Implement initial authentication flow

app/build.gradle

@@ -4,6 +4,7 @@ plugins {
     id 'com.android.application'
     id 'androidx.navigation.safeargs.kotlin'
     id 'dagger.hilt.android.plugin'
+    id 'org.jetbrains.kotlin.plugin.serialization'
 }
 
 android {

app/src/main/AndroidManifest.xml

@@ -2,6 +2,8 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
 	package="gq.kirmanak.mealie">
 
+	<uses-permission android:name="android.permission.INTERNET" />
+
 	<application
 		android:name=".MealieApp"
 		android:allowBackup="true"

app/src/main/java/gq/kirmanak/mealie/MealieApp.kt

@@ -0,0 +1,7 @@
+package gq.kirmanak.mealie
+
+import android.app.Application
+import dagger.hilt.android.HiltAndroidApp
+
+@HiltAndroidApp
+class MealieApp : Application()

app/src/main/java/gq/kirmanak/mealie/data/RetrofitBuilder.kt

@@ -0,0 +1,20 @@
+package gq.kirmanak.mealie.data
+
+import com.jakewharton.retrofit2.converter.kotlinx.serialization.asConverterFactory
+import kotlinx.serialization.ExperimentalSerializationApi
+import kotlinx.serialization.json.Json
+import okhttp3.MediaType
+import retrofit2.Retrofit
+import javax.inject.Inject
+
+@ExperimentalSerializationApi
+class RetrofitBuilder @Inject constructor() {
+    fun buildRetrofit(baseUrl: String): Retrofit {
+        val url = if (baseUrl.startsWith("http")) baseUrl else "https://$baseUrl"
+        val contentType = MediaType.get("application/json")
+        return Retrofit.Builder()
+            .baseUrl(url)
+            .addConverterFactory(Json.asConverterFactory(contentType))
+            .build()
+    }
+}

app/src/main/java/gq/kirmanak/mealie/data/auth/AuthDataSource.kt

@@ -0,0 +1,8 @@
+package gq.kirmanak.mealie.data.auth
+
+interface AuthDataSource {
+    /**
+     * Tries to acquire authentication token using the provided credentials on specified server.
+     */
+    suspend fun authenticate(username: String, password: String, baseUrl: String): Result<String>
+}

app/src/main/java/gq/kirmanak/mealie/data/auth/AuthDataSourceImpl.kt

@@ -0,0 +1,25 @@
+package gq.kirmanak.mealie.data.auth
+
+import gq.kirmanak.mealie.data.RetrofitBuilder
+import kotlinx.serialization.ExperimentalSerializationApi
+import retrofit2.create
+import javax.inject.Inject
+
+@ExperimentalSerializationApi
+class AuthDataSourceImpl @Inject constructor(
+    private val retrofitBuilder: RetrofitBuilder
+) : AuthDataSource {
+    override suspend fun authenticate(
+        username: String,
+        password: String,
+        baseUrl: String
+    ): Result<String> {
+        val authService = retrofitBuilder.buildRetrofit(baseUrl).create<AuthService>()
+        val response = try {
+            authService.getToken(username, password)
+        } catch (e: Exception) {
+            return Result.failure(e)
+        }
+        return Result.success(response.accessToken)
+    }
+}

app/src/main/java/gq/kirmanak/mealie/data/auth/AuthModule.kt

@@ -0,0 +1,21 @@
+package gq.kirmanak.mealie.data.auth
+
+import dagger.Binds
+import dagger.Module
+import dagger.hilt.InstallIn
+import dagger.hilt.android.components.ViewModelComponent
+import kotlinx.serialization.ExperimentalSerializationApi
+
+@ExperimentalSerializationApi
+@Module
+@InstallIn(ViewModelComponent::class)
+abstract class AuthModule {
+    @Binds
+    abstract fun bindAuthDataSource(authDataSourceImpl: AuthDataSourceImpl): AuthDataSource
+
+    @Binds
+    abstract fun bindAuthStorage(authStorageImpl: AuthStorageImpl): AuthStorage
+
+    @Binds
+    abstract fun bindAuthRepo(authRepo: AuthRepoImpl): AuthRepo
+}

app/src/main/java/gq/kirmanak/mealie/data/auth/AuthRepo.kt

@@ -0,0 +1,7 @@
+package gq.kirmanak.mealie.data.auth
+
+interface AuthRepo {
+    suspend fun isAuthenticated(): Boolean
+
+    suspend fun authenticate(username: String, password: String, baseUrl: String): Throwable?
+}

app/src/main/java/gq/kirmanak/mealie/data/auth/AuthRepoImpl.kt

@@ -0,0 +1,22 @@
+package gq.kirmanak.mealie.data.auth
+
+import javax.inject.Inject
+
+class AuthRepoImpl @Inject constructor(
+    private val dataSource: AuthDataSource,
+    private val storage: AuthStorage
+) : AuthRepo {
+    override suspend fun isAuthenticated(): Boolean = storage.isAuthenticated()
+
+    override suspend fun authenticate(
+        username: String,
+        password: String,
+        baseUrl: String
+    ): Throwable? {
+        val authResult = dataSource.authenticate(username, password, baseUrl)
+        if (authResult.isFailure) return authResult.exceptionOrNull()
+        val token = checkNotNull(authResult.getOrNull())
+        storage.storeToken(token)
+        return null
+    }
+}

app/src/main/java/gq/kirmanak/mealie/data/auth/AuthService.kt

@@ -0,0 +1,18 @@
+package gq.kirmanak.mealie.data.auth
+
+import retrofit2.http.Field
+import retrofit2.http.FormUrlEncoded
+import retrofit2.http.POST
+
+interface AuthService {
+    @FormUrlEncoded
+    @POST("/api/auth/token")
+    suspend fun getToken(
+        @Field("username") username: String,
+        @Field("password") password: String,
+        @Field("grant_type") grantType: String? = null,
+        @Field("scope") scope: String? = null,
+        @Field("client_id") clientId: String? = null,
+        @Field("client_secret") clientSecret: String? = null
+    ): GetTokenResponse
+}

app/src/main/java/gq/kirmanak/mealie/data/auth/AuthStorage.kt

@@ -0,0 +1,6 @@
+package gq.kirmanak.mealie.data.auth
+
+interface AuthStorage {
+    suspend fun isAuthenticated(): Boolean
+    suspend fun storeToken(token: String)
+}

app/src/main/java/gq/kirmanak/mealie/data/auth/AuthStorageImpl.kt

@@ -0,0 +1,24 @@
+package gq.kirmanak.mealie.data.auth
+
+import android.content.Context
+import android.content.SharedPreferences
+import androidx.preference.PreferenceManager
+import dagger.hilt.android.qualifiers.ApplicationContext
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+import javax.inject.Inject
+
+private const val TOKEN_KEY = "AUTH_TOKEN"
+
+class AuthStorageImpl @Inject constructor(@ApplicationContext private val context: Context) : AuthStorage {
+    private val sharedPreferences: SharedPreferences
+        get() = PreferenceManager.getDefaultSharedPreferences(context)
+
+    override suspend fun isAuthenticated(): Boolean = withContext(Dispatchers.IO) {
+        sharedPreferences.getString(TOKEN_KEY, null) != null
+    }
+
+    override suspend fun storeToken(token: String) {
+        sharedPreferences.edit().putString(TOKEN_KEY, token).apply()
+    }
+}

app/src/main/java/gq/kirmanak/mealie/data/auth/GetTokenResponse.kt

@@ -0,0 +1,10 @@
+package gq.kirmanak.mealie.data.auth
+
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class GetTokenResponse(
+    @SerialName("access_token") val accessToken: String,
+    @SerialName("token_type") val tokenType: String
+)

app/src/main/java/gq/kirmanak/mealie/ui/auth/AuthenticationFragment.kt

@@ -1,18 +1,32 @@
 package gq.kirmanak.mealie.ui.auth
 
 import android.os.Bundle
+import android.util.Log
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
+import android.widget.EditText
+import android.widget.Toast
 import androidx.fragment.app.Fragment
+import androidx.fragment.app.viewModels
+import androidx.lifecycle.lifecycleScope
+import com.google.android.material.textfield.TextInputLayout
 import dagger.hilt.android.AndroidEntryPoint
 import gq.kirmanak.mealie.databinding.FragmentAuthenticationBinding
 
+private const val TAG = "AuthenticationFragment"
+
 @AndroidEntryPoint
 class AuthenticationFragment : Fragment() {
     private var _binding: FragmentAuthenticationBinding? = null
     private val binding: FragmentAuthenticationBinding
         get() = checkNotNull(_binding) { "Binding requested when fragment is off screen" }
+    private val viewModel by viewModels<AuthenticationViewModel>()
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        checkIfAuthenticatedAlready()
+    }
 
     override fun onCreateView(
         inflater: LayoutInflater,
@@ -23,6 +37,63 @@ class AuthenticationFragment : Fragment() {
         return binding.root
     }
 
+    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
+        super.onViewCreated(view, savedInstanceState)
+        binding.button.setOnClickListener {
+            onLoginClicked()
+        }
+    }
+
+    private fun checkIfAuthenticatedAlready() {
+        lifecycleScope.launchWhenCreated {
+            Toast.makeText(
+                requireContext(),
+                if (viewModel.isAuthenticated()) "User is authenticated"
+                else "User isn't authenticated",
+                Toast.LENGTH_SHORT
+            ).show()
+        }
+    }
+
+    private fun onLoginClicked() {
+        val email: String
+        val pass: String
+        val url: String
+        with(binding) {
+            email = checkIfInputIsEmpty(emailInput, emailInputLayout) {
+                "Email is empty"
+            } ?: return
+            pass = checkIfInputIsEmpty(passwordInput, passwordInputLayout) {
+                "Pass is empty"
+            } ?: return
+            url = checkIfInputIsEmpty(urlInput, urlInputLayout) {
+                "URL is empty"
+            } ?: return
+        }
+        lifecycleScope.launchWhenResumed {
+            val exception = viewModel.authenticate(email, pass, url)
+            Log.e(TAG, "onLoginClicked: ", exception)
+            Toast.makeText(
+                requireContext(),
+                "Exception is ${exception?.message ?: "null"}",
+                Toast.LENGTH_SHORT
+            ).show()
+        }
+    }
+
+    private fun checkIfInputIsEmpty(
+        input: EditText,
+        inputLayout: TextInputLayout,
+        errorText: () -> String
+    ): String? {
+        val text = input.text?.toString()
+        if (text.isNullOrBlank()) {
+            inputLayout.error = errorText()
+            return null
+        }
+        return text
+    }
+
     override fun onDestroyView() {
         super.onDestroyView()
         _binding = null

app/src/main/java/gq/kirmanak/mealie/ui/auth/AuthenticationViewModel.kt

@@ -0,0 +1,17 @@
+package gq.kirmanak.mealie.ui.auth
+
+import androidx.lifecycle.ViewModel
+import dagger.hilt.android.lifecycle.HiltViewModel
+import gq.kirmanak.mealie.data.auth.AuthRepo
+import javax.inject.Inject
+
+@HiltViewModel
+class AuthenticationViewModel @Inject constructor(
+    private val authRepo: AuthRepo
+) : ViewModel() {
+    suspend fun isAuthenticated(): Boolean = authRepo.isAuthenticated()
+
+    suspend fun authenticate(username: String, password: String, baseUrl: String): Throwable? {
+        return authRepo.authenticate(username, password, baseUrl)
+    }
+}

app/src/main/res/layout/fragment_authentication.xml

@@ -6,15 +6,64 @@
 	android:layout_height="match_parent"
 	tools:context=".ui.auth.AuthenticationFragment">
 
-	<!-- TODO implement correct authentication screen -->
-	<TextView
-		android:id="@+id/textView"
+	<com.google.android.material.textfield.TextInputLayout
+		android:id="@+id/email_input_layout"
 		android:layout_width="0dp"
-		android:layout_height="0dp"
-		android:gravity="center"
-		android:text="@string/app_name"
+		android:layout_height="wrap_content"
+		app:layout_constraintBottom_toTopOf="@+id/password_input_layout"
+		app:layout_constraintEnd_toEndOf="parent"
+		app:layout_constraintStart_toStartOf="parent"
+		app:layout_constraintTop_toTopOf="parent">
+
+		<com.google.android.material.textfield.TextInputEditText
+			android:id="@+id/email_input"
+			android:layout_width="match_parent"
+			android:layout_height="wrap_content"
+			android:hint="@string/fragment_authentication_input_hint_email"
+			android:inputType="textEmailAddress" />
+	</com.google.android.material.textfield.TextInputLayout>
+
+	<com.google.android.material.textfield.TextInputLayout
+		android:id="@+id/password_input_layout"
+		android:layout_width="0dp"
+		android:layout_height="wrap_content"
+		app:layout_constraintBottom_toTopOf="@+id/url_input_layout"
+		app:layout_constraintEnd_toEndOf="parent"
+		app:layout_constraintStart_toStartOf="parent"
+		app:layout_constraintTop_toBottomOf="@+id/email_input_layout">
+
+		<com.google.android.material.textfield.TextInputEditText
+			android:id="@+id/password_input"
+			android:layout_width="match_parent"
+			android:layout_height="wrap_content"
+			android:hint="@string/fragment_authentication_input_hint_password"
+			android:inputType="textPassword" />
+	</com.google.android.material.textfield.TextInputLayout>
+
+	<com.google.android.material.textfield.TextInputLayout
+		android:id="@+id/url_input_layout"
+		android:layout_width="0dp"
+		android:layout_height="wrap_content"
+		app:layout_constraintBottom_toTopOf="@+id/button"
+		app:layout_constraintEnd_toEndOf="parent"
+		app:layout_constraintStart_toStartOf="parent"
+		app:layout_constraintTop_toBottomOf="@+id/password_input_layout">
+
+		<com.google.android.material.textfield.TextInputEditText
+			android:id="@+id/url_input"
+			android:layout_width="match_parent"
+			android:layout_height="wrap_content"
+			android:hint="@string/fragment_authnetication_input_hint_url"
+			android:inputType="textUri" />
+	</com.google.android.material.textfield.TextInputLayout>
+
+	<Button
+		android:id="@+id/button"
+		android:layout_width="wrap_content"
+		android:layout_height="wrap_content"
+		android:text="@string/fragment_authentication_button_login"
 		app:layout_constraintBottom_toBottomOf="parent"
 		app:layout_constraintEnd_toEndOf="parent"
 		app:layout_constraintStart_toStartOf="parent"
-		app:layout_constraintTop_toTopOf="parent" />
+		app:layout_constraintTop_toBottomOf="@+id/url_input_layout" />
 </androidx.constraintlayout.widget.ConstraintLayout>

app/src/main/res/values/strings.xml

@@ -1,3 +1,7 @@
 <resources>
 	<string name="app_name">Mealie</string>
+	<string name="fragment_authentication_input_hint_email">E-mail</string>
+	<string name="fragment_authentication_input_hint_password">Password</string>
+	<string name="fragment_authnetication_input_hint_url">Url</string>
+	<string name="fragment_authentication_button_login">Login</string>
 </resources>

build.gradle

@@ -2,13 +2,15 @@
 buildscript {
     ext.nav_version = "2.3.5"
     ext.hilt_version = "2.38.1"
+    ext.kotlin_version = "1.5.31"
     repositories {
         google()
         mavenCentral()
     }
     dependencies {
         classpath "com.android.tools.build:gradle:7.0.3"
-        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:1.5.31"
+        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
+        classpath "org.jetbrains.kotlin:kotlin-serialization:$kotlin_version"
         classpath "androidx.navigation:navigation-safe-args-gradle-plugin:$nav_version"
         classpath "com.google.dagger:hilt-android-gradle-plugin:$hilt_version"