Solution w dagger

app/build.gradle

@@ -1,6 +1,8 @@
 plugins {
     id 'com.android.application'
     id 'org.jetbrains.kotlin.android'
+    id 'org.jetbrains.kotlin.kapt'
+    id 'com.google.dagger.hilt.android'
 }
 
 android {
@@ -9,7 +11,7 @@ android {
 
     defaultConfig {
         applicationId "ru.otus.basicarchitecture"
-        minSdk 24
+        minSdk 26
         targetSdk 33
         versionCode 1
         versionName "1.0"
@@ -24,11 +26,14 @@ android {
         }
     }
     compileOptions {
-        sourceCompatibility JavaVersion.VERSION_1_8
-        targetCompatibility JavaVersion.VERSION_1_8
+        sourceCompatibility JavaVersion.VERSION_17
+        targetCompatibility JavaVersion.VERSION_17
     }
     kotlinOptions {
-        jvmTarget = '1.8'
+        jvmTarget = '17'
+    }
+    buildFeatures {
+        viewBinding true
     }
 }
 
@@ -38,7 +43,15 @@ dependencies {
     implementation 'androidx.appcompat:appcompat:1.6.1'
     implementation 'com.google.android.material:material:1.9.0'
     implementation 'androidx.constraintlayout:constraintlayout:2.1.4'
-    testImplementation 'junit:junit:4.13.2'
-    androidTestImplementation 'androidx.test.ext:junit:1.1.5'
-    androidTestImplementation 'androidx.test.espresso:espresso-core:3.5.1'
+
+    implementation deps.fragment
+    implementation deps.navigation
+    implementation deps.viewmodel
+    implementation deps.livedata
+
+//    implementation deps.dagger
+//    kapt deps.dagger_compiler
+
+    implementation deps.hilt
+    kapt deps.hilt_compiler
 }

app/src/main/AndroidManifest.xml

@@ -11,10 +11,17 @@
         android:roundIcon="@mipmap/ic_launcher_round"
         android:supportsRtl="true"
         android:theme="@style/Theme.BasicArchitecture"
-        tools:targetApi="31">
+        tools:targetApi="31"
+        android:name=".di.HiltWizardApp">
         <activity
             android:name=".MainActivity"
-            android:exported="false" />
+            android:exported="true">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+        </activity>
     </application>
 
 </manifest>

app/src/main/java/ru/otus/basicarchitecture/MainActivity.kt

@@ -1,9 +1,12 @@
 package ru.otus.basicarchitecture
 
-import androidx.appcompat.app.AppCompatActivity
 import android.os.Bundle
+import androidx.appcompat.app.AppCompatActivity
+import dagger.hilt.android.AndroidEntryPoint
 
+@AndroidEntryPoint
 class MainActivity : AppCompatActivity() {
+
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         setContentView(R.layout.activity_main)

app/src/main/java/ru/otus/basicarchitecture/di/HiltCacheModule.kt

@@ -0,0 +1,19 @@
+package ru.otus.basicarchitecture.di
+
+import dagger.Binds
+import dagger.Module
+import dagger.hilt.InstallIn
+import dagger.hilt.android.components.ActivityRetainedComponent
+import dagger.hilt.android.scopes.ActivityRetainedScoped
+import ru.otus.basicarchitecture.wizardcache.WizardCache
+import ru.otus.basicarchitecture.wizardcache.WizardCacheImpl
+
+
+@Module
+@InstallIn(ActivityRetainedComponent::class)
+interface HiltCacheModule {
+
+    @Binds
+    @ActivityRetainedScoped
+    fun bindsCache(impl: WizardCacheImpl): WizardCache
+}

app/src/main/java/ru/otus/basicarchitecture/di/HiltWizardApp.kt

@@ -0,0 +1,7 @@
+package ru.otus.basicarchitecture.di
+
+import android.app.Application
+import dagger.hilt.android.HiltAndroidApp
+
+@HiltAndroidApp
+class HiltWizardApp : Application()

app/src/main/java/ru/otus/basicarchitecture/ui/address/AddressDataFragment.kt

@@ -0,0 +1,104 @@
+package ru.otus.basicarchitecture.ui.address
+
+import android.os.Bundle
+import android.text.InputType
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import android.widget.Toast
+import androidx.fragment.app.Fragment
+import androidx.fragment.app.viewModels
+import androidx.navigation.fragment.findNavController
+import dagger.hilt.android.AndroidEntryPoint
+import ru.otus.basicarchitecture.R
+import ru.otus.basicarchitecture.databinding.UserDataLayoutBinding
+import ru.otus.basicarchitecture.util.WizardTextWatcher
+
+@AndroidEntryPoint
+class AddressDataFragment : Fragment() {
+
+    private var _binding: UserDataLayoutBinding? = null
+    private val binding get() = _binding!!
+
+    private val viewModel: AddressFragViewModel by viewModels()
+
+    override fun onCreateView(
+        inflater: LayoutInflater,
+        container: ViewGroup?,
+        savedInstanceState: Bundle?
+    ): View {
+        _binding = UserDataLayoutBinding.inflate(inflater, container, false)
+        return binding.root
+    }
+
+    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
+        super.onViewCreated(view, savedInstanceState)
+
+        binding.apply {
+            nameOrCountryEditText.hint = getString(R.string.country)
+            surnameOrCityEditText.hint = getString(R.string.city)
+            ageOrAddressEditText.hint = getString(R.string.address)
+            ageOrAddressEditText.inputType = InputType.TYPE_CLASS_TEXT
+
+            WizardTextWatcher(nameOrCountryEditText).startListen { setButtonState() }
+            WizardTextWatcher(surnameOrCityEditText).startListen { setButtonState() }
+            WizardTextWatcher(ageOrAddressEditText).startListen { setButtonState() }
+
+            nextButton.setOnClickListener {
+                viewModel.onNextButtonClick(nextButton.isSelected)
+            }
+        }
+
+        viewModel.getCurrentData()
+
+        viewModel.state.observe(viewLifecycleOwner) { state ->
+            handleState(state)
+        }
+        viewModel.event.observe(viewLifecycleOwner) { event ->
+            handleEvent(event)
+        }
+    }
+
+    private fun handleState(state: AddressFragState) {
+        binding.apply {
+            nameOrCountryEditText.setText(state.country)
+            surnameOrCityEditText.setText(state.city)
+            ageOrAddressEditText.setText(state.address)
+            nextButton.isSelected = state.isButtonEnabled
+        }
+    }
+
+    private fun handleEvent(event: AddressFragEvent) {
+        when (event) {
+            is AddressFragEvent.Error -> {
+                showToast(event.message)
+            }
+            is AddressFragEvent.Success -> {
+                viewModel.updateAddressData(
+                    binding.nameOrCountryEditText.text.toString(),
+                    binding.surnameOrCityEditText.text.toString(),
+                    binding.ageOrAddressEditText.text.toString(),
+                )
+                findNavController().navigate(R.id.action_addressDataFragment_to_interestsDataFragment)
+            }
+            is AddressFragEvent.Empty -> {}
+        }
+    }
+
+    private fun setButtonState() {
+        binding.apply {
+            nextButton.isSelected = ageOrAddressEditText.text.isNotEmpty()
+                    && nameOrCountryEditText.text.isNotEmpty()
+                    && surnameOrCityEditText.text.isNotEmpty()
+        }
+    }
+
+    private fun showToast(msg: String) {
+        Toast.makeText(this.context, msg, Toast.LENGTH_SHORT).show()
+    }
+
+    override fun onDestroyView() {
+        super.onDestroyView()
+        _binding = null
+    }
+}

app/src/main/java/ru/otus/basicarchitecture/ui/address/AddressFragEvent.kt

@@ -0,0 +1,7 @@
+package ru.otus.basicarchitecture.ui.address
+
+sealed interface AddressFragEvent {
+    object Empty : AddressFragEvent
+    data class Error(val message: String) : AddressFragEvent
+    object Success : AddressFragEvent
+}

app/src/main/java/ru/otus/basicarchitecture/ui/address/AddressFragState.kt

@@ -0,0 +1,8 @@
+package ru.otus.basicarchitecture.ui.address
+
+data class AddressFragState(
+    val country: String = "",
+    val city: String = "",
+    val address: String = "",
+    val isButtonEnabled: Boolean = false
+)

app/src/main/java/ru/otus/basicarchitecture/ui/address/AddressFragViewModel.kt

@@ -0,0 +1,55 @@
+package ru.otus.basicarchitecture.ui.address
+
+import androidx.lifecycle.LiveData
+import androidx.lifecycle.MutableLiveData
+import androidx.lifecycle.ViewModel
+import dagger.hilt.android.lifecycle.HiltViewModel
+import ru.otus.basicarchitecture.wizardcache.WizardCache
+import javax.inject.Inject
+
+@HiltViewModel
+class AddressFragViewModel @Inject constructor(
+    private val cache: WizardCache
+) : ViewModel() {
+
+    private val _state = MutableLiveData(AddressFragState())
+    val state: LiveData<AddressFragState> get() = _state
+
+    private val _event = MutableLiveData<AddressFragEvent>()
+    val event: LiveData<AddressFragEvent> get() = _event
+
+    init {
+        getCurrentData()
+    }
+
+    fun getCurrentData() {
+        cache.getUserData().also { data ->
+            _state.value = _state.value?.copy(
+                country = data.country,
+                city = data.city,
+                address = data.address,
+                isButtonEnabled = data.country.isNotEmpty()
+                        && data.city.isNotEmpty()
+                        && data.address.isNotEmpty()
+            )
+        }
+    }
+
+    fun updateAddressData(country: String, city: String, address: String) {
+        cache.updateAddress(country, city, address)
+    }
+
+    fun onNextButtonClick(isButtonEnabled: Boolean) {
+        if (isButtonEnabled) {
+            _event.value = AddressFragEvent.Success
+            onEventHandled()
+        } else {
+            _event.value = AddressFragEvent.Error("Enter country, city, address")
+            onEventHandled()
+        }
+    }
+
+    private fun onEventHandled() {
+        _event.value = AddressFragEvent.Empty
+    }
+}

app/src/main/java/ru/otus/basicarchitecture/ui/interests/InterestsDataFragment.kt

@@ -0,0 +1,80 @@
+package ru.otus.basicarchitecture.ui.interests
+
+import android.os.Bundle
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import androidx.core.view.children
+import androidx.fragment.app.Fragment
+import androidx.fragment.app.viewModels
+import androidx.navigation.fragment.findNavController
+import com.google.android.material.chip.Chip
+import dagger.hilt.android.AndroidEntryPoint
+import ru.otus.basicarchitecture.R
+import ru.otus.basicarchitecture.databinding.UserInterestsLayoutBinding
+
+@AndroidEntryPoint
+class InterestsDataFragment : Fragment() {
+
+    private var _binding: UserInterestsLayoutBinding? = null
+    private val binding get() = _binding!!
+
+    private val viewModel: InterestsFragViewModel by viewModels()
+
+    override fun onCreateView(
+        inflater: LayoutInflater,
+        container: ViewGroup?,
+        savedInstanceState: Bundle?
+    ): View {
+        _binding = UserInterestsLayoutBinding.inflate(inflater, container, false)
+        return binding.root
+    }
+
+    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
+        super.onViewCreated(view, savedInstanceState)
+
+        initChipGroup(viewModel.getListOfInterests())
+
+        viewModel.state.observe(viewLifecycleOwner) { state ->
+            handleState(state)
+        }
+
+        binding.goToSummaryButton.setOnClickListener {
+            viewModel.onSummaryButtonClick()
+            findNavController().navigate(R.id.action_interestsDataFragment_to_summaryFragment)
+        }
+    }
+
+    private fun handleState(state: InterestsFragState) {
+       setCheckedInterests(state.checkedInterests)
+    }
+
+    private fun setCheckedInterests(checkedInterests: List<String>) {
+        binding.chipGroup.children.forEach {
+            it as Chip
+            if (checkedInterests.contains(it.text)) {
+                it.isChecked = true
+            }
+        }
+    }
+    private fun initChipGroup(listOfInterests: List<String>) {
+        listOfInterests.forEach { interest ->
+            val chip = Chip(this.context)
+            chip.text = interest
+
+            chip.setOnClickListener {
+                if (chip.isChecked) {
+                    viewModel.addInterest(chip.text.toString())
+                } else {
+                    viewModel.removeInterest(chip.text.toString())
+                }
+            }
+            binding.chipGroup.addView(chip)
+        }
+    }
+
+    override fun onDestroyView() {
+        super.onDestroyView()
+        _binding = null
+    }
+}

app/src/main/java/ru/otus/basicarchitecture/ui/interests/InterestsFragState.kt

@@ -0,0 +1,5 @@
+package ru.otus.basicarchitecture.ui.interests
+
+data class InterestsFragState(
+    val checkedInterests: List<String> = emptyList()
+)