Chat history.

client/public/wsModule.js

@@ -12,6 +12,7 @@ import {
   updateUser,
   getGroupedUsers,
   setMyId,
+  clearData,
   users,
   setFocused,
   setReplyTo,
@@ -49,11 +50,25 @@ export function initWebSocket(username, chatEl, inputContainer, usersListEl) {
       case "welcome": {
         // Initial user list.
         const myId = packet.data.you;
+        clearData();
         setMyId(myId);
         const users = packet.data.users || [];
         users.forEach(({ id, username }) => addUser(id, username));
         const groups = getGroupedUsers();
         usersListEl.innerHTML = "Online: " + groups.join(", ");
+        // Replay chat history.
+        const history = packet.data.history || [];
+        history.forEach((raw) => {
+          try {
+            const histPkt = JSON.parse(raw);
+            if (histPkt.type === "msg-event") {
+              const { id, username: u, content, ts, parent } = histPkt.data;
+              addMessage({ id, username: u, content, ts, parent });
+            }
+          } catch (e) {
+            console.error("Invalid history entry", raw);
+          }
+        });
         //addNotice(`<i>Users online: ${groups.join(", ")}</i>`);
         break;
       }