/**
 * AriaEngine SSTable Builder + Reader 单元测试
 */
import { SSTableBuilder } from '../../src/engine/aria/index/sstable_builder';
import { SSTableReader } from '../../src/engine/aria/index/sstable';
import type { SSTableMeta } from '../../src/engine/aria/types';

// ===================================================================
//  SSTable Builder + Reader
// ===================================================================
describe('AriaEngine — SSTable Builder + Reader', () => {
  const makeMeta = (data: Uint8Array): SSTableMeta => ({
    id: 1, level: 0, minKey: '', maxKey: '\uffff',
    blockCount: 1, totalSize: data.byteLength, bloomData: null,
  });

  it('构建单条目 SSTable 并精确读取', () => {
    const builder = new SSTableBuilder(4096);
    builder.add('key1', { name: 'Alice', age: 30 });
    const { sstableData } = builder.build();

    const reader = new SSTableReader(sstableData, makeMeta(sstableData));
    const result = reader.get('key1');
    expect(result).not.toBeNull();
    expect(result!.name).toBe('Alice');
    expect(result!.age).toBe(30);
  });

  it('构建多条 SSTable 并全部读取', () => {
    const builder = new SSTableBuilder(4096);
    const items: [string, Record<string, unknown>][] = [];
    for (let i = 0; i < 100; i++) {
      const key = `user-${String(i).padStart(3, '0')}`;
      const value = { idx: i, name: `User${i}` };
      items.push([key, value]);
      builder.add(key, value);
    }
    const { sstableData } = builder.build();

    const reader = new SSTableReader(sstableData, makeMeta(sstableData));
    for (const [key, value] of items) {
      const result = reader.get(key);
      expect(result).not.toBeNull();
      expect(result!.idx).toBe(value.idx);
    }
  });

  it('get — 不存在的 key 返回 null', () => {
    const builder = new SSTableBuilder(4096);
    builder.add('a', { v: 1 });
    const { sstableData } = builder.build();

    const reader = new SSTableReader(sstableData, makeMeta(sstableData));
    expect(reader.get('nonexistent')).toBeNull();
  });

  it('rangeScan — 范围查询', () => {
    const builder = new SSTableBuilder(4096);
    for (let i = 0; i < 20; i++) {
      builder.add(`k-${String(i).padStart(2, '0')}`, { v: i });
    }
    const { sstableData } = builder.build();

    const reader = new SSTableReader(sstableData, makeMeta(sstableData));
    const results: [string, Record<string, unknown>][] = [];
    reader.rangeScan('k-05', 'k-10', (k, v) => results.push([k, v]));
    expect(results).toHaveLength(6);
    expect(results[0][0]).toBe('k-05');
    expect(results[results.length - 1][0]).toBe('k-10');
  });

  it('scanAll — 遍历所有条目', () => {
    const builder = new SSTableBuilder(4096);
    const count = 50;
    for (let i = 0; i < count; i++) {
      builder.add(`item-${i}`, { idx: i });
    }
    const { sstableData } = builder.build();

    const reader = new SSTableReader(sstableData, makeMeta(sstableData));
    const items: [string, Record<string, unknown>][] = [];
    reader.scanAll((k, v) => items.push([k, v]));
    expect(items).toHaveLength(count);
  });

  it('getIndexBlockCount 返回索引块数', () => {
    const builder = new SSTableBuilder(256); // 小 block size 触发多个 block
    for (let i = 0; i < 100; i++) {
      builder.add(`k-${i}`, { data: 'x'.repeat(50) });
    }
    const { sstableData } = builder.build();

    const reader = new SSTableReader(sstableData, makeMeta(sstableData));
    expect(reader.getIndexBlockCount()).toBeGreaterThanOrEqual(1);
  });

  it('边界 — 空 SSTable 不抛异常', () => {
    const builder = new SSTableBuilder(4096);
    const { sstableData } = builder.build();

    const reader = new SSTableReader(sstableData, makeMeta(sstableData));
    expect(reader.get('any')).toBeNull();
    const results: [string, Record<string, unknown>][] = [];
    reader.scanAll((k, v) => results.push([k, v]));
    expect(results).toHaveLength(0);
  });

  it('带特殊字符的 key', () => {
    const builder = new SSTableBuilder(4096);
    builder.add('key-with-dash', { v: 1 });
    builder.add('key.with.dot', { v: 2 });
    builder.add('key with space', { v: 3 });
    const { sstableData } = builder.build();

    const reader = new SSTableReader(sstableData, makeMeta(sstableData));
    expect(reader.get('key-with-dash')!.v).toBe(1);
    expect(reader.get('key.with.dot')!.v).toBe(2);
    expect(reader.get('key with space')!.v).toBe(3);
  });

  it('getEntryCount 返回正确条目数', () => {
    const builder = new SSTableBuilder(4096);
    builder.add('a', { v: 1 });
    builder.add('b', { v: 2 });
    builder.add('c', { v: 3 });
    expect(builder.getEntryCount()).toBe(3);
  });
});