package <%= java_package %>

import android.app.Activity
import android.content.Intent
import android.os.Bundle
import android.util.Size
import android.view.ViewGroup
import android.widget.FrameLayout
import android.widget.ImageButton
import androidx.annotation.OptIn
import androidx.appcompat.app.AppCompatActivity
import androidx.camera.core.*
import androidx.camera.lifecycle.ProcessCameraProvider
import androidx.camera.view.PreviewView
import androidx.core.content.ContextCompat
import com.google.mlkit.vision.barcode.BarcodeScanning
import com.google.mlkit.vision.barcode.common.Barcode
import com.google.mlkit.vision.common.InputImage
import java.util.concurrent.Executors

/**
 * Full-screen barcode/QR scanner activity.
 *
 * Uses CameraX + ML Kit BarcodeScanning.
 *
 * Required build.gradle dependencies:
 *   implementation 'androidx.camera:camera-camera2:1.3.0'
 *   implementation 'androidx.camera:camera-lifecycle:1.3.0'
 *   implementation 'androidx.camera:camera-view:1.3.0'
 *   implementation 'com.google.mlkit:barcode-scanning:17.2.0'
 *
 * Required AndroidManifest.xml entry:
 *   <activity android:name=".MobScannerActivity" />
 */
class MobScannerActivity : AppCompatActivity() {

    private val executor = Executors.newSingleThreadExecutor()
    private var scanHandled = false

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        val container = FrameLayout(this)
        setContentView(container)

        val previewView = PreviewView(this).also {
            it.layoutParams = FrameLayout.LayoutParams(
                ViewGroup.LayoutParams.MATCH_PARENT,
                ViewGroup.LayoutParams.MATCH_PARENT
            )
            container.addView(it)
        }

        // Cancel button
        val cancelBtn = ImageButton(this).also {
            it.setImageResource(android.R.drawable.ic_menu_close_clear_cancel)
            it.layoutParams = FrameLayout.LayoutParams(128, 128).apply { setMargins(32, 80, 0, 0) }
            it.setOnClickListener { setResult(Activity.RESULT_CANCELED); finish() }
            container.addView(it)
        }

        val cameraProviderFuture = ProcessCameraProvider.getInstance(this)
        cameraProviderFuture.addListener({
            val cameraProvider = cameraProviderFuture.get()
            val preview = Preview.Builder().build().also {
                it.setSurfaceProvider(previewView.surfaceProvider)
            }
            val imageAnalyzer = ImageAnalysis.Builder()
                .setTargetResolution(Size(1280, 720))
                .setBackpressureStrategy(ImageAnalysis.STRATEGY_KEEP_ONLY_LATEST)
                .build()
                .also { analysis ->
                    val scanner = BarcodeScanning.getClient()
                    analysis.setAnalyzer(executor) { imageProxy ->
                        @OptIn(ExperimentalGetImage::class)
                        val mediaImage = imageProxy.image
                        if (mediaImage != null && !scanHandled) {
                            val image = InputImage.fromMediaImage(mediaImage, imageProxy.imageInfo.rotationDegrees)
                            scanner.process(image)
                                .addOnSuccessListener { barcodes ->
                                    barcodes.firstOrNull()?.rawValue?.let { value ->
                                        if (!scanHandled) {
                                            scanHandled = true
                                            val type = when (barcodes.first().format) {
                                                Barcode.FORMAT_QR_CODE      -> "qr"
                                                Barcode.FORMAT_EAN_13       -> "ean13"
                                                Barcode.FORMAT_EAN_8        -> "ean8"
                                                Barcode.FORMAT_CODE_128     -> "code128"
                                                Barcode.FORMAT_CODE_39      -> "code39"
                                                Barcode.FORMAT_PDF417       -> "pdf417"
                                                Barcode.FORMAT_AZTEC        -> "aztec"
                                                Barcode.FORMAT_DATA_MATRIX  -> "data_matrix"
                                                else -> "qr"
                                            }
                                            val result = Intent().apply {
                                                putExtra("scan_value", value)
                                                putExtra("scan_type",  type)
                                            }
                                            setResult(Activity.RESULT_OK, result)
                                            finish()
                                        }
                                    }
                                }
                                .addOnCompleteListener { imageProxy.close() }
                        } else {
                            imageProxy.close()
                        }
                    }
                }
            try {
                cameraProvider.unbindAll()
                cameraProvider.bindToLifecycle(this, CameraSelector.DEFAULT_BACK_CAMERA, preview, imageAnalyzer)
            } catch (e: Exception) {
                setResult(Activity.RESULT_CANCELED); finish()
            }
        }, ContextCompat.getMainExecutor(this))
    }

    override fun onDestroy() {
        super.onDestroy()
        executor.shutdown()
    }
}