var previousTextLength;
var config_data;
var unread_words = 0;

document.getElementById("wordinput").focus();

function loadSentences(alertIfNew = false) {
	fetch("./data/sentences.txt", {headers: {"Cache-Control": "no-cache, no-store"}})
		.then((response) => { 
			return response.text().then((text) => {
				document.querySelector(".sentences").innerHTML = text;
				if (text.length > previousTextLength) {
					document.getElementsByTagName("title")[0].innerText = (config_data.title ? config_data.title : "One Word Each") + " (" + ++unread_words + ")";
					if (alertIfNew) {
						var newtxt = text.substring(previousTextLength, text.length);
						//var parser = new DOMParser();
						//var xmltxt = parser.parseFromString(newtxt, "text/xml");
						//var newword = xmltxt.getElementsByTagName("span")[0].innerHTML.trim();
						var htmltxt = document.createElement("html");
						htmltxt.innerHTML = newtxt;
						var newword = htmltxt.getElementsByTagName("span")[0].innerHTML.trim();
						if (Notification.permission == 'granted') {
							displayNotification(newword);
						}
						else {
							alert("Neues Wort: " + newword);
						}
					}
				}
				previousTextLength = text.length;
				
				// color
				var spans = document.querySelector(".sentences").getElementsByTagName("span");
				// we expect this to be from the user who's turn it is now (3 users)
				var histurnspan = spans[spans.length - 3];
				//console.log(histurnspan.getAttribute("style"));
				document.getElementById("wordinput").setAttribute("style", histurnspan.getAttribute("style"));
			});
		});
}

function loadConfig() {
	fetch("./data/config.json").then((response) => {
		return response.text().then((text) => {
			config_data = JSON.parse(text);
		});
	}).catch(() => {
		config_data = Object(); // leave empty
	});
}

function onReloadClicked() {
	loadSentences();
	document.querySelector("#but-reload").style.visibility = "hidden";
	setTimeout(function(){
		document.querySelector("#but-reload").style.visibility = "initial";
	}, 100);
}

function displayNotification(word) {
  if (Notification.permission == 'granted') {
	navigator.serviceWorker.getRegistration().then(function(reg) {
	  reg.showNotification("Neues Wort auf " + (config_data.title ? config_data.title : "OWE"), 
		{ body: word, icon: (config_data.logo? config_data.logo.image_path : "OWE_Logo.png"), requireInteraction: true });
	});
  }
}

window.onfocus = function() {
	unread_words = 0;
	document.getElementsByTagName("title")[0].innerText = (config_data.title ? config_data.title : "One Word Each");
}

//setTimeout(loadSentences, 500);
loadConfig();
loadSentences();
setInterval(loadSentences, 5000, true);

if ('serviceWorker' in navigator) {
  navigator.serviceWorker.register('./service-worker.js')
  .then(function(registration) {
	console.log('Registration successful, scope is:', registration.scope);
  })
  .catch(function(error) {
	console.log('Service worker registration failed, error:', error);
  });
}

navigator.serviceWorker.register('./service-worker.js', {
  scope: './'
});

navigator.serviceWorker.register('./service-worker.js', {
  scope: '.'
});

Notification.requestPermission(function(status) {
	console.log('Notification permission status:', status);
});