/**
 * QueryBuilder 和 Compiler/Executor 测试
 */

import { MemoryEngine } from '../../src/engine/memory';
import { createSchema } from '../../src/table/schema';
import { SelectQueryBuilder, UpdateQueryBuilder, DeleteQueryBuilder } from '../../src/query/builder';
import { compileStatement } from '../../src/query/compiler';
import { QueryExecutor } from '../../src/query/executor';
import { parse } from '../../src/sql/parser';

describe('QueryBuilder', () => {
  let engine: MemoryEngine;

  beforeEach(async () => {
    engine = new MemoryEngine();
    await engine.open('test-qb', 1);
  });

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

  // ---- SelectQueryBuilder ----

  describe('SelectQueryBuilder', () => {
    it('基础查询', () => {
      const qb = new SelectQueryBuilder(engine, 'users');
      expect(qb.toAST()).toMatchObject({
        type: 'SELECT',
        columns: ['*'],
        from: 'users',
        where: {},
      });
    });

    it('链式调用', () => {
      const qb = new SelectQueryBuilder(engine, 'users', ['id', 'name']);
      qb.where({ age: { $gt: 18 } }).orderBy('name', 'asc').limit(10).offset(5);

      const ast = qb.toAST();
      expect(ast.columns).toEqual(['id', 'name']);
      expect(ast.where).toEqual({ age: { $gt: 18 } });
      expect(ast.orderBy).toEqual([{ column: 'name', direction: 'asc' }]);
      expect(ast.limit).toBe(10);
      expect(ast.offset).toBe(5);
    });

    it('多次 where 合并条件', () => {
      const qb = new SelectQueryBuilder(engine, 'users');
      qb.where({ age: { $gt: 18 } }).where({ active: true });
      expect(qb.toAST().where).toEqual({ age: { $gt: 18 }, active: true });
    });

    it('多次 orderBy 追加排序', () => {
      const qb = new SelectQueryBuilder(engine, 'users');
      qb.orderBy('age', 'desc').orderBy('name', 'asc');
      expect(qb.toAST().orderBy).toHaveLength(2);
    });
  });

  // ---- UpdateQueryBuilder ----

  describe('UpdateQueryBuilder', () => {
    it('基础更新', () => {
      const qb = new UpdateQueryBuilder(engine, 'users', { age: 31 });
      qb.where({ id: '1' });
      const ast = qb.toAST();
      expect(ast).toMatchObject({
        type: 'UPDATE',
        table: 'users',
        sets: { age: 31 },
        where: { id: '1' },
      });
    });

    it('不带 where', () => {
      const qb = new UpdateQueryBuilder(engine, 'users', { active: false });
      expect(qb.toAST().where).toEqual({});
    });
  });

  // ---- DeleteQueryBuilder ----

  describe('DeleteQueryBuilder', () => {
    it('基础删除', () => {
      const qb = new DeleteQueryBuilder(engine, 'users');
      qb.where({ id: '1' });
      const ast = qb.toAST();
      expect(ast).toMatchObject({
        type: 'DELETE',
        from: 'users',
        where: { id: '1' },
      });
    });

    it('不带 where', () => {
      const qb = new DeleteQueryBuilder(engine, 'users');
      expect(qb.toAST().where).toEqual({});
    });
  });
});

// ===================================================================

describe('Compiler', () => {
  it('编译 SELECT', () => {
    const ast = parse('SELECT id, name FROM users WHERE age > 18 ORDER BY age DESC LIMIT 10');
    const plan = compileStatement(ast);
    expect(plan.table).toBe('users');
    expect(plan.columns).toEqual(['id', 'name']);
    expect(plan.where).toBeDefined();
    expect(plan.orderBy).toEqual([{ column: 'age', direction: 'desc' }]);
    expect(plan.limit).toBe(10);
  });

  it('编译 DELETE', () => {
    const ast = parse("DELETE FROM users WHERE id = '1'");
    const plan = compileStatement(ast);
    expect(plan.table).toBe('users');
    expect(plan.where).toBeDefined();
  });

  it('编译 UPDATE', () => {
    const ast = parse("UPDATE users SET age = 31 WHERE id = '1'");
    const plan = compileStatement(ast);
    expect(plan.table).toBe('users');
    expect(plan.where).toBeDefined();
  });

  it('非查询语句抛出错误', () => {
    const ast = parse('CREATE TABLE users (id STRING PRIMARY KEY)');
    expect(() => compileStatement(ast)).toThrow('Cannot compile');
  });
});

// ===================================================================

describe('QueryExecutor', () => {
  let engine: MemoryEngine;
  let executor: QueryExecutor;

  beforeEach(async () => {
    engine = new MemoryEngine();
    await engine.open('test-exec', 1);
    executor = new QueryExecutor(engine);
  });

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

  it('执行 CREATE TABLE', async () => {
    const ast = parse('CREATE TABLE users (id STRING PRIMARY KEY, name STRING)');
    await executor.execute(ast);
    expect(await engine.hasTable('users')).toBe(true);
  });

  it('执行 INSERT + SELECT', async () => {
    await executor.execute(parse('CREATE TABLE users (id STRING PRIMARY KEY, name STRING, age NUMBER)'));
    await executor.execute(parse("INSERT INTO users (id, name, age) VALUES ('1', 'Alice', 30)"));
    await executor.execute(parse("INSERT INTO users VALUES ('2', 'Bob', 25)"));

    const result = await executor.execute(parse('SELECT * FROM users')) as Record<string, unknown>[];
    expect(result).toHaveLength(2);
  });

  it('执行 UPDATE', async () => {
    await executor.execute(parse('CREATE TABLE users (id STRING PRIMARY KEY, name STRING, age NUMBER)'));
    await executor.execute(parse("INSERT INTO users VALUES ('1', 'Alice', 30)"));
    await executor.execute(parse("UPDATE users SET age = 31 WHERE id = '1'"));

    const result = await executor.execute(parse("SELECT * FROM users WHERE id = '1'")) as Record<string, unknown>[];
    expect(result[0].age).toBe(31);
  });

  it('执行 DELETE', async () => {
    await executor.execute(parse('CREATE TABLE users (id STRING PRIMARY KEY, name STRING)'));
    await executor.execute(parse("INSERT INTO users VALUES ('1', 'Alice')"));
    await executor.execute(parse("INSERT INTO users VALUES ('2', 'Bob')"));
    await executor.execute(parse("DELETE FROM users WHERE id = '1'"));

    const result = await executor.execute(parse('SELECT * FROM users')) as Record<string, unknown>[];
    expect(result).toHaveLength(1);
  });

  it('执行 DROP TABLE', async () => {
    await executor.execute(parse('CREATE TABLE users (id STRING PRIMARY KEY)'));
    await executor.execute(parse('DROP TABLE users'));
    expect(await engine.hasTable('users')).toBe(false);
  });

  it('操作不存在的表抛出错误', async () => {
    await expect(
      executor.execute(parse('SELECT * FROM nonexistent')),
    ).rejects.toThrow('does not exist');
  });

  it('getEngine', () => {
    expect(executor.getEngine()).toBe(engine);
  });
});