refactor(chat): reorganize helper functions and update imports

src/stores/chat/helper/promotion.ts

@@ -0,0 +1,68 @@
+import type { UiMessage } from "@/data/dto/chat";
+import type { PendingChatPromotion } from "@/data/storage/navigation";
+import { todayString } from "@/utils/date";
+
+import {
+  applySingleUnlockOutput,
+  type UnlockMessageOutput,
+} from "./unlock";
+
+const PROMOTION_COPY = {
+  voice: "I left a voice message for you. Unlock it to listen.",
+  image: "I sent you a private photo. Unlock it to view.",
+  private: "I have something private to tell you. Unlock it to read.",
+} as const;
+
+export interface ChatPromotionState {
+  session: PendingChatPromotion;
+  message: UiMessage;
+}
+
+export function createChatPromotionState(
+  session: PendingChatPromotion,
+  messageId?: string,
+): ChatPromotionState {
+  const isImage = session.promotionType === "image";
+  const isPrivate = session.promotionType === "private";
+
+  return {
+    session,
+    message: {
+      id: messageId || `promotion:${session.clientLockId}`,
+      content: "",
+      isFromAI: true,
+      date: todayString(),
+      locked: true,
+      lockReason: session.lockType,
+      imagePaywalled: isImage ? true : undefined,
+      lockedPrivate: isPrivate ? true : undefined,
+      privateMessageHint: PROMOTION_COPY[session.promotionType],
+    },
+  };
+}
+
+export function appendPromotionMessage(
+  messages: readonly UiMessage[],
+  promotion: ChatPromotionState | null,
+): UiMessage[] {
+  if (!promotion) return [...messages];
+  return [
+    ...messages.filter((message) => message.id !== promotion.message.id),
+    promotion.message,
+  ];
+}
+
+export function applyPromotionUnlockOutput(
+  promotion: ChatPromotionState | null,
+  output: UnlockMessageOutput,
+): ChatPromotionState | null {
+  if (!promotion || promotion.message.id !== output.displayMessageId) {
+    return promotion;
+  }
+  return {
+    ...promotion,
+    message:
+      applySingleUnlockOutput([promotion.message], output)[0] ??
+      promotion.message,
+  };
+}