js-waku/examples/web-chat/src/App.tsx

import { useEffect, useReducer, useState } from "react";
import "./App.css";
import {
  PageDirection,
  getPredefinedBootstrapNodes,
  Waku,
  WakuMessage,
} from "js-waku";
import handleCommand from "./command";
import Room from "./Room";
import { WakuContext } from "./WakuContext";
import { ThemeProvider } from "@livechat/ui-kit";
import { generate } from "server-name-generator";
import { Message } from "./Message";
import { Fleet } from "js-waku/lib/discovery/predefined";

const themes = {
  AuthorName: {
    css: {
      fontSize: "1.1em",
    },
  },
  Message: {
    css: {
      margin: "0em",
      padding: "0em",
      fontSize: "0.83em",
    },
  },
  MessageText: {
    css: {
      margin: "0em",
      padding: "0.1em",
      paddingLeft: "1em",
      fontSize: "1.1em",
    },
  },
  MessageGroup: {
    css: {
      margin: "0em",
      padding: "0.2em",
    },
  },
};

export const ChatContentTopic = "/toy-chat/2/huilong/proto";

async function retrieveStoreMessages(
  waku: Waku,
  setArchivedMessages: (value: Message[]) => void
): Promise<number> {
  const callback = (wakuMessages: WakuMessage[]): void => {
    const messages: Message[] = [];
    wakuMessages
      .map((wakuMsg) => Message.fromWakuMessage(wakuMsg))
      .forEach((message) => {
        if (message) {
          messages.push(message);
        }
      });
    setArchivedMessages(messages);
  };

  const startTime = new Date();
  // Only retrieve a week of history
  startTime.setTime(Date.now() - 1000 * 60 * 60 * 24 * 7);

  const endTime = new Date();

  try {
    const res = await waku.store.queryHistory([ChatContentTopic], {
      pageSize: 5,
      pageDirection: PageDirection.FORWARD,
      timeFilter: {
        startTime,
        endTime,
      },
      callback,
    });

    return res.length;
  } catch (e) {
    console.log("Failed to retrieve messages", e);
    return 0;
  }
}

export default function App() {
  const [messages, dispatchMessages] = useReducer(reduceMessages, []);
  const [waku, setWaku] = useState<Waku | undefined>(undefined);
  const [nick, setNick] = useState<string>(() => {
    const persistedNick = window.localStorage.getItem("nick");
    return persistedNick !== null ? persistedNick : generate();
  });
  const [historicalMessagesRetrieved, setHistoricalMessagesRetrieved] =
    useState(false);

  useEffect(() => {
    localStorage.setItem("nick", nick);
  }, [nick]);

  useEffect(() => {
    initWaku(setWaku)
      .then(() => console.log("Waku init done"))
      .catch((e) => console.log("Waku init failed ", e));
  }, []);

  useEffect(() => {
    if (!waku) return;
    // Let's retrieve previous messages before listening to new messages
    if (!historicalMessagesRetrieved) return;

    const handleRelayMessage = (wakuMsg: WakuMessage) => {
      console.log("Message received: ", wakuMsg);
      const msg = Message.fromWakuMessage(wakuMsg);
      if (msg) {
        dispatchMessages([msg]);
      }
    };

    waku.relay.addObserver(handleRelayMessage, [ChatContentTopic]);

    return function cleanUp() {
      waku?.relay.deleteObserver(handleRelayMessage, [ChatContentTopic]);
    };
  }, [waku, historicalMessagesRetrieved]);

  useEffect(() => {
    if (!waku) return;
    if (historicalMessagesRetrieved) return;

    const retrieveMessages = async () => {
      await waku.waitForRemotePeer();
      console.log(`Retrieving archived messages`);

      try {
        retrieveStoreMessages(waku, dispatchMessages).then((length) => {
          console.log(`Messages retrieved:`, length);
          setHistoricalMessagesRetrieved(true);
        });
      } catch (e) {
        console.log(`Error encountered when retrieving archived messages`, e);
      }
    };

    retrieveMessages();
  }, [waku, historicalMessagesRetrieved]);

  return (
    <div
      className="chat-app"
      style={{ height: "100vh", width: "100vw", overflow: "hidden" }}
    >
      <WakuContext.Provider value={{ waku: waku }}>
        <ThemeProvider theme={themes}>
          <Room
            nick={nick}
            messages={messages}
            commandHandler={(input: string) => {
              handleCommand(input, waku, setNick).then(
                ({ command, response }) => {
                  const commandMessages = response.map((msg) => {
                    return Message.fromUtf8String(command, msg);
                  });
                  dispatchMessages(commandMessages);
                }
              );
            }}
          />
        </ThemeProvider>
      </WakuContext.Provider>
    </div>
  );
}

async function initWaku(setter: (waku: Waku) => void) {
  try {
    const waku = await Waku.create({
      libp2p: {
        config: {
          pubsub: {
            enabled: true,
            emitSelf: true,
          },
        },
      },
      bootstrap: {
        peers: getPredefinedBootstrapNodes(selectFleetEnv()),
      },
    });

    setter(waku);
  } catch (e) {
    console.log("Issue starting waku ", e);
  }
}

function selectFleetEnv() {
  // Works with react-scripts
  if (process?.env?.NODE_ENV === "development") {
    return Fleet.Test;
  } else {
    return Fleet.Prod;
  }
}

function reduceMessages(state: Message[], newMessages: Message[]) {
  return state.concat(newMessages);
}