created LocationViewModel

- added function to fetch locations from fhirEngine

app/src/main/java/org/openmrs/android/fhir/viewmodel/LocationViewModel.kt

@@ -0,0 +1,64 @@
+package org.openmrs.android.fhir.viewmodel
+
+import android.app.Application
+import androidx.lifecycle.AndroidViewModel
+import androidx.lifecycle.MutableLiveData
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.ViewModelProvider
+import androidx.lifecycle.viewModelScope
+import com.google.android.fhir.FhirEngine
+import com.google.android.fhir.search.search
+import kotlinx.coroutines.launch
+import org.hl7.fhir.r4.model.Location
+
+class LocationViewModel(application: Application, private val fhirEngine: FhirEngine) : AndroidViewModel(application) {
+
+    init {
+        getLocations()
+    }
+
+    val locations = MutableLiveData<List<LocationItem>>()
+
+    private fun getLocations() {
+        viewModelScope.launch {
+            val locationsList : MutableList<LocationItem> = mutableListOf()
+            fhirEngine.search<Location> {  }
+                .mapIndexed { index, fhirLocation -> fhirLocation.resource.toLocationItem(index + 1) }
+                .let { locationsList.addAll(it) }
+            locations.value = locationsList
+        }
+
+    }
+
+    private fun Location.toLocationItem(position: Int): LocationItem {
+        return LocationItem(
+            id = position.toString(),
+            resourceId = idElement.idPart,
+            status = status.name,
+            name = name,
+            description = description
+        )
+    }
+
+    data class LocationItem(
+        val id:String,
+        val resourceId: String,
+        val status:String,
+        val name:String,
+        val description:String,
+    )
+
+    class LocationViewModelFactory(
+        private val application: Application,
+        private val fhirEngine: FhirEngine,
+    ) : ViewModelProvider.Factory {
+        @Suppress("UNCHECKED_CAST")
+        override fun <T : ViewModel> create(modelClass: Class<T>): T {
+            if (modelClass.isAssignableFrom(LocationViewModel::class.java)) {
+                return LocationViewModel(application, fhirEngine) as T
+            }
+            throw IllegalArgumentException("Unknown ViewModel class")
+        }
+    }
+
+}