Vladislav_Postnikov
/
HomeWork1


			
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							<!DOCTYPE html>
<html>
<head>
	<meta charset="utf-8">
	<title>await paradise (chat)</title>
</head>
<body>

	<div id="cont">
		
	</div>

	<script>

//-----------stage 0
let gbl=0;
	function jsonPost(url, data){
    	return new Promise((resolve, reject) => {
       		var x = new XMLHttpRequest();   
        	x.onerror = () => reject(new Error('jsonPost failed'))
        	x.open("POST", url, true);
        	x.send(JSON.stringify(data))

        	x.onreadystatechange = () => {
            	if (x.readyState == XMLHttpRequest.DONE && x.status == 200){
                	resolve(JSON.parse(x.responseText))
            	}else if (x.status != 200){
                	reject(new Error('status is not 200'))
            	}
        	}
    	})
	}
	
//-------------stage 1
		let n=document.createElement('input');
		let mes=document.createElement('input');
		let btn=document.createElement('input');
		btn.type='submit';
		btn.value='Send';
		n.placeholder='nick';
		mes.placeholder='message';	
		let btn2=document.createElement('input');
		btn2.value='GetMessage';
		btn2.type='submit';
		cont.append(n,mes,btn,btn2);

		btn.onclick=()=>{
			jsonPost("http://students.a-level.com.ua:10012", {func: 'addMessage', nick: n.value, message: mes.value})
			.then(value =>{
					console.log(value);
					console.log(value.nextMessageId);
				}, 
				err=> console.log(err)
			);
		}

		btn2.onclick=()=>{
			jsonPost("http://students.a-level.com.ua:10012", {func: "getMessages", messageId: 0})
			.then(value => console.log(value), err=> console.log(err));
		}

//----------------stage 2
		async function allMessages(){
			let div=document.createElement('div');
			let mail=await jsonPost("http://students.a-level.com.ua:10012", {func: "getMessages",messageId: 0});
			for(let item in mail.data){
				let p=document.createElement('p');
				 let newdate = new Date(mail.data[item].timestamp).toLocaleString()
				p.innerHTML=`<b>${mail['data'][item]['nick']}</b>: ${mail['data'][item]['message']} ---- ${newdate}`;
				div.append(p);
			}
			document.body.append(div);
			gbl=mail.nextMessageId;
		}

		allMessages()


//--------------stage 3
	async function getNewMessages(){
        let mail = await jsonPost("http://students.a-level.com.ua:10012", {func: "getMessages", messageId: gbl});
        let locale = mail.nextMessageId;
       	gbl < locale ? gbl = locale : null;
            for (let item in mail.data) {
                let div = document.createElement('div');
                cont.append(div);
                let newdate = new Date(mail.data[item].timestamp).toLocaleString()
                div.innerHTML = `<b>${mail.data[item].nick}</b>: ${mail.data[item].message} <small><i>${newdate}</i></small>`;
            }
        return mail.data;
	}
	//getNewMessages();

//------------------stage 4
	setInterval(()=>getNewMessages(),2000);

//-------------------stage 5
	btn.addEventListener('click', buttonHandler);

	function buttonHandler() {
    	sendAndCheck(n.value, mes.value) ;
	}

	async function sendMessage(nick,mes){
		jsonPost("http://students.a-level.com.ua:10012", {func: 'addMessage', nick: nick, message: mes})
			.then(value =>{
					console.log(value);
					console.log(value.nextMessageId);
				}, 
				err=> console.log("something wrong: "+err)
			);
	}

	async function sendAndCheck(nick, message) {
    	await Promise.all([sendMessage(nick, message), getNewMessages()]);
	}

	async function checkLoop() {
	    let delay = ms => new Promise(ok => setTimeout(() => ok(ms), ms))
	    while(true) {
	        await delay(2000).then(() => getNewMessages())
	    }
	}
	
	checkLoop()

//----------------stage 6
		
	async function jsonPost2(url, data) {
	   return  fetch(url, {method: 'POST', body: JSON.stringify(data)})
	}

	jsonPost2("http://students.a-level.com.ua:10012", {func: 'addMessage', nick: n.value, message: mes.value})
	.then(res=>res.json())
	.then(res=>console.log(res));

	</script>
</body>
</html>