refactor(stores): tighten chat and payment boundaries

src/stores/chat/chat-send-state.ts

@@ -0,0 +1,114 @@
+import type { UiMessage } from "@/data/dto/chat";
+import { ChatSendResponse } from "@/data/dto/chat/chat_send_response";
+
+import type { ChatState, ChatUpgradeReason } from "./chat-state";
+
+export type HttpSendOutput = {
+  response: ChatSendResponse;
+  reply: UiMessage | null;
+};
+
+export function beginPendingReply(context: ChatState): Pick<
+  ChatState,
+  "isReplyingAI" | "pendingReplyCount"
+> {
+  return {
+    pendingReplyCount: context.pendingReplyCount + 1,
+    isReplyingAI: true,
+  };
+}
+
+export function finishPendingReply(context: ChatState): Pick<
+  ChatState,
+  "isReplyingAI" | "pendingReplyCount"
+> {
+  const pendingReplyCount = Math.max(0, context.pendingReplyCount - 1);
+  return {
+    pendingReplyCount,
+    isReplyingAI: pendingReplyCount > 0,
+  };
+}
+
+export function applyHttpSendOutput(
+  context: ChatState,
+  output: HttpSendOutput,
+): Partial<ChatState> {
+  const { response, reply } = output;
+
+  const lockDetail = response.lockDetail;
+  const isWeeklyLimitBlocked =
+    lockDetail.locked &&
+    lockDetail.showUpgrade &&
+    lockDetail.reason === "weekly_limit";
+  const isInsufficientCredits =
+    response.canSendMessage === false &&
+    response.cannotSendReason === "insufficient_credits";
+  const upgradeReason: ChatUpgradeReason | null = isWeeklyLimitBlocked
+    ? "weekly_limit"
+    : isInsufficientCredits
+      ? "insufficient_credits"
+      : null;
+  const sendCapabilityState = getSendCapabilityState(response);
+
+  if (upgradeReason) {
+    const lastMessage = context.messages[context.messages.length - 1];
+    const messages =
+      !reply && lastMessage && !lastMessage.isFromAI
+        ? context.messages.slice(0, -1)
+        : context.messages;
+
+    return {
+      messages: reply ? [...messages, reply] : messages,
+      ...finishPendingReply(context),
+      upgradePromptVisible: true,
+      upgradeReason,
+      ...sendCapabilityState,
+    };
+  }
+
+  if (!reply) {
+    return {
+      ...finishPendingReply(context),
+      ...sendCapabilityState,
+    };
+  }
+
+  if (lockDetail.showUpgrade && lockDetail.reason === "private_message") {
+    return {
+      messages: [...context.messages, reply],
+      ...finishPendingReply(context),
+      upgradePromptVisible: false,
+      upgradeReason: null,
+      ...sendCapabilityState,
+    };
+  }
+
+  return {
+    messages: [...context.messages, reply],
+    ...finishPendingReply(context),
+    upgradePromptVisible: false,
+    upgradeReason: null,
+    ...sendCapabilityState,
+  };
+}
+
+function getSendCapabilityState(
+  response: ChatSendResponse,
+): Pick<
+  ChatState,
+  | "canSendMessage"
+  | "cannotSendReason"
+  | "creditBalance"
+  | "creditsCharged"
+  | "requiredCredits"
+  | "shortfallCredits"
+> {
+  return {
+    canSendMessage: response.canSendMessage,
+    cannotSendReason: response.cannotSendReason,
+    creditBalance: response.creditBalance,
+    creditsCharged: response.creditsCharged,
+    requiredCredits: response.requiredCredits,
+    shortfallCredits: response.shortfallCredits,
+  };
+}