/* jshint esversion: 6 */

var localModeEnabled = false;
var selectedTags = [];

// References to howler objects
var howlerSounds = [];

function ready(fn) {
	if (document.attachEvent ? document.readyState === "complete" : document.readyState !== "loading") {
		fn();
	} else {
		document.addEventListener("DOMContentLoaded", fn);
	}
}

function sleep(ms) {
	return new Promise(resolve => setTimeout(resolve, ms));
}

ready(function() {
	hideSections();

	var sections = document.querySelectorAll("section");
	var nav = document.querySelectorAll("nav > a");

	if (sections.length > 0)
		sections[0].style.display = "block";

	nav.forEach(function(item) {
		item.onclick = function(e) {
			e.preventDefault();

			var target = e.target.href.split("#");
			var id = target[target.length - 1];

			hideSections();

			document.querySelector("#" + id).style.display = "block";
		};
	});

	var searchfield = document.querySelector("#search");
	searchfield.focus();

	searchFilter(searchfield, ".sound", "inline-block");

	var reset = document.querySelector("#reset");
	var sounds_nav = document.querySelector("#sounds-nav");

	reset.addEventListener("click", resetSearch, false);
	sounds_nav.addEventListener("click", resetSearch, false);

	addKeyListeners();
});

function searchFilter(searchfield, itemSelector, unHideStyle) {
	if (searchfield !== null) {
		searchfield.addEventListener("keyup", function() {
			var items = document.querySelectorAll(itemSelector);

			items.forEach(function(item) {
				item.style.display = unHideStyle;
			});

			items.forEach(function(item) {
				var name = item.firstChild.innerHTML;

				if (name.toLowerCase().indexOf(searchfield.value.toLowerCase()) === -1) {
					item.style.display = "none";
				}
			});
		});
	}
}

function tagFilter(sounds) {
	var items = document.querySelectorAll(".sound");

	items.forEach(function(item) {
		item.style.display = "inline-block";
	});

	items.forEach(function(item) {
		var name = item.firstChild.innerHTML;

		if (sounds.length > 0 && sounds.indexOf(name) === -1) {
			item.style.display = "none";
		}
	});
}

/*
* Adds all necessary KeyListeners to document
*/
function addKeyListeners() {
	// keyboard listener for global key strokes/inputs
	document.onkeydown = function(evt) {
		evt = evt || window.event;
		if (evt.keyCode == 27) {
			// esc key
			resetSearch();
		} else if ((evt.keyCode == 75 || evt.keyCode == 67) && evt.ctrlKey) {
			// ctrl+k and ctrl+c key binding
			killAllAudio();
		} else if (evt.keyCode == 88 && evt.ctrlKey){
			// ctrl+x key binding
			toggleLocalMode();
		}
	};

	// keyboard listener for playing sounds using enter key
	var buttons = document.querySelectorAll(".sound");

	buttons.forEach(function(item) {
		item.firstChild.addEventListener('keypress', async function (e) {
			var key = e.keyCode;
			var source = e.target;
			// keylistener for enter or ctrl+enter (which is k10 on chrome)
			if (key === 13 || (key === 10 && e.ctrlKey)) {
				if (e.ctrlKey){
					killAllAudio();
					await sleep(100);
				}
				source.classList.add("sound-pressed");
				source.onclick();
				await sleep(300);
				source.classList.remove("sound-pressed");
			}
		});
	});

	var tags = document.querySelectorAll(".tags li");

	tags.forEach(function(tag) {
		tag.addEventListener("click", function(e) {
			var className = "tagged";
			var el = this.firstChild;

			var classes = el.className.split(" ");
			var existingIndex = classes.indexOf(className);

			if (existingIndex >= 0)
				classes.splice(existingIndex, 1);
			else
				classes.push(className);

			el.className = classes.join(" ");

			var i = selectedTags.indexOf(el.innerHTML);

			if (i == -1)
				selectedTags.push(el.innerHTML);
			else
				selectedTags.splice(i, 1);

			if (selectedTags.length > 0) {
				ajaxRequest("/tags/" + encodeURI(selectedTags.join()), function() {
					tagFilter(JSON.parse(this.responseText));
				});
			} else {
				tagFilter([]);
			}
		});
	});
}


function resetSearch() {
	var searchfield = document.querySelector("#search");
	var buttons = document.querySelectorAll(".sound");
	searchfield.blur();
	searchfield.value = "";

	buttons.forEach(function(item) {
		item.style.display = "inline-block";
	});

	searchfield.focus();
}

/*
* Reads the stream url from input with id #streaming-url and forwards it to the server using AJAX.
*/
function playStream() {
	var streamUrl = document.querySelector("#streaming-url").value;
	ajaxRequest("/?video="+encodeURI(streamUrl));
}

function hideSections() {
	var sections = document.querySelectorAll("section");

	sections.forEach(function(item, i) {
		item.style.display = "none";
	});
}

function ajaxRequest(url, callback) {
	var ajaxRequest;
	try {
		ajaxRequest = new XMLHttpRequest();
		ajaxRequest.open("GET", url, true);

		if (typeof callback !== 'undefined')
			ajaxRequest.onload = callback;

		ajaxRequest.send(null);
	} catch (e) {
		alert("Unfortunately we were unable to handle your request. Please try again later and contact the server administrator if the problem persists.");
		return false;
	}
}

/*
* Switches between local and remote playback mode.
* Additionally changes the button text and its color so that the user has a visible feedback.
*/
function toggleLocalMode() {
	toggleButton = document.getElementById("local-mode-button").children[0];
	if (localModeEnabled) {
		localModeEnabled = false;
		toggleButton.classList.remove("local");
		toggleButton.innerHTML = "[S]";
		toggleButton.title = "play sounds on server";
	} else {
		localModeEnabled = true;
		toggleButton.classList.add("local");
		toggleButton.innerHTML = "[L]";
		toggleButton.title = "play sounds locally";
	}
}

/*
* Either plays the given sound file locally by using howler.js or forwards the request to the remote server using AJAX.
*/
function playSound(filename) {
	if (localModeEnabled){
		// play local audio using howler.js
		var sound = new Howl({
			src: ['/sounds/' + filename]
		});
		sound.play();
		howlerSounds.push(sound);
	} else {
		ajaxRequest("/play/" + filename);
	}
}

function killAllHowlerAudio() {
	for (var i = 0; i < howlerSounds.length; i++) {
		howlerSounds[i].stop();
	}
}

/*
* Kills all local or remote audio, depending on localModeEnabled
*/
function killAllAudio() {
	if (localModeEnabled) {
		killAllHowlerAudio();
	} else {
		ajaxRequest("/?killvideo=yes");
	}
}