feat(chat): unlock paid messages before payment

src/lib/navigation/__tests__/subscription_exit.test.ts

@@ -3,23 +3,36 @@ import { beforeEach, describe, expect, it, vi } from "vitest";
 import { ROUTES } from "@/router/routes";
 
 import { consumePendingChatImageReturn } from "../chat_image_return_session";
+import {
+  clearPendingChatUnlock,
+  peekPendingChatUnlock,
+} from "../chat_unlock_session";
 import {
   consumeSubscriptionExitUrl,
   consumeSubscriptionExplicitExitUrl,
   getSubscriptionFallbackExitUrl,
+  peekSubscriptionExplicitExitUrl,
 } from "../subscription_exit";
 
 vi.mock("../chat_image_return_session", () => ({
   consumePendingChatImageReturn: vi.fn(),
 }));
+vi.mock("../chat_unlock_session", () => ({
+  clearPendingChatUnlock: vi.fn(),
+  peekPendingChatUnlock: vi.fn(),
+}));
 
 const consumePendingChatImageReturnMock = vi.mocked(
   consumePendingChatImageReturn,
 );
+const clearPendingChatUnlockMock = vi.mocked(clearPendingChatUnlock);
+const peekPendingChatUnlockMock = vi.mocked(peekPendingChatUnlock);
 
 describe("subscription exit helpers", () => {
   beforeEach(() => {
     consumePendingChatImageReturnMock.mockReset();
+    clearPendingChatUnlockMock.mockReset();
+    peekPendingChatUnlockMock.mockReset();
   });
 
   it("uses explicit chat image return urls first", () => {
@@ -35,14 +48,45 @@ describe("subscription exit helpers", () => {
 
   it("falls back to chat when requested", () => {
     consumePendingChatImageReturnMock.mockReturnValue(null);
+    peekPendingChatUnlockMock.mockReturnValue(null);
 
     expect(consumeSubscriptionExitUrl("chat")).toBe(ROUTES.chat);
   });
 
   it("falls back to sidebar by default", () => {
     consumePendingChatImageReturnMock.mockReturnValue(null);
+    peekPendingChatUnlockMock.mockReturnValue(null);
 
     expect(getSubscriptionFallbackExitUrl(null)).toBe(ROUTES.sidebar);
     expect(consumeSubscriptionExitUrl(null)).toBe(ROUTES.sidebar);
   });
+
+  it("peeks chat unlock return urls without clearing them", () => {
+    peekPendingChatUnlockMock.mockReturnValue({
+      reason: "single_message_unlock",
+      messageId: "msg_1",
+      kind: "image",
+      returnUrl: "/chat/image/msg_1",
+      stage: "payment",
+      createdAt: 1,
+    });
+
+    expect(peekSubscriptionExplicitExitUrl()).toBe("/chat/image/msg_1");
+    expect(clearPendingChatUnlockMock).not.toHaveBeenCalled();
+  });
+
+  it("clears chat unlock return urls when consumed", () => {
+    consumePendingChatImageReturnMock.mockReturnValue(null);
+    peekPendingChatUnlockMock.mockReturnValue({
+      reason: "single_message_unlock",
+      messageId: "msg_1",
+      kind: "image",
+      returnUrl: "/chat/image/msg_1",
+      stage: "payment",
+      createdAt: 1,
+    });
+
+    expect(consumeSubscriptionExplicitExitUrl()).toBe("/chat/image/msg_1");
+    expect(clearPendingChatUnlockMock).toHaveBeenCalledTimes(1);
+  });
 });

src/lib/navigation/chat_unlock_session.ts

@@ -0,0 +1,109 @@
+"use client";
+
+const STORAGE_KEY = "cozsweet.chat.pendingUnlock";
+const MAX_AGE_MS = 30 * 60 * 1000;
+
+export type PendingChatUnlockKind = "private" | "voice" | "image";
+export type PendingChatUnlockStage = "auth" | "payment";
+
+export interface PendingChatUnlock {
+  reason: "single_message_unlock";
+  messageId: string;
+  kind: PendingChatUnlockKind;
+  returnUrl: string;
+  stage: PendingChatUnlockStage;
+  createdAt: number;
+}
+
+export function savePendingChatUnlock(input: {
+  messageId: string;
+  kind: PendingChatUnlockKind;
+  returnUrl: string;
+  stage: PendingChatUnlockStage;
+}): void {
+  if (typeof window === "undefined") return;
+  const payload: PendingChatUnlock = {
+    reason: "single_message_unlock",
+    messageId: input.messageId,
+    kind: input.kind,
+    returnUrl: input.returnUrl,
+    stage: input.stage,
+    createdAt: Date.now(),
+  };
+  window.sessionStorage.setItem(STORAGE_KEY, JSON.stringify(payload));
+}
+
+export function consumePendingChatUnlock(): PendingChatUnlock | null {
+  if (typeof window === "undefined") return null;
+
+  const raw = window.sessionStorage.getItem(STORAGE_KEY);
+  window.sessionStorage.removeItem(STORAGE_KEY);
+  if (!raw) return null;
+
+  return parsePendingChatUnlock(raw);
+}
+
+export function peekPendingChatUnlock(): PendingChatUnlock | null {
+  if (typeof window === "undefined") return null;
+
+  const raw = window.sessionStorage.getItem(STORAGE_KEY);
+  if (!raw) return null;
+
+  const value = parsePendingChatUnlock(raw);
+  if (!value) {
+    window.sessionStorage.removeItem(STORAGE_KEY);
+  }
+  return value;
+}
+
+export function hasPendingChatUnlock(): boolean {
+  return peekPendingChatUnlock() !== null;
+}
+
+export function clearPendingChatUnlock(): void {
+  if (typeof window === "undefined") return;
+  window.sessionStorage.removeItem(STORAGE_KEY);
+}
+
+function parsePendingChatUnlock(raw: string): PendingChatUnlock | null {
+  try {
+    const value = JSON.parse(raw) as Partial<PendingChatUnlock>;
+    if (value.reason !== "single_message_unlock") return null;
+    if (typeof value.messageId !== "string" || value.messageId.length === 0) {
+      return null;
+    }
+    if (!isPendingChatUnlockKind(value.kind)) return null;
+    if (!isPendingChatUnlockStage(value.stage)) return null;
+    if (typeof value.returnUrl !== "string" || value.returnUrl.length === 0) {
+      return null;
+    }
+    if (!value.returnUrl.startsWith("/") || value.returnUrl.startsWith("//")) {
+      return null;
+    }
+    if (typeof value.createdAt !== "number") return null;
+    if (Date.now() - value.createdAt > MAX_AGE_MS) return null;
+
+    return {
+      reason: value.reason,
+      messageId: value.messageId,
+      kind: value.kind,
+      returnUrl: value.returnUrl,
+      stage: value.stage,
+      createdAt: value.createdAt,
+    };
+  } catch {
+    return null;
+  }
+}
+
+function isPendingChatUnlockKind(
+  value: unknown,
+): value is PendingChatUnlockKind {
+  return value === "private" || value === "voice" || value === "image";
+}
+
+function isPendingChatUnlockStage(
+  value: unknown,
+): value is PendingChatUnlockStage {
+  return value === "auth" || value === "payment";
+}

src/lib/navigation/subscription_exit.ts

@@ -3,12 +3,27 @@
 import { ROUTES } from "@/router/routes";
 
 import { consumePendingChatImageReturn } from "./chat_image_return_session";
+import {
+  clearPendingChatUnlock,
+  peekPendingChatUnlock,
+} from "./chat_unlock_session";
 
 export type SubscriptionReturnTo = "chat" | null;
 
 export function consumeSubscriptionExplicitExitUrl(): string | null {
   const pendingImageReturn = consumePendingChatImageReturn();
   if (pendingImageReturn) return pendingImageReturn.returnUrl;
+  const pendingChatUnlock = peekPendingChatUnlock();
+  if (pendingChatUnlock) {
+    clearPendingChatUnlock();
+    return pendingChatUnlock.returnUrl;
+  }
+  return null;
+}
+
+export function peekSubscriptionExplicitExitUrl(): string | null {
+  const pendingChatUnlock = peekPendingChatUnlock();
+  if (pendingChatUnlock) return pendingChatUnlock.returnUrl;
   return null;
 }