!this.readyState || this.readyState == 'complete') )
  	{
  	  r = true;
  	  if(callback) callback();
  	}
    },
    target = target || document.body;
    target.appendChild(s);
  }
  
 EPUBJS.core.prefixed = function(unprefixed) {
 	var vendors = ["Webkit", "Moz", "O", "ms" ],
 		prefixes = ['-Webkit-', '-moz-', '-o-', '-ms-'],
 		upper = unprefixed[0].toUpperCase() + unprefixed.slice(1),
 		length = vendors.length,
 		i = 0;

 	if (typeof(document.body.style[unprefixed]) != 'undefined') {
 		return unprefixed;
 	}
 
 	for ( ; i < length; i++ ) {
 		if (typeof(document.body.style[vendors[i] + upper]) != 'undefined') {
 			return vendors[i] + upper;
 		}		
 	}

 	return unprefixed;
 
 
 }
 
 EPUBJS.core.resolveUrl = function(base, path) {
	var url,
		segments = [],
	 	folders = base.split("/"),
	 	paths;
	 	
	 folders.pop();
	 
	 paths = path.split("/");
	 paths.forEach(function(p){
		if(p === ".."){
			folders.pop();
		}else{
			segments.push(p);
		}
	 });
	 
	 url = folders.concat(segments);
	 
	 return url.join("/");
 }