Use store waku to get older messages

Chronological order is preserved and dupes are removed.

web-chat/src/App.tsx

@@ -5,6 +5,7 @@ import './App.css';
 import { ChatMessage } from 'waku-chat/chat_message';
 import { WakuMessage } from 'waku/waku_message';
 import { RelayDefaultTopic } from 'waku/waku_relay';
+import { StoreCodec } from 'waku/waku_store';
 import handleCommand from './command';
 import Room from './Room';
 import Waku from 'waku/waku';
@@ -23,7 +24,29 @@ export default function App() {
     const handleNewMessages = (event: { data: Uint8Array }) => {
       const chatMsg = decodeWakuMessage(event.data);
       if (chatMsg) {
-        copyAndReplace([chatMsg], stateMessages, setMessages);
+        copyAppendReplace([chatMsg], stateMessages, setMessages);
+      }
+    };
+
+    const handleProtocolChange = async (
+      waku: Waku,
+      { peerId, protocols }: { peerId: PeerId; protocols: string[] }
+    ) => {
+      if (protocols.includes(StoreCodec)) {
+        console.log(
+          `Retrieving archived messages from ${peerId.toB58String()}`
+        );
+        const response = await waku.store.queryHistory(peerId, [
+          ChatContentTopic,
+        ]);
+
+        if (response) {
+          const messages = response
+            .map((wakuMsg) => wakuMsg.payload)
+            .filter((payload) => !!payload)
+            .map((payload) => ChatMessage.decode(payload as Uint8Array));
+          copyMergeUniqueReplace(messages, stateMessages, setMessages);
+        }
       }
     };
 
@@ -34,12 +57,21 @@ export default function App() {
     } else {
       stateWaku.libp2p.pubsub.on(RelayDefaultTopic, handleNewMessages);
 
+      stateWaku.libp2p.peerStore.once(
+        'change:protocols',
+        handleProtocolChange.bind({}, stateWaku)
+      );
+
       // To clean up listener when component unmounts
       return () => {
         stateWaku?.libp2p.pubsub.removeListener(
           RelayDefaultTopic,
           handleNewMessages
         );
+        stateWaku?.libp2p.peerStore.removeListener(
+          'change:protocols',
+          handleProtocolChange.bind({}, stateWaku)
+        );
       };
     }
   }, [stateWaku, stateMessages]);
@@ -63,7 +95,7 @@ export default function App() {
               const commandMessages = response.map((msg) => {
                 return new ChatMessage(new Date(), command, msg);
               });
-              copyAndReplace(commandMessages, stateMessages, setMessages);
+              copyAppendReplace(commandMessages, stateMessages, setMessages);
             }}
           />
         </ThemeProvider>
@@ -104,7 +136,7 @@ function decodeWakuMessage(data: Uint8Array): null | ChatMessage {
   return ChatMessage.decode(wakuMsg.payload);
 }
 
-function copyAndReplace<T>(
+function copyAppendReplace<T>(
   newValues: Array<T>,
   currentValues: Array<T>,
   setter: (val: Array<T>) => void
@@ -112,3 +144,26 @@ function copyAndReplace<T>(
   const copy = currentValues.slice();
   setter(copy.concat(newValues));
 }
+
+function copyMergeUniqueReplace(
+  newValues: ChatMessage[],
+  currentValues: ChatMessage[],
+  setter: (val: ChatMessage[]) => void
+) {
+  const copy = currentValues.slice();
+  newValues.forEach((msg) => {
+    if (!copy.find(isEqual.bind({}, msg))) {
+      copy.push(msg);
+    }
+  });
+  copy.sort((a, b) => a.timestamp.valueOf() - b.timestamp.valueOf());
+  setter(copy);
+}
+
+function isEqual(lhs: ChatMessage, rhs: ChatMessage): boolean {
+  return (
+    lhs.nick === rhs.nick &&
+    lhs.message === rhs.message &&
+    lhs.timestamp.toString() === rhs.timestamp.toString()
+  );
+}