import { TestBed } from '@angular/core/testing';
import { UnreadService } from './unread.service';
import { SessionService } from './session.service';

/**
 * 未读计数单测 —— **直接守护本次开发抓出的两个 bug**
 *
 * ① 「刚连接就有 39 条未读」：初次 `/sync` 的历史回填被算成未读
 *    → 用 `catchingUp` 分界覆盖
 * ② `data.liveEvent` 不能区分历史与实时（实测初次同步历史也为 `true`）
 *    → 改用「初次同步完成分界 + 已读时间戳」双判据
 *
 * 覆盖 SPEC FR-04 的未读口径与 FR-14（每域唯一 owner）。
 */
describe('UnreadService', () => {
  let svc: UnreadService;
  let session: SessionService;

  beforeEach(() => {
    localStorage.clear();
    TestBed.configureTestingModule({});
    session = TestBed.inject(SessionService);
    svc = TestBed.inject(UnreadService);
  });

  afterEach(() => localStorage.clear());

  describe('catchingUp 分界（bug①回归）', () => {
    it('初次同步回填阶段：历史消息一律不计未读', () => {
      // 模拟 5 条历史按时间升序回填 —— 全部不应计数
      const base = 1_700_000_000_000;
      for (let i = 0; i < 5; i++) {
        const counted = svc.onIncoming('agent-a', base + i * 1000, /*catchingUp*/ true);
        expect(counted).toBe(false);
      }
      expect(svc.countOf('agent-a')).toBe(0);
    });

    it('分界之后：晚于基线的消息计入', () => {
      const base = 1_700_000_000_000;
      svc.onIncoming('agent-a', base, true); // 回填阶段建立基线
      const counted = svc.onIncoming('agent-a', base + 5000, false);
      expect(counted).toBe(true);
      expect(svc.countOf('agent-a')).toBe(1);
    });
  });

  describe('时间戳口径（bug②回归）', () => {
    it('早于已读基线的消息不计（已读 / 重复投递）', () => {
      const base = 1_700_000_000_000;
      svc.onIncoming('a', base, true);
      expect(svc.onIncoming('a', base - 1000, false)).toBe(false);
      expect(svc.onIncoming('a', base, false)).toBe(false); // 等于基线也不计
      expect(svc.countOf('a')).toBe(0);
    });

    it('首次见到房间时只推进基线，不计未读', () => {
      expect(svc.onIncoming('new-agent', 1_700_000_000_000, false)).toBe(false);
      expect(svc.countOf('new-agent')).toBe(0);
      // 基线已建立，后续更新的消息才计
      expect(svc.onIncoming('new-agent', 1_700_000_001_000, false)).toBe(true);
      expect(svc.countOf('new-agent')).toBe(1);
    });

    it('离线期间积累的消息（晚于基线）全部计入', () => {
      const base = 1_700_000_000_000;
      svc.onIncoming('a', base, true);
      for (let i = 1; i <= 7; i++) svc.onIncoming('a', base + i * 1000, false);
      expect(svc.countOf('a')).toBe(7);
    });
  });

  describe('markRead', () => {
    it('清零该 agent 的未读并推进基线', () => {
      const base = 1_700_000_000_000;
      svc.onIncoming('a', base, true);
      svc.onIncoming('a', base + 1000, false);
      svc.onIncoming('a', base + 2000, false);
      expect(svc.countOf('a')).toBe(2);

      svc.markRead('a', base + 2000);
      expect(svc.countOf('a')).toBe(0);
      // 基线已推进 → 早于它的消息不再计
      expect(svc.onIncoming('a', base + 1500, false)).toBe(false);
    });

    it('只影响目标 agent，不误伤其它', () => {
      const t = 1_700_000_000_000;
      svc.onIncoming('a', t, true);
      svc.onIncoming('a', t + 1, false);
      svc.onIncoming('b', t, true);
      svc.onIncoming('b', t + 1, false);

      svc.markRead('a', t + 1);
      expect(svc.countOf('a')).toBe(0);
      expect(svc.countOf('b')).toBe(1);
    });
  });

  describe('total 与多 agent', () => {
    it('total 为各 agent 之和', () => {
      const t = 1_700_000_000_000;
      for (const id of ['a', 'b', 'c']) {
        svc.onIncoming(id, t, true);
        svc.onIncoming(id, t + 1, false);
        svc.onIncoming(id, t + 2, false);
      }
      expect(svc.countOf('a')).toBe(2);
      expect(svc.total()).toBe(6);
    });
  });

  describe('持久化（退出浏览器不丢）', () => {
    it('按用户隔离：不同用户互不串号', () => {
      // 用户1
      session.setSession('t1', { id: 'u1', name: 'A' });
      svc.reload();
      const t = 1_700_000_000_000;
      svc.onIncoming('a', t, true);
      svc.onIncoming('a', t + 1, false);
      expect(svc.countOf('a')).toBe(1);

      // 换用户2 → 重新载入应为空
      session.setSession('t2', { id: 'u2', name: 'B' });
      svc.reload();
      expect(svc.countOf('a')).toBe(0);

      // 切回用户1 → 计数恢复
      session.setSession('t1', { id: 'u1', name: 'A' });
      svc.reload();
      expect(svc.countOf('a')).toBe(1);
    });

    it('reset 清空并移除存储', () => {
      session.setSession('t1', { id: 'u1', name: 'A' });
      const t = 1_700_000_000_000;
      svc.onIncoming('a', t, true);
      svc.onIncoming('a', t + 1, false);
      svc.reset();
      expect(svc.countOf('a')).toBe(0);
      expect(svc.total()).toBe(0);
    });
  });

  describe('边界', () => {
    it('空 agentId 不计数', () => {
      expect(svc.onIncoming('', 1_700_000_000_000, false)).toBe(false);
      expect(svc.total()).toBe(0);
    });
  });
});