feat(splash): load latest chat message

src/app/splash/hooks/use-splash-latest-message.ts

@@ -0,0 +1,79 @@
+"use client";
+
+import { useEffect, useState } from "react";
+
+import type { LoginStatus } from "@/data/dto/auth";
+import { fetchSplashLatestMessagePreview } from "@/lib/chat/splash_latest_message";
+import { Logger, Result } from "@/utils";
+
+const log = new Logger("SplashLatestMessage");
+
+export interface UseSplashLatestMessageInput {
+  hasInitialized: boolean;
+  isAuthLoading: boolean;
+  loginStatus: LoginStatus;
+}
+
+export interface UseSplashLatestMessageOutput {
+  message: string | null;
+  isLoading: boolean;
+}
+
+interface SplashLatestMessageState {
+  key: string;
+  loaded: boolean;
+  message: string | null;
+}
+
+export function useSplashLatestMessage({
+  hasInitialized,
+  isAuthLoading,
+  loginStatus,
+}: UseSplashLatestMessageInput): UseSplashLatestMessageOutput {
+  const [state, setState] = useState<SplashLatestMessageState>({
+    key: "",
+    loaded: false,
+    message: null,
+  });
+  const shouldLoad =
+    hasInitialized && !isAuthLoading && loginStatus !== "notLoggedIn";
+  const requestKey = shouldLoad ? loginStatus : "";
+
+  useEffect(() => {
+    if (!shouldLoad) return;
+
+    let cancelled = false;
+
+    const loadLatestMessage = async () => {
+      const result = await fetchSplashLatestMessagePreview();
+      if (cancelled) return;
+
+      if (Result.isErr(result)) {
+        log.warn(
+          { err: result.error.message },
+          "[splash] latest message history request failed",
+        );
+        setState({ key: requestKey, loaded: true, message: null });
+        return;
+      }
+
+      setState({
+        key: requestKey,
+        loaded: true,
+        message: result.data,
+      });
+    };
+
+    void loadLatestMessage();
+
+    return () => {
+      cancelled = true;
+    };
+  }, [requestKey, shouldLoad]);
+
+  if (!shouldLoad) return { message: null, isLoading: false };
+  if (state.key !== requestKey || !state.loaded) {
+    return { message: null, isLoading: true };
+  }
+  return { message: state.message, isLoading: false };
+}