Add state as well as fix SortType needs.

app/src/main/java/com/hyperling/expensetracker/ExpenseEvent.kt

@@ -7,6 +7,6 @@ sealed interface ExpenseEvent {
     data class SetRate(val rate: Rate): ExpenseEvent
     object ShowDialog: ExpenseEvent
     object HideDialog: ExpenseEvent
-    data class SortExpenses(val rate: Rate): ExpenseEvent
+    data class SortExpenses(val sortType: SortType): ExpenseEvent
     data class DeleteExpense(val expense: Expense): ExpenseEvent
 }

app/src/main/java/com/hyperling/expensetracker/ExpenseState.kt

@@ -0,0 +1,10 @@
+package com.hyperling.expensetracker
+
+data class ExpenseState(
+    val expenses: List<Expense> = emptyList(),
+    val firstName: String = "",
+    val lastName: String = "",
+    val phoneNumber: String = "",
+    val isAddingExpense: Boolean = false,
+    val sortType: SortType = SortType.NAME,
+)

app/src/main/java/com/hyperling/expensetracker/SortType.kt

@@ -0,0 +1,7 @@
+package com.hyperling.expensetracker
+
+enum class SortType {
+    NAME,
+    COST,
+    RATE,
+}