type GuardedTitleUpdate = {
  eq: (column: string, value: string) => GuardedTitleUpdate;
  select: (columns: "id") => PromiseLike<{ data: Array<{ id?: string }> | null; error: unknown }>;
};

export type GuardedTitleClient = {
  from: (table: "chat_sessions") => {
    update: (values: { title: string }) => GuardedTitleUpdate;
  };
};

export async function persistGuardedSessionTitle(input: {
  client: GuardedTitleClient;
  sessionId: string;
  userId: string;
  expectedTitle: string;
  title: string;
  warn?: (message: string, extra?: unknown) => void;
}): Promise<"updated" | "missed" | "failed"> {
  const warn = input.warn ?? ((message: string, extra?: unknown) => console.warn(message, extra));
  try {
    const { data, error } = await input.client.from("chat_sessions").update({ title: input.title })
      .eq("id", input.sessionId)
      .eq("user_id", input.userId)
      .eq("title", input.expectedTitle)
      .select("id");
    if (error) {
      warn("session title persist failed", error);
      return "failed";
    }
    if (!data?.length) {
      warn("session title guard missed");
      return "missed";
    }
    return "updated";
  } catch (error) {
    warn("session title persist failed", error);
    return "failed";
  }
}