import { render, html } from '/uhtml.js';

let msg;

function sendMessage(e) {
	e.preventDefault();
	if (!msg.value)
		return;
	window.emit('send_message', {
		message: msg.value,
		thread: window.threadId
	});
	msg.value = '';
}

let earliestMessage;

window.socket.on('new_message', message => {
	if (message.thread !== window.threadId)
		return;
	const messages = document.getElementById('messages');
	let scroll = messages.scrollHeight - messages.scrollTop <= messages.clientHeight;
	messages.appendChild(html.node`
		<div class='message'>
			<strong>${message.name}: </strong>
			${message.message}
		</div>`);
	if (scroll)
		messages.scroll(0, messages.scrollHeight - messages.clientHeight);
	if (!earliestMessage)
		earliestMessage = message.id;
});

function loadMessages() {
   if (!msg) {
      render(document.getElementById('message'), html`
         <button id='loadmore' class='hidden' onclick=${loadMessages}>
         load more messages
         </button>
         <div id='messages'></div>
         <form id='msginput' onsubmit=${sendMessage}>
            <input id='msg' placeholder='write a message...' />
            <button type='submit' id='sendmsg'>send</button>
         </form>
      `);
      msg = document.getElementById('msg');
   }
   const messages = document.getElementById('messages');
   if (!this) { // called from chooseThread, initializing thread
   	messages.innerHTML = '';
      earliestMessage = null;
   }
	window.emit(
		'get_history',
		{
			before: earliestMessage,
			thread: window.threadId
		},
		msg => {
         if (!msg.success)
            console.log('get_history failed: ' + msg.message);
			if (msg.messages.length > 0) {
				earliestMessage = msg.messages[msg.messages.length - 1].id;
				for (let message of msg.messages)
					messages.prepend(html.node`
                  <div class='message'>
                     <strong>${message.name}: </strong>
                     ${message.message}
                  </div>`);
			}
			if (msg.more)
				document.getElementById('loadmore').classList.remove('hidden');
			else
				document.getElementById('loadmore').classList.add('hidden');
			messages.scroll(0, messages.scrollHeight - messages.clientHeight);
		}
	);
}

export default loadMessages;