refactor(characters): drive shared UI from active character

src/stores/chat/__tests__/chat-actor-cancellation.test.ts

@@ -62,15 +62,18 @@ describe("chat actor request cancellation", () => {
       () => new Promise(() => undefined),
     );
     const actor = createActor(loadHistoryActor, {
-      input: { characterId: "character_elio" },
+      input: {
+        characterId: "character_elio",
+        emptyChatGreeting: "Hello from Elio",
+      },
     }).start();
     await vi.waitFor(() =>
       expect(historySync.syncNetworkHistory).toHaveBeenCalled(),
     );
 
-    const signal = getSignal(
-      historySync.syncNetworkHistory.mock.calls[0]?.[3],
-    );
+    const historyCall = historySync.syncNetworkHistory.mock.calls[0];
+    expect(historyCall?.[3]).toBe("Hello from Elio");
+    const signal = getSignal(historyCall?.[4]);
     expect(signal.aborted).toBe(false);
     actor.stop();
     expect(signal.aborted).toBe(true);
@@ -81,7 +84,10 @@ describe("chat actor request cancellation", () => {
       () => new Promise(() => undefined),
     );
     const actor = createActor(unlockHistoryActor, {
-      input: { characterId: "character_elio" },
+      input: {
+        characterId: "character_elio",
+        emptyChatGreeting: "Hello from Elio",
+      },
     }).start();
     await vi.waitFor(() => expect(repository.unlockHistory).toHaveBeenCalled());
 

src/stores/chat/__tests__/chat-helpers.test.ts

@@ -1,6 +1,9 @@
 import { describe, expect, it } from "vitest";
 
-import { DEFAULT_CHARACTER_ID } from "@/data/constants/character";
+import {
+  DEFAULT_CHARACTER,
+  DEFAULT_CHARACTER_ID,
+} from "@/data/constants/character";
 import {
   ChatSendResponseSchema,
   type ChatSendResponse,
@@ -35,6 +38,7 @@ function makeResponse(
 function makeChatState(overrides: Partial<ChatState> = {}): ChatState {
   return {
     characterId: DEFAULT_CHARACTER_ID,
+    emptyChatGreeting: DEFAULT_CHARACTER.emptyChatGreeting,
     messages: [],
     promotion: null,
     outgoingMessageRevision: 0,

src/stores/chat/__tests__/chat-history-flow.test.ts

@@ -4,7 +4,10 @@ import { createActor, fromCallback, waitFor } from "xstate";
 import type { UiMessage } from "@/stores/chat/ui-message";
 import type { ChatEvent } from "@/stores/chat/chat-events";
 import { chatMachine } from "@/stores/chat/chat-machine";
-import type { LoadMoreHistoryActorEvent } from "@/stores/chat/machine/actors/history";
+import type {
+  ChatHistoryActorInput,
+  LoadMoreHistoryActorEvent,
+} from "@/stores/chat/machine/actors/history";
 
 import {
   createLoadHistoryCallback,
@@ -50,7 +53,7 @@ describe("chat history flow", () => {
       actors: {
         loadHistory: fromCallback<
           ChatEvent,
-          { characterId: string }
+          ChatHistoryActorInput
         >(({ sendBack }) => {
           sendBack({
             type: "ChatLocalHistoryLoaded",
@@ -119,7 +122,7 @@ describe("chat history flow", () => {
         ),
         loadMoreHistory: fromCallback<
           LoadMoreHistoryActorEvent,
-          { characterId: string }
+          ChatHistoryActorInput
         >(
           ({ receive, sendBack }) => {
             receive((event) => {
@@ -198,7 +201,7 @@ describe("chat history flow", () => {
         }),
         loadMoreHistory: fromCallback<
           LoadMoreHistoryActorEvent,
-          { characterId: string }
+          ChatHistoryActorInput
         >(
           ({ receive, sendBack }) => {
             receive((event) => {
@@ -260,7 +263,7 @@ describe("chat history flow", () => {
         }),
         loadMoreHistory: fromCallback<
           LoadMoreHistoryActorEvent,
-          { characterId: string }
+          ChatHistoryActorInput
         >(
           ({ receive }) => {
             receive(() => {

src/stores/chat/__tests__/chat-machine.test-utils.ts

@@ -1,6 +1,9 @@
 import { fromCallback, fromPromise } from "xstate";
 
-import { DEFAULT_CHARACTER_ID } from "@/data/constants/character";
+import {
+  DEFAULT_CHARACTER,
+  DEFAULT_CHARACTER_ID,
+} from "@/data/constants/character";
 import {
   ChatSendResponseSchema,
   UnlockPrivateResponseSchema,
@@ -36,6 +39,7 @@ export interface TestUnlockMessageOutput {
 
 export const TEST_CHAT_MACHINE_INPUT = {
   characterId: DEFAULT_CHARACTER_ID,
+  emptyChatGreeting: DEFAULT_CHARACTER.emptyChatGreeting,
 };
 
 export function makeChatSendResponse(): ChatSendResponse {
@@ -109,7 +113,10 @@ export function createTestChatMachine(
           return () => undefined;
         },
       ),
-      unlockHistory: fromPromise<UnlockHistoryOutput, { characterId: string }>(
+      unlockHistory: fromPromise<
+        UnlockHistoryOutput,
+        { characterId: string; emptyChatGreeting: string }
+      >(
         async () => {
           if (options.unlockHistoryError) {
             throw options.unlockHistoryError;

src/stores/chat/__tests__/chat-send-flow.test.ts

@@ -155,7 +155,7 @@ describe("chat send flow", () => {
         ),
         unlockHistory: fromPromise<
           UnlockHistoryOutput,
-          { characterId: string }
+          { characterId: string; emptyChatGreeting: string }
         >(async () => ({
           unlocked: true,
           reason: "ok",

src/stores/chat/__tests__/chat-session-flow.test.ts

@@ -9,10 +9,43 @@ import {
 describe("chat session flow", () => {
   it("initializes the conversation from the supplied character", () => {
     const actor = createActor(createTestChatMachine(), {
-      input: { characterId: "character_aria" },
+      input: {
+        characterId: "character_maya",
+        emptyChatGreeting: "Hello from Maya",
+      },
     }).start();
 
-    expect(actor.getSnapshot().context.characterId).toBe("character_aria");
+    expect(actor.getSnapshot().context).toMatchObject({
+      characterId: "character_maya",
+      emptyChatGreeting: "Hello from Maya",
+    });
+    actor.stop();
+  });
+
+  it("keeps the active character greeting across login state changes", async () => {
+    const actor = createActor(createTestChatMachine(), {
+      input: {
+        characterId: "character_maya",
+        emptyChatGreeting: "Hello from Maya",
+      },
+    }).start();
+
+    actor.send({ type: "ChatUserLogin", token: "token" });
+    await waitFor(actor, (snapshot) =>
+      snapshot.matches({ userSession: "ready" }),
+    );
+    expect(actor.getSnapshot().context.emptyChatGreeting).toBe(
+      "Hello from Maya",
+    );
+
+    actor.send({ type: "ChatGuestLogin" });
+    await waitFor(actor, (snapshot) =>
+      snapshot.matches({ guestSession: "ready" }),
+    );
+    expect(actor.getSnapshot().context.emptyChatGreeting).toBe(
+      "Hello from Maya",
+    );
+
     actor.stop();
   });
 

src/stores/chat/chat-context.tsx

@@ -4,8 +4,6 @@ import { type Dispatch, type ReactNode, useMemo } from "react";
 import { createActorContext, shallowEqual } from "@xstate/react";
 import type { SnapshotFrom } from "xstate";
 
-import { DEFAULT_CHARACTER_ID } from "@/data/constants/character";
-
 import { chatMachine } from "./chat-machine";
 import type { ChatEvent, ChatState as MachineContext } from "./chat-machine";
 import { appendPromotionMessage } from "./helper/promotion";
@@ -46,15 +44,19 @@ const ChatActorContext = createActorContext(chatMachine);
 
 export interface ChatProviderProps {
   children: ReactNode;
-  characterId?: string;
+  characterId: string;
+  emptyChatGreeting: string;
 }
 
 export function ChatProvider({
   children,
-  characterId = DEFAULT_CHARACTER_ID,
+  characterId,
+  emptyChatGreeting,
 }: ChatProviderProps) {
   return (
-    <ChatActorContext.Provider options={{ input: { characterId } }}>
+    <ChatActorContext.Provider
+      options={{ input: { characterId, emptyChatGreeting } }}
+    >
       {children}
     </ChatActorContext.Provider>
   );

src/stores/chat/chat-history-sync.ts

@@ -30,12 +30,9 @@ export type LocalHistorySnapshotOutput = {
 
 export type NetworkHistorySyncOutput = ReadAndSyncHistoryOutput;
 
-export function createGreetingMessage(): UiMessage {
+export function createGreetingMessage(content: string): UiMessage {
   return {
-    content:
-      "You're here! Facebook is so restrictive, " +
-      "there were things I couldn't say there. " +
-      "Finally I can relax. How was your day out?",
+    content,
     isFromAI: true,
     date: todayString(),
     isSynthetic: true,
@@ -51,9 +48,10 @@ export async function resolveHistoryCacheIdentity(
 
 export async function readLocalHistorySnapshot(
   cacheIdentity: string | null,
+  emptyChatGreeting: string,
 ): Promise<LocalHistorySnapshotOutput> {
   const chatRepo = await loadChatRepository();
-  const greetingMessage = createGreetingMessage();
+  const greetingMessage = createGreetingMessage(emptyChatGreeting);
 
   const localResult = cacheIdentity
     ? await chatRepo.getLocalMessages(cacheIdentity)
@@ -82,10 +80,11 @@ export async function syncNetworkHistory(
   characterId: string,
   localCount: number,
   cacheIdentity: string | null,
+  emptyChatGreeting: string,
   signal?: AbortSignal,
 ): Promise<NetworkHistorySyncOutput | null> {
   const chatRepo = await loadChatRepository();
-  const greetingMessage = createGreetingMessage();
+  const greetingMessage = createGreetingMessage(emptyChatGreeting);
 
   const networkResult = await chatRepo.getHistory(
     characterId,
@@ -149,14 +148,19 @@ export async function syncNetworkHistory(
  */
 export async function readAndSyncHistory(
   characterId: string,
+  emptyChatGreeting: string,
   signal?: AbortSignal,
 ): Promise<ReadAndSyncHistoryOutput> {
   const cacheIdentity = await resolveHistoryCacheIdentity(characterId);
-  const localSnapshot = await readLocalHistorySnapshot(cacheIdentity);
+  const localSnapshot = await readLocalHistorySnapshot(
+    cacheIdentity,
+    emptyChatGreeting,
+  );
   const networkSnapshot = await syncNetworkHistory(
     characterId,
     localSnapshot.localCount,
     cacheIdentity,
+    emptyChatGreeting,
     signal,
   );
   if (networkSnapshot) return networkSnapshot;

src/stores/chat/chat-machine.ts

@@ -2,7 +2,10 @@ import {
   chatMachineSetup,
   chatRootStateConfig,
 } from "./machine/session-flow";
-import { DEFAULT_CHARACTER_ID } from "@/data/constants/character";
+import {
+  DEFAULT_CHARACTER,
+  DEFAULT_CHARACTER_ID,
+} from "@/data/constants/character";
 
 import { createInitialChatState } from "./chat-state";
 
@@ -13,7 +16,10 @@ export type { ChatEvent } from "./chat-events";
 export const chatMachine = chatMachineSetup.createMachine({
   id: "chat",
   context: ({ input }) =>
-    createInitialChatState(input?.characterId ?? DEFAULT_CHARACTER_ID),
+    createInitialChatState(
+      input?.characterId ?? DEFAULT_CHARACTER_ID,
+      input?.emptyChatGreeting ?? DEFAULT_CHARACTER.emptyChatGreeting,
+    ),
   ...chatRootStateConfig,
 });
 

src/stores/chat/chat-state.ts

@@ -2,7 +2,10 @@ import type { UiMessage } from "@/stores/chat/ui-message";
 import type { PendingChatUnlockKind } from "@/lib/navigation/chat_unlock_session";
 import type { ChatLockType } from "@/data/schemas/chat";
 import type { PendingChatPromotion } from "@/data/storage/navigation";
-import { DEFAULT_CHARACTER_ID } from "@/data/constants/character";
+import {
+  DEFAULT_CHARACTER,
+  DEFAULT_CHARACTER_ID,
+} from "@/data/constants/character";
 import type { ChatPromotionState } from "./helper/promotion";
 
 export type ChatUpgradeReason = "insufficient_credits";
@@ -26,6 +29,7 @@ export interface ChatUnlockPaywallRequest
 
 export interface ChatState {
   characterId: string;
+  emptyChatGreeting: string;
   messages: UiMessage[];
   promotion: ChatPromotionState | null;
   outgoingMessageRevision: number;
@@ -55,9 +59,11 @@ export interface ChatState {
 
 export function createInitialChatState(
   characterId: string = DEFAULT_CHARACTER_ID,
+  emptyChatGreeting: string = DEFAULT_CHARACTER.emptyChatGreeting,
 ): ChatState {
   return {
     characterId,
+    emptyChatGreeting,
     messages: [],
     promotion: null,
     outgoingMessageRevision: 0,

src/stores/chat/machine/actors/history.ts

@@ -25,6 +25,7 @@ export interface LoadMoreHistoryActorEvent {
 
 export interface ChatHistoryActorInput {
   characterId: string;
+  emptyChatGreeting: string;
 }
 
 export interface LoadMoreHistoryOutput {
@@ -43,7 +44,10 @@ export const loadHistoryActor = fromCallback<
 
   void (async () => {
     const cacheIdentity = await resolveHistoryCacheIdentity(input.characterId);
-    const localSnapshot = await readLocalHistorySnapshot(cacheIdentity);
+    const localSnapshot = await readLocalHistorySnapshot(
+      cacheIdentity,
+      input.emptyChatGreeting,
+    );
     if (cancelled) return;
     sendBack({
       type: "ChatLocalHistoryLoaded",
@@ -54,6 +58,7 @@ export const loadHistoryActor = fromCallback<
       input.characterId,
       localSnapshot.localCount,
       cacheIdentity,
+      input.emptyChatGreeting,
       controller.signal,
     );
     if (cancelled || !networkSnapshot) return;

src/stores/chat/machine/actors/unlock.ts

@@ -25,7 +25,7 @@ export interface UnlockHistoryOutput {
 
 export const unlockHistoryActor = fromPromise<
   UnlockHistoryOutput,
-  { characterId: string }
+  { characterId: string; emptyChatGreeting: string }
 >(async ({ input, signal }) => {
   const chatRepo = await loadChatRepository();
   const unlockResult = await chatRepo.unlockHistory(input.characterId, {
@@ -40,7 +40,11 @@ export const unlockHistoryActor = fromPromise<
   }
 
   signal.throwIfAborted();
-  const history = await readAndSyncHistory(input.characterId, signal);
+  const history = await readAndSyncHistory(
+    input.characterId,
+    input.emptyChatGreeting,
+    signal,
+  );
   return {
     unlocked: unlockResult.data.unlocked,
     reason: unlockResult.data.reason,

src/stores/chat/machine/session-flow.ts

@@ -19,20 +19,26 @@ import {
 
 const startGuestSessionAction = unlockMachineSetup.assign(
   ({ context }) => ({
-    ...createInitialChatState(context.characterId),
+    ...createInitialChatState(
+      context.characterId,
+      context.emptyChatGreeting,
+    ),
     promotion: context.promotion,
   }),
 );
 
 const startUserSessionAction = unlockMachineSetup.assign(
   ({ context }) => ({
-    ...createInitialChatState(context.characterId),
+    ...createInitialChatState(
+      context.characterId,
+      context.emptyChatGreeting,
+    ),
     promotion: context.promotion,
   }),
 );
 
 const clearChatSessionAction = unlockMachineSetup.assign(({ context }) => ({
-  ...createInitialChatState(context.characterId),
+  ...createInitialChatState(context.characterId, context.emptyChatGreeting),
 }));
 
 const injectPromotionAction = unlockMachineSetup.assign(({ event }) => {
@@ -80,12 +86,18 @@ const guestSessionState = chatMachineSetup.createStateConfig({
     {
       id: "loadHistory",
       src: "loadHistory",
-      input: ({ context }) => ({ characterId: context.characterId }),
+      input: ({ context }) => ({
+        characterId: context.characterId,
+        emptyChatGreeting: context.emptyChatGreeting,
+      }),
     },
     {
       id: "loadMoreHistory",
       src: "loadMoreHistory",
-      input: ({ context }) => ({ characterId: context.characterId }),
+      input: ({ context }) => ({
+        characterId: context.characterId,
+        emptyChatGreeting: context.emptyChatGreeting,
+      }),
     },
   ],
   on: {
@@ -162,12 +174,18 @@ const userSessionState = chatMachineSetup.createStateConfig({
     {
       id: "loadHistory",
       src: "loadHistory",
-      input: ({ context }) => ({ characterId: context.characterId }),
+      input: ({ context }) => ({
+        characterId: context.characterId,
+        emptyChatGreeting: context.emptyChatGreeting,
+      }),
     },
     {
       id: "loadMoreHistory",
       src: "loadMoreHistory",
-      input: ({ context }) => ({ characterId: context.characterId }),
+      input: ({ context }) => ({
+        characterId: context.characterId,
+        emptyChatGreeting: context.emptyChatGreeting,
+      }),
     },
   ],
   on: {

src/stores/chat/machine/setup.ts

@@ -17,6 +17,7 @@ import type { ChatState } from "../chat-state";
 
 export interface ChatMachineInput {
   characterId?: string;
+  emptyChatGreeting?: string;
 }
 
 export const baseChatMachineSetup = setup({

src/stores/chat/machine/unlock-flow.ts

@@ -188,7 +188,10 @@ export const unlockingHistoryState = unlockMachineSetup.createStateConfig({
   invoke: {
     id: "unlockHistory",
     src: "unlockHistory",
-    input: ({ context }) => ({ characterId: context.characterId }),
+    input: ({ context }) => ({
+      characterId: context.characterId,
+      emptyChatGreeting: context.emptyChatGreeting,
+    }),
     onDone: {
       target: "ready",
       actions: applyUnlockHistoryOutputAction,