feat(map): create the viewmodel for the list of hike routes

Implemented the ListOfHikeRoutesViewModel to later retrieve the hike routes from the repository.

Author: rBergCode

app/src/main/java/ch/hikemate/app/model/map/ListOfHikeRoutesViewModel.kt

@@ -0,0 +1,51 @@
+package ch.hikemate.app.model.map
+
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.ViewModelProvider
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+
+/**
+ * ViewModel for the list of hike routes
+ *
+ * @param TODO: should take a repository as a parameter
+ */
+open class ListOfHikeRoutesViewModel() : ViewModel() {
+  // List of all routes in the database
+  private val hikeRoutes_ =
+      MutableStateFlow<List<String>>(emptyList()) // TODO: should be a list of Route objects
+  val hikeRoutes: StateFlow<List<String>> = hikeRoutes_.asStateFlow()
+
+  // Selected route, i.e the route for the detail view
+  private val selectedHikeRoute_ = MutableStateFlow<String?>(null) // TODO: should be a Route object
+  open val selectedHikeRoute: StateFlow<String?> = selectedHikeRoute_.asStateFlow()
+
+  // Creates a factory
+  companion object {
+    val Factory: ViewModelProvider.Factory =
+        object : ViewModelProvider.Factory {
+          @Suppress("UNCHECKED_CAST")
+          override fun <T : ViewModel> create(modelClass: Class<T>): T {
+            return ListOfHikeRoutesViewModel() as T
+          }
+        }
+  }
+
+  /** Gets all the routes from the database and updates the routes_ variable */
+  fun getRoutes() {
+    // TODO: should call the repository to get all the routes
+    // repository.getRoutes(onSuccess = { routes_.value = it }, onFailure = {})
+
+    hikeRoutes_.value = listOf("Route 1", "Route 2", "Route 3")
+  }
+
+  /**
+   * Selects a route to be displayed in the detail view
+   *
+   * @param hikeRoute The route to be displayed
+   */
+  fun selectRoute(hikeRoute: String) { // TODO: should take a Route object
+    selectedHikeRoute_.value = hikeRoute
+  }
+}

app/src/test/java/ch/hikemate/app/model/map/ListOfHikeRoutesViewModelTest.kt

@@ -0,0 +1,34 @@
+package ch.hikemate.app.model.map
+
+import org.junit.Assert.*
+import org.junit.Before
+import org.junit.Test
+
+/** Testing the ListOfRoutesViewModel class */
+class ListOfHikeRoutesViewModelTest {
+  private lateinit var listOfHikeRoutesViewModel: ListOfHikeRoutesViewModel
+
+  @Before
+  fun setUp() {
+    listOfHikeRoutesViewModel = ListOfHikeRoutesViewModel()
+  }
+
+  @Test
+  fun canBeCreatedAsFactory() {
+    val factory = ListOfHikeRoutesViewModel.Factory
+    val viewModel = factory.create(ListOfHikeRoutesViewModel::class.java)
+    assertNotNull(viewModel)
+  }
+
+  @Test
+  fun canGetRoutes() {
+    listOfHikeRoutesViewModel.getRoutes()
+    assertNotEquals(listOfHikeRoutesViewModel.hikeRoutes.value.size, 0)
+  }
+
+  @Test
+  fun canSelectRoute() {
+    listOfHikeRoutesViewModel.selectRoute("Route 1")
+    assertEquals(listOfHikeRoutesViewModel.selectedHikeRoute.value, "Route 1")
+  }
+}