[WIP] Setting up Kodein, implementing Google sign in

There's still a lot of work to do here. Maybe would be good to break
things here in smaller commits? (the first feature is always a bit
problematic on its commits size)

app/build.gradle

@@ -1,5 +1,7 @@
 apply plugin: 'com.android.application'
 apply plugin: 'org.jetbrains.kotlin.android'
+apply plugin: 'org.jetbrains.kotlin.kapt'
+apply plugin: 'com.getkeepsafe.dexcount'
 
 apply from: "$rootDir/gradle/coverage.gradle"
 
@@ -13,6 +15,8 @@ android {
         versionCode 1
         versionName '1.0'
 
+        vectorDrawables.useSupportLibrary = true
+
         testInstrumentationRunner 'android.support.test.runner.AndroidJUnitRunner'
     }
 
@@ -22,6 +26,8 @@ android {
         androidTest.java.srcDirs += 'src/androidTest/kotlin'
     }
 
+    dataBinding.enabled true
+
     signingConfigs {
         debug {
             storeFile file("$rootDir/distribution/debug.keystore")
@@ -40,13 +46,17 @@ android {
 
     buildTypes {
         debug {
+            buildConfigField 'String', 'GOOGLE_REQUEST_ID_TOKEN', "\"$System.env.GOOGLE_REQUEST_ID_TOKEN_DEVELOPMENT\""
+
             testCoverageEnabled true
 
             applicationIdSuffix '.dev'
             signingConfig signingConfigs.debug
         }
 
         release {
+            buildConfigField 'String', 'GOOGLE_REQUEST_ID_TOKEN', "\"$System.env.GOOGLE_REQUEST_ID_TOKEN_RELEASE\""
+
             signingConfig signingConfigs.release
             minifyEnabled false
             proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
@@ -58,12 +68,31 @@ android {
     }
 }
 
+kotlin {
+    experimental {
+        coroutines 'enable'
+    }
+}
+
 dependencies {
     implementation "com.android.support:appcompat-v7:$versions.supportLibrary"
+    implementation "com.android.support:design:$versions.supportLibrary"
+
+    implementation 'androidx.constraintlayout:constraintlayout:1.1.0'
+
+    implementation "android.arch.lifecycle:extensions:$versions.arch"
+    kapt "android.arch.lifecycle:compiler:$versions.arch"
 
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$versions.kotlin"
+    implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-core:0.22.5'
 
     implementation "com.google.firebase:firebase-core:$versions.googleServices"
+    implementation "com.google.firebase:firebase-auth:$versions.googleServices"
+
+    implementation "com.google.android.gms:play-services-auth:$versions.googleServices"
+
+    implementation "org.kodein.di:kodein-di-generic-jvm:$versions.kodein"
+    implementation "org.kodein.di:kodein-di-framework-android:$versions.kodein"
 
     testImplementation 'junit:junit:4.12'
     testImplementation 'org.robolectric:robolectric:3.8'

app/src/main/AndroidManifest.xml

@@ -3,19 +3,23 @@
     package="net.rafaeltoledo.social">
 
     <application
+        android:name=".SocialApp"
         android:allowBackup="false"
         android:icon="@mipmap/ic_launcher"
         android:label="@string/app_name"
         android:roundIcon="@mipmap/ic_launcher_round"
         android:supportsRtl="true"
         android:theme="@style/AppTheme"
         tools:ignore="GoogleAppIndexingWarning">
-        <activity android:name=".MainActivity">
+
+        <activity android:name=".ui.feature.main.MainActivity">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
 
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
+
+        <activity android:name=".ui.feature.signin.SignInActivity" />
     </application>
 </manifest>

app/src/main/kotlin/net/rafaeltoledo/social/SocialApp.kt

@@ -0,0 +1,21 @@
+package net.rafaeltoledo.social
+
+import android.app.Application
+import net.rafaeltoledo.social.di.authModule
+import net.rafaeltoledo.social.di.firebaseModule
+import net.rafaeltoledo.social.di.viewModelModule
+import org.kodein.di.Kodein
+import org.kodein.di.KodeinAware
+import org.kodein.di.android.androidModule
+
+open class SocialApp : Application(), KodeinAware {
+
+    override val kodein = initKodein()
+
+    private fun initKodein() = Kodein.lazy {
+        import(androidModule(this@SocialApp))
+        import(firebaseModule)
+        import(authModule)
+        import(viewModelModule)
+    }
+}

app/src/main/kotlin/net/rafaeltoledo/social/data/Models.kt

@@ -0,0 +1,3 @@
+package net.rafaeltoledo.social.data
+
+data class User(val id: String)

app/src/main/kotlin/net/rafaeltoledo/social/data/auth/AuthManager.kt

@@ -0,0 +1,11 @@
+package net.rafaeltoledo.social.data.auth
+
+import kotlinx.coroutines.experimental.Deferred
+import net.rafaeltoledo.social.data.User
+
+interface AuthManager {
+
+    fun googleSignIn(token: String): Deferred<User>
+
+    fun isUserLoggedIn(): Boolean
+}

app/src/main/kotlin/net/rafaeltoledo/social/data/auth/DelegatedAuth.kt

@@ -0,0 +1,19 @@
+package net.rafaeltoledo.social.data.auth
+
+import android.app.Activity
+import android.content.Intent
+
+interface DelegatedAuth {
+
+    fun <T : DelegatedAuth> build(activity: Activity): T
+
+    fun signIn(activity: Activity)
+
+    fun onResult(requestCode: Int, resultCode: Int, data: Intent?): AuthResult
+
+    fun signOut(callback: (Status) -> Unit)
+}
+
+enum class Status { CANCELED, SUCCESS, FAILURE }
+
+data class AuthResult(val status: Status, val token: String? = null)

app/src/main/kotlin/net/rafaeltoledo/social/data/auth/GoogleAuth.kt

@@ -0,0 +1,51 @@
+package net.rafaeltoledo.social.data.auth
+
+import android.app.Activity
+import android.content.Intent
+import com.google.android.gms.auth.api.signin.GoogleSignIn
+import com.google.android.gms.auth.api.signin.GoogleSignInClient
+import com.google.android.gms.auth.api.signin.GoogleSignInOptions
+import com.google.android.gms.common.api.ApiException
+import net.rafaeltoledo.social.BuildConfig
+
+class GoogleAuth : DelegatedAuth {
+
+    private var client: GoogleSignInClient? = null
+
+    override fun <T : DelegatedAuth> build(activity: Activity): T {
+        if (client != null) {
+            @Suppress("UNCHECKED_CAST") return this as T
+        }
+
+        val options = GoogleSignInOptions.Builder()
+                .requestIdToken(BuildConfig.GOOGLE_REQUEST_ID_TOKEN)
+                .requestEmail()
+                .build()
+
+        client = GoogleSignIn.getClient(activity, options)
+
+        @Suppress("UNCHECKED_CAST") return this as T
+    }
+
+    override fun signIn(activity: Activity) {
+        activity.startActivityForResult(client?.signInIntent, RESULT_SIGN_IN)
+    }
+
+    override fun onResult(requestCode: Int, resultCode: Int, data: Intent?): AuthResult {
+        val task = GoogleSignIn.getSignedInAccountFromIntent(data)
+        try {
+            val account = task.getResult(ApiException::class.java)
+            return AuthResult(Status.SUCCESS, account.idToken)
+        } catch (e: ApiException) {
+            return AuthResult(Status.FAILURE)
+        }
+    }
+
+    override fun signOut(callback: (Status) -> Unit) {
+        client?.signOut()?.addOnCompleteListener { callback.invoke(if (it.isSuccessful) Status.SUCCESS else Status.FAILURE) }
+    }
+
+    companion object {
+        const val RESULT_SIGN_IN = 1441
+    }
+}

app/src/main/kotlin/net/rafaeltoledo/social/data/firebase/FirebaseAuthManager.kt

@@ -0,0 +1,30 @@
+package net.rafaeltoledo.social.data.firebase
+
+import com.google.firebase.auth.FirebaseAuth
+import com.google.firebase.auth.GoogleAuthProvider
+import kotlinx.coroutines.experimental.CompletableDeferred
+import kotlinx.coroutines.experimental.Deferred
+import net.rafaeltoledo.social.data.User
+import net.rafaeltoledo.social.data.auth.AuthManager
+
+class FirebaseAuthManager : AuthManager {
+
+    private val auth = FirebaseAuth.getInstance()
+
+    override fun googleSignIn(token: String): Deferred<User> {
+        val deferred = CompletableDeferred<User>()
+
+        auth.signInWithCredential(GoogleAuthProvider.getCredential(token, null))
+                .addOnCompleteListener {
+                    if (it.isSuccessful) {
+                        deferred.complete(User(it.result.user.uid))
+                    } else {
+                        deferred.completeExceptionally(it.exception!!)
+                    }
+                }
+
+        return deferred
+    }
+
+    override fun isUserLoggedIn() = auth.currentUser != null
+}

app/src/main/kotlin/net/rafaeltoledo/social/di/AuthModule.kt

@@ -0,0 +1,12 @@
+package net.rafaeltoledo.social.di
+
+import net.rafaeltoledo.social.data.auth.DelegatedAuth
+import net.rafaeltoledo.social.data.auth.GoogleAuth
+import org.kodein.di.Kodein
+import org.kodein.di.generic.bind
+import org.kodein.di.generic.instance
+
+val authModule = Kodein.Module {
+
+    bind<DelegatedAuth>() with instance(GoogleAuth())
+}

app/src/main/kotlin/net/rafaeltoledo/social/di/FirebaseModule.kt

@@ -0,0 +1,12 @@
+package net.rafaeltoledo.social.di
+
+import net.rafaeltoledo.social.data.auth.AuthManager
+import net.rafaeltoledo.social.data.firebase.FirebaseAuthManager
+import org.kodein.di.Kodein
+import org.kodein.di.generic.bind
+import org.kodein.di.generic.singleton
+
+val firebaseModule = Kodein.Module {
+
+    bind<AuthManager>() with singleton { FirebaseAuthManager() }
+}

app/src/main/kotlin/net/rafaeltoledo/social/di/ViewModelModule.kt

@@ -0,0 +1,26 @@
+package net.rafaeltoledo.social.di
+
+import android.arch.lifecycle.ViewModel
+import android.arch.lifecycle.ViewModelProvider
+import net.rafaeltoledo.social.ui.BaseViewModel
+import org.kodein.di.Kodein
+import org.kodein.di.generic.bind
+import org.kodein.di.generic.singleton
+
+val viewModelModule = Kodein.Module {
+
+    bind<ViewModelProvider.Factory>() with singleton {
+        object : ViewModelProvider.Factory {
+            override fun <T : ViewModel?> create(modelClass: Class<T>): T {
+
+                val newInstance = modelClass.newInstance()
+
+                if (BaseViewModel::class.java.isInstance(newInstance)) {
+                    (newInstance as BaseViewModel).whenReady(kodein)
+                }
+
+                return newInstance
+            }
+        }
+    }
+}

app/src/main/kotlin/net/rafaeltoledo/social/ui/BaseActivity.kt

@@ -0,0 +1,21 @@
+package net.rafaeltoledo.social.ui
+
+import android.arch.lifecycle.ViewModel
+import android.arch.lifecycle.ViewModelProvider
+import android.arch.lifecycle.ViewModelProviders
+import android.support.v7.app.AppCompatActivity
+import org.kodein.di.KodeinAware
+import org.kodein.di.android.closestKodein
+import org.kodein.di.generic.instance
+import kotlin.reflect.KClass
+
+abstract class BaseActivity : AppCompatActivity(), KodeinAware {
+
+    override val kodein by closestKodein()
+
+    private val viewModelFactory: ViewModelProvider.Factory by instance()
+
+    protected fun <T : ViewModel> getViewModelInstance(kClass: KClass<T>) =
+            ViewModelProviders.of(this, viewModelFactory)
+                    .get(kClass.java)
+}

app/src/main/kotlin/net/rafaeltoledo/social/ui/BaseViewModel.kt

@@ -0,0 +1,21 @@
+package net.rafaeltoledo.social.ui
+
+import android.arch.lifecycle.MutableLiveData
+import android.arch.lifecycle.ViewModel
+import org.kodein.di.Kodein
+import org.kodein.di.KodeinAware
+
+abstract class BaseViewModel : ViewModel(), KodeinAware {
+
+    override lateinit var kodein: Kodein
+
+    val loading = MutableLiveData<Boolean>()
+
+    init {
+        loading.postValue(false)
+    }
+
+    fun whenReady(kodein: Kodein) {
+        this.kodein = kodein
+    }
+}

app/src/main/kotlin/net/rafaeltoledo/social/ui/feature/main/MainActivity.kt

@@ -0,0 +1,31 @@
+package net.rafaeltoledo.social.ui.feature.main
+
+import android.content.Intent
+import android.databinding.DataBindingUtil
+import android.os.Bundle
+import net.rafaeltoledo.social.R
+import net.rafaeltoledo.social.data.auth.AuthManager
+import net.rafaeltoledo.social.databinding.ActivityMainBinding
+import net.rafaeltoledo.social.ui.BaseActivity
+import net.rafaeltoledo.social.ui.feature.signin.SignInActivity
+import org.kodein.di.generic.instance
+
+class MainActivity : BaseActivity() {
+
+    private val auth: AuthManager by instance()
+
+    private lateinit var binding: ActivityMainBinding
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        binding = DataBindingUtil.setContentView(this, R.layout.activity_main)
+    }
+
+    override fun onStart() {
+        super.onStart()
+        if (!auth.isUserLoggedIn()) {
+            startActivity(Intent(this, SignInActivity::class.java))
+            finish()
+        }
+    }
+}