// Config
const DEBUG = 0;
const CMD_PORT = "8888";
const TIMELINE_COLOR_CURSOR = "#FF8839";
const TIMELINE_COLOR_BG = "#2EB8E600";
const DEFAULT_LOCALE = "en";
// t9n
let t9n =
{   fr : {
	statusDefault : "Recherche des clients connectés...",
	confirmMessage : "Êtes vous certain de vouloir effectuer cette action ?",
	filename : "Nom",
	duration : "Durée",
	size : "Taille",
	sync : "Transfert des fichiers..." ,
	size_unit : " Mio",
	of : " de ", 
	upload_sent_count_msg : " éléments envoyés", 
	item_queued : "Synchronisation en attente...",
    },
    en : {
	statusDefault : "Searching network for live hosts...",
	confirmMessage : "Are you sure?",
	filename : "Filename",
	duration : "Duration",
	size : "Size",
	sync : "Syncing files...",
	size_unit : " MB",
	of : " of ", 
	upload_sent_count_msg : " elements transferred.", 
	item_queued : "Queued for file synchronisation...",
    }
};
// Timeline drag and drop elements default attributes
const tl_cont_attr = {"id":"tl_cont", "ondrop": "drop(event, this)", "ondragover":"allow_drop(event)"};
const tl_drag_attr = {"id":"tl_drag", "draggable":"true", "ondragstart":"drag(event, this)"};
//  Global object
window.currentUser = {
  scan_interval : 3000,
  status_all :  t9n[LOCALE].statusDefault,
  medias_status : {},
  freeze_timeline_update : 0,
  freeze_ul : 0,
  last_ul_host : 0,
  ul_queue : [],
};


function sleep(ms) {
    let delay = new Promise(function(resolve) {
	setTimeout(resolve, ms);
    });
    return delay ;
    // arrow notation equivalent
    // return new Promise(resolve => setTimeout(resolve, ms));
}


async function update_sort_VLC_playlist(host) {
    // Update host's VLC playlist according to web UI timeline
    let media_count = document.getElementById(`timeline_${host}`).children.length;
    // Reversed loop
    for (let i=media_count, l=0; i>l; i--) {
	// Find current's timeline element children's 'media_id' value
	//~ console.log(document.getElementById(`timeline_${host}`).children[i-1].children[0])
	let to_shift = document.getElementById(`timeline_${host}`).children[i-1].children[0].getAttribute("media_id");
	//~ console.log(to_shift + " : " + document.getElementById(`timeline_${host}`).children[i-1].children[0].innerText);
	// Move 'to_shift' after element with id '1' :
	// In VLC's playlist XML representation, the playlist node always gets id '1', so moving to that id
	// really means moving to the the very start of the playlist.
	send_ajax_cmd("/" + host + "/move/" + to_shift + "/1");
	await sleep(200);
    }
    // Un-freeze timeline update flag
    currentUser.freeze_timeline_update = 0;
}
function get_child_by_id(id, parent_element, depth=0){
    Array.from(parent_element.children).forEach(function(child){
	if (depth){
	    if (child.children[0].id == id){
		result = child.children[0];
	    } 
	} else if (child.id == id) {
	    result = child;
	}
    });
    return result;
}

async function update_delete_VLC_playlist(host, delete_element_id) {
    // Delete item from timeline and send corresponding VLC command
    let current_timeline = document.getElementById("timeline_" + host);
    let delete_media = get_child_by_id(delete_element_id, current_timeline, 1);
    let delete_media_cont = delete_media.parentElement;
    let delete_media_id = delete_media.getAttribute("media_id");
    
    current_timeline.removeChild(delete_media_cont);
    send_ajax_cmd("/" + host + "/delete/" + delete_media_id);
    await sleep(200);
    adjust_timeline(host);
    //~ currentUser.freeze_timeline_update = 0;
}

function find_target_index(element, index) {
    if (element == this) {
	return index + 1;
    }
    return 0;
}


function shift_elements(source_element, target_element) {
    // Shift elements in the timeline UI 
    //
    // Get a list of current element siblings
    let siblings_list = Array.from(source_element.parentElement.children);
    let siblings_list_slice;
    // Find indexes of source and target elements in the timeline
    let source_index = siblings_list.findIndex(find_target_index, source_element);
    let target_index = siblings_list.findIndex(find_target_index, target_element);
    let insert_at = 0;
    // Target element is on the left of the source element
    if (source_index < target_index){
	siblings_list_slice = siblings_list.slice(source_index + 1, target_index + 1);
	insert_at = source_index;
    } else {
    // Target element is on the right of the source element
	siblings_list_slice = siblings_list.slice(target_index, source_index );
	insert_at = target_index + 1;
    }
    // Shift elements according to insert_at
    for (let i=0, l=siblings_list_slice.length; i<l;i++){
	siblings_list[insert_at + i].appendChild(siblings_list_slice[i].children[0]);
    }
    return insert_at;
}


function allow_drop(event) {
    event.preventDefault();
}


function drag_over_bin(event) {
    event.preventDefault();
    let dropped_id = event.dataTransfer.getData("target_id");
    let source_id = event.dataTransfer.getData("parent_element_id");
    let source_element = document.getElementById(source_id);
    let cont_element = get_child_by_id(dropped_id, source_element, 1);
    let current_host =  source_id.split("_")[1];
    cont_element.style.opacity = 0.5;
    //~ document.getElement("delete_" + current_host).style.backgroundColor = "#f00";
    //~ document.getElementById("delete_" + current_host).style.boxShadow = "0 0 10px #fff;";
    document.getElementById("delete_btn").style.backgroundColor = "#f00";
    document.getElementById("delete_btn").style.boxShadow = "0 0 10px #fff;";
}


function drag_leave_bin(event) {
    event.preventDefault();
    let dropped_id = event.dataTransfer.getData("target_id");
    let source_id = event.dataTransfer.getData("parent_element_id");
    let source_element = document.getElementById(source_id);
    let cont_element = get_child_by_id(dropped_id, source_element, 1);
    let current_host =  source_id.split("_")[1];
    cont_element.style.opacity = 1;
    document.getElementById("delete_btn").style.backgroundColor = "#df7474";
}


function drag(event, source) {
    // Freeze timeline update flag
    currentUser.freeze_timeline_update = 1;
    event.dataTransfer.setData("target_id", event.target.id);
    event.dataTransfer.setData("parent_element_id", source.parentElement.parentElement.id);
}


function drop(event, target_element) {
    // If the currently dragged element is dropped on another element, 
    // shift HTML elements in the timeline to the left or right from the target element.
    event.preventDefault();
    // Get dragged element id
    let dropped_id = event.dataTransfer.getData("target_id");
    let source_id = event.dataTransfer.getData("parent_element_id");
    let source_element = document.getElementById(source_id);
    let current_host =  source_id.split("_")[1];
    source_element.style.border = "none";
    // Only shift if not dropping on self
    if (source_element.id != target_element.id) {
	//~ if ( target_element.id.indexOf("delete_") > -1 ) {
	if ( target_element.id == "delete_btn") {
	    update_delete_VLC_playlist(current_host, dropped_id);
	    document.getElementById("delete_btn").style.backgroundColor = "#df7474";
	} else {
	    dropped_element = get_child_by_id(dropped_id, source_element, 1);
	    let dropTarget = shift_elements(dropped_element.parentElement, target_element);
	    //~ console.log(target_element);
	    //~ if (dropTarget) {
		// Append dropped element to drop target.
		//~ target_element.appendChild(source_element);
	    target_element.appendChild(dropped_element);
	    update_sort_VLC_playlist(current_host);
	    //~ }
	}
    // Un-freeze timeline update flag
    //~ currentUser.freeze_timeline_update = 0;
    }
    send_ajax_cmd("/" + current_host + "/list");
}


function adjust_timeline(host) {
    // Adapt timeline's UI elements to fit the width of their parent container.
    //~ let timeline_div = document.querySelector('[id^="timeline_"]').children;
    let timeline_div = document.getElementById("timeline_" + host).children;
    let div_width = 100 / timeline_div.length;
    for (let i=0, l=timeline_div.length; i<l; i++) {
      timeline_div[i].style.width= div_width + "%";
    }
    return timeline_div.length;
}


function add_HTML_attr(id, attribute, val , child=-1) {
    // Add attribute 'attr' with value 'val' to the HTML element with id 'id'.
    // If child is other than -1, the attribute is applied to the HTML element's child at position 'child'
    let HTML_element = document.getElementById(id);
    if (child > -1){
	HTML_element = HTML_element.children[child];
    }
    let HTML_attr = document.createAttribute(attribute);
    HTML_attr.value = val;
    HTML_element.setAttributeNode(HTML_attr);
}


function add_HTML_element(type, attribute, meta=0, uid=-1){
    // Add HTML element with type 'type' and attributes 'attribute'. 
    // 'attribute' should be a javascript object containing HTML attributes keys/values to be applied to the new element
    // 'meta' should be an array
    // 'uid' is used to make the HTML id attribute unique. If not set, this will use the loop's iteration count i
    //
    let HTML_element = document.createElement(type);
    let HTML_attributes = Object.keys(attribute);
    for (let i=0, l=HTML_attributes.length; i<l; i++) {
	let new_attribute = document.createAttribute(HTML_attributes[i]);
	if(HTML_attributes[i] == "id") {
	    // HTML id needs to be unique
	    new_attribute.value = Object.values(attribute)[i] + (uid != -1 ? uid : i);
	} else {
	    new_attribute.value = Object.values(attribute)[i];
	}
	HTML_element.setAttributeNode(new_attribute);
    }	
    // Set media_id attribute if metadata is provided
    if (meta) {
	let media_attribute = document.createAttribute("media_id");
	media_attribute.value = meta[0];
	HTML_element.setAttributeNode(media_attribute);
	// Set filename as inner text 
	HTML_element.innerText = meta[1];
    }
    return HTML_element;
}


function toggle_indicator(infos_array_element, property) {
    // Toggle element bg color
    toggle_state = 0;
    if (infos_array_element[property] == "true") { 
	document.getElementById(`${property}_ind_${infos_array_element.host}`).style.backgroundColor = "#78E738";
	toggle_state = 1;
    } else {
	document.getElementById(`${property}_ind_${infos_array_element.host}`).style.backgroundColor = "#A42000";
    }
    return toggle_state;
}


function update_status(infos_array_element) {
    if (infos_array_element.status) {
	document.getElementById("status_" + infos_array_element.host).innerHTML = infos_array_element.file + " <br/> " + infos_array_element.time + " / " + infos_array_element.leng;
	currentUser.medias_status[infos_array_element.id] = infos_array_element.pos;
	// Highlight currently playing element
	let current_timeline = document.getElementById("timeline_" + infos_array_element.host);
	let timeline_medias_array = Array.from(current_timeline.querySelectorAll('[media_id]'));
	timeline_medias_array.forEach(function(media_element){
	    if ( media_element.getAttribute("media_id") == infos_array_element.id ) {
		let first_CSS_gradient_stop = infos_array_element.pos * 100;
		let second_CSS_gradient_stop = first_CSS_gradient_stop - 1  + "%";
		first_CSS_gradient_stop = first_CSS_gradient_stop + "%";
		let media_url_str = "url(https://" + infos_array_element.host + ":" + CMD_PORT + "/thumb/" + infos_array_element.file + ")";
		let media_cssgrad_rule = "linear-gradient(90deg," + TIMELINE_COLOR_BG + " " + second_CSS_gradient_stop + ", " + TIMELINE_COLOR_CURSOR + " " + first_CSS_gradient_stop + ", " + TIMELINE_COLOR_BG + " " + first_CSS_gradient_stop + ")," + media_url_str;
		media_element.style.backgroundImage = media_cssgrad_rule;
		media_element.style.borderBottom = "4px solid " + TIMELINE_COLOR_CURSOR;
	    } else {
		let media_url_str = "url(https://" + infos_array_element.host + ":" + CMD_PORT + "/thumb/" + media_element.innerText + ")";
		media_element.style.backgroundImage = media_url_str;
		media_element.style.borderBottom = "None";
	    }
	});
    } else {
	document.getElementById("status_" + infos_array_element.host).innerHTML = "<br><br>";
    }
    toggle_indicator(infos_array_element, "loop");
    toggle_indicator(infos_array_element, "repeat");
    return infos_array_element.status;
}


function update_list(infos_array_element){
    // Playlist infos are displayed in a div ; number of items in list and total duration.
    //~ document.getElementById("playlist_"+infos_array[i].host).innerHTML = infos_array[i].leng + " item(s) in playlist - " + infos_array[i].duration;
    // Populate timeline according to the content of the playlist
    // Get returned items as an array
    let items_array = Array.from(infos_array_element.items);
    let host = infos_array_element.host;
    // If playlist is empty, remove all media divs in the timeline UI.
    if (items_array.length == 0){
	let child_list = Array.from(document.getElementById("timeline_" + host).children);
	child_list.forEach(function(child){
	    document.getElementById("timeline_" + host).removeChild(child);
	});
    } else {
	current_timeline = document.getElementById("timeline_" + host);
	items_array.forEach(function(item, j){
	    item_meta = item.split(';');
	    let child_node = add_HTML_element("div", tl_drag_attr, item_meta, j);
	    let len = current_timeline.children.length;
	    add_HTML_attr("timeline_" + host, "length", len);
	    if ( len < items_array.length ) {
		current_timeline.appendChild( add_HTML_element("div", tl_cont_attr, 0, len) );
	    }
	    //~ document.getElementById(tl_cont_attr.id + j).replaceChildren(child_node);
	    current_timeline_children = Array.from(current_timeline.children);
	    current_timeline_children[j].replaceChildren(child_node);
	    let media_name = current_timeline_children[j].children[0].innerText;
	    let media_url_str = "url(https://" + host + ":" + CMD_PORT + "/thumb/" + media_name + ")";
	    current_timeline_children[j].children[0].style.backgroundImage = media_url_str;
	    // Adjust elements width
	    adjust_timeline(host);
	});
    }
    return items_array.length;
}


function populate_HTML_table(inner_text, host="all", CSS_class="file_selection") {
    tr = document.createElement("tr");
    td = document.createElement("td");
    tr.appendChild(td);
    tr.setAttribute("class", CSS_class);
    tr.host = host;
    td.innerText = inner_text;
    // Add an event to the created element to send enqueue command when a file is clicked in the list
    tr.addEventListener("click", enqueue_file, false);
    document.getElementById("file_sel_" + host).appendChild(tr);
}


function empty_HTML_table(host="all", keep=1) {
    
    let HTML_table_element = document.getElementById("file_sel_" + host);
    let HTML_table_element_length = HTML_table_element.childElementCount;
    for (let i=keep; i<HTML_table_element_length; HTML_table_element_length--) {
	HTML_table_element.removeChild(HTML_table_element.children[i]);
    }
}


function update_remote_filelist(infos_array_element) {
    hosts = Object.keys(infos_array_element);
    for (let j=0, m=hosts.length; j<m; j++) {
	empty_HTML_table(hosts[j]);
	let media_item = Object.keys(infos_array_element[hosts[j]]);
	for (let k=0, n=media_item.length; k<n; k++) {
	    media_item_meta = infos_array_element[hosts[j]][media_item[k]];
	    populate_HTML_table(media_item_meta.name, hosts[j]);
	}
    }
}


function update_rssi_indicator(infos_array_element){
    let base_height = 0.5;
    let signal_color = 40;
    let best_rssi = 30;
    let worst_rssi = 70;
    let rssi_norm = Math.ceil( (worst_rssi - parseInt(infos_array_element.rssi) ) / ( worst_rssi - best_rssi ) * 4 );
    signal_color = (rssi_norm-1) * signal_color;
    // Reset to grey
    for (let i=0, l=4; i<l; i++) {
	document.getElementById("wl_" + infos_array_element.host + "_" +i).style.height = base_height + i * 0.15 + "em";
	document.getElementById("wl_" + infos_array_element.host + "_" + i).style.backgroundColor = "hsl(0, 0%, 65%)";
    }
    // Color it
    for (let i=0, l=rssi_norm > 4 ? 4 : rssi_norm; i<l; i++) {
	document.getElementById("wl_" + infos_array_element.host + "_" +i).style.height = base_height + i * 0.15 + "em";
	document.getElementById("wl_" + infos_array_element.host + "_" +i).style.backgroundColor = "hsl(" + signal_color + ", 100%, 50%)";
    }
    return rssi_norm;
}


//~ function update_local_filelist(infos_array) {
    //~ let html_table  = "<table>" + 
		       //~ "<tr>" + 
			    //~ "<th>" + t9n[LOCALE].filename + "</th>" + 
			    //~ "<th>" + t9n[LOCALE].duration + "</th>" + 
		       //~ "</tr>";
    //~ infos_array.forEach(function(element){
	//~ html_table += "<tr>" + 
			    //~ "<td>" + element + "</td>" +
			    //~ "<td>" + "00:00" + "</td>" +
		      //~ "</tr>" ;
    //~ });
    //~ html_table += "</table>";
    //~ return html_table;
//~ }


function update_host_list(infos_array){
    let host_up = infos_array[0];
    let host_down = infos_array[1];
    if (host_up.length) { 
	host_up.forEach(function(host){
	    adjust_timeline(host);
	    document.getElementById(host).style.display = 'block';
	    send_ajax_cmd("/" + host + "/list");
	    send_ajax_cmd("/" + host + "/rssi");
	});
	currentUser.scan_interval = 10000;
    }
    host_down.forEach(function(element){
	document.getElementById(element).style.display = 'none';
    });
    currentUser.hosts_up = host_up;
    currentUser.hosts_down = host_down;
    currentUser.status_all = host_up.length + " client(s).";
    return host_up.length;
}


function freeze_ui_host(host, html_attributes, inner_html=0, inner_text=0){
    // Add an overlay element to freeze part of the UI
    // html_attributes, inner_html are objects with structure {"id":, 0 "class": 0, "attr" : "value", }
    let container_element = document.getElementById(host);
    let siblings = container_element.children;
    // Upload dialog container / background
    let upload_dialog_cont_element = add_HTML_element("div", html_attributes, 0, host);
    container_element.insertBefore(upload_dialog_cont_element, siblings[0]);
    if (inner_html){
	let child_node = add_HTML_element("div", inner_html, 0, host);
	let new_node = container_element.children.item(html_attributes.id + host).appendChild(child_node);
	if (inner_text){
	    new_node.innerHTML = inner_text;
	}
    }
}

function freeze_queued_container(command){
    freeze_attributes = {"id":"ul_queued_freeze_", "class": "ul_queued_freeze"};
    inner_html = {"id":"ul_queued_msg_", "class": "ul_queued_msg"};
    inner_text = t9n[LOCALE].item_queued;
    let host = command.split("/")[2];
    inner_text += '<buttton id="sync_unqueue_' + host + '" onclick="cancel_sync(this)" class="command btn btn-block btn-lg btn-default btn-unqueue" role="button">X</button';
    freeze_ui_host(host, freeze_attributes, inner_html, inner_text);
}

function unfreeze_queued_container(host){
    let container = document.getElementById(host);
    let exists = container.querySelector("div.ul_queued_freeze");
    if (exists){
	exists.remove();
    }
}

function unfreeze_all_containers(){
    if (currentUser.hosts_up){
	currentUser.hosts_up.forEach(function(host){
	    unfreeze_queued_container(host);
	});
    }
}

function exec_all_hosts(command){
    let authorized_commands = ['reboot', 'poweroff'];
    // Only send authorized commands
    if (authorized_commands.indexOf(command) == -1 ){
	return 0;
    }
    if ( confirm(t9n[LOCALE].confirmMessage) ) {
	if (currentUser.hosts_up){
	    currentUser.hosts_up.forEach(function(host){
		send_ajax_cmd("/" + host + "/" + command);
	    });
	}
    }
}

function display_upload_status(command) {
    let host = command.split("/")[2];
    let container_element = document.getElementById(host);
    let siblings = container_element.children;
    // Upload dialog container / background
    let upload_dialog_cont_attributes = {"id":"ul_dialog_cont_", "class": "upload_dialog_cont"};
    let upload_dialog_cont_element = add_HTML_element("div", upload_dialog_cont_attributes, 0, host);
    let ul_cont_exists = document.getElementById(upload_dialog_cont_attributes.id + host);
    // Upload dialog
    //~ let upload_dialog_attributes = {"id":"ul_dialog_", "class": "upload_dialog"};
    //~ let upload_dialog_element = add_HTML_element("div", upload_dialog_attributes, 0, host);
    //~ let ul_dialog_exists = document.getElementById(upload_dialog_cont_attributes["id"] + host);
    let upload_status_table = `
			      <table>
				<tbody>
				  <tr>
				    <th colspan="2" id="ul_status_title_${host}">${t9n[LOCALE].sync}</th>
				  </tr>
				  <tr>
				    <td id="ul_status_progress_cnt_${host}"></td>
				    <td id="ul_status_progress_size_${host}"></td>
				  </tr>
				  <tr>
				    <td id="ul_status_filename_${host}"></td>
				    <td id="ul_status_filesize_${host}"></td>
				  </tr>
				</tbody>
			      </table>
			      `;
    let upload_dialog_HTML = `
			    <div id='ul_dialog_${host}'  class='upload_dialog'>
				<div id="ul_status_${host}" class="upload_status"></div>
				<div id="ul_progress_${host}" class="progress_bar"></div>
				<button id="ul_stop_btn_${host}" value="/sync/${host}/stop" class="command btn btn-block btn-lg btn-default" role="button">&#x23f9;<span class="btn_txt">Stop</span></button>
			    </div>
			    `;
    if ( ul_cont_exists != undefined) {
    	container_element.removeChild(ul_cont_exists);
  	}
    container_element.insertBefore(upload_dialog_cont_element, siblings[0]);
    document.getElementById(upload_dialog_cont_attributes.id + host).innerHTML = upload_dialog_HTML;
    document.getElementById("ul_stop_btn_" + host).addEventListener("click", send_btn_cmd, false);
    document.getElementById("ul_status_" + host).innerHTML = upload_status_table;
}


function destroy_upload_status(host) {
    let container_element = document.getElementById(host);
    let ul_cont_exists = document.getElementById("ul_dialog_cont_" + host);
    if ( ul_cont_exists != undefined) {
	// Remove ul dialog
    	container_element.removeChild(ul_cont_exists);
	// Clear update callback
	clearTimeout(currentUser["ul_timeout_" + host]);
    }
} 


async function update_upload_status(current_upload) {
    if (current_upload.status == -1){
	// Upload finished
	console.log("Upload finished - Destroying dialog for " + currentUser.last_ul_host);
	destroy_upload_status(currentUser.last_ul_host);

	// Remove first item from command queue
	currentUser.ul_queue.shift();
	// Upload done, un-freeze
	currentUser.freeze_ul = 0;
	// Call sync_host() again
	setTimeout(sync_host, 1000);
	
    } else if (current_upload.status) {
	unfreeze_queued_container(currentUser.last_ul_host);
	// Upload in progress
	console.log("Updating dialog...");
	//document.getElementById("ul_dialog_cont_" + current_upload.host).style.display = "block";
	document.getElementById("ul_dialog_cont_" + currentUser.last_ul_host).style.display = "block";
	// Fill table 
	document.getElementById("ul_status_progress_cnt_" + currentUser.last_ul_host).innerHTML = current_upload.progress + " / " + current_upload.total_count + t9n[LOCALE].upload_sent_count_msg;
	document.getElementById("ul_status_progress_size_" + currentUser.last_ul_host).innerHTML = current_upload.transferred_size + t9n[LOCALE].size_unit + t9n[LOCALE].of + current_upload.total_size + t9n[LOCALE].size_unit;
	document.getElementById("ul_status_filename_" + currentUser.last_ul_host).innerHTML = t9n[LOCALE].filename + ": " + current_upload.filename;
	document.getElementById("ul_status_filesize_" + currentUser.last_ul_host).innerHTML = t9n[LOCALE].size + ": " + current_upload.size + t9n[LOCALE].size_unit;
	// Progress bar CSS
	// FIXME : cursor stops updating after upload ?
	if (current_upload.transferred_percent) {
	    document.getElementById("ul_progress_" + currentUser.last_ul_host).innerText = current_upload.transferred_percent + "%";
	    document.getElementById("ul_progress_" + currentUser.last_ul_host).style.background = "linear-gradient(90deg, " + TIMELINE_COLOR_CURSOR + " " + current_upload.transferred_percent + "%, #fff " + current_upload.transferred_percent + "%)";
	}
	// Update status callback
	currentUser["ul_timeout_" + currentUser.last_ul_host] = setTimeout(send_ajax_cmd, 1000, `/sync/${currentUser.last_ul_host}/status`);
    } else {
	// Upload is starting
	console.log("Requesting data to update dialog for " + currentUser.last_ul_host);
	// Freeze ul cmd
	currentUser.freeze_ul = 1;
	//~ currentUser.last_ul_host = current_upload.host;
	// This will end up calling update_upload_status() again, expecting the ul status value to change from 0 to int
	send_ajax_cmd(`/sync/${currentUser.last_ul_host}/status`);
	//~ send_ajax_cmd(`/sync/${current_upload.host}/status`);
	// Wait a bit for response
	await sleep(200);
    }
}   

// <div id="ul_status_10.42.0.10" class="upload_status"></div>
// Metadata display
function parse_result(command, infos_array) {
	if (command == "/all/status") {
	    // Requests current status of every instances, especially current media file's name, position and length. 
	    // Also retrieves loop and repeat status.
	    infos_array.forEach(update_status);
	    
	} else if (command.indexOf("/list") > -1 ) {
	    // Requests playlist of every instances
	    if (!currentUser.freeze_timeline_update){
		infos_array.forEach(update_list);
	    }
	    
	} else if (command == "/scan") {
	    // Scan for live hosts
	    update_host_list(infos_array);
	    
	} else if (command == "/browse_local") {
	    // Display local media files in a table
	    //~ document.getElementById("filelist").innerHTML = update_local_filelist(infos_array);
	    
	} else if (command == "/all/rssi") {
	    // RSSI strength indicator
	    infos_array.forEach(update_rssi_indicator);
	    
	//~ } else if ( command == "/all/browse") {
	} else if (command.indexOf("/browse") > -1) {
	    // Display remote media files in a table
	    infos_array.forEach(update_remote_filelist);
	    
	} else if (command.indexOf("/sync/") > -1) {
	    if (command.indexOf("/status") > -1 ) {
		//~ console.log("updating infos...");
		//~ console.log(infos_array);
		update_upload_status(infos_array);
	    } else if (command.indexOf("/stop") > -1 ) {
		//~ console.log("stopping upload...");
		//~ console.log(infos_array);
		//~ destroy_upload_status();
	    }
	} else {
	    setTimeout(send_ajax_cmd, 180, "/all/list");
	    setTimeout(send_ajax_cmd, 180, "/all/status");
	}
}


function send_ajax_cmd(command) {
    let request = new XMLHttpRequest();
    request.onload = function() {
	if (request.readyState === request.DONE) {
	    if (request.status === 200) {
	    // responseText is a string, use parse to get an array.
		if (!currentUser.freeze_timeline_update) {
		    let infos_array = JSON.parse(request.responseText);
		    parse_result(command, infos_array);
		}
	    }
	}
    };
    request.open("GET", command, true);
    request.send();
}


function enqueue_file(evt) {
    send_ajax_cmd("/" + evt.currentTarget.host + "/enqueue/" + evt.currentTarget.innerText);
    // User can't be interacting with timeline when clicking on file so unfreeze it.
    currentUser.freeze_timeline_update = 0;
    setTimeout(send_ajax_cmd, 40, "/" + evt.currentTarget.host + "/list");
}

function send_btn_cmd(evt) {
    let clickedButton = event.currentTarget;
    let command = clickedButton.value;
    send_ajax_cmd(command);
    //~ setTimeout(send_ajax_cmd, 40, "/" + evt.currentTarget.host + "/list");
}


function update_statusall_content() {
    document.getElementById("status_all").innerHTML = currentUser.status_all;
}


function scan_hosts() {
    send_ajax_cmd("/scan");
    update_statusall_content();
    setTimeout(scan_hosts, currentUser.scan_interval);
}


function sync_host() {
    // If ul is not in progress
    if (!currentUser.freeze_ul){
	// If there's something in the queue
	if (currentUser.ul_queue.length){
	    // Send first command in queue.
	    let command_q = currentUser.ul_queue[0];
	    console.log("Sending command " + command_q);
	    let host = command_q.split("/")[2];
	    // Send ul command 
	    send_ajax_cmd(command_q);
	    // Update status
	    currentUser.status_all = t9n[LOCALE].sync;
	    // Create dialog
	    display_upload_status(command_q);
	    // Set current host
	    currentUser.last_ul_host = host;
	    // Send command to update dialog according to upload status
	    // This ends up calling update_upload_status()
	    setTimeout(send_ajax_cmd, 200, command_q + "/status");
	} else {
	    console.log("Nothing else in the queue !");
	    // Make sure sane values are set back
	    unfreeze_all_containers();
	    currentUser.last_ul_host = 0;
	    return 0;
	}
    }
    console.log("UL freezed, waiting a bit...");
    return 0;
}


function cancel_sync(host_btn_id){
    let host =  host_btn_id.id.split("_")[2];
    let command = "/sync/" + host;
    if (currentUser.ul_queue){
	let item_index = currentUser.ul_queue.indexOf(command);
	// Skip [0]
	if (item_index > 0){
	    console.log(host + " unqueuing");
	    currentUser.ul_queue.splice(item_index, 1);
	    unfreeze_queued_container(host);
	}
    }
}

// UI 
addEventListener("DOMContentLoaded", function() {
    //~ adjust_timeline();
    let commandButtons = document.querySelectorAll(".command");
    for (let i=0, l=commandButtons.length; i<l; i++) {
	let button = commandButtons[i];
	button.addEventListener("click", function(event) {
	    event.preventDefault();
	    let clickedButton = event.currentTarget;
	    let command = clickedButton.value;
	    
	    if ( command.indexOf("/reboot" ) > -1  ||  command.indexOf("/poweroff") > -1 ) {
		if (command.indexOf("/all" ) == -1){
		    if ( !confirm(t9n[LOCALE].confirmMessage) ) {
			return 0;
		    }
		}
	    } else if ( command == "/scan" ) {
		document.getElementById("status_all").innerHTML = currentUser.status_all;
		
	    } else if ( command.indexOf("/sort") > -1 ){ 
		if (command.indexOf('/1/') > -1 ) {
		    clickedButton.value = clickedButton.value.replace('/1/','/0/');
		    
		} else {
		    clickedButton.value = clickedButton.value.replace('/0/','/1/');
		}
	    }
	    // AJAX request
	    let request = new XMLHttpRequest();
	    if ( command == "/scan") {
		request.onload = send_ajax_cmd(command);
		
	    } else if ( command.indexOf("/clear") > -1 || command.indexOf("/sort") > -1) {
		request.onload = send_ajax_cmd(command);
		
	    } else if ( command.indexOf("/sync/") > -1 ) {
		if ( command.indexOf("/all") > -1 ) {
		    console.log("Sync all request");
		    // If command is /sync/all, add live hosts to sync queue
		    if (currentUser.hosts_up){
			currentUser.hosts_up.forEach(function(host){
			    let command = "/sync/" + host;
			    if (currentUser.ul_queue.indexOf(command) == -1){
				console.log("Adding " + host + " to sync queue...");
				currentUser.ul_queue.push(command);
				freeze_queued_container(command);
			    }
			});
		    }
		    if (currentUser.ul_queue.length > 1){
			sync_host();
		    }
		    // Prevent request 
		    return 0;
		} 
		// If command not already in queue, add it
		if (!currentUser.ul_queue.includes(command)){
		    currentUser.ul_queue.push(command);
		    freeze_queued_container(command);
		} else {
		    console.log("Command already in queue...");
		    return 0;
		}
		sync_host();
		// Prevent request 
		return 1;
	    } 
	    else if ( command.indexOf("/browse") > -1 ) {
		request.onload = send_ajax_cmd("/all/browse");
	    }
	    request.open("GET", command, true);
	    request.send();
	});
    }
}, true);
send_ajax_cmd("/scan");
send_ajax_cmd("/browse_local");
setInterval(send_ajax_cmd, 500, "/all/status");
setTimeout(send_ajax_cmd, 1000, "/all/list");
setTimeout(send_ajax_cmd, 3000, "/all/browse");
setInterval(send_ajax_cmd, 20000, "/all/rssi");
setTimeout(scan_hosts, currentUser.scan_interval);