From 5a4eb03b3d3f574421ea31d882a9ebe542c91acc Mon Sep 17 00:00:00 2001
From: Nyck <nyckbrandao1236@gmail.com>
Date: Thu, 9 May 2024 02:50:25 +0100
Subject: [PATCH] Pharmacy medicines list now updates after just adding a new
 medicine. Uses a MutableStateFlow to do a flatMap on the Pager.

---
 .../ist/pharmacist/PharmacistApplication.kt   |  2 +-
 .../ui/screens/pharmacy/PharmacyViewModel.kt  | 50 +++++++++----------
 2 files changed, 26 insertions(+), 26 deletions(-)

diff --git a/src/frontend/app/src/main/kotlin/pt/ulisboa/ist/pharmacist/PharmacistApplication.kt b/src/frontend/app/src/main/kotlin/pt/ulisboa/ist/pharmacist/PharmacistApplication.kt
index 9869a13..0241c90 100644
--- a/src/frontend/app/src/main/kotlin/pt/ulisboa/ist/pharmacist/PharmacistApplication.kt
+++ b/src/frontend/app/src/main/kotlin/pt/ulisboa/ist/pharmacist/PharmacistApplication.kt
@@ -84,7 +84,7 @@ class PharmacistApplication : DependenciesContainer, Application() {
 
     companion object {
         const val MEDICINE_NOTIFICATION_CHANNEL = "MedicineNotifications"
-        const val API_ENDPOINT = "https://pharmacist-e9t4.onrender.com" // "http://10.0.2.2:8080"
+        const val API_ENDPOINT = "http://10.0.2.2:8080" // "https://pharmacist-e9t4.onrender.com"
         const val TAG = "PharmacistApp"
     }
 }
diff --git a/src/frontend/app/src/main/kotlin/pt/ulisboa/ist/pharmacist/ui/screens/pharmacy/PharmacyViewModel.kt b/src/frontend/app/src/main/kotlin/pt/ulisboa/ist/pharmacist/ui/screens/pharmacy/PharmacyViewModel.kt
index 976519e..893a664 100644
--- a/src/frontend/app/src/main/kotlin/pt/ulisboa/ist/pharmacist/ui/screens/pharmacy/PharmacyViewModel.kt
+++ b/src/frontend/app/src/main/kotlin/pt/ulisboa/ist/pharmacist/ui/screens/pharmacy/PharmacyViewModel.kt
@@ -9,8 +9,10 @@ import androidx.paging.PagingConfig
 import androidx.paging.PagingData
 import androidx.paging.cachedIn
 import androidx.paging.map
+import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.combine
+import kotlinx.coroutines.flow.flatMapLatest
 import kotlinx.coroutines.launch
 import pt.ulisboa.ist.pharmacist.service.http.PharmacistService
 import pt.ulisboa.ist.pharmacist.service.http.connection.isSuccess
@@ -48,24 +50,29 @@ class PharmacyViewModel(
 
     private val modificationEvents = MutableStateFlow<List<ModificationEvent>>(emptyList())
 
-    private val _medicinesState = Pager(
-        config = PagingConfig(
-            pageSize = PAGE_SIZE,
-            prefetchDistance = PREFETCH_DISTANCE,
-            enablePlaceholders = false
-        ),
-        pagingSourceFactory = {
-            PharmacyMedicinesPagingSource(
-                pharmaciesService = pharmacistService.pharmaciesService,
-                pid = pharmacyId
-            )
-        }
-    ).flow.cachedIn(viewModelScope)
-        .combine(modificationEvents) { pagingData, modificationEvents ->
-            modificationEvents.fold(pagingData) { pagingDataAcc, modificationEvent ->
-                applyModificationEvent(pagingDataAcc, modificationEvent)
+    private val newMedicineFlow = MutableStateFlow<Long?>(null)
+
+    @OptIn(ExperimentalCoroutinesApi::class)
+    private val _medicinesState = newMedicineFlow.flatMapLatest {
+        Pager(
+            config = PagingConfig(
+                pageSize = PAGE_SIZE,
+                prefetchDistance = PREFETCH_DISTANCE,
+                enablePlaceholders = false
+            ),
+            pagingSourceFactory = {
+                PharmacyMedicinesPagingSource(
+                    pharmaciesService = pharmacistService.pharmaciesService,
+                    pid = pharmacyId
+                )
             }
-        }
+        ).flow.cachedIn(viewModelScope)
+            .combine(modificationEvents) { pagingData, modificationEvents ->
+                modificationEvents.fold(pagingData) { pagingDataAcc, modificationEvent ->
+                    applyModificationEvent(pagingDataAcc, modificationEvent)
+                }
+            }
+    }
 
     private fun applyModificationEvent(
         pagingData: PagingData<MedicineStockModel>,
@@ -216,14 +223,7 @@ class PharmacyViewModel(
     }
 
     fun onMedicineAdded(medicineId: Long, quantity: Long) {
-        // TODO: This does not work. This paging is sus
-        pharmacy?.let {
-            modificationEvents.value += StockModificationEvent(
-                medicineId,
-                MedicineStockOperation.ADD,
-                quantity
-            )
-        }
+        viewModelScope.launch { newMedicineFlow.emit(medicineId) }
     }