/**
 * v0.1.13 事务回滚测试
 * 覆盖 Memory / IndexedDB / Hybrid 三种引擎的 begin/commit/rollback
 */

import { MetonaSqlark } from '../src/core';
import 'fake-indexeddb/auto';

let idbCounter = 0;

// ===================================================================
//  Memory 引擎事务回滚
// ===================================================================

describe('v0.1.13 事务回滚 — Memory 模式', () => {
  let db: MetonaSqlark;

  beforeEach(async () => {
    db = new MetonaSqlark({ name: 'tx-test-mem', mode: 'memory' });
    await db.init();
    await db.defineTable('users', {
      id: { type: 'string', primaryKey: true },
      name: { type: 'string', required: true },
      balance: { type: 'number', default: 0 },
    });
  });

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

  it('commit: 事务成功后数据持久化', async () => {
    await db.transaction(async (trx) => {
      await trx.table('users').insert({ id: '1', name: 'Alice', balance: 100 });
      await trx.table('users').insert({ id: '2', name: 'Bob', balance: 200 });
    });
    const rows = await db.table('users').select().execute();
    expect(rows).toHaveLength(2);
  });

  it('rollback: 事务失败后数据恢复', async () => {
    // 先插入一条
    await db.table('users').insert({ id: '1', name: 'Alice', balance: 100 });

    try {
      await db.transaction(async (trx) => {
        await trx.table('users').insert({ id: '2', name: 'Bob', balance: 200 });
        // 故意触发重复主键错误
        await trx.table('users').insert({ id: '2', name: 'Duplicate', balance: 0 });
      });
    } catch { /* expected */ }

    // 回滚后：只有最初的那条数据
    const rows = await db.table('users').select().execute();
    expect(rows).toHaveLength(1);
    expect(rows[0].name).toBe('Alice');
  });

  it('rollback: 更新操作回滚', async () => {
    await db.table('users').insert({ id: '1', name: 'Alice', balance: 100 });

    try {
      await db.transaction(async (trx) => {
        await trx.table('users').update({ balance: 999 }).where({ id: '1' }).execute();
        throw new Error('手动失败');
      });
    } catch { /* expected */ }

    const rows = await db.table('users').select().execute();
    expect(rows[0].balance).toBe(100); // 回滚到 100
  });

  it('rollback: 删除操作回滚', async () => {
    await db.table('users').insert({ id: '1', name: 'Alice', balance: 100 });
    await db.table('users').insert({ id: '2', name: 'Bob', balance: 200 });

    try {
      await db.transaction(async (trx) => {
        await trx.table('users').delete().where({ id: '1' }).execute();
        throw new Error('手动失败');
      });
    } catch { /* expected */ }

    const rows = await db.table('users').select().execute();
    expect(rows).toHaveLength(2); // 两条都在
  });

  it('rollback: 混合操作回滚', async () => {
    await db.table('users').insert({ id: '1', name: 'Alice', balance: 100 });
    await db.table('users').insert({ id: '2', name: 'Bob', balance: 200 });

    try {
      await db.transaction(async (trx) => {
        await trx.table('users').insert({ id: '3', name: 'Charlie', balance: 300 });
        await trx.table('users').update({ balance: 0 }).where({ id: '1' }).execute();
        await trx.table('users').delete().where({ id: '2' }).execute();
        throw new Error('手动失败');
      });
    } catch { /* expected */ }

    const rows = await db.table('users').select().execute();
    expect(rows).toHaveLength(2);
    expect(rows.find((r: any) => r.id === '1')!.balance).toBe(100);
    expect(rows.find((r: any) => r.id === '2')).toBeTruthy();
  });

  it('事务返回结果', async () => {
    const result = await db.transaction(async (trx) => {
      await trx.table('users').insert({ id: '1', name: 'Alice' });
      return 'OK';
    });
    expect(result).toBe('OK');
    expect(await db.table('users').count()).toBe(1);
  });

  it('事务错误抛出 DatabaseError', async () => {
    await expect(db.transaction(async () => {
      throw new Error('custom error');
    })).rejects.toThrow('Transaction failed');
  });
});

// ===================================================================
//  IndexedDB 引擎事务回滚
// ===================================================================

describe('v0.1.13 事务回滚 — Disk 模式 (IndexedDB)', () => {
  let db: MetonaSqlark;
  let dbName: string;

  beforeEach(async () => {
    dbName = `tx-disk-${++idbCounter}`;
    db = new MetonaSqlark({ name: dbName, mode: 'disk', diskEngine: 'indexeddb' });
    await db.init();
    await db.defineTable('users', {
      id: { type: 'string', primaryKey: true },
      name: { type: 'string', required: true },
    });
  });

  afterEach(async () => {
    await db.close();
    try { indexedDB.deleteDatabase(dbName); } catch {}
  });

  it('commit: 事务成功数据持久化', async () => {
    await db.transaction(async (trx) => {
      await trx.table('users').insert({ id: '1', name: 'Alice' });
      await trx.table('users').insert({ id: '2', name: 'Bob' });
    });
    const rows = await db.table('users').select().execute();
    expect(rows).toHaveLength(2);
  });

  it('rollback: 事务失败数据恢复', async () => {
    await db.table('users').insert({ id: '1', name: 'Alice' });

    try {
      await db.transaction(async (trx) => {
        await trx.table('users').insert({ id: '2', name: 'Bob' });
        await trx.table('users').insert({ id: '2', name: 'Dup' });
      });
    } catch { /* expected */ }

    const rows = await db.table('users').select().execute();
    expect(rows).toHaveLength(1);
  });
});

// ===================================================================
//  Hybrid 引擎事务回滚
// ===================================================================

describe('v0.1.13 事务回滚 — Hybrid 模式', () => {
  let db: MetonaSqlark;
  let dbName: string;

  beforeEach(async () => {
    dbName = `tx-hybrid-${++idbCounter}`;
    db = new MetonaSqlark({ name: dbName, mode: 'hybrid', diskEngine: 'indexeddb' });
    await db.init();
    await db.defineTable('users', {
      id: { type: 'string', primaryKey: true },
      name: { type: 'string', required: true },
    });
  });

  afterEach(async () => {
    await db.close();
    try { indexedDB.deleteDatabase(dbName); } catch {}
  });

  it('commit: 事务成功', async () => {
    await db.transaction(async (trx) => {
      await trx.table('users').insert({ id: '1', name: 'Alice' });
    });
    expect(await db.table('users').count()).toBe(1);
  });

  it('rollback: 事务失败回滚', async () => {
    await db.table('users').insert({ id: '1', name: 'Alice' });

    try {
      await db.transaction(async (trx) => {
        await trx.table('users').insert({ id: '2', name: 'Bob' });
        await trx.table('users').delete().where({ id: '1' }).execute();
        throw new Error('fail');
      });
    } catch { /* expected */ }

    const rows = await db.table('users').select().execute();
    expect(rows).toHaveLength(1);
    expect(rows[0].id).toBe('1');
  });
});