tauri-plugins-workspace/plugins/barcode-scanner/android/src/main/java/BarcodeScannerPlugin.kt

package app.tauri.barcodescanner

import android.Manifest
import android.annotation.SuppressLint
import android.app.Activity
import android.content.Context
import android.content.Context.MODE_PRIVATE
import android.content.Intent
import android.content.SharedPreferences
import android.content.pm.PackageManager
import android.net.Uri
import android.os.Build
import android.os.VibrationEffect
import android.os.Vibrator
import android.provider.Settings
import android.util.Size
import android.view.ViewGroup
import android.webkit.WebView
import android.widget.FrameLayout
import androidx.activity.result.ActivityResult
import androidx.camera.core.Camera
import androidx.camera.core.CameraSelector
import androidx.camera.core.ImageAnalysis
import androidx.camera.core.ImageProxy
import androidx.camera.core.Preview
import androidx.camera.lifecycle.ProcessCameraProvider
import androidx.camera.view.PreviewView
import androidx.core.content.ContextCompat
import androidx.lifecycle.LifecycleOwner
import app.tauri.Logger
import app.tauri.PermissionState
import app.tauri.annotation.ActivityCallback
import app.tauri.annotation.Command
import app.tauri.annotation.Permission
import app.tauri.annotation.PermissionCallback
import app.tauri.annotation.TauriPlugin
import app.tauri.plugin.Invoke
import app.tauri.plugin.JSArray
import app.tauri.plugin.JSObject
import app.tauri.plugin.Plugin
import com.google.common.util.concurrent.ListenableFuture
import com.google.mlkit.vision.barcode.BarcodeScannerOptions
import com.google.mlkit.vision.barcode.BarcodeScanning
import com.google.mlkit.vision.barcode.common.Barcode
import com.google.mlkit.vision.common.InputImage
import org.json.JSONException
import java.util.Collections
import java.util.concurrent.ExecutionException

private const val PERMISSION_ALIAS_CAMERA = "camera"
private const val PERMISSION_NAME = Manifest.permission.CAMERA
private const val PREFS_PERMISSION_FIRST_TIME_ASKING = "PREFS_PERMISSION_FIRST_TIME_ASKING"

@TauriPlugin(
    permissions = [
        Permission(strings = [Manifest.permission.CAMERA], alias = "camera")
    ]
)
class BarcodeScannerPlugin(private val activity: Activity) : Plugin(activity),
    ImageAnalysis.Analyzer {
    private lateinit var webView: WebView
    private var previewView: PreviewView? = null
    private var cameraProviderFuture: ListenableFuture<ProcessCameraProvider>? = null
    private var cameraProvider: ProcessCameraProvider? = null
    private var graphicOverlay: GraphicOverlay? = null
    private var camera: Camera? = null
    private var vibrator: Vibrator? = null

    private var scannerOptions: BarcodeScannerOptions? = null
    private var scanner: com.google.mlkit.vision.barcode.BarcodeScanner? = null

    private var requestPermissionResponse: JSObject? = null
    private var cameraReady = false

    // declare a map constant for allowed barcode formats
    private val supportedFormats = supportedFormats()

    private var savedInvoke: Invoke? = null

    override fun load(webView: WebView) {
        super.load(webView)
        this.webView = webView
    }

    private fun supportedFormats(): Map<String, Int> {
        val map: MutableMap<String, Int> = HashMap()
        map["UPC_A"] = Barcode.FORMAT_UPC_A
        map["UPC_E"] = Barcode.FORMAT_UPC_E
        map["EAN_8"] = Barcode.FORMAT_EAN_8
        map["EAN_13"] = Barcode.FORMAT_EAN_13
        map["CODE_39"] = Barcode.FORMAT_CODE_39
        map["CODE_93"] = Barcode.FORMAT_CODE_93
        map["CODE_128"] = Barcode.FORMAT_CODE_128
        map["CODABAR"] = Barcode.FORMAT_CODABAR
        map["ITF"] = Barcode.FORMAT_ITF
        map["AZTEC"] = Barcode.FORMAT_AZTEC
        map["DATA_MATRIX"] = Barcode.FORMAT_DATA_MATRIX
        map["PDF_417"] = Barcode.FORMAT_PDF417
        map["QR_CODE"] = Barcode.FORMAT_QR_CODE
        return Collections.unmodifiableMap(map)
    }

    private fun hasCamera(): Boolean {
        return activity.packageManager
            .hasSystemFeature(PackageManager.FEATURE_CAMERA_ANY)
    }

    private fun setupCamera(cameraDirection: String) {
        activity
            .runOnUiThread {

                val previewView = PreviewView(activity)
                previewView.layoutParams = FrameLayout.LayoutParams(
                    ViewGroup.LayoutParams.MATCH_PARENT,
                    ViewGroup.LayoutParams.MATCH_PARENT
                )
                this.previewView = previewView

                val graphicOverlay = GraphicOverlay(activity)
                graphicOverlay.layoutParams = FrameLayout.LayoutParams(
                    ViewGroup.LayoutParams.MATCH_PARENT,
                    ViewGroup.LayoutParams.MATCH_PARENT
                )
                this.graphicOverlay = graphicOverlay

                val parent = webView.parent as ViewGroup
                parent.addView(previewView)
                parent.addView(graphicOverlay)

                val cameraProviderFuture = ProcessCameraProvider.getInstance(activity)
                cameraProviderFuture.addListener(
                    {
                        try {
                            val cameraProvider = cameraProviderFuture.get()
                            bindPreview(
                                cameraProvider,
                                if (cameraDirection == "front") CameraSelector.LENS_FACING_FRONT else CameraSelector.LENS_FACING_BACK
                            )
                            this.cameraProvider = cameraProvider
                        } catch (e: InterruptedException) {
                            // ignored
                        } catch (_: ExecutionException) {
                            // ignored
                        }
                    },
                    ContextCompat.getMainExecutor(activity)
                )
                this.cameraProviderFuture = cameraProviderFuture
            }
    }

    private fun bindPreview(cameraProvider: ProcessCameraProvider, cameraDirection: Int) {
        activity
            .runOnUiThread {
                val preview = Preview.Builder().build()
                val cameraSelector =
                    CameraSelector.Builder().requireLensFacing(cameraDirection).build()
                preview.setSurfaceProvider(previewView?.surfaceProvider)
                val imageAnalysis = ImageAnalysis.Builder()
                    .setBackpressureStrategy(ImageAnalysis.STRATEGY_KEEP_ONLY_LATEST)
                    .setTargetResolution(Size(1280, 720))
                    .build()
                imageAnalysis.setAnalyzer(
                    ContextCompat.getMainExecutor(activity),
                    this
                )
                camera = cameraProvider.bindToLifecycle(
                    activity as LifecycleOwner,
                    cameraSelector,
                    preview,
                    imageAnalysis
                )
            }
    }

    private fun dismantleCamera() {
        // opposite of setupCamera
        activity
            .runOnUiThread {
                if (cameraProvider != null) {
                    cameraProvider?.unbindAll()
                    val parent = webView.parent as ViewGroup
                    parent.removeView(previewView)
                    parent.removeView(graphicOverlay)
                    camera = null
                    previewView = null
                    graphicOverlay = null
                }
            }
    }

    private fun getFormats(invoke: Invoke): List<Int> {
        val jsFormats = invoke.getArray("formats", JSArray())
        val formats = ArrayList<Int>()
        for (i in 0 until jsFormats.length()) {
            try {
                val targetedFormat: String = jsFormats.getString(i)
                val targetedBarcodeFormat =
                    supportedFormats[targetedFormat]
                if (targetedBarcodeFormat != null) {
                    formats.add(targetedBarcodeFormat)
                }
            } catch (e: JSONException) {
                e.printStackTrace()
            }
        }
        return formats
    }

    private fun prepareInternal(direction: String) {
        dismantleCamera()
        setupCamera(direction)
    }

    private fun destroy() {
        dismantleCamera()
        savedInvoke = null
    }

    @Suppress("DEPRECATION")
    private fun configureCamera(formats: List<Int>) {
        activity
            .runOnUiThread {
                val vibrator =
                    activity.getSystemService(Context.VIBRATOR_SERVICE) as Vibrator
                this.vibrator = vibrator
                if (previewView == null) {
                    throw Exception("Something went wrong configuring the BarcodeScanner")
                }

                if (formats.isNotEmpty()) {
                    val mappedFormats = mapFormats(formats)
                    val options =
                        BarcodeScannerOptions.Builder()
                            .setBarcodeFormats(Barcode.FORMAT_QR_CODE, *mappedFormats).build()
                    scannerOptions = options
                    scanner = BarcodeScanning.getClient(options)
                } else {
                    val options = BarcodeScannerOptions.Builder()
                        .setBarcodeFormats(Barcode.FORMAT_ALL_FORMATS).build()
                    scannerOptions = options
                    scanner = BarcodeScanning.getClient(options)
                }
            }
    }

    private fun mapFormats(integers: List<Int>): IntArray {
        val ret = IntArray(integers.size)
        for (i in ret.indices) {
            if (integers[i] != Barcode.FORMAT_QR_CODE) ret[i] = integers[i]
        }
        return ret
    }

    override fun analyze(image: ImageProxy) {
        @SuppressLint("UnsafeOptInUsageError") val mediaImage = image.image
        if (mediaImage != null) {
            val inputImage =
                InputImage.fromMediaImage(mediaImage, image.imageInfo.rotationDegrees)
            scanner
                ?.process(inputImage)
                ?.addOnSuccessListener { barcodes ->
                    for (barcode in barcodes) {
                        val bounds = barcode.boundingBox
                        val rawValue = barcode.rawValue ?: ""

                        // add vibration logic here
                        val s = bounds?.flattenToString()
                        val jsObject = JSObject()
                        jsObject.put("content", rawValue)
                        jsObject.put("bounds", s)

                        savedInvoke?.resolve(jsObject)
                        destroy()
                    }
                }
                ?.addOnFailureListener { e ->
                    Logger.error(e.message ?: e.toString())
                }
                ?.addOnCompleteListener {
                    image.close()
                    mediaImage.close()
                }
        }
    }

    @Command
    fun vibrate(invoke: Invoke) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            vibrator!!.vibrate(
                VibrationEffect.createOneShot(
                    50,
                    VibrationEffect.DEFAULT_AMPLITUDE
                )
            )
        }
        invoke.resolve()
    }

    @Command
    fun prepare(invoke: Invoke) {
        prepareInternal(invoke.getString("cameraDirection", "back"))
        cameraReady = true
        invoke.resolve()
    }

    @Command
    fun cancel(invoke: Invoke) {
        savedInvoke?.reject("cancelled")
        destroy()
        invoke.resolve()
    }

    @Command
    fun scan(invoke: Invoke) {
        savedInvoke = invoke
        if (hasCamera()) {
            if (getPermissionState("camera") != PermissionState.GRANTED) {
                throw Exception("No permission to use camera. Did you request it yet?")
            } else {
                if (!cameraReady) {
                    prepareInternal(invoke.getString("cameraDirection", "back"))
                }
                cameraReady = false
                configureCamera(getFormats(invoke))
            }
        }
    }

    private fun markFirstPermissionRequest() {
        val sharedPreference: SharedPreferences =
            activity.getSharedPreferences(PREFS_PERMISSION_FIRST_TIME_ASKING, MODE_PRIVATE)
        sharedPreference.edit().putBoolean(PERMISSION_NAME, false).apply()
    }

    private fun firstPermissionRequest(): Boolean {
        return activity.getSharedPreferences(PREFS_PERMISSION_FIRST_TIME_ASKING, MODE_PRIVATE)
            .getBoolean(PERMISSION_NAME, true)
    }

    @SuppressLint("ObsoleteSdkInt")
    @PermissionCallback
    fun cameraPermissionCallback(invoke: Invoke) {
        if (requestPermissionResponse == null) {
            return
        }

        val requestPermissionResponse = requestPermissionResponse!!

        val granted = getPermissionState(PERMISSION_ALIAS_CAMERA) === PermissionState.GRANTED

        if (granted) {
            requestPermissionResponse.put(PERMISSION_ALIAS_CAMERA, PermissionState.GRANTED)
        } else {
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
                if (!activity.shouldShowRequestPermissionRationale(PERMISSION_NAME)) {
                    requestPermissionResponse.put(PERMISSION_ALIAS_CAMERA, PermissionState.DENIED)
                }
            } else {
                requestPermissionResponse.put(PERMISSION_ALIAS_CAMERA, PermissionState.GRANTED)
            }
        }

        invoke.resolve(requestPermissionResponse)
        this.requestPermissionResponse = null
    }

    @SuppressLint("ObsoleteSdkInt")
    @Command
    override fun requestPermissions(invoke: Invoke) {
        val requestPermissionResponse = JSObject()
        this.requestPermissionResponse = requestPermissionResponse
        if (getPermissionState(PERMISSION_ALIAS_CAMERA) === PermissionState.GRANTED) {
            requestPermissionResponse.put(PERMISSION_ALIAS_CAMERA, PermissionState.GRANTED)
        } else {
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
                if (firstPermissionRequest() || activity.shouldShowRequestPermissionRationale(
                        PERMISSION_NAME
                    )
                ) {
                    markFirstPermissionRequest()
                    requestPermissionForAlias(
                        PERMISSION_ALIAS_CAMERA,
                        invoke,
                        "cameraPermissionCallback"
                    )
                    return
                } else {
                    requestPermissionResponse.put(PERMISSION_ALIAS_CAMERA, PermissionState.DENIED)
                }
            } else {
                requestPermissionResponse.put(PERMISSION_ALIAS_CAMERA, PermissionState.GRANTED)
            }
        }
        invoke.resolve(requestPermissionResponse)
    }

    @Command
    fun openAppSettings(invoke: Invoke) {
        val intent = Intent(
            Settings.ACTION_APPLICATION_DETAILS_SETTINGS,
            Uri.fromParts("package", activity.packageName, null)
        )
        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK)
        startActivityForResult(invoke, intent, "openSettingsResult")
    }

    @ActivityCallback
    private fun openSettingsResult(invoke: Invoke, result: ActivityResult) {
        invoke.resolve()
    }
}