logos-messaging-js/web-chat/src/Room.tsx

import {
  Box,
  Grid,
  List,
  ListItem,
  ListItemText
} from '@material-ui/core';
import React, { useState } from 'react';
import { ChatMessage } from 'waku-chat/chat_message';
import { WakuMessage } from 'waku/waku_message';
import { ChatContentTopic } from './App';
import MessageInput from './MessageInput';
import Send from './Send';
import { useWaku } from './WakuContext';

interface Props {
  lines: ChatMessage[],
}

export default function  Room (props :Props)  {
  let [messageToSend, setMessageToSend] = useState<string>('');
  const { waku } = useWaku();

  const messageHandler = (msg: string) => {
    setMessageToSend(msg);
  }

  const sendMessage = async () => {
    const chatMessage = new ChatMessage(new Date(), 'web-chat', messageToSend);
    const wakuMsg = WakuMessage.fromBytes(chatMessage.encode(), ChatContentTopic);
    await waku!.relay.send(wakuMsg);
  }

    return (
      <Grid container spacing={2}>

        <Grid item xs={12}>
          <Box height={800} maxHeight={800}
               style={{ flex: 1, maxHeight: '100%', overflow: 'scroll' }}>
            <Lines messages={props.lines} />
          </Box>
        </Grid>

        <Grid item xs={12}>
          <Grid container spacing={2} direction='row' alignItems='center'>
            <Grid item xs={11}>
              <MessageInput messageHandler={messageHandler} sendMessage={sendMessage} />
            </Grid>
            <Grid item xs={1}>
              <Send sendMessage={sendMessage} />
            </Grid>
          </Grid>
        </Grid>

      </Grid>
    );
}

interface LinesProps {
  messages: ChatMessage[]
}

const Lines = (props: LinesProps) => {
  const renderedLines = [];

  for (const i in props.messages) {
    renderedLines.push(<ListItem>
      <ListItemText key={"chat-message-" + i}
        primary={printMessage(props.messages[i])}
      />
    </ListItem>);
  }

  return (
    <List dense={true}>
      {renderedLines}
    </List>
  );
};

// TODO: Make it a proper component
function printMessage(chatMsg: ChatMessage) {
  const timestamp = chatMsg.timestamp.toLocaleString([], {
    month: 'short',
    day: 'numeric',
    hour: 'numeric',
    minute: '2-digit',
    hour12: false
  });
  return `<${timestamp}> ${chatMsg.nick}: ${chatMsg.message}`;
}