From c3c19ebb49a035fd8ffb5adcba305f4f96907f2c Mon Sep 17 00:00:00 2001
From: Vitor Pamplona <vitor@vitorpamplona.com>
Date: Wed, 1 Feb 2023 13:51:03 -0300
Subject: [PATCH] Only showing notifications if it directly cites the account
 holder

---
 .../com/vitorpamplona/amethyst/model/Note.kt  | 29 +++++++++++++++++++
 .../service/NostrNotificationDataSource.kt    |  5 +++-
 2 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/app/src/main/java/com/vitorpamplona/amethyst/model/Note.kt b/app/src/main/java/com/vitorpamplona/amethyst/model/Note.kt
index e70832230..e94a8e019 100644
--- a/app/src/main/java/com/vitorpamplona/amethyst/model/Note.kt
+++ b/app/src/main/java/com/vitorpamplona/amethyst/model/Note.kt
@@ -2,6 +2,8 @@ package com.vitorpamplona.amethyst.model
 
 import androidx.lifecycle.LiveData
 import com.vitorpamplona.amethyst.service.NostrSingleEventDataSource
+import com.vitorpamplona.amethyst.service.model.ReactionEvent
+import com.vitorpamplona.amethyst.service.model.RepostEvent
 import com.vitorpamplona.amethyst.ui.note.toShortenHex
 import fr.acinq.secp256k1.Hex
 import java.time.Instant
@@ -14,8 +16,12 @@ import kotlinx.coroutines.Job
 import kotlinx.coroutines.delay
 import kotlinx.coroutines.launch
 import com.vitorpamplona.amethyst.service.relays.Relay
+import java.util.regex.Matcher
+import java.util.regex.Pattern
 import nostr.postr.events.Event
 
+val tagSearch = Pattern.compile("(?:\\s|\\A)\\#\\[([0-9]+)\\]")
+
 class Note(val idHex: String) {
     // These fields are always available.
     // They are immutable
@@ -117,6 +123,29 @@ class Note(val idHex: String) {
         }
     }
 
+    fun directlyCiteUsers(): Set<User> {
+        val matcher = tagSearch.matcher(event?.content ?: "")
+        val returningList = mutableSetOf<User>()
+        while (matcher.find()) {
+            try {
+                val tag = event?.tags?.get(matcher.group(1).toInt())
+                if (tag != null && tag[0] == "p") {
+                    returningList.add(LocalCache.getOrCreateUser(tag[1]))
+                }
+            } catch (e: Exception) {
+
+            }
+        }
+        return returningList
+    }
+
+    fun directlyCites(userProfile: User): Boolean {
+        return author == userProfile
+          || (userProfile in directlyCiteUsers())
+          || (event is ReactionEvent && replyTo?.lastOrNull()?.directlyCites(userProfile) == true)
+          || (event is RepostEvent && replyTo?.lastOrNull()?.directlyCites(userProfile) == true)
+    }
+
     // Observers line up here.
     val live: NoteLiveData = NoteLiveData(this)
 
diff --git a/app/src/main/java/com/vitorpamplona/amethyst/service/NostrNotificationDataSource.kt b/app/src/main/java/com/vitorpamplona/amethyst/service/NostrNotificationDataSource.kt
index b40f53ac3..ed5440d8f 100644
--- a/app/src/main/java/com/vitorpamplona/amethyst/service/NostrNotificationDataSource.kt
+++ b/app/src/main/java/com/vitorpamplona/amethyst/service/NostrNotificationDataSource.kt
@@ -4,6 +4,7 @@ import com.vitorpamplona.amethyst.model.Account
 import com.vitorpamplona.amethyst.model.Note
 import com.vitorpamplona.amethyst.model.User
 import com.vitorpamplona.amethyst.service.model.ChannelCreateEvent
+import com.vitorpamplona.amethyst.service.model.ChannelMessageEvent
 import com.vitorpamplona.amethyst.service.model.ChannelMetadataEvent
 import com.vitorpamplona.amethyst.service.model.RepostEvent
 import nostr.postr.JsonFilter
@@ -25,7 +26,9 @@ object NostrNotificationDataSource: NostrDataSource<Note>("NotificationFeed") {
     }
 
     return filtered.filter {
-      it.event !is ChannelCreateEvent && it.event !is ChannelMetadataEvent
+           it.event !is ChannelCreateEvent
+        && it.event !is ChannelMetadataEvent
+        && it.directlyCites(account.userProfile())
     }.sortedBy { it.event?.createdAt }.reversed()
   }