/**
 * v0.3.3 修复验证测试
 * 验证所有 P0/P1 修复点：
 * - P0-1: Aria WAL DROP_TABLE 崩溃恢复（表/数据不复活）+ WAL 恢复后截断
 * - P0-2: MemoryEngine update/delete 索引维护（unique 约束 + 索引查询 + 级联清理）
 * - P1-3: Aria 事务内读到自己写入的变更（insert 后 update/delete）
 * - P1-4: Aria clear() 写 WAL + 事务化
 * - P1-5: WAL 字节数跟踪（full 模式 walSizeThreshold 生效）
 * - P1-6: Aria 主键列不建冗余二级索引（PK $in / 范围查询走主 LSM）
 * - P1-7: ORDER BY 支持 SELECT 别名
 * - P1-8: SQL 字符串 '' 标准转义
 * - P1-9: Savepoint 回滚后 MVCC 版本链一致 + rollback 索引重建
 */

import { VERSION } from '../src/constants';
import { MetonaSqlark } from '../src/core';
import { AriaEngine } from '../src/engine/aria/index';
import { MemoryEngine } from '../src/engine/memory';
import { WAL } from '../src/engine/aria/wal/log';
import { tokenize } from '../src/sql/lexer';

import { installOPFSMock } from './helpers/opfs-mock';

beforeEach(() => { installOPFSMock(new Map()); });

// ---------------------------------------------------------------------------
// P0-1: Aria WAL DROP_TABLE 崩溃恢复
// ---------------------------------------------------------------------------

describe('[v0.3.3] P0-1: WAL DROP_TABLE 崩溃恢复', () => {
  const mkEngine = async (name: string): Promise<AriaEngine> => {
    const e = new AriaEngine({ storageBackend: 'opfs', walSyncMode: 'full' });
    await e.open(name, 1);
    return e;
  };

  test('删表后崩溃（不 close），重启后表与数据不复活', async () => {
    const dbName = `crash-drop-${Date.now()}-${Math.random().toString(36).slice(2, 8)}`;
    let e = await mkEngine(dbName);
    await e.createTable({ name: 't', columns: { id: { type: 'string', primaryKey: true } } });
    await e.insert('t', [{ id: '1' }, { id: '2' }]);
    await e.dropTable('t');

    // 模拟崩溃：不 close，直接重建引擎（WAL 未 checkpoint）
    e = await mkEngine(dbName);
    const names = await e.getTableNames();
    expect(names).not.toContain('t');
    await e.close();
  });

  test('删表崩溃后重建同名表，旧数据不复活', async () => {
    const dbName = `crash-drop2-${Date.now()}-${Math.random().toString(36).slice(2, 8)}`;
    let e = await mkEngine(dbName);
    await e.createTable({ name: 't', columns: { id: { type: 'string', primaryKey: true } } });
    await e.insert('t', [{ id: '1' }, { id: '2' }]);
    await e.dropTable('t');

    e = await mkEngine(dbName);
    await e.createTable({ name: 't', columns: { id: { type: 'string', primaryKey: true } } });
    const rows = await e.find('t', { table: 't' });
    expect(rows).toHaveLength(0);
    await e.close();
  });

  test('WAL 恢复后截断：重启不再重复回放（checkpoint 后 WAL 空）', async () => {
    const dbName = `crash-wal-${Date.now()}-${Math.random().toString(36).slice(2, 8)}`;
    let e = await mkEngine(dbName);
    await e.createTable({ name: 't', columns: { id: { type: 'string', primaryKey: true }, v: { type: 'number' } } });
    await e.insert('t', [{ id: '1', v: 1 }, { id: '2', v: 2 }]);
    await e.dropTable('t');

    // 第一次恢复：WAL 回放 + 截断
    e = await mkEngine(dbName);
    expect(await e.getTableNames()).not.toContain('t');

    // 第二次恢复：WAL 已空，不再有任何回放副作用
    await e.close();
    e = await mkEngine(dbName);
    expect(await e.getTableNames()).not.toContain('t');
    await e.close();
  });
});

// ---------------------------------------------------------------------------
// P0-2: MemoryEngine update/delete 索引维护
// ---------------------------------------------------------------------------

describe('[v0.3.3] P0-2: Memory 引擎索引维护', () => {
  test('update 修改唯一列后，重复值插入被拦截（unique 约束不被绕过）', async () => {
    const e = new MemoryEngine();
    await e.open('x', 1);
    await e.createTable({ name: 't', columns: { id: { type: 'string', primaryKey: true }, email: { type: 'string', unique: true, index: true } } });
    await e.insert('t', [{ id: '1', email: 'a@x.com' }]);
    await e.update('t', { table: 't', where: { id: '1' } }, { email: 'b@x.com' });
    await expect(e.insert('t', [{ id: '2', email: 'b@x.com' }])).rejects.toThrow('Unique constraint');
  });

  test('update 后按新值索引查询命中', async () => {
    const e = new MemoryEngine();
    await e.open('x', 1);
    await e.createTable({ name: 't', columns: { id: { type: 'string', primaryKey: true }, email: { type: 'string', index: true } } });
    await e.insert('t', [{ id: '1', email: 'a@x.com' }]);
    await e.update('t', { table: 't', where: { id: '1' } }, { email: 'b@x.com' });
    const rows = await e.find('t', { table: 't', where: { email: 'b@x.com' } });
    expect(rows).toHaveLength(1);
    expect(rows[0].id).toBe('1');
  });

  test('update 到已存在的唯一值时抛 UNIQUE_VIOLATION', async () => {
    const e = new MemoryEngine();
    await e.open('x', 1);
    await e.createTable({ name: 't', columns: { id: { type: 'string', primaryKey: true }, email: { type: 'string', unique: true, index: true } } });
    await e.insert('t', [{ id: '1', email: 'a@x.com' }, { id: '2', email: 'b@x.com' }]);
    await expect(e.update('t', { table: 't', where: { id: '1' } }, { email: 'b@x.com' })).rejects.toThrow('Unique constraint');
  });

  test('delete 后索引清理：同值可重新插入且索引查询正确', async () => {
    const e = new MemoryEngine();
    await e.open('x', 1);
    await e.createTable({ name: 't', columns: { id: { type: 'string', primaryKey: true }, email: { type: 'string', unique: true, index: true } } });
    await e.insert('t', [{ id: '1', email: 'a@x.com' }]);
    await e.delete('t', { table: 't', where: { id: '1' } });
    await e.insert('t', [{ id: '2', email: 'a@x.com' }]);
    const rows = await e.find('t', { table: 't', where: { email: 'a@x.com' } });
    expect(rows).toHaveLength(1);
    expect(rows[0].id).toBe('2');
  });

  test('级联删除清理子表索引条目', async () => {
    const e = new MemoryEngine();
    await e.open('x', 1);
    await e.createTable({ name: 'users', columns: { id: { type: 'string', primaryKey: true } } });
    await e.createTable({ name: 'orders', columns: { id: { type: 'string', primaryKey: true }, user_id: { type: 'string', index: true, references: 'users.id', onDelete: 'CASCADE' } } });
    await e.insert('users', [{ id: 'u1' }]);
    await e.insert('orders', [{ id: 'o1', user_id: 'u1' }]);
    await e.delete('users', { table: 'users', where: { id: 'u1' } });
    // u1 已删，o1 级联删除 → 按 user_id 索引查询应为空
    const rows = await e.find('orders', { table: 'orders', where: { user_id: 'u1' } });
    expect(rows).toHaveLength(0);
  });
});

// ---------------------------------------------------------------------------
// P1-3: Aria 事务内读到自己写入的变更
// ---------------------------------------------------------------------------

describe('[v0.3.3] P1-3: Aria 事务内读写一致', () => {
  test('事务内 insert 后 update 同一行生效', async () => {
    const e = new AriaEngine({ storageBackend: 'memory', walSyncMode: 'full' });
    await e.open('txn1', 1);
    await e.createTable({ name: 't', columns: { id: { type: 'string', primaryKey: true }, name: { type: 'string' } } });
    await e.beginTransaction();
    await e.insert('t', [{ id: '1', name: 'Alice' }]);
    const n = await e.update('t', { table: 't', where: { id: '1' } }, { name: 'Bob' });
    await e.commitTransaction();
    const rows = await e.find('t', { table: 't' });
    expect(n).toBe(1);
    expect(rows[0].name).toBe('Bob');
    await e.close();
  });

  test('事务内 insert 后 delete 该行生效', async () => {
    const e = new AriaEngine({ storageBackend: 'memory', walSyncMode: 'full' });
    await e.open('txn2', 1);
    await e.createTable({ name: 't', columns: { id: { type: 'string', primaryKey: true } } });
    await e.beginTransaction();
    await e.insert('t', [{ id: '1' }, { id: '2' }]);
    const d = await e.delete('t', { table: 't', where: { id: '2' } });
    await e.commitTransaction();
    const rows = await e.find('t', { table: 't' });
    expect(d).toBe(1);
    expect(rows).toHaveLength(1);
    await e.close();
  });

  test('rollback 后索引无残留（事务内写入的索引被重建清理）', async () => {
    const e = new AriaEngine({ storageBackend: 'memory', walSyncMode: 'full' });
    await e.open('txn3', 1);
    await e.createTable({ name: 't', columns: { id: { type: 'string', primaryKey: true }, name: { type: 'string', index: true } } });
    await e.beginTransaction();
    await e.insert('t', [{ id: '1', name: 'Dave' }]);
    await e.rollbackTransaction();
    const rows = await e.find('t', { table: 't', where: { name: 'Dave' } });
    expect(rows).toHaveLength(0);
    await e.close();
  });

  test('rollback 更新后索引恢复旧值', async () => {
    const e = new AriaEngine({ storageBackend: 'memory', walSyncMode: 'full' });
    await e.open('txn4', 1);
    await e.createTable({ name: 't', columns: { id: { type: 'string', primaryKey: true }, name: { type: 'string', index: true } } });
    await e.insert('t', [{ id: '1', name: 'Bob' }]);
    await e.beginTransaction();
    await e.update('t', { table: 't', where: { id: '1' } }, { name: 'Eve' });
    await e.rollbackTransaction();
    const rows = await e.find('t', { table: 't', where: { name: 'Bob' } });
    expect(rows).toHaveLength(1);
    const stale = await e.find('t', { table: 't', where: { name: 'Eve' } });
    expect(stale).toHaveLength(0);
    await e.close();
  });

  test('事务内 clear 生效且可提交', async () => {
    const e = new AriaEngine({ storageBackend: 'memory', walSyncMode: 'full' });
    await e.open('txn5', 1);
    await e.createTable({ name: 't', columns: { id: { type: 'string', primaryKey: true } } });
    await e.insert('t', [{ id: '1' }, { id: '2' }]);
    await e.beginTransaction();
    await e.clear('t');
    await e.commitTransaction();
    expect(await e.count('t')).toBe(0);
    await e.close();
  });
});

// ---------------------------------------------------------------------------
// P1-5: WAL 字节数跟踪
// ---------------------------------------------------------------------------

describe('[v0.3.3] P1-5: WAL 字节数跟踪', () => {
  test('full 模式 append 后 getBufferedBytes 反映实际字节数', async () => {
    const chunks: Uint8Array[] = [];
    const wal = new WAL({
      append: async (d) => { chunks.push(d); },
      readAll: async () => { const t = chunks.reduce((s, c) => s + c.byteLength, 0); const out = new Uint8Array(t); let o = 0; for (const c of chunks) { out.set(c, o); o += c.byteLength; } return out; },
      truncate: async () => { chunks.length = 0; },
      exists: async () => chunks.length > 0,
    }, true, 'full');

    await wal.append({ type: 1, txnId: 0, tableName: 't', key: '1', data: { a: 1 } } as never);
    const bytesAfterAppend = wal.getBufferedBytes();
    expect(bytesAfterAppend).toBeGreaterThan(0);

    await wal.checkpoint();
    expect(wal.getBufferedBytes()).toBe(0);
  });

  test('batch 模式 flush 后字节数保留（未 checkpoint 前）', async () => {
    const chunks: Uint8Array[] = [];
    const wal = new WAL({
      append: async (d) => { chunks.push(d); },
      readAll: async () => new Uint8Array(0),
      truncate: async () => { chunks.length = 0; },
      exists: async () => chunks.length > 0,
    }, true, 'batch');

    await wal.append({ type: 1, txnId: 0, tableName: 't', key: '1', data: { a: 1 } } as never);
    await wal.flush();
    expect(wal.getBufferedBytes()).toBeGreaterThan(0); // 已写盘但未 checkpoint
    await wal.checkpoint();
    expect(wal.getBufferedBytes()).toBe(0);
  });
});

// ---------------------------------------------------------------------------
// P1-6: Aria 主键列走主 LSM（无冗余二级索引）
// ---------------------------------------------------------------------------

describe('[v0.3.3] P1-6: Aria 主键查询优化', () => {
  test('PK $in 查询走主 LSM 返回正确行', async () => {
    const e = new AriaEngine({ storageBackend: 'memory', walSyncMode: 'full' });
    await e.open('pk1', 1);
    await e.createTable({ name: 't', columns: { id: { type: 'string', primaryKey: true }, v: { type: 'number' } } });
    await e.insert('t', [{ id: '1', v: 10 }, { id: '2', v: 20 }, { id: '3', v: 30 }]);
    const rows = await e.find('t', { table: 't', where: { id: { $in: ['1', '3'] } } });
    expect(rows.map((r) => r.id).sort()).toEqual(['1', '3']);
    await e.close();
  });

  test('PK 范围查询（字符串字典序）', async () => {
    const e = new AriaEngine({ storageBackend: 'memory', walSyncMode: 'full' });
    await e.open('pk2', 1);
    await e.createTable({ name: 't', columns: { id: { type: 'string', primaryKey: true }, v: { type: 'number' } } });
    await e.insert('t', [{ id: 'a', v: 1 }, { id: 'b', v: 2 }, { id: 'c', v: 3 }]);
    const rows = await e.find('t', { table: 't', where: { id: { $gte: 'b' } } });
    expect(rows.map((r) => r.id)).toEqual(['b', 'c']);
    const lt = await e.find('t', { table: 't', where: { id: { $lt: 'b' } } });
    expect(lt.map((r) => r.id)).toEqual(['a']);
    await e.close();
  });

  test('主键列不再创建独立二级索引（dropIndex 仍保护主键）', async () => {
    const e = new AriaEngine({ storageBackend: 'memory', walSyncMode: 'full' });
    await e.open('pk3', 1);
    await e.createTable({ name: 't', columns: { id: { type: 'string', primaryKey: true }, name: { type: 'string', index: true } } });
    // 主键索引保护仍在
    await expect(e.dropIndex('t', 'id')).rejects.toThrow('Cannot drop primary key');
    // 二级索引（name）仍可正常使用
    await e.insert('t', [{ id: '1', name: 'x' }]);
    const rows = await e.find('t', { table: 't', where: { name: 'x' } });
    expect(rows).toHaveLength(1);
    await e.close();
  });
});

// ---------------------------------------------------------------------------
// P1-7: ORDER BY 别名
// ---------------------------------------------------------------------------

describe('[v0.3.3] P1-7: ORDER BY 别名', () => {
  test('SELECT 别名可被 ORDER BY 引用', async () => {
    const db = new MetonaSqlark({ name: `alias-${Date.now()}-${Math.random().toString(36).slice(2, 8)}`, mode: 'memory' });
    await db.init();
    await db.defineTable('users', {
      id: { type: 'string', primaryKey: true },
      name: { type: 'string' },
      age: { type: 'number' },
    });
    await db.query("INSERT INTO users VALUES ('1', 'Alice', 30)");
    await db.query("INSERT INTO users VALUES ('2', 'Bob', 25)");
    await db.query("INSERT INTO users VALUES ('3', 'Carol', 35)");

    const rows = await db.query('SELECT name AS n FROM users ORDER BY n DESC') as Record<string, unknown>[];
    expect(rows.map((r) => r.n)).toEqual(['Carol', 'Bob', 'Alice']);

    const withLimit = await db.query('SELECT name AS n FROM users ORDER BY n ASC LIMIT 2') as Record<string, unknown>[];
    expect(withLimit.map((r) => r.n)).toEqual(['Alice', 'Bob']);
    await db.close();
  });

  test('GROUP BY 场景 ORDER BY 聚合别名', async () => {
    const db = new MetonaSqlark({ name: `alias2-${Date.now()}-${Math.random().toString(36).slice(2, 8)}`, mode: 'memory' });
    await db.init();
    await db.defineTable('emp', {
      id: { type: 'string', primaryKey: true },
      dept: { type: 'string' },
      salary: { type: 'number' },
    });
    await db.query("INSERT INTO emp VALUES ('1', 'eng', 100)");
    await db.query("INSERT INTO emp VALUES ('2', 'eng', 200)");
    await db.query("INSERT INTO emp VALUES ('3', 'ops', 300)");

    const rows = await db.query('SELECT dept, COUNT(*) AS cnt FROM emp GROUP BY dept ORDER BY cnt DESC') as Record<string, unknown>[];
    expect(rows[0]).toEqual({ dept: 'eng', cnt: 2 });
    await db.close();
  });
});

// ---------------------------------------------------------------------------
// P1-8: SQL 字符串 '' 标准转义
// ---------------------------------------------------------------------------

describe('[v0.3.3] P1-8: SQL 字符串转义', () => {
  test("'' 双引号转义为单个引号", async () => {
    const db = new MetonaSqlark({ name: `esc-${Date.now()}-${Math.random().toString(36).slice(2, 8)}`, mode: 'memory' });
    await db.init();
    await db.defineTable('t', {
      id: { type: 'string', primaryKey: true },
      note: { type: 'string' },
    });
    await db.query("INSERT INTO t VALUES ('1', 'it''s a test')");
    const rows = await db.query('SELECT * FROM t') as Record<string, unknown>[];
    expect(rows[0].note).toBe("it's a test");
    await db.close();
  });

  test('反斜杠转义仍兼容', () => {
    const tokens = tokenize("SELECT 'a\\'b'");
    expect(tokens[1].value).toBe("a'b");
  });
});

// ---------------------------------------------------------------------------
// P1-9: Savepoint 回滚后 MVCC 一致
// ---------------------------------------------------------------------------

describe('[v0.3.3] P1-9: Savepoint + MVCC 一致性', () => {
  test('rollbackToSavepoint 后提交，数据为 savepoint 时状态', async () => {
    const e = new AriaEngine({ storageBackend: 'memory', walSyncMode: 'full' });
    await e.open('sp1', 1);
    await e.createTable({ name: 't', columns: { id: { type: 'string', primaryKey: true }, v: { type: 'number' } } });
    await e.insert('t', [{ id: '1', v: 1 }]);
    await e.beginTransaction();
    await e.insert('t', [{ id: '2', v: 2 }]);
    await e.savepoint('sp');
    await e.insert('t', [{ id: '3', v: 3 }]);
    await e.rollbackToSavepoint('sp');
    await e.commitTransaction();
    const rows = await e.find('t', { table: 't' });
    expect(rows.map((r) => r.id).sort()).toEqual(['1', '2']);
    await e.close();
  });

  test('savepoint 回滚后事务仍可继续写入并提交', async () => {
    const e = new AriaEngine({ storageBackend: 'memory', walSyncMode: 'full' });
    await e.open('sp2', 1);
    await e.createTable({ name: 't', columns: { id: { type: 'string', primaryKey: true } } });
    await e.beginTransaction();
    await e.savepoint('sp');
    await e.insert('t', [{ id: '1' }]);
    await e.rollbackToSavepoint('sp');
    await e.insert('t', [{ id: '2' }]);
    await e.commitTransaction();
    const rows = await e.find('t', { table: 't' });
    expect(rows.map((r) => r.id)).toEqual(['2']);
    await e.close();
  });
});

// ---------------------------------------------------------------------------
// 端到端冒烟
// ---------------------------------------------------------------------------

describe('[v0.3.3] 端到端', () => {
  test('全部修复点可共存于 MetonaSqlark API', async () => {
    expect(VERSION).toBe('0.6.2');
    const db = new MetonaSqlark({ name: `e2e-${Date.now()}-${Math.random().toString(36).slice(2, 8)}`, mode: 'memory' });
    await db.init();
    await db.defineTable('users', {
      id: { type: 'string', primaryKey: true },
      email: { type: 'string', unique: true, index: true },
      age: { type: 'number' },
    });
    await db.query("INSERT INTO users VALUES ('1', 'a@x.com', 20)");
    await db.query("INSERT INTO users VALUES ('2', 'b@x.com', 30)");
    // 别名排序 + 唯一约束组合
    const rows = await db.query('SELECT email AS e FROM users ORDER BY e DESC') as Record<string, unknown>[];
    expect(rows.map((r) => r.e)).toEqual(['b@x.com', 'a@x.com']);
    await db.close();
  });
});