[WOOMOB-1583] Fix POS orders split view to show empty state when search returns no results

WooCommerce/src/main/kotlin/com/woocommerce/android/ui/woopos/orders/WooPosOrdersLoadingState.kt

@@ -123,7 +123,7 @@ fun WooPosOrdersListLoadingPane(modifier: Modifier = Modifier) {
 }
 
 @Composable
-private fun OrderDetailsLoadingPane(modifier: Modifier = Modifier) {
+fun OrderDetailsLoadingPane(modifier: Modifier = Modifier) {
     Column(
         modifier = modifier
             .fillMaxSize()

WooCommerce/src/main/kotlin/com/woocommerce/android/ui/woopos/orders/WooPosOrdersScreen.kt

@@ -199,12 +199,37 @@ private fun OrdersContent(
                 .weight(0.7f)
                 .background(MaterialTheme.colorScheme.surface)
         ) {
-            WooPosOrderDetails(
-                modifier = Modifier
-                    .fillMaxHeight(),
-                details = state.selectedDetails,
-                onEmailReceiptButtonClicked = onEmailReceiptButtonClicked
-            )
+            when {
+                state.selectedDetails != null -> {
+                    WooPosOrderDetails(
+                        modifier = Modifier
+                            .fillMaxHeight(),
+                        details = state.selectedDetails,
+                        onEmailReceiptButtonClicked = onEmailReceiptButtonClicked
+                    )
+                }
+                state.items is WooPosOrdersState.Content.Items.Searching -> {
+                    OrderDetailsLoadingPane(
+                        modifier = Modifier
+                            .fillMaxHeight()
+                            .padding(
+                                start = WooPosSpacing.Medium.value,
+                                end = WooPosSpacing.Medium.value,
+                                top = WooPosSpacing.XLarge.value,
+                                bottom = WooPosSpacing.XLarge.value
+                            )
+                    )
+                }
+                else -> {
+                    WooPosEmptyScreen(
+                        modifier = Modifier.fillMaxSize(),
+                        icon = WooPosIcons.OrdersEmpty,
+                        title = stringResource(R.string.woopos_orders_no_order_selected),
+                        message = "",
+                        contentDescription = stringResource(R.string.woopos_orders_empty_list_image_description)
+                    )
+                }
+            }
         }
     }
 }
@@ -637,6 +662,30 @@ fun WooPosOrdersNothingFoundStatePreview() {
     }
 }
 
+@WooPosPreview
+@Composable
+fun WooPosOrdersEmptyStatePreview() {
+    WooPosTheme {
+        WooPosOrdersScreen(
+            state = WooPosOrdersState.Empty(
+                pullToRefreshState = WooPosPullToRefreshState.Enabled,
+                searchInputState = WooPosSearchInputState.Closed,
+            ),
+            scrollToTopEvent = MutableSharedFlow(),
+            onBackClicked = {},
+            onRefresh = {},
+            onOrderSelected = {},
+            onEndOfOrdersListReached = {},
+            onPaginationErrorTryAgain = {},
+            onSearchEvent = {},
+            onSearchErrorRetry = {},
+            onOrdersEmptyActionClicked = {},
+            onOrdersLoadingErrorRetryButtonClicked = {},
+            onEmailReceiptButtonClicked = {}
+        )
+    }
+}
+
 @Suppress("MagicNumber")
 private fun sampleOrderDetails(
     id: Long = 1L,

WooCommerce/src/main/kotlin/com/woocommerce/android/ui/woopos/orders/WooPosOrdersState.kt

@@ -83,7 +83,7 @@ sealed class WooPosOrdersState {
         val items: Items,
         override val pullToRefreshState: WooPosPullToRefreshState,
         override val searchInputState: WooPosSearchInputState,
-        val selectedDetails: OrderDetailsViewState.Computed.Details,
+        val selectedDetails: OrderDetailsViewState.Computed.Details?,
         val paginationState: WooPosPaginationState
     ) : WooPosOrdersState() {
         sealed class Items {

WooCommerce/src/main/kotlin/com/woocommerce/android/ui/woopos/orders/WooPosOrdersViewModel.kt

@@ -282,7 +282,7 @@ class WooPosOrdersViewModel @Inject constructor(
 
     private fun refreshSelectedOrder() {
         val current = _state.value as? WooPosOrdersState.Content ?: return
-        val selectedOrderId = current.selectedDetails.id
+        val selectedOrderId = current.selectedDetails?.id ?: return
 
         viewModelScope.launch {
             ordersDataSource.refreshOrderById(selectedOrderId)
@@ -329,7 +329,7 @@ class WooPosOrdersViewModel @Inject constructor(
     private fun performSearch(query: String, isRefreshing: Boolean = false) {
         cancelJobs()
 
-        val currentSelectedDetails = (_state.value as? WooPosOrdersState.Content)?.selectedDetails!!
+        val currentSelectedDetails = (_state.value as? WooPosOrdersState.Content)?.selectedDetails
         searchJob = viewModelScope.launch {
             delay(SEARCH_DEBOUNCE_DELAY_MS)
             if (!isRefreshing) {
@@ -355,7 +355,7 @@ class WooPosOrdersViewModel @Inject constructor(
                         ),
                         pullToRefreshState = WooPosPullToRefreshState.Enabled,
                         searchInputState = _state.value.searchInputState,
-                        selectedDetails = currentSelectedDetails,
+                        selectedDetails = null,
                         paginationState = WooPosPaginationState.None
                     )
                 }
@@ -369,7 +369,7 @@ class WooPosOrdersViewModel @Inject constructor(
                             ),
                             pullToRefreshState = WooPosPullToRefreshState.Enabled,
                             searchInputState = _state.value.searchInputState,
-                            selectedDetails = currentSelectedDetails,
+                            selectedDetails = null,
                             paginationState = WooPosPaginationState.None
                         )
                     } else {
@@ -453,7 +453,15 @@ class WooPosOrdersViewModel @Inject constructor(
 
         val orders = ordersWithRefunds.keys.toList()
         val newFirstOrderId = orders.firstOrNull()?.id
-        val newSelectedId = requireNotNull(newFirstOrderId) { "Content requires at least one order" }
+
+        val currentSelectedId = (currentState as? WooPosOrdersState.Content)?.selectedDetails?.id
+        val isSelectedOrderStillInList = currentSelectedId != null && orders.any { it.id == currentSelectedId }
+        val newSelectedId =
+            if (isSelectedOrderStillInList) {
+                currentSelectedId
+            } else {
+                requireNotNull(newFirstOrderId) { "Content requires at least one order" }
+            }
         val items = buildItemsMap(ordersWithRefunds, newSelectedId)
         val selectedEntry = items.entries.first { (item, _) -> item.isSelected }
         val selectedDetails = when (val details = selectedEntry.value) {

WooCommerce/src/main/res/values/strings.xml

@@ -3789,6 +3789,7 @@
     <string name="woopos_orders_empty_list_message">Explore how you can increase your store sales.</string>
     <string name="woopos_orders_empty_action_label">Learn more</string>
     <string name="woopos_orders_empty_list_image_description">No orders</string>
+    <string name="woopos_orders_no_order_selected">No order selected.</string>
     <string name="woopos_orders_loading_error_title">Unable to load orders</string>
     <string name="woopos_orders_loading_error_message">Please check your connection try again.</string>
     <string name="woopos_orders_loading_error_retry_button">Retry</string>