/**
 * v0.1.13 子查询测试
 * 覆盖 SQL Parser 子查询解析 + Executor 子查询执行
 */

import { MetonaSqlark } from '../src/core';
import { parse } from '../src/sql/parser';

// ===================================================================
//  SQL 子查询解析
// ===================================================================

describe('v0.1.13 子查询 — Parser', () => {
  it('IN 子查询解析', () => {
    const stmt = parse('SELECT * FROM users WHERE id IN (SELECT user_id FROM orders)');
    expect(stmt.type).toBe('SELECT');
  });

  it('NOT IN 子查询解析', () => {
    const stmt = parse('SELECT * FROM users WHERE id NOT IN (SELECT user_id FROM orders)');
    expect(stmt.type).toBe('SELECT');
  });

  it('标量子查询解析 (eq)', () => {
    const stmt = parse('SELECT * FROM users WHERE age = (SELECT AVG(age) FROM users)');
    expect(stmt.type).toBe('SELECT');
  });

  it('标量子查询解析 (gt)', () => {
    const stmt = parse('SELECT * FROM users WHERE age > (SELECT AVG(age) FROM users)');
    expect(stmt.type).toBe('SELECT');
  });

  it('子查询带 WHERE', () => {
    const stmt = parse("SELECT * FROM users WHERE id IN (SELECT user_id FROM orders WHERE amount > 100)");
    expect(stmt.type).toBe('SELECT');
  });

  it('子查询带 JOIN', () => {
    const stmt = parse(`SELECT * FROM users u
      WHERE u.id IN (SELECT o.user_id FROM orders o INNER JOIN products p ON o.product = p.name)`);
    expect(stmt.type).toBe('SELECT');
  });
});

// ===================================================================
//  子查询执行
// ===================================================================

describe('v0.1.13 子查询 — Executor', () => {
  let db: MetonaSqlark;

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

    // Seed data
    await db.table('users').insertMany([
      { id: '1', name: 'Alice', age: 30 },
      { id: '2', name: 'Bob', age: 25 },
      { id: '3', name: 'Charlie', age: 35 },
      { id: '4', name: 'Diana', age: 20 },
    ]);
    await db.table('orders').insertMany([
      { id: 'o1', user_id: '1', amount: 100 },
      { id: 'o2', user_id: '1', amount: 200 },
      { id: 'o3', user_id: '2', amount: 50 },
    ]);
  });

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

  it('IN 子查询: 有订单的用户', async () => {
    const rows = await db.query(
      "SELECT * FROM users WHERE id IN (SELECT user_id FROM orders)"
    ) as Record<string, unknown>[];
    expect(rows).toHaveLength(2); // Alice + Bob
    const names = rows.map((r) => r.name);
    expect(names).toContain('Alice');
    expect(names).toContain('Bob');
  });

  it('NOT IN 子查询: 无订单的用户', async () => {
    const rows = await db.query(
      "SELECT * FROM users WHERE id NOT IN (SELECT user_id FROM orders)"
    ) as Record<string, unknown>[];
    expect(rows).toHaveLength(2); // Charlie + Diana
    const names = rows.map((r) => r.name);
    expect(names).toContain('Charlie');
    expect(names).toContain('Diana');
  });

  it('IN 子查询 + WHERE 过滤', async () => {
    const rows = await db.query(
      "SELECT * FROM users WHERE id IN (SELECT user_id FROM orders WHERE amount > 100)"
    ) as Record<string, unknown>[];
    expect(rows).toHaveLength(1); // 只有 Alice 有 >100 订单
    expect(rows[0].name).toBe('Alice');
  });

  it('标量子查询: 年龄大于平均值的用户', async () => {
    const rows = await db.query(
      "SELECT * FROM users WHERE age > (SELECT AVG(age) FROM users)"
    ) as Record<string, unknown>[];
    // AVG = (30+25+35+20)/4 = 27.5 → age > 27.5: Alice(30), Charlie(35)
    expect(rows).toHaveLength(2);
    const names = rows.map((r) => r.name);
    expect(names).toContain('Alice');
    expect(names).toContain('Charlie');
  });

  it('标量子查询: 年龄等于最大值的用户', async () => {
    const rows = await db.query(
      "SELECT * FROM users WHERE age = (SELECT MAX(age) FROM users)"
    ) as Record<string, unknown>[];
    expect(rows).toHaveLength(1);
    expect(rows[0].name).toBe('Charlie');
  });

  it('空子查询结果处理', async () => {
    const rows = await db.query(
      "SELECT * FROM users WHERE id IN (SELECT user_id FROM orders WHERE amount > 9999)"
    ) as Record<string, unknown>[];
    expect(rows).toHaveLength(0);
  });
});