import { describe, expect, it } from "bun:test";
import { HistoryCursorError, sessionHistoryPage, sessionMessagePage } from "../../src/sessions/history-page.js";

describe("scoped history pagination", () => {
  const records = Array.from({ length: 65 }, (_, i) => ({ sessionId: `session-${String(i).padStart(3, "0")}`,
    updatedAt: "2026-10-22T01:00:00Z", title: i === 0 ? "城南压力复核" : `对话 ${i}` }));
  it("continues equal timestamps deterministically and searches beyond the first page", () => {
    const first = sessionHistoryPage(records, { scope: "owner-project", limit: 30 });
    const second = sessionHistoryPage(records, { scope: "owner-project", limit: 30, cursor: first.next_cursor! });
    const last = sessionHistoryPage(records, { scope: "owner-project", limit: 30, cursor: second.next_cursor! });
    expect(first.sessions).toHaveLength(30);
    expect(last.has_more).toBe(false);
    expect(new Set([...first.sessions, ...second.sessions, ...last.sessions].map((item) => item.sessionId)).size).toBe(65);
    expect(sessionHistoryPage(records, { scope: "owner-project", limit: 30, q: "压力" }).sessions[0]?.sessionId).toBe("session-000");
    expect(() => sessionHistoryPage(records, { scope: "another-project", limit: 30, cursor: first.next_cursor! })).toThrow(HistoryCursorError);
    expect(() => sessionHistoryPage(records, { scope: "owner-project", q: "压力", limit: 30, cursor: first.next_cursor! })).toThrow(HistoryCursorError);
  });
  it("pages older messages without truncating the store or moving when messages arrive", () => {
    const messages = Array.from({ length: 105 }, (_, i) => ({ id: `message-${i}` }));
    const latest = sessionMessagePage(messages, { scope: "owner-session", limit: 40 });
    expect(latest.messages).toEqual(messages.slice(65));
    messages.push({ id: "message-105" });
    const older = sessionMessagePage(messages, { scope: "owner-session", limit: 40, before: latest.message_page.before_cursor! });
    expect(older.messages).toEqual(messages.slice(25, 65));
    const oldest = sessionMessagePage(messages, { scope: "owner-session", limit: 40, before: older.message_page.before_cursor! });
    expect(oldest.messages).toEqual(messages.slice(0, 25));
    expect(oldest.message_page.has_more).toBe(false);
    expect(messages).toHaveLength(106);
    expect(() => sessionMessagePage(messages, { scope: "another-session", limit: 40, before: latest.message_page.before_cursor! })).toThrow(HistoryCursorError);
    messages.splice(0, 1);
    expect(() => sessionMessagePage(messages, { scope: "owner-session", limit: 40, before: latest.message_page.before_cursor! })).toThrow("history changed");
  });
});