import { describe, expect, it } from 'vitest';
import { MemoryBackend, MobileBeanStore, createMobileStore } from '../src/domain/mobileStore';
import { parseLedger } from '../src/domain/ledger';
import type { TransactionDraft } from '../src/domain/types';

const ledger = parseLedger([{ path: 'main.bean', content: '2026-01-01 open Assets:Alipay CNY\n2026-01-01 open Expenses:Food CNY\n' }]);

const draft = (n: number): TransactionDraft => ({
  date: '2026-02-01',
  narration: `test${n}`,
  postings: [{ account: 'Assets:Alipay', amount: `-${n}`, currency: 'CNY' }, { account: 'Expenses:Food', amount: `${n}`, currency: 'CNY' }],
});

describe('MobileBeanStore - 基础写入', () => {
  it('init 后内容为空（无初始）', async () => {
    const store = createMobileStore(new MemoryBackend());
    await store.init();
    expect(store.getContent()).toBe('');
  });

  it('append 一笔后内容含交易', async () => {
    const store = createMobileStore(new MemoryBackend());
    await store.init();
    const commit = await store.append(draft(1), ledger);
    expect(commit.content).toContain('test1');
    expect(commit.content).toContain('Assets:Alipay');
    expect(store.getContent()).toBe(commit.content);
  });

  it('append 多笔依次追加（不覆盖）', async () => {
    const store = createMobileStore(new MemoryBackend());
    await store.init();
    await store.append(draft(1), ledger);
    await store.append(draft(2), ledger);
    const content = store.getContent();
    expect(content).toContain('test1');
    expect(content).toContain('test2');
  });

  it('appendWithSource 携带 sourceEventId', async () => {
    const store = createMobileStore(new MemoryBackend());
    await store.init();
    await store.appendWithSource(draft(1), ledger, 'evt-001');
    // sourceEventId 不写入 .bean 内容（仅内存关联），验证不报错即可
    expect(store.getContent()).toContain('test1');
  });

  it('replace 直接替换内容（导入/恢复场景）', async () => {
    const store = createMobileStore(new MemoryBackend());
    await store.init();
    await store.replace('2026-02-01 * "x" "y"\n  Assets:Alipay  -1 CNY\n  Expenses:Food  1 CNY\n');
    expect(store.getContent()).toContain('"x"');
  });
});

describe('MobileBeanStore - 并发安全', () => {
  it('并发 append 串行化，内容不丢失不交错', async () => {
    const backend = new MemoryBackend();
    const store = createMobileStore(backend);
    await store.init();
    // 同时发起 10 笔 append
    await Promise.all(Array.from({ length: 10 }, (_, i) => store.append(draft(i + 1), ledger)));
    const content = store.getContent();
    // 10 笔都应存在
    for (let i = 1; i <= 10; i++) {
      expect(content).toContain(`test${i}`);
    }
    // 写入次数 = 10（每次 append 一次原子写）
    expect(backend.writeCount).toBe(10);
  });

  it('并发 append 与 replace 混合也串行化', async () => {
    const store = createMobileStore(new MemoryBackend());
    await store.init();
    await Promise.all([
      store.append(draft(1), ledger),
      store.replace('REPLACED'),
      store.append(draft(2), ledger),
    ]);
    // 最终内容二选一（取决于调度顺序），但不应崩溃或损坏
    const content = store.getContent();
    expect(['REPLACED', 'test1', 'test2'].some(s => content.includes(s))).toBe(true);
  });
});

describe('MobileBeanStore - checksum（替代不可靠的 content.length）', () => {
  it('相同内容 checksum 一致', async () => {
    const s1 = createMobileStore(new MemoryBackend());
    const s2 = createMobileStore(new MemoryBackend());
    await s1.init(); await s2.init();
    await s1.append(draft(1), ledger);
    await s2.append(draft(1), ledger);
    expect(s1.checksum()).toBe(s2.checksum());
  });

  it('不同内容 checksum 不同', async () => {
    const s1 = createMobileStore(new MemoryBackend());
    const s2 = createMobileStore(new MemoryBackend());
    await s1.init(); await s2.init();
    await s1.append(draft(1), ledger);
    await s2.append(draft(2), ledger);
    expect(s1.checksum()).not.toBe(s2.checksum());
  });

  it('checksum 不依赖内容长度（订正：原方案用 content.length）', async () => {
    // 长度相同但内容不同，checksum 必须不同（FNV-1a 对真实账本内容区分度足够）
    const s1 = createMobileStore(new MemoryBackend('2026-02-01 * "甲" "咖啡"'));
    const s2 = createMobileStore(new MemoryBackend('2026-02-01 * "乙" "午餐"'));
    await s1.init(); await s2.init();
    expect(s1.checksum()).not.toBe(s2.checksum());
  });
});

describe('MobileBeanStore - 崩溃恢复', () => {
  it('init 时清理上次崩溃的 tmp 残留', async () => {
    const backend = new MemoryBackend('已有内容');
    backend.simulateCrashMidWrite('写了 tmp 未 rename');
    const store = createMobileStore(backend);
    await store.init();
    // 恢复后读到的是原内容（tmp 被丢弃）
    expect(store.getContent()).toBe('已有内容');
    expect(backend.recovered).toBe(true);
  });

  it('无残留时正常加载', async () => {
    const backend = new MemoryBackend('正常内容');
    const store = createMobileStore(backend);
    await store.init();
    expect(store.getContent()).toBe('正常内容');
    expect(backend.recovered).toBe(false);
  });
});

describe('MobileBeanStore - preview（不写入）', () => {
  it('preview 只序列化不改变内容', async () => {
    const store = createMobileStore(new MemoryBackend());
    await store.init();
    const before = store.getContent();
    const preview = store.preview(draft(1));
    expect(preview).toContain('test1');
    expect(store.getContent()).toBe(before);  // 内容未变
  });
});

describe('createMobileStore 工厂', () => {
  it('返回 MobileBeanStore 实例', () => {
    const store = createMobileStore(new MemoryBackend());
    expect(store).toBeInstanceOf(MobileBeanStore);
  });
});