// PowerSync 本地库单例 (0.2.1 离线编辑)
// 页面用法: usePowerSyncQuery 等见 src/lib/powersync/react.jsx; 写入用 db.execute/writeTransaction
import { PowerSyncDatabase } from '@powersync/web'
import { AppSchema } from './schema.js'
import { IBoardConnector } from './connector.js'

let dbInstance = null

export function getPowersyncDb() {
  if (!dbInstance) {
    dbInstance = new PowerSyncDatabase({
      schema: AppSchema,
      database: {
        // 默认 IDBBatchAtomicVFS (IndexedDB), 兼容性最广; WebView2 (Chromium) 后续可切 OPFS 加速
        dbFilename: 'iboard-powersync.db',
      },
    })
  }
  return dbInstance
}

/** 登录后调用: 建立同步连接 (幂等) */
export async function connectPowersync() {
  const db = getPowersyncDb()
  db.connect(new IBoardConnector())
  return db
}

/** 退出登录时调用: 断开同步并清空本地库 */
export async function disconnectAndClearPowersync() {
  if (!dbInstance) return
  try {
    await dbInstance.disconnectAndClear()
  } catch {
    /* ignore */
  }
}