export const RECTIFICATION_OPENING_COMPOSER_PLACEHOLDER = "正在打开生时校正…";
export const RECTIFICATION_REOPEN_LABEL = "重新打开生时校正";
export const SESSION_NOT_CONSULTATION_CODE = "session_not_consultation";

export function isRectificationChatSession(
  session: { sessionType?: string } | null | undefined,
): boolean {
  return session?.sessionType === "birth_time_rectification";
}

/** First non-rectification session, else the first session, else empty. */
export function fallbackSessionId<T extends { id: string; sessionType: string }>(
  sessions: readonly T[],
): string {
  return sessions.find((session) => session.sessionType !== "birth_time_rectification")?.id
    ?? sessions[0]?.id
    ?? "";
}

export function consultSendBlockedByRectificationSession(
  session: { sessionType?: string } | null | undefined,
): boolean {
  return isRectificationChatSession(session);
}

/** Empty active session with only rectification rows still occupies the ordinary composer. */
export function composerLocksAsRectification(
  activeSession: { sessionType?: string } | null | undefined,
  sessions: readonly { sessionType: string }[],
): boolean {
  if (isRectificationChatSession(activeSession)) return true;
  if (activeSession) return false;
  return sessions.some((session) => session.sessionType === "birth_time_rectification");
}

export function missingActiveSessionSendAction(
  sessions: readonly { id: string; sessionType: string }[],
): { openSessionId: string } | { notice: string } {
  const rectification = sessions.find((session) => session.sessionType === "birth_time_rectification");
  if (rectification) return { openSessionId: rectification.id };
  return { notice: "请先选一条对话，或点上方「新建对话」。" };
}

export function dropRectificationStoredPending<
  S extends { sessionId: string },
  T extends { id: string; sessionType: string },
>(
  stored: S | null,
  sessions: readonly T[],
): S | null {
  if (!stored) return null;
  const session = sessions.find((item) => item.id === stored.sessionId);
  if (session?.sessionType === "birth_time_rectification") return null;
  return stored;
}

export function ordinaryComposerPlaceholder(input: {
  locked: boolean;
  hasAccount: boolean;
  profileComplete: boolean;
  onboardingName: boolean;
  presetMessageFinished: boolean;
  creditsEmpty: boolean;
  subjectDeleted?: boolean;
}): string {
  if (input.locked) return RECTIFICATION_OPENING_COMPOSER_PLACEHOLDER;
  if (input.subjectDeleted) return "这份资料已经删除，这段对话只能看";
  if (!input.hasAccount) return "正在读取账户…";
  if (!input.profileComplete) {
    if (!input.onboardingName) return "请先完成上方资料";
    return input.presetMessageFinished ? "输入你的称呼" : "Jyotisha 正在输入…";
  }
  if (input.creditsEmpty) return "余额不足，可在账户与点数中补充";
  return "想聊什么都可以";
}

export function rectificationOrdinaryComposerReopen(input: {
  activeRectificationSession: boolean;
  error: string;
  errorSessionId: string | null;
  sessionId: string | undefined;
}): boolean {
  if (!input.activeRectificationSession || !input.error || input.error === "profile_incomplete") {
    return false;
  }
  if (!input.sessionId) return true;
  return !input.errorSessionId || input.errorSessionId === input.sessionId;
}