[WOOMOB-382] Update Coupons Fetching/Loading Business Logic

WooCommerce/src/main/kotlin/com/woocommerce/android/ui/woopos/home/items/coupons/WooPosCouponsListViewStateManager.kt

@@ -6,13 +6,16 @@ import com.woocommerce.android.ui.woopos.home.items.WooPosItemSelectionViewState
 import com.woocommerce.android.ui.woopos.home.items.WooPosPaginationState.Error
 import com.woocommerce.android.ui.woopos.home.items.WooPosPaginationState.Loading
 import com.woocommerce.android.ui.woopos.home.items.WooPosPaginationState.None
+import com.woocommerce.android.ui.woopos.home.items.WooPosPullToRefreshState.Disabled
 import com.woocommerce.android.ui.woopos.home.items.WooPosPullToRefreshState.Enabled
 import com.woocommerce.android.ui.woopos.home.items.WooPosPullToRefreshState.Refreshing
 import com.woocommerce.android.ui.woopos.home.items.coupons.WooPosCouponsListViewStateManager.FetchingCouponsState.ERROR_FETCHING_FIRST_PAGE
 import com.woocommerce.android.ui.woopos.home.items.coupons.WooPosCouponsListViewStateManager.FetchingCouponsState.ERROR_FETCHING_MORE
 import com.woocommerce.android.ui.woopos.home.items.coupons.WooPosCouponsListViewStateManager.FetchingCouponsState.FETCHING_FIRST_PAGE
 import com.woocommerce.android.ui.woopos.home.items.coupons.WooPosCouponsListViewStateManager.FetchingCouponsState.FETCHING_MORE
 import com.woocommerce.android.ui.woopos.home.items.coupons.WooPosCouponsListViewStateManager.FetchingCouponsState.IDLE
+import com.woocommerce.android.ui.woopos.home.items.coupons.WooPosCouponsListViewStateManager.FetchingCouponsState.PTR_FETCHING_FIRST_PAGE
+import com.woocommerce.android.ui.woopos.home.items.coupons.WooPosCouponsListViewStateManager.FetchingCouponsState.RETRY_FETCHING_FIRST_PAGE
 import com.woocommerce.android.ui.woopos.util.WooPosGetCachedStoreCurrency
 import com.woocommerce.android.ui.woopos.util.format.WooPosFormatCouponSummary
 import kotlinx.coroutines.CoroutineScope
@@ -37,50 +40,77 @@ class WooPosCouponsListViewStateManager @Inject constructor(
 
     private var loadingMoreJob: Job? = null
     private var fetchingFirstPageJob: Job? = null
-    private var canLoadMore: Boolean = false
+    private var canLoadMore: Boolean = true
 
     enum class FetchingCouponsState {
-        IDLE, FETCHING_FIRST_PAGE, FETCHING_MORE, ERROR_FETCHING_FIRST_PAGE, ERROR_FETCHING_MORE
+        IDLE, FETCHING_FIRST_PAGE, PTR_FETCHING_FIRST_PAGE, RETRY_FETCHING_FIRST_PAGE, FETCHING_MORE,
+        ERROR_FETCHING_FIRST_PAGE, ERROR_FETCHING_MORE
     }
 
     private val contentFlow = couponsDataSource.couponsFlow.combine(fetchingState) { coupons, fetchingState ->
         if (!cachedCouponEnabledChecker.isEnabled()) {
             return@combine WooPosCouponsViewState.Error.CouponsDisabledError()
         }
         when (fetchingState) {
-            FETCHING_FIRST_PAGE -> {
-                WooPosCouponsViewState.Loading()
+            FETCHING_FIRST_PAGE, PTR_FETCHING_FIRST_PAGE -> {
+                if (coupons.isEmpty()) {
+                    createLoadingState(fetchingState)
+                } else {
+                    createContentViewState(coupons, fetchingState)
+                }
+            }
+            RETRY_FETCHING_FIRST_PAGE -> {
+                createLoadingState(fetchingState)
             }
 
             ERROR_FETCHING_FIRST_PAGE -> {
                 WooPosCouponsViewState.Error.GenericError()
             }
 
             IDLE, FETCHING_MORE, ERROR_FETCHING_MORE -> {
-                when {
-                    coupons.isEmpty() -> WooPosCouponsViewState.Empty()
-                    else -> {
-                        WooPosCouponsViewState.Content(
-                            items = mapCouponsToSelectionState(coupons),
-                            paginationState = getPaginationState(fetchingState),
-                            pullToRefreshState = getPullToRefreshState(fetchingState)
-                        )
-                    }
+                if (coupons.isEmpty()) {
+                    WooPosCouponsViewState.Empty()
+                } else {
+                    createContentViewState(coupons, fetchingState)
                 }
             }
         }
     }
 
+    private fun createLoadingState(fetchingState: FetchingCouponsState) =
+        WooPosCouponsViewState.Loading(
+            pullToRefreshState = if (fetchingState == PTR_FETCHING_FIRST_PAGE) {
+                Refreshing
+            } else {
+                Disabled
+            }
+        )
+
+    private suspend fun createContentViewState(
+        coupons: List<Coupon>,
+        fetchingState: FetchingCouponsState
+    ) = WooPosCouponsViewState.Content(
+        items = mapCouponsToSelectionState(coupons),
+        paginationState = getPaginationState(fetchingState),
+        pullToRefreshState = getPullToRefreshState(fetchingState)
+    )
+
     val viewState: Flow<WooPosCouponsViewState> = contentFlow
 
-    fun fetchCoupons(viewModelScope: CoroutineScope) {
+    fun fetchCoupons(viewModelScope: CoroutineScope, refreshType: WooPosCouponsListRefreshType) {
         if (fetchingFirstPageJob?.isActive == true) {
             return
         }
 
         fetchingFirstPageJob = viewModelScope.launch {
             loadingMoreJob?.cancelAndJoin()
-            fetchingState.emit(FETCHING_FIRST_PAGE)
+            fetchingState.emit(
+                when (refreshType) {
+                    WooPosCouponsListRefreshType.INITIAL -> FETCHING_FIRST_PAGE
+                    WooPosCouponsListRefreshType.PULL_TO_REFRESH -> PTR_FETCHING_FIRST_PAGE
+                    WooPosCouponsListRefreshType.RETRY -> RETRY_FETCHING_FIRST_PAGE
+                }
+            )
             val result = couponsDataSource.clearCacheAndFetchFirstPage()
             if (result.isSuccess) {
                 canLoadMore = result.getOrNull() ?: false
@@ -130,15 +160,23 @@ class WooPosCouponsListViewStateManager @Inject constructor(
 
     private fun getPaginationState(fetchingState: FetchingCouponsState) =
         when (fetchingState) {
-            IDLE, FETCHING_FIRST_PAGE, FETCHING_MORE -> if (canLoadMore) Loading else None
+            IDLE, FETCHING_FIRST_PAGE, PTR_FETCHING_FIRST_PAGE, RETRY_FETCHING_FIRST_PAGE, FETCHING_MORE -> {
+                if (canLoadMore) Loading else None
+            }
+
             ERROR_FETCHING_MORE -> Error
             ERROR_FETCHING_FIRST_PAGE -> error("Full screen error should be displayed")
         }
 
     private fun getPullToRefreshState(fetchingState: FetchingCouponsState) =
         when (fetchingState) {
-            ERROR_FETCHING_MORE, IDLE, FETCHING_MORE -> Enabled
-            FETCHING_FIRST_PAGE -> Refreshing
+            IDLE, FETCHING_MORE -> Enabled
+            FETCHING_FIRST_PAGE, RETRY_FETCHING_FIRST_PAGE, ERROR_FETCHING_MORE -> Disabled
+            PTR_FETCHING_FIRST_PAGE -> Refreshing
             ERROR_FETCHING_FIRST_PAGE -> error("Full screen error should be displayed")
         }
+
+    enum class WooPosCouponsListRefreshType {
+        INITIAL, PULL_TO_REFRESH, RETRY
+    }
 }

WooCommerce/src/main/kotlin/com/woocommerce/android/ui/woopos/home/items/coupons/WooPosCouponsViewModel.kt

@@ -6,6 +6,7 @@ import com.woocommerce.android.ui.woopos.home.ChildToParentEvent
 import com.woocommerce.android.ui.woopos.home.WooPosChildrenToParentEventSender
 import com.woocommerce.android.ui.woopos.home.items.WooPosCouponsViewState
 import com.woocommerce.android.ui.woopos.home.items.WooPosItemsViewModel.ItemClickedData
+import com.woocommerce.android.ui.woopos.home.items.coupons.WooPosCouponsListViewStateManager.WooPosCouponsListRefreshType
 import com.woocommerce.android.ui.woopos.home.items.coupons.WooPosCouponsUIEvent.BackButtonClicked
 import com.woocommerce.android.ui.woopos.home.items.coupons.WooPosCouponsUIEvent.CouponClicked
 import com.woocommerce.android.ui.woopos.home.items.coupons.WooPosCouponsUIEvent.EndOfListReached
@@ -46,7 +47,7 @@ class WooPosCouponsViewModel @Inject constructor(
             }
         }
 
-        listViewStateManager.fetchCoupons(viewModelScope)
+        fetchCoupons(WooPosCouponsListRefreshType.INITIAL)
     }
 
     fun onUIEvent(event: WooPosCouponsUIEvent) {
@@ -55,7 +56,7 @@ class WooPosCouponsViewModel @Inject constructor(
                 handleCouponClicked(event)
             }
 
-            PullToRefreshTriggered -> fetchCoupons()
+            PullToRefreshTriggered -> fetchCoupons(WooPosCouponsListRefreshType.PULL_TO_REFRESH)
 
             is EndOfListReached -> {
                 onEndOfListReached()
@@ -69,16 +70,16 @@ class WooPosCouponsViewModel @Inject constructor(
                 navigateBackToItemListScreen()
             }
 
-            RetryTriggered -> fetchCoupons()
+            RetryTriggered -> fetchCoupons(WooPosCouponsListRefreshType.RETRY)
 
             is WooPosCouponsUIEvent.CreateCouponClicked -> {
                 error("Create coupon clicked event not implemented yet")
             }
         }
     }
 
-    private fun fetchCoupons() {
-        listViewStateManager.fetchCoupons(viewModelScope)
+    private fun fetchCoupons(refreshType: WooPosCouponsListRefreshType) {
+        listViewStateManager.fetchCoupons(viewModelScope, refreshType)
     }
 
     private fun onEndOfListReached() {