/**
 * iData 扫码插件实现
 * 使用 iData-BarcodePlugin-BarcodeModule + globalEvent
 */

class ScanIdataImpl {
  constructor(iDataModule) {
    this.barcodeModule = iDataModule
    this.globalEvent = null
    this._callback = null
    this._isScanning = false
    this._isInitialized = false
    this._lastScanTime = 0
    this._debounceTime = 500 // 防抖间隔 ms
  }

  /**
   * 初始化扫码模块
   */
  init() {
    if (!this.barcodeModule) {
      throw new Error('[Scan-iData] 扫码模块不可用')
    }

    this.globalEvent = uni.requireNativePlugin('globalEvent')

    var self = this
    this.barcodeModule.initScan(function (res) {
      console.log('[Scan-iData] 初始化结果:', res)
      self._isInitialized = true
      self.barcodeModule.setScanKeyEnable(true, function () {})
      self._setupListener()
    })
  }

  /**
   * 设置扫码结果监听
   */
  _setupListener() {
    var self = this
    this.globalEvent.addEventListener('iDataBarcodeEvent', function (res) {
      console.log('[Scan-iData] 扫码事件:', res)

      if (res && res.barcode) {
        // 防抖处理
        var now = Date.now()
        if (now - self._lastScanTime < self._debounceTime) {
          console.log('[Scan-iData] 防抖过滤')
          return
        }
        self._lastScanTime = now

        self._isScanning = false
        if (self._callback) {
          self._callback(res.barcode)
        }
      }
    })
  }

  /**
   * 注册扫码结果回调
   * @param {Function} callback - (codeStr: string) => void
   */
  register(callback) {
    this._callback = callback
  }

  /**
   * 注销监听（页面卸载时调用）
   * 注意：iData 模式下不注销 globalEvent，只清除回调
   */
  unregister() {
    this._callback = null
  }

  /**
   * 开始扫描
   */
  startScan() {
    if (!this._isInitialized || !this.barcodeModule) return

    var self = this
    this.barcodeModule.setScanKeyEnable(true, function () {
      self.barcodeModule.scanStart(function () {
        self._isScanning = true
        console.log('[Scan-iData] 扫码已启动')
      })
    })
  }

  /**
   * 停止扫描
   */
  stopScan() {
    if (!this.barcodeModule) return

    var self = this
    this.barcodeModule.setScanKeyEnable(false, function () {})
    this.barcodeModule.scanStop(function () {
      self._isScanning = false
      console.log('[Scan-iData] 扫码已停止')
    })
  }

  /**
   * 是否正在扫描
   */
  isScanning() {
    return this._isScanning
  }

  /**
   * 完全销毁（应用退出时调用）
   */
  destroy() {
    this.unregister()
    if (this.barcodeModule) {
      this.barcodeModule.setScanKeyEnable(false, function () {})
      this.barcodeModule.scanStop(function () {})
      this.barcodeModule.closeScan(function () {})
      this.barcodeModule = null
    }
    if (this.globalEvent) {
      this.globalEvent.removeEventListener('iDataBarcodeEvent')
      this.globalEvent = null
    }
    this._isInitialized = false
  }
}

export default ScanIdataImpl