code cleanup and refactor

app/src/main/java/dgca/wallet/app/android/DgcaWalletApplication.kt

@@ -23,12 +23,12 @@
 package dgca.wallet.app.android
 
 import android.app.Application
-import dagger.hilt.android.AndroidEntryPoint
 import dagger.hilt.android.HiltAndroidApp
 import timber.log.Timber
 
 @HiltAndroidApp
 class DgcaWalletApplication : Application() {
+
     override fun onCreate() {
         super.onCreate()
         if (BuildConfig.DEBUG) {

app/src/main/java/dgca/wallet/app/android/Event.kt

@@ -19,9 +19,4 @@ open class Event<out T>(private val content: T) {
             content
         }
     }
-
-    /**
-     * Returns the content, even if it's already been handled.
-     */
-    fun peekContent(): T = content
 }

app/src/main/java/dgca/wallet/app/android/MainActivity.kt

@@ -64,11 +64,11 @@ class MainActivity : AppCompatActivity() {
     override fun onOptionsItemSelected(item: MenuItem): Boolean {
         val navHostFragment = supportFragmentManager.findFragmentById(R.id.nav_host_fragment) as NavHostFragment
         val navController = navHostFragment.navController
-        if (item.itemId == R.id.settings) {
+        return if (item.itemId == R.id.settings) {
             navController.navigate(R.id.settingsFragment)
-            return true
+            true
         } else {
-            return navController.navigateUp()
+            navController.navigateUp()
         }
     }
 

app/src/main/java/dgca/wallet/app/android/certificate/claim/ClaimCertificateFragment.kt

@@ -37,7 +37,6 @@ import dagger.hilt.android.AndroidEntryPoint
 import dgca.wallet.app.android.FORMATTED_YEAR_MONTH_DAY
 import dgca.wallet.app.android.R
 import dgca.wallet.app.android.YEAR_MONTH_DAY
-import dgca.wallet.app.android.data.CertificateData
 import dgca.wallet.app.android.data.CertificateModel
 import dgca.wallet.app.android.data.getCertificateListData
 import dgca.wallet.app.android.databinding.FragmentCertificateClaimBinding
@@ -93,21 +92,25 @@ class ClaimCertificateFragment : Fragment() {
         binding.personFullName.text =
             getString(R.string.person_full_name_placeholder, certificate.person.givenName, certificate.person.familyName)
         binding.personStandardisedFamilyName.text = certificate.person.standardisedFamilyName
+        binding.personStandardisedFamilyNameTitle.isVisible = true
         binding.personStandardisedGivenName.text = certificate.person.standardisedGivenName
+        binding.personStandardisedGivenNameTitle.isVisible = true
         binding.dateOfBirth.text = certificate.dateOfBirth.parseFromTo(YEAR_MONTH_DAY, FORMATTED_YEAR_MONTH_DAY)
+        binding.dateOfBirthTitle.isVisible = true
     }
 
     private fun onViewModelEvent(event: ClaimCertificateViewModel.ClaimCertEvent) {
         when (event) {
             is ClaimCertificateViewModel.ClaimCertEvent.OnCertClaimed -> {
-                if (event.result) {
+                if (event.isClaimed) {
                     Toast.makeText(requireContext(), "Certificate claimed", Toast.LENGTH_SHORT).show()
                     val action = ClaimCertificateFragmentDirections.actionClaimCertificateFragmentToCertificatesFragment()
                     findNavController().navigate(action)
-                } else {
-                    Toast.makeText(requireContext(), "Certificate not claimed", Toast.LENGTH_SHORT).show()
                 }
             }
+            is ClaimCertificateViewModel.ClaimCertEvent.OnCertNotClaimed -> {
+                Toast.makeText(requireContext(), event.error, Toast.LENGTH_SHORT).show()
+            }
         }
     }
 }

app/src/main/java/dgca/wallet/app/android/certificate/claim/ClaimCertificateViewModel.kt

@@ -40,6 +40,8 @@ import dgca.wallet.app.android.Event
 import dgca.wallet.app.android.data.CertificateModel
 import dgca.wallet.app.android.data.WalletRepository
 import dgca.wallet.app.android.data.local.toCertificateModel
+import dgca.wallet.app.android.data.remote.ApiResult
+import dgca.wallet.app.android.data.remote.ClaimResponse
 import dgca.wallet.app.android.model.ClaimRequest
 import dgca.wallet.app.android.model.PublicKeyData
 import kotlinx.coroutines.Dispatchers
@@ -99,7 +101,7 @@ class ClaimCertificateViewModel @Inject constructor(
     fun save(qrCode: String, tan: String) {
         viewModelScope.launch {
             _inProgress.value = true
-            var result = false
+            var claimResult: ApiResult<ClaimResponse>? = null
 
             withContext(Dispatchers.IO) {
                 if (greenCertificate == null || cose.isEmpty()) {
@@ -134,18 +136,16 @@ class ClaimCertificateViewModel @Inject constructor(
                     signature
                 )
 
-//                TODO: handle response
-                result = walletRepository.claimCertificate(qrCode, request)
-                if (result) {
-
-                }
+                claimResult = walletRepository.claimCertificate(qrCode, request)
             }
             _inProgress.value = false
-            _event.value = Event(ClaimCertEvent.OnCertClaimed(result))
+            claimResult?.success?.let { _event.value = Event(ClaimCertEvent.OnCertClaimed(true)) }
+            claimResult?.error?.let { _event.value = Event(ClaimCertEvent.OnCertNotClaimed(it.details)) }
         }
     }
 
     sealed class ClaimCertEvent {
-        data class OnCertClaimed(val result: Boolean) : ClaimCertEvent()
+        data class OnCertClaimed(val isClaimed: Boolean) : ClaimCertEvent()
+        data class OnCertNotClaimed(val error: String) : ClaimCertEvent()
     }
 }

app/src/main/java/dgca/wallet/app/android/certificate/claim/TanFragment.kt

@@ -30,6 +30,7 @@ import androidx.fragment.app.Fragment
 import androidx.navigation.fragment.findNavController
 import androidx.navigation.fragment.navArgs
 import dagger.hilt.android.AndroidEntryPoint
+import dgca.wallet.app.android.R
 import dgca.wallet.app.android.databinding.FragmentCertificateTanBinding
 
 @AndroidEntryPoint
@@ -48,8 +49,12 @@ class TanFragment : Fragment() {
         super.onViewCreated(view, savedInstanceState)
         binding.nextBtn.setOnClickListener {
             val tan = binding.tanTextField.editText?.text.toString()
-            val action = TanFragmentDirections.actionTanFragmentToClaimCertificateFragment(args.qrCodeText, tan)
-            findNavController().navigate(action)
+            if (tan.isEmpty()) {
+                binding.tanTextField.error = getString(R.string.tan_empty_error)
+            } else {
+                val action = TanFragmentDirections.actionTanFragmentToClaimCertificateFragment(args.qrCodeText, tan)
+                findNavController().navigate(action)
+            }
         }
     }
 

app/src/main/java/dgca/wallet/app/android/certificate/view/ViewCertificateFragment.kt

@@ -93,10 +93,14 @@ class ViewCertificateFragment : Fragment() {
     }
 
     private fun showUserData(certificate: CertificateModel) {
+        binding.nameTitle.isVisible = true
         binding.personFullName.text =
             getString(R.string.person_full_name_placeholder, certificate.person.givenName, certificate.person.familyName)
         binding.personStandardisedFamilyName.text = certificate.person.standardisedFamilyName
+        binding.personStandardisedFamilyNameTitle.isVisible = true
         binding.personStandardisedGivenName.text = certificate.person.standardisedGivenName
+        binding.personStandardisedGivenNameTitle.isVisible = true
         binding.dateOfBirth.text = certificate.dateOfBirth.parseFromTo(YEAR_MONTH_DAY, FORMATTED_YEAR_MONTH_DAY)
+        binding.dateOfBirthTitle.isVisible = true
     }
 }

app/src/main/java/dgca/wallet/app/android/data/BaseRepository.kt

@@ -22,34 +22,69 @@
 
 package dgca.wallet.app.android.data
 
+import dgca.wallet.app.android.data.remote.ApiResult
+import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.withContext
-import okhttp3.ResponseBody
+import retrofit2.Response
 import timber.log.Timber
 import java.net.SocketTimeoutException
 import java.net.UnknownHostException
+import kotlin.coroutines.CoroutineContext
 
 abstract class BaseRepository : Repository {
 
     suspend fun <P> execute(doOnAsyncBlock: suspend () -> P): P? {
         return withContext(Dispatchers.IO) {
             return@withContext try {
-                Timber.d("Do network coroutine work")
                 doOnAsyncBlock.invoke()
+            } catch (throwable: Throwable) {
+                Timber.w(throwable, "Throwable")
+                null
+            }
+        }
+    }
+
+    suspend fun <P> doApiBackgroundWork(doOnAsyncBlock: suspend CoroutineScope.() -> Response<P>): ApiResult<P> =
+        doCoroutineWork(doOnAsyncBlock, Dispatchers.IO)
+
+    private suspend inline fun <P> doCoroutineWork(
+        crossinline doOnAsyncBlock: suspend CoroutineScope.() -> Response<P>,
+        context: CoroutineContext
+    ): ApiResult<P> {
+        var error: ApiResult<P>? = null
+        val response = withContext(context) {
+            return@withContext try {
+                Timber.v("Do network coroutine work")
+                doOnAsyncBlock.invoke(this)
             } catch (e: UnknownHostException) {
                 Timber.w(e, "UnknownHostException")
+                error = ApiResult.error(
+                    error = e.toString(),
+                    errorDescription = "Server is unreachable. Please, check network connection."
+                )
                 null
             } catch (e: SocketTimeoutException) {
                 Timber.w(e, "SocketTimeoutException")
+                error = ApiResult.error(
+                    error = e.toString(),
+                    errorDescription = "No internet connection"
+                )
                 null
             } catch (throwable: Throwable) {
                 Timber.w(throwable, "Throwable")
+                error = ApiResult.error(
+                    error = throwable.toString(),
+                    errorDescription = "Unknown exception. Please, try again."
+                )
                 null
             }
         }
-    }
-}
 
-@Suppress("BlockingMethodInNonBlockingContext")
-suspend fun ResponseBody.stringSuspending() =
-    withContext(Dispatchers.IO) { string() }
+        return if (error != null) {
+            error!!
+        } else {
+            ApiResult(response)
+        }
+    }
+}

app/src/main/java/dgca/wallet/app/android/data/WalletRepository.kt

@@ -23,11 +23,13 @@
 package dgca.wallet.app.android.data
 
 import dgca.wallet.app.android.certificate.CertificateCard
+import dgca.wallet.app.android.data.remote.ApiResult
+import dgca.wallet.app.android.data.remote.ClaimResponse
 import dgca.wallet.app.android.model.ClaimRequest
 
 interface WalletRepository {
 
-    suspend fun claimCertificate(qrCode: String, request: ClaimRequest): Boolean
+    suspend fun claimCertificate(qrCode: String, request: ClaimRequest): ApiResult<ClaimResponse>
 
     suspend fun getCertificates(): List<CertificateCard>?
 

app/src/main/java/dgca/wallet/app/android/data/WalletRepositoryImpl.kt

@@ -28,7 +28,9 @@ import dgca.wallet.app.android.certificate.CertificateCard
 import dgca.wallet.app.android.data.local.CertificateDao
 import dgca.wallet.app.android.data.local.CertificateEntity
 import dgca.wallet.app.android.data.local.toCertificateModel
+import dgca.wallet.app.android.data.remote.ApiResult
 import dgca.wallet.app.android.data.remote.ApiService
+import dgca.wallet.app.android.data.remote.ClaimResponse
 import dgca.wallet.app.android.model.ClaimRequest
 import dgca.wallet.app.android.security.KeyStoreCryptor
 import javax.inject.Inject
@@ -40,33 +42,23 @@ class WalletRepositoryImpl @Inject constructor(
     private val certificateDecoder: CertificateDecoder
 ) : BaseRepository(), WalletRepository {
 
-
-    override suspend fun claimCertificate(qrCode: String, request: ClaimRequest): Boolean {
-        return execute {
-            val response = apiService.claimCertificate(request)
-            if (response.isSuccessful) {
-                val tan = response.body()?.tan ?: ""
+    override suspend fun claimCertificate(qrCode: String, request: ClaimRequest): ApiResult<ClaimResponse> {
+        return doApiBackgroundWork { apiService.claimCertificate(request) }.also { result ->
+            result.success?.let {
+                val tan = result.rawResponse?.body()?.tan ?: ""
                 val codeEncrypted = keyStoreCryptor.encrypt(qrCode)
                 val tanEncrypted = keyStoreCryptor.encrypt(tan)
 
-                if (codeEncrypted == null || tanEncrypted == null) {
-                    return@execute false
-                }
-
-                val result = certificateDao.insert(
-                    CertificateEntity(
-                        qrCodeText = codeEncrypted,
-                        tan = tanEncrypted
+                if (codeEncrypted != null && tanEncrypted != null) {
+                    certificateDao.insert(
+                        CertificateEntity(
+                            qrCodeText = codeEncrypted,
+                            tan = tanEncrypted
+                        )
                     )
-                )
-
-                if (result != -1L) {
-                    return@execute true
                 }
             }
-
-            return@execute false
-        } == true
+        }
     }
 
     override suspend fun getCertificates(): List<CertificateCard>? {

app/src/main/java/dgca/wallet/app/android/data/remote/ApiResult.kt

@@ -0,0 +1,80 @@
+/*
+ *  ---license-start
+ *  eu-digital-green-certificates / dgca-verifier-app-android
+ *  ---
+ *  Copyright (C) 2021 T-Systems International GmbH and all other contributors
+ *  ---
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *  ---license-end
+ *
+ *  Created by mykhailo.nester on 5/14/21 2:03 PM
+ */
+
+package dgca.wallet.app.android.data.remote
+
+import com.google.gson.Gson
+import okhttp3.ResponseBody
+import retrofit2.Response
+
+class ApiResult<T>(response: Response<T>? = null) {
+
+    var success: T? = response?.body()
+    var error: CommonError? = response?.errorBody().parseError(response)
+    var rawResponse: Response<T>? = response
+
+    companion object {
+
+        fun <T> error(
+            error: String = "Unknown",
+            errorDescription: String = "Unknown exception."
+        ): ApiResult<T> {
+            val result = ApiResult<T>()
+            result.error =
+                CommonError(problem = error, details = errorDescription)
+            return result
+        }
+    }
+
+    private fun ResponseBody?.parseError(response: Response<T>?): CommonError? {
+        var error: CommonError? =
+            try {
+                var responseError: CommonError?
+                this?.charStream().use { reader ->
+                    val json = reader?.readText()
+                    val result: CommonError? = Gson().fromJson(json, CommonError::class.java)
+
+                    responseError = if (result != null && result.details.isEmpty()) {
+                        null
+                    } else {
+                        result
+                    }
+                }
+                responseError
+            } catch (e: Exception) {
+                null
+            }
+
+        if (this != null && error == null) {
+            error = CommonError(problem = "unknown", details = response?.message() ?: "")
+        }
+
+        return error
+    }
+}
+
+data class CommonError(
+    val problem: String,
+    val details: String,
+    val code: String = "",
+    val sendValue: String = ""
+)

app/src/main/java/dgca/wallet/app/android/security/SecurityKeyWrapper.kt

@@ -72,7 +72,7 @@ class SecurityKeyWrapper(private val keyPair: KeyPair) {
             var counter = 0
             val originalSum = ByteArray(chunksAmount * BLOCK_SIZE) { EMPTY_BYTE }
             for (i in 0 until chunksAmount) {
-                val chunk: ByteArray = ByteArray(OUTPUT_BLOCK_SIZE)
+                val chunk = ByteArray(OUTPUT_BLOCK_SIZE)
                 for (j in 0 until OUTPUT_BLOCK_SIZE) {
                     chunk[j] = decoded[i * OUTPUT_BLOCK_SIZE + j]
                 }