import { describe, expect, it } from 'vitest';

import {
  directHistoryAnchorGateToWaitFor,
  openDirectHistoryAnchorGate,
  reuseOrOpenDirectHistoryAnchorGate,
} from '../src/view/project-development/chat/history/directHistoryAnchorGate';

const projectA = '/tmp/项目A';
const projectB = '/tmp/项目B';

/** 订阅侧的回执：一次订阅只 settle 一次。 */
function subscribeReceipt(gate: { settle: (anchor: string | null) => void }) {
  gate.settle('turn-2-user');
}

describe('openDirectHistoryAnchorGate', () => {
  it('默认不解析：回执到达前首屏必须等它', async () => {
    const gate = openDirectHistoryAnchorGate(projectA);
    const settled = { value: 'pending' as string | null | 'pending' };
    void gate.anchor.then((anchor) => {
      settled.value = anchor;
    });

    // 让微任务跑一轮：没有回执就不该有结果。
    await Promise.resolve();
    await Promise.resolve();
    expect(settled.value).toBe('pending');
    expect(gate.projectPath).toBe(projectA);
    expect(gate.consumed).toBe(false);
  });

  it('settle 之后 anchor 解析成回执里的 lastCompletedItemId', async () => {
    const gate = openDirectHistoryAnchorGate(projectA);
    subscribeReceipt(gate);

    await expect(gate.anchor).resolves.toBe('turn-2-user');
  });

  it('订阅不可用时 settle(null)：首屏退化成取文件尾', async () => {
    const gate = openDirectHistoryAnchorGate(projectA);
    gate.settle(null);

    await expect(gate.anchor).resolves.toBeNull();
  });
});

describe('reuseOrOpenDirectHistoryAnchorGate', () => {
  it('同一个项目复用同一道闸门：订阅侧要 settle 首屏已经开好的那道', () => {
    const opened = openDirectHistoryAnchorGate(projectA);

    expect(reuseOrOpenDirectHistoryAnchorGate(opened, projectA)).toBe(opened);
  });

  it('换项目开一道新闸门，不复用旧项目的回执', () => {
    const opened = openDirectHistoryAnchorGate(projectA);
    const next = reuseOrOpenDirectHistoryAnchorGate(opened, projectB);

    expect(next).not.toBe(opened);
    expect(next.projectPath).toBe(projectB);
    expect(next.consumed).toBe(false);
  });

  it('还没有闸门时新开一道', () => {
    expect(reuseOrOpenDirectHistoryAnchorGate(null, projectA).projectPath).toBe(
      projectA,
    );
  });
});

describe('directHistoryAnchorGateToWaitFor', () => {
  it('没有闸门（首屏比订阅 effect 先跑）时开一道给调用方登记', async () => {
    const gate = directHistoryAnchorGateToWaitFor(null, projectA);

    expect(gate).not.toBeNull();
    expect(gate?.projectPath).toBe(projectA);
    subscribeReceipt(gate!);
    await expect(gate!.anchor).resolves.toBe('turn-2-user');
  });

  it('同项目未消费的闸门直接复用：首屏等到订阅回执', async () => {
    const opened = openDirectHistoryAnchorGate(projectA);
    const toWaitFor = directHistoryAnchorGateToWaitFor(opened, projectA);

    expect(toWaitFor).toBe(opened);
    subscribeReceipt(opened);
    await expect(toWaitFor!.anchor).resolves.toBe('turn-2-user');
  });

  it('同项目已消费返回 null：重开项目没有新回执可等，退回取文件尾', () => {
    const opened = openDirectHistoryAnchorGate(projectA);
    opened.consumed = true;

    expect(directHistoryAnchorGateToWaitFor(opened, projectA)).toBeNull();
  });

  it('换项目不复用旧闸门：新项目的首屏要等新订阅的回执', () => {
    const opened = openDirectHistoryAnchorGate(projectA);
    subscribeReceipt(opened);
    opened.consumed = true;

    const toWaitFor = directHistoryAnchorGateToWaitFor(opened, projectB);

    expect(toWaitFor).not.toBeNull();
    expect(toWaitFor).not.toBe(opened);
    expect(toWaitFor?.projectPath).toBe(projectB);
  });
});