package org.signal.qr

import android.annotation.SuppressLint
import android.content.Context
import android.widget.FrameLayout
import androidx.lifecycle.DefaultLifecycleObserver
import androidx.lifecycle.LifecycleOwner
import org.signal.qr.kitkat.QrCameraView
import org.signal.qr.kitkat.ScanListener
import org.signal.qr.kitkat.ScanningThread

/**
 * API19 version of QR scanning. Uses deprecated camera APIs.
 */
@SuppressLint("ViewConstructor")
internal class ScannerView19 constructor(
  context: Context,
  private val scanListener: ScanListener
) : FrameLayout(context), ScannerView {

  private var scanningThread: ScanningThread? = null
  private val cameraView: QrCameraView

  init {
    cameraView = QrCameraView(context)
    cameraView.layoutParams = LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT)
    addView(cameraView)
  }

  override fun start(lifecycleOwner: LifecycleOwner) {
    lifecycleOwner.lifecycle.addObserver(object : DefaultLifecycleObserver {
      override fun onResume(owner: LifecycleOwner) {
        val scanningThread = ScanningThread()
        scanningThread.setScanListener(scanListener)
        cameraView.onResume()
        cameraView.setPreviewCallback(scanningThread)
        scanningThread.start()

        this@ScannerView19.scanningThread = scanningThread
      }

      override fun onPause(owner: LifecycleOwner) {
        cameraView.onPause()
        scanningThread?.stopScanning()
        scanningThread = null
      }
    })
  }
}