/**
 * AriaEngine Bloom Filter + MemTable 单元测试
 */
import { BloomFilter } from '../../src/engine/aria/index/bloom';
import { MemTable } from '../../src/engine/aria/index/memtable';

// ===================================================================
//  BloomFilter
// ===================================================================
describe('AriaEngine — BloomFilter', () => {
  it('插入后 mayContain 返回 true', () => {
    const bf = new BloomFilter(100);
    bf.insert('hello');
    expect(bf.mayContain('hello')).toBe(true);
  });

  it('未插入的 key mayContain 返回 false', () => {
    const bf = new BloomFilter(100);
    bf.insert('hello');
    expect(bf.mayContain('world')).toBe(false);
  });

  it('批量插入后所有 key 都判定存在', () => {
    const bf = new BloomFilter(500);
    const keys: string[] = [];
    for (let i = 0; i < 200; i++) {
      const k = `key-${i}`;
      keys.push(k);
      bf.insert(k);
    }
    for (const k of keys) {
      expect(bf.mayContain(k)).toBe(true);
    }
  });

  it('False positive 率可控', () => {
    const n = 500;
    const bf = new BloomFilter(n, 10);
    for (let i = 0; i < n; i++) {
      bf.insert(`present-${i}`);
    }
    let fp = 0;
    for (let i = 0; i < 500; i++) {
      if (bf.mayContain(`absent-${i}`)) fp++;
    }
    expect(fp).toBeLessThan(25);
  });

  it('getHashCount 返回哈希函数数量', () => {
    const bf = new BloomFilter(1000, 10);
    expect(bf.getHashCount()).toBeGreaterThan(0);
  });

  it('serialize + fromData 往返', () => {
    const bf1 = new BloomFilter(100);
    bf1.insert('a');
    bf1.insert('b');
    const data = bf1.serialize();

    const bf2 = BloomFilter.fromData(data, bf1.getHashCount());
    expect(bf2.mayContain('a')).toBe(true);
    expect(bf2.mayContain('b')).toBe(true);
    expect(bf2.mayContain('c')).toBe(false);
  });

  it('空过滤器 mayContain 返回 false', () => {
    const bf = new BloomFilter(100);
    expect(bf.mayContain('anything')).toBe(false);
  });

  it('最少 1 个哈希函数', () => {
    const bf = new BloomFilter(10, 1);
    expect(bf.getHashCount()).toBeGreaterThanOrEqual(1);
  });
});

// ===================================================================
//  MemTable
// ===================================================================
describe('AriaEngine — MemTable', () => {
  let mt: MemTable;

  beforeEach(() => {
    mt = new MemTable(4 * 1024 * 1024);
  });

  it('put + get 往返', () => {
    mt.put('key1', { name: 'Alice', age: 30 });
    const val = mt.get('key1');
    expect(val).not.toBeNull();
    expect(val!.name).toBe('Alice');
  });

  it('get — 不存在的 key 返回 null', () => {
    expect(mt.get('nonexistent')).toBeNull();
  });

  it('put 更新已存在的 key', () => {
    mt.put('k', { v: 1 });
    mt.put('k', { v: 2 });
    expect(mt.get('k')!.v).toBe(2);
  });

  it('delete 删除成功', () => {
    mt.put('k', { v: 1 });
    expect(mt.delete('k')).toBe(true);
    expect(mt.get('k')).toBeNull();
  });

  it('delete — 不存在的 key 返回 false', () => {
    expect(mt.delete('ghost')).toBe(false);
  });

  it('getAllEntries 返回所有条目（有序）', () => {
    mt.put('c', { v: 3 });
    mt.put('a', { v: 1 });
    mt.put('b', { v: 2 });
    const entries = mt.getAllEntries();
    expect(entries).toHaveLength(3);
    expect(entries[0][0]).toBe('a');
    expect(entries[1][0]).toBe('b');
    expect(entries[2][0]).toBe('c');
  });

  it('rangeScan — 范围查询', () => {
    mt.put('a', { v: 1 });
    mt.put('b', { v: 2 });
    mt.put('c', { v: 3 });
    mt.put('d', { v: 4 });
    const results = mt.rangeScan('b', 'c');
    expect(results).toHaveLength(2);
    expect(results[0][0]).toBe('b');
    expect(results[1][0]).toBe('c');
  });

  it('rangeScan — 空结果', () => {
    mt.put('a', { v: 1 });
    const results = mt.rangeScan('z', 'zz');
    expect(results).toHaveLength(0);
  });

  it('getEntryCount 正确计数', () => {
    expect(mt.getEntryCount()).toBe(0);
    mt.put('a', { v: 1 });
    mt.put('b', { v: 2 });
    expect(mt.getEntryCount()).toBe(2);
    mt.delete('a');
    expect(mt.getEntryCount()).toBe(1);
  });


  it('shouldFlush — 未达阈值返回 false', () => {
    expect(mt.shouldFlush()).toBe(false);
  });

  it('clear 清空所有数据', () => {
    mt.put('a', { v: 1 });
    mt.put('b', { v: 2 });
    mt.clear();
    expect(mt.getEntryCount()).toBe(0);
    expect(mt.get('a')).toBeNull();
  });

  it('getEstimatedSize 返回合理估计值', () => {
    expect(mt.getEstimatedSize()).toBe(0);
    mt.put('hello', { name: 'world', count: 42 });
    expect(mt.getEstimatedSize()).toBeGreaterThan(0);
  });

  it('大量数据插入保持有序', () => {
    const count = 100;
    for (let i = count - 1; i >= 0; i--) {
      mt.put(`key-${String(i).padStart(3, '0')}`, { idx: i });
    }
    const entries = mt.getAllEntries();
    expect(entries).toHaveLength(count);
    for (let i = 0; i < count; i++) {
      expect(entries[i][1].idx).toBe(i);
    }
  });

  it('删除后重新插入', () => {
    mt.put('k', { v: 1 });
    mt.delete('k');
    mt.put('k', { v: 2 });
    expect(mt.get('k')!.v).toBe(2);
  });

  it('范围扫描包含边界', () => {
    mt.put('aa', { v: 1 });
    mt.put('ab', { v: 2 });
    mt.put('ac', { v: 3 });
    const results = mt.rangeScan('aa', 'ab');
    expect(results).toHaveLength(2);
    expect(results[0][0]).toBe('aa');
    expect(results[1][0]).toBe('ab');
  });
});