From f73052ed488ac36a519541e6960301a13e612498 Mon Sep 17 00:00:00 2001
From: Vitor Pamplona <vitor@vitorpamplona.com>
Date: Tue, 21 May 2024 15:56:51 -0400
Subject: [PATCH] Checks cache before making a new request to DVM

---
 .../ui/screen/loggedIn/AccountViewModel.kt        | 15 +++++++++++++++
 .../loggedIn/NIP90ContentDiscoveryScreen.kt       |  7 ++++++-
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/app/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/AccountViewModel.kt b/app/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/AccountViewModel.kt
index cd31b9071..b214b1e0a 100644
--- a/app/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/AccountViewModel.kt
+++ b/app/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/AccountViewModel.kt
@@ -48,6 +48,7 @@ import com.vitorpamplona.amethyst.model.Note
 import com.vitorpamplona.amethyst.model.UrlCachedPreviewer
 import com.vitorpamplona.amethyst.model.User
 import com.vitorpamplona.amethyst.model.UserState
+import com.vitorpamplona.amethyst.model.observables.CreatedAtComparator
 import com.vitorpamplona.amethyst.model.observables.LatestByKindWithETag
 import com.vitorpamplona.amethyst.service.CashuProcessor
 import com.vitorpamplona.amethyst.service.CashuToken
@@ -81,6 +82,7 @@ import com.vitorpamplona.quartz.events.EventInterface
 import com.vitorpamplona.quartz.events.GiftWrapEvent
 import com.vitorpamplona.quartz.events.LnZapEvent
 import com.vitorpamplona.quartz.events.LnZapRequestEvent
+import com.vitorpamplona.quartz.events.NIP90ContentDiscoveryRequestEvent
 import com.vitorpamplona.quartz.events.Participant
 import com.vitorpamplona.quartz.events.ReportEvent
 import com.vitorpamplona.quartz.events.Response
@@ -1354,6 +1356,19 @@ class AccountViewModel(val account: Account, val settings: SettingsState) : View
         }
     }
 
+    suspend fun cachedDVMContentDiscovery(pubkeyHex: String): Note? {
+        val fifteenMinsAgo = TimeUtils.fifteenMinutesAgo()
+        return LocalCache.notes.maxOrNullOf(
+            filter = { key, note ->
+                val noteEvent = note.event
+                noteEvent is NIP90ContentDiscoveryRequestEvent &&
+                    noteEvent.isTaggedUser(pubkeyHex) &&
+                    noteEvent.createdAt > fifteenMinsAgo
+            },
+            comparator = CreatedAtComparator,
+        )
+    }
+
     fun sendZapPaymentRequestFor(
         bolt11: String,
         zappedNote: Note?,
diff --git a/app/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/NIP90ContentDiscoveryScreen.kt b/app/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/NIP90ContentDiscoveryScreen.kt
index 1ef99181b..b80867e49 100644
--- a/app/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/NIP90ContentDiscoveryScreen.kt
+++ b/app/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/NIP90ContentDiscoveryScreen.kt
@@ -142,7 +142,12 @@ fun NIP90ContentDiscoveryScreen(
     }
 
     LaunchedEffect(key1 = appDefinition) {
-        onRefresh()
+        val existingResult = accountViewModel.cachedDVMContentDiscovery(noteAuthor.pubkeyHex)
+        if (existingResult == null) {
+            onRefresh()
+        } else {
+            requestEventID = existingResult
+        }
     }
 
     RefresheableBox(