feature/MM/437-development_onboarding_doc

feature/onboarding-language/README.md

@@ -0,0 +1,45 @@
+# Onboarding Language Module
+
+## Dependencies
+
+![Dependency Graph](../docs/images/graphs/dep_graph_feature_onboarding_language.svg)
+
+## Sequence Diagram
+
+```mermaid
+sequenceDiagram
+    participant User
+    participant Screen as SetOnboardingLanguageScreen
+    participant ViewModel as SetOnboardingLanguageViewModel
+    participant Repository as UserPreferencesRepository
+
+    User->>Screen: Selects language
+    Screen->>ViewModel: handleAction(SetLanguage(language))
+    ViewModel->>Repository: setLanguage(language)
+    Repository-->>ViewModel: Language updated
+    ViewModel->>Screen: Update UI with new language
+
+    Note over Screen,Repository: Language preference is now persisted
+```
+
+## Architecture
+
+```mermaid
+graph TD
+    subgraph UI Layer
+        A[SetOnboardingLanguageScreen] -->|Observes| B[SetOnboardingLanguageViewModel]
+    end
+
+    subgraph Domain Layer
+        B -->|Uses| C[UserPreferencesRepository]
+    end
+
+    subgraph Data Layer
+        C -->|Manages| D[Language Preferences]
+    end
+
+    style A fill:#e3f2fd,stroke:#1565c0
+    style B fill:#e8f5e9,stroke:#2e7d32
+    style C fill:#fff3e0,stroke:#f57c00
+    style D fill:#f3e5f5,stroke:#7b1fa2
+```

feature/onboarding-language/src/commonMain/kotlin/org/mifos/mobile/feature/onboarding/language/SetOnboardingLanguageViewModel.kt

@@ -19,6 +19,16 @@ import org.mifos.mobile.core.datastore.UserPreferencesRepository
 import org.mifos.mobile.core.model.LanguageConfig
 import org.mifos.mobile.core.ui.utils.BaseViewModel
 
+/**
+ * ViewModel responsible for managing the onboarding language selection screen state and business logic.
+ *
+ * This ViewModel handles:
+ * - Loading the current language preference
+ * - Updating the selected language
+ * - Managing the onboarding flow state
+ *
+ * @property repository [UserPreferencesRepository] for accessing and modifying user preferences
+ */
 internal class SetOnboardingLanguageViewModel(
     private val repository: UserPreferencesRepository,
 ) : BaseViewModel<OnboardingLanguageState, OnboardingLanguageEvent, OnboardingLanguageAction>(
@@ -31,13 +41,35 @@ internal class SetOnboardingLanguageViewModel(
             .launchIn(viewModelScope)
     }
 
+    /**
+     * Processes incoming actions and delegates to appropriate handlers.
+     * @param action The action to process
+     */
     override fun handleAction(action: OnboardingLanguageAction) {
         when (action) {
             is OnboardingLanguageAction.Internal.LoadLanguage -> handleLoadLanguage(action)
             is OnboardingLanguageAction.SetLanguage -> handleSetLanguage(action)
         }
     }
 
+    /**
+     * Updates the selected language and updates onboarding state.
+     * 
+     * This method will:
+     * 1. Persist the new language preference
+     * 2. Update the UI state
+     * 3. Mark onboarding as complete
+     *
+     * @param action Contains the new language configuration
+     * 
+     * Example:
+     * ```kotlin
+     * // When user selects a language
+     * viewModel.trySendAction(
+     *     OnboardingLanguageAction.SetLanguage(selectedLanguage)
+     * )
+     * ```
+     */
     private fun handleSetLanguage(action: OnboardingLanguageAction.SetLanguage) {
         viewModelScope.launch {
             repository.setLanguage(action.languageConfig)
@@ -49,23 +81,62 @@ internal class SetOnboardingLanguageViewModel(
         }
     }
 
+    /**
+     * Updates the current language in the state.
+     * 
+     * This is called internally when the language preference changes.
+     *
+     * @param action Contains the language to load
+     * 
+     * Example:
+     * ```kotlin
+     * // Internal usage - triggered by language preference changes
+     * private fun onLanguagePreferenceChanged(newLanguage: LanguageConfig) {
+     *     trySendAction(
+     *         OnboardingLanguageAction.Internal.LoadLanguage(newLanguage)
+     *     )
+     * }
+     * ```
+     */
     private fun handleLoadLanguage(action: OnboardingLanguageAction.Internal.LoadLanguage) {
         mutableStateFlow.update {
             it.copy(currentLanguage = action.language)
         }
     }
 }
 
+/**
+ * Represents the UI state for the language selection screen.
+ * @property currentLanguage The currently selected language
+ */
 internal data class OnboardingLanguageState(
     val currentLanguage: LanguageConfig,
 )
 
+/**
+ * Events that can be triggered from the UI.
+ * Currently not used but available for future extensions.
+ */
 internal sealed interface OnboardingLanguageEvent
 
+/**
+ * Actions that can be processed by the ViewModel.
+ */
 internal sealed interface OnboardingLanguageAction {
+    /**
+     * Action to set a new language.
+     * @property languageConfig The language configuration to set
+     */
     data class SetLanguage(val languageConfig: LanguageConfig) : OnboardingLanguageAction
 
+    /**
+     * Internal actions used by the ViewModel for state management.
+     */
     sealed interface Internal : OnboardingLanguageAction {
+        /**
+         * Action to load a language configuration.
+         * @property language The language configuration to load
+         */
         data class LoadLanguage(val language: LanguageConfig) : Internal
     }
 }