/**
 *@file upload.js
 *@version 20170907 ms
 *@type JS
 *
 * Komponente zum Hochladen einer oder mehrerer Dateien mit Fortschrittsanzeige. Setzt die Server-seitige Verwendung eines speziellen PHP-Skipts voraus.
 */

/**
 * @class KUpload
 * @constructor
 */
function KUpload() {
	this.fieldName="file";
	this.running=false;
	
	this.uploadedTotalBytes=0;
	this.uploadFiles;
	this.countProgress=null;
	
	this.win=null; // define in WinOpen() as table
	this.winModal=null; //define  
	this.inpUpload=null; // HTMLElement::input@type=file
	
	var d=document.createElement("div");with(d.style){position="absolute";width="0";height="0";overflow="hidden"};document.body.appendChild(d);
	this.inpUpload=document.createElement("input");this.inpUpload.type="file";d.appendChild(this.inpUpload);
	var m=this;
	m.inpUpload.onchange=function(){if(!m.running) m.UploadPrepare(m.inpUpload.files)};
}

/**
 * @fn UploadShow
 * @memberof KUpload
 * @param {string} url
 * @param {boolean} multiple
 * @param {function} completedFunc
 * @param {function} checkFunc
 * @param {function} beforeFunc
 * @param {function} afterFunc
 * Public method.
 * Open browsers file dialog.
 */
KUpload.prototype.UploadShow=function(url,multiple,completedFunc,checkFunc,beforeFunc,afterFunc){
	if(this.running) return;
	this.uploadCompleteFunc=completedFunc;
	this.checkFunc=checkFunc;
	this.beforeFunc=beforeFunc;
	this.afterFunc=afterFunc;
	this.uploadUrl=url;
	this.inpUpload.multiple=multiple?true:false;
	this.inpUpload.click();
};

/**
 * @fn Upload
 * @memberof KUpload
 * @param {string} url
 * @param {FileList} files
 * @param {function} completedFunc
 * @param {function} checkFunc
 * @param {function} beforeFunc
 * @param {function} afterFunc
 * Public method.
 * Begin file upload.
 */
KUpload.prototype.Upload=function(url,files,completedFunc,checkFunc,beforeFunc,afterFunc){
	if(this.running) return;
	this.uploadUrl=url;
	this.uploadCompleteFunc=completedFunc;
	this.checkFunc=checkFunc;
	this.beforeFunc=beforeFunc;
	this.afterFunc=afterFunc;
	this.UploadPrepare(files);
};

/**
 * @fn UploadPrepare
 * @memberof KUpload
 * @param {FileList} files
 * @call this.UploadInit()
 * @callby this.Upload(), Event::onchange of HTMLElement::input
 * Private method.
 */
KUpload.prototype.UploadPrepare=function(files){
	var m=this,a=-1,upFiles=[];
	var doFunc=function(){
		a++;
		if(a==files.length){
			if(upFiles.length) m.UploadInit(upFiles);
		}else{
			if(files[a].size){
				if(m.checkFunc){
					m.checkFunc(files[a],function(file,formData){
						if(file) upFiles.push({file:file,formData:formData?formData:{}});
						doFunc();
					});
				}else{
					upFiles.push({file:files[a],formData:{}});
					doFunc();
				}
			}else
				doFunc();
		}
	};
	doFunc();
};

/**
 * @fn UploadInit
 * @memberof KUpload
 * @param upFiles
 * @call this.UploadStart()
 * @referredby this.UploadPrepare()
 * Private method.
 */
KUpload.prototype.UploadInit=function(upFiles){
	this.uploadFiles=upFiles;
	this.uploadedTotalBytes=0;
	this.uploadTotalBytes=0;
	for(var a=0;a<upFiles.length;a++) this.uploadTotalBytes+=upFiles[a].file.size;
	this.UploadStart();
};

/**
 * @fn UploadStart
 * @memberof KUpload
 * Private method.
 */
KUpload.prototype.UploadStart=function(){
	var o=this.WinOpen("div");
	var t=document.createElement("table");o.appendChild(t);
	t.cellPadding="2px";t.cellSpacing="0";t.border="0";t.style.padding="10px";t.style.borderCollapse="separate";
	var tr=t.insertRow(0);var td=tr.insertCell(0);
	this.sizeProgress=document.createElement("progress");td.appendChild(this.sizeProgress);this.sizeProgress.style.width=(KUpload.WindowWidth()/2)+"px";
	tr=t.insertRow(1);this.sizeProgressState=tr.insertCell(0);this.sizeProgressState.style.textAlign="center";

	tr=t.insertRow(0);if(this.uploadFiles.length==1) tr.style.display="none";td=tr.insertCell(0);
	this.countProgress=document.createElement("progress");td.appendChild(this.countProgress);this.countProgress.style.width=(KUpload.WindowWidth()/2)+"px";
	this.countProgress.max=this.uploadTotalBytes;
	tr=t.insertRow(1);if(this.uploadFiles.length==1) tr.style.display="none";this.countProgressState=tr.insertCell(0);this.countProgressState.style.textAlign="center";
	
	this.WinResize();
	this.UploadIDs=[];
	this.running=true;
	this.UploadFile(0);
};

/**
 * @fn UploadFile
 * @memberof KUpload
 * @param index
 * Private method.
 */
KUpload.prototype.UploadFile=function(index){
	var m=this;
	m.countProgressState.innerHTML=(index+1)+" / "+m.uploadFiles.length;
	m.sizeProgress.value=0;
	m.sizeProgress.max=m.uploadFiles[index].file.size;
	m.sizeProgressState.innerHTML="0 %";
	if(m.beforeFunc) m.beforeFunc(m.uploadFiles[index].file,m.uploadFiles[index].formData);

	var r=new XMLHttpRequest();
	r.open("POST",this.uploadUrl,true);
	r.onload=function(){
		if(r.readyState===4){
			if(r.status===200){
				if(r.responseText.substr(0,3)=="ID="){
					var newId=parseInt(r.responseText.substr(3));
					if(newId){
						if(m.afterFunc) m.afterFunc(m.uploadFiles[index].file,m.uploadFiles[index].formData,newId);
						m.UploadIDs.push(newId);
						if(index==m.uploadFiles.length-1){
							m.UploadComplete();
						}else{
							m.uploadedTotalBytes+=m.uploadFiles[index].file.size;
							m.UploadFile(index+1)
						}
					}else{
						alert("Could not parse ID from '"+r.responseText.substr(3)+"'");
						m.UploadComplete();
					}
				}else{
					alert(r.responseText.replace(/ERR=/g,""));
					m.UploadComplete();
				}
			}else{
				console.error(r.statusText);
				m.UploadComplete();
			}
		}
	};
	r.onerror=function(e){
		alert("an error occurred while uploading the file");
		m.UploadComplete();
	};
	r.onabort=function(e){
		alert("file upload canceled");
		m.UploadComplete();
	};
	r.upload.addEventListener("progress",function(e){
		if(e.lengthComputable){
			m.sizeProgress.value=e.loaded;
			m.sizeProgressState.innerHTML=Math.round((100/e.total)*e.loaded)+" %";
		}
		m.countProgress.value=m.uploadedTotalBytes+e.loaded;
	});

	var fd=new FormData();
	var ffd=m.uploadFiles[index].formData;
	if(typeof ffd=="object")
		for(var key in ffd) fd.append(key,typeof ffd[key]==='string' || ffd[key] instanceof String || ffd[key] instanceof Blob?ffd[key]:JSON.stringify(ffd[key]));
	fd.append(m.fieldName,m.uploadFiles[index].file);
	r.send(fd);
};

/**
 * @fn UploadComplete
 * @memberof KUpload
 * Private method.
 */
KUpload.prototype.UploadComplete=function(){
	if(this.running){
		this.running=false;
		this.WinClose();
		this.uploadCompleteFunc(this.UploadIDs);
	}
};

/**
 * @fn WinOpen
 * @memberof
 * @param o
 * @param closable
 * @returns {DOMnode::div | DOMnode::iframe}
 * Private method.
 * defines an append to DOM 
 * this.winModal as HTMLtable 
 * this.win as HTMLiframe or HTMLdiv
 */
KUpload.prototype.WinOpen=function(o,closable){
	this.winModal=document.createElement("table");document.body.appendChild(this.winModal);
	var st=this.winModal.style;st.position="absolute";st.left="0";st.top="0";st.width="100%";st.height="100%";st.borderSpacing="0";st.borderCollapse="collapse";st.backgroundColor="rgba(0,0,0,0.5)";st.zIndex=9998;st.cursor="not-allowed";
	var m=this;
	this.winModal.ondblclick=function(){m.WinClose()};
	var tr=this.winModal.insertRow(0);
	var td=tr.insertCell(0);
	td.innerHTML="&nbsp;";

	if(typeof(o)=="undefined" || o=="div")
		this.win=document.createElement("div");
	else if(o=="iframe"){
		this.win=document.createElement("iframe");this.win.frameBorder=1;this.win.scrolling="no";
	}
	st=this.win.style;st.position="absolute";st.zIndex=9999;st.backgroundColor="#F4F5F6";st.border="black solid 1px";
	document.body.appendChild(this.win);
	this.WinResize();
	return this.win;
};

/**
 * @fn WinResize
 * @memberof KUpload
 * @param w
 * @param h
 * Private method.
 */
KUpload.prototype.WinResize=function(w,h){
	if(w>0 && h>0){this.win.style.width=w+"px";this.win.style.height=h+"px";}
	this.win.style.left=(KUpload.WindowWidth()-this.win.offsetWidth)/2+"px";
	this.win.style.top=(KUpload.WindowHeight()-this.win.offsetHeight)/2+"px";
};

/**
 * @fn WinClose
 * @memberof KUpload
 * Private method.
 */
KUpload.prototype.WinClose=function(){
	if(this.win){document.body.removeChild(this.win);this.win=null;document.body.removeChild(this.winModal)}
};

/**
 * @fn WindowWidth
 * @returns
 * Private method.
 */
KUpload.WindowWidth=function(){
	return window.innerWidth && document.documentElement.clientWidth? 
		Math.min(window.innerWidth, document.documentElement.clientWidth) : 
		window.innerWidth || 
		document.documentElement.clientWidth || 
		document.body.clientWidth;
};

/**
 * @fn WindowHeight
 * @returns
 * Private method.
 */
KUpload.WindowHeight=function(){
	return window.innerHeight && document.documentElement.clientHeight? 
		Math.min(window.innerHeight, document.documentElement.clientHeight) : 
		window.innerHeight || 
		document.documentElement.clientHeight || 
		document.body.clientHeight;
};