/*
 * TODO:
 *	check if files exist
 *	check file sizes
 */

var running = false;
var queue = [];

function queue_work(){
	let i = 0;
	for(; i < queue.length; i++){
		item = queue[i];
		if(!item.started){
			console.log(item);
			console.log("Starting " + item.file.name);
			item.started = true;

			let req = new XMLHttpRequest();
			let data = new FormData();
			data.append("file", item.file);                                
			req.upload.addEventListener("progress", function(evt){
				if(evt.lengthComputable){
					console.log("Upload for " + item.file.name + " at " + evt.loaded / evt.total);
					item.node.childNodes[1].value = evt.loaded;
				}
			});
			req.onloadstart = function(evt){
				console.log("Upload for " + item.file.name + " started");
				item.node.childNodes[1].max = item.file.size;
				item.node.childNodes[1].value = 0;
			};
			req.onloadend = function(evt){
				console.log("Upload for " + item.file.name + " ended");
				queue_work();
			};
			req.onerror = function(evt){
				console.log("Upload for " + item.file.name + " errored");
				item.node.className += " errored";
			};
			req.onabort = function(evt){
				console.log("Upload for " + item.file.name + " aborted");
				item.node.className += " errored";
			};
			req.onreadystatechange = function(evt){
				console.log("Upload for " + item.file.name + " state " + req.readyState);
				if(req.readyState === XMLHttpRequest.DONE && req.status != 200){
					console.log("Upload for " + item.file.name + " failed with " + req.status);
					item.node.className += " errored";
				}
			};
			req.open("POST", 'upload');
			req.send(data);
			return;
		}
	}

	console.log("Queue run done");
	running = false;
}

function queue_run(){
	if(running || queue.length == 0){
		return;
	}

	running = true;

	console.log("Starting queue run");
	queue_work();
}

function element(id){
	return document.getElementById(id);
}

function node(tag, style, text){
	let new_node = document.createElement(tag);
	new_node.className = style;
	if(text){
		new_node.textContent = text;
	}
	return new_node;
}

function upload_element(file){
	let new_node = node("div", "queue-entry");
	new_node.appendChild(node("span", "name", file.name));
	new_node.appendChild(node("progress", "progress"));
	element("queue").appendChild(new_node);
	return new_node;
}

function upload_start(element){
	for(let i = 0; i < element.target.files.length; i++){
		console.log(element.target.files[i]);
		queue.push({"file": element.target.files[i], "node": upload_element(element.target.files[i]), "progress": 0, "started": false});
	}
	queue_run();
}

function listing_clear(){
	element("dirlisting").innerHTML = "";
}

function interface_update(access){
	if(!access.includes("c")){
		element("tab-upload-label").style.display = "none";
	}

	if(!access.includes("r")){
		element("tab-view-label").style.display = "none";
		element("tab-upload").checked = "checked";
	}
}

function listing_add(file, style = "default"){
	let link = node("a", "listing-entry", file.name);
	link.href = "file/" + encodeURIComponent(file.name);
	link.setAttribute("data-filename", file.name)

	if(style == "gallery"){
		let image = node("img", "preview");
		image.src = "preview/" + encodeURIComponent(file.name);
		//link.insertBefore(image, link.firstChild);
		link.appendChild(image);
	}

	element("dirlisting").appendChild(link);
}

function listing_update(){
	listing_clear();
	let req = new XMLHttpRequest();
	req.onload = function(evt){
		let data = JSON.parse(req.response);
		interface_update(data.access);

		for(let i = 0; i < data.files.length; i++){
			listing_add(data.files[i], data.display);
		}

		element("download-all").innerText = "Download all (" + data.files.length + " Files, " + (data.total / 1024 /1024) + "MB)";
	};
	req.open("GET", "listing");
	req.send();
}

function download_all(ev){
	let links = document.getElementsByClassName("listing-entry");
	var current = 0;
	var interval = setInterval(function(){
		if(current < links.length){
			link = links[current];
			link.download = link.getAttribute("data-filename");
			link.click();
			link.removeAttribute("download");
			current++;
		}
		else{
			clearInterval(interval);
		}
	}, 1000);
}

function init(){
	element("file-submit").style.display = "none";
	element("files").onchange = upload_start;
	element("download-all").onclick = download_all;
	listing_update();
}

window.onload = init;