/**
 * OPFSEngine 测试 — mock FileSystemDirectoryHandle，验证逻辑不卡死
 * 注：jsdom 无 OPFS API，全部使用 mock 模拟
 */
import { OPFSEngine } from '../../src/engine/opfs';
import { createSchema } from '../../src/table/schema';

// Mock navigator.storage.getDirectory + FileSystemDirectoryHandle
function mockOPFS() {
  const files = new Map<string, string>();

  const dirMock = {
    getDirectoryHandle: async (_name: string, _opts?: any) => dirMock as any,
    getFileHandle: async (name: string, opts?: any) => {
      if (opts?.create) {
        return { createWritable: async () => ({ write: async (d: string) => { files.set(name, d); }, close: async () => {} }) };
      }
      if (!files.has(name)) throw new Error('Not found');
      return { getFile: async () => ({ text: async () => files.get(name)!, arrayBuffer: async () => new ArrayBuffer(0) }) };
    },
    removeEntry: async (name: string) => { files.delete(name); },
  };

  // 为 entries() 添加可迭代接口
  (dirMock as any).entries = () => ({
    [Symbol.asyncIterator]: async function* () {
      for (const [k] of files) yield [k];
    },
  });

  // jsdom 环境下 navigator 可能已存在，直接设置 storage 属性
  const nav = (globalThis as any).navigator || {};
  nav.storage = { getDirectory: async () => dirMock };
  (globalThis as any).navigator = nav;

  return { files };
}

const userSchema = createSchema('users', {
  id: { type: 'string', primaryKey: true },
  name: { type: 'string', required: true },
  age: { type: 'number', default: 0 },
});

describe('OPFSEngine', () => {
  let engine: OPFSEngine;
  let mocks: ReturnType<typeof mockOPFS>;

  beforeEach(async () => {
    mocks = mockOPFS();
    engine = new OPFSEngine();
    await engine.open('test-opfs', 1);
  });

  afterEach(async () => {
    await engine.close();
  });

  // ---- 生命周期 ----
  it('打开后 isOpen 返回 true', () => {
    expect(engine.isOpen()).toBe(true);
  });

  it('关闭后 isOpen 返回 false', async () => {
    await engine.close();
    expect(engine.isOpen()).toBe(false);
  });

  // ---- 表管理 ----
  it('创建表后 hasTable 返回 true', async () => {
    await engine.createTable(userSchema);
    expect(await engine.hasTable('users')).toBe(true);
  });

  it('获取表名列表', async () => {
    await engine.createTable(userSchema);
    const names = await engine.getTableNames();
    expect(names).toContain('users');
  });

  it('删除表后 hasTable 返回 false', async () => {
    await engine.createTable(userSchema);
    await engine.dropTable('users');
    expect(await engine.hasTable('users')).toBe(false);
  });

  // ---- CRUD ----
  it('插入后立即可查询', async () => {
    await engine.createTable(userSchema);
    await engine.insert('users', [
      { id: '1', name: 'Alice', age: 30 },
      { id: '2', name: 'Bob', age: 25 },
    ]);
    const rows = await engine.find('users', { table: 'users' });
    expect(rows).toHaveLength(2);
  });

  it('count 返回正确行数', async () => {
    await engine.createTable(userSchema);
    await engine.insert('users', [{ id: '1', name: 'Alice' }]);
    expect(await engine.count('users')).toBe(1);
  });

  it('更新后数据变化', async () => {
    await engine.createTable(userSchema);
    await engine.insert('users', [{ id: '1', name: 'Alice', age: 30 }]);
    await engine.update('users', { table: 'users', where: { id: '1' } }, { age: 31 });
    const rows = await engine.find('users', { table: 'users', where: { id: '1' } });
    expect(rows[0].age).toBe(31);
  });

  it('删除后 count 减少', async () => {
    await engine.createTable(userSchema);
    await engine.insert('users', [{ id: '1', name: 'Alice' }, { id: '2', name: 'Bob' }]);
    await engine.delete('users', { table: 'users', where: { id: '1' } });
    expect(await engine.count('users')).toBe(1);
  });

  // ---- 数据持久化（模拟重启） ----
  it('close + reopen 后数据恢复', async () => {
    // 写入数据
    await engine.createTable(userSchema);
    await engine.insert('users', [
      { id: '1', name: 'Alice', age: 30 },
      { id: '2', name: 'Bob', age: 25 },
    ]);
    const beforeRows = await engine.find('users', { table: 'users' });
    expect(beforeRows).toHaveLength(2);

    // 关闭后重新打开（模拟重启）
    await engine.close();
    engine = new OPFSEngine();
    await engine.open('test-opfs', 1);

    // 数据应恢复
    const afterRows = await engine.find('users', { table: 'users' });
    expect(afterRows).toHaveLength(2);
    expect(afterRows.map((r: any) => r.name).sort()).toEqual(['Alice', 'Bob']);
  });

  // ---- 事务 ----
  it('事务 commit 后数据持久化', async () => {
    await engine.createTable(userSchema);
    await engine.beginTransaction();
    await engine.insert('users', [{ id: '1', name: 'Alice' }]);
    await engine.commitTransaction();
    expect(await engine.count('users')).toBe(1);
  });

  it('事务 rollback 后数据恢复', async () => {
    await engine.createTable(userSchema);
    await engine.insert('users', [{ id: '1', name: 'Alice' }]);
    await engine.beginTransaction();
    await engine.insert('users', [{ id: '2', name: 'Bob' }]);
    await engine.rollbackTransaction();
    expect(await engine.count('users')).toBe(1);
  });
});