Message Details: Show "me" as display name if there's only a single identity

app/ui/legacy/src/main/java/com/fsck/k9/ui/messagedetails/KoinModule.kt

@@ -20,5 +20,5 @@ val messageDetailsUiModule = module {
     factory { ContactSettingsProvider() }
     factory { AddToContactsLauncher() }
     factory { ShowContactLauncher() }
-    factory { createMessageDetailsParticipantFormatter(contactNameProvider = get()) }
+    factory { createMessageDetailsParticipantFormatter(contactNameProvider = get(), resources = get()) }
 }

app/ui/legacy/src/main/java/com/fsck/k9/ui/messagedetails/MessageDetailsParticipantFormatter.kt

@@ -1,12 +1,15 @@
 package com.fsck.k9.ui.messagedetails
 
+import android.content.res.Resources
 import android.text.Spannable.SPAN_EXCLUSIVE_EXCLUSIVE
 import android.text.SpannableString
 import android.text.style.ForegroundColorSpan
 import com.fsck.k9.Account
+import com.fsck.k9.Identity
 import com.fsck.k9.K9
 import com.fsck.k9.helper.ContactNameProvider
 import com.fsck.k9.mail.Address
+import com.fsck.k9.ui.R
 
 /**
  * Get the display name for a participant to be shown in the message details screen.
@@ -19,11 +22,12 @@ internal class RealMessageDetailsParticipantFormatter(
     private val contactNameProvider: ContactNameProvider,
     private val showContactNames: Boolean,
     private val contactNameColor: Int?,
+    private val meText: String,
 ) : MessageDetailsParticipantFormatter {
     override fun getDisplayName(address: Address, account: Account): CharSequence? {
-        val identityDisplayName = account.findIdentity(address)?.name
+        val identity = account.findIdentity(address)
-        if (identityDisplayName != null) {
+        if (identity != null) {
-            return identityDisplayName
+            return getIdentityName(identity, account)
         }
 
         return if (showContactNames) {
@@ -33,6 +37,14 @@ internal class RealMessageDetailsParticipantFormatter(
         }
     }
 
+    private fun getIdentityName(identity: Identity, account: Account): String {
+        return if (account.identities.size == 1) {
+            meText
+        } else {
+            identity.description ?: identity.name ?: meText
+        }
+    }
+
     private fun getContactNameOrNull(address: Address): CharSequence? {
         val contactName = contactNameProvider.getNameForAddress(address.address) ?: return null
 
@@ -48,10 +60,12 @@ internal class RealMessageDetailsParticipantFormatter(
 
 internal fun createMessageDetailsParticipantFormatter(
     contactNameProvider: ContactNameProvider,
+    resources: Resources,
 ): MessageDetailsParticipantFormatter {
     return RealMessageDetailsParticipantFormatter(
         contactNameProvider = contactNameProvider,
         showContactNames = K9.isShowContactName,
         contactNameColor = if (K9.isChangeContactNameColor) K9.contactNameColor else null,
+        meText = resources.getString(R.string.message_view_me_text),
     )
 }

app/ui/legacy/src/test/java/com/fsck/k9/ui/messagedetails/MessageDetailsParticipantFormatterTest.kt

@@ -14,6 +14,7 @@ import org.junit.Test
 
 private const val IDENTITY_NAME = "Alice"
 private const val IDENTITY_ADDRESS = "me@domain.example"
+private const val ME_TEXT = "me"
 
 class MessageDetailsParticipantFormatterTest : RobolectricTest() {
     private val contactNameProvider = object : ContactNameProvider {
@@ -33,7 +34,19 @@ class MessageDetailsParticipantFormatterTest : RobolectricTest() {
     private val participantFormatter = createParticipantFormatter()
 
     @Test
-    fun `identity address`() {
+    fun `identity address with single identity`() {
+        val displayName = participantFormatter.getDisplayName(Address(IDENTITY_ADDRESS, "irrelevant"), account)
+
+        assertThat(displayName).isEqualTo(ME_TEXT)
+    }
+
+    @Test
+    fun `identity address with multiple identities`() {
+        val account = Account("uuid").apply {
+            identities += Identity(name = IDENTITY_NAME, email = IDENTITY_ADDRESS)
+            identities += Identity(name = "Another identity", email = "irrelevant@domain.example")
+        }
+
         val displayName = participantFormatter.getDisplayName(Address(IDENTITY_ADDRESS, "irrelevant"), account)
 
         assertThat(displayName).isEqualTo(IDENTITY_NAME)
@@ -47,18 +60,19 @@ class MessageDetailsParticipantFormatterTest : RobolectricTest() {
 
         val displayName = participantFormatter.getDisplayName(Address(IDENTITY_ADDRESS, "Bob"), account)
 
-        assertThat(displayName).isEqualTo("Bob")
+        assertThat(displayName).isEqualTo(ME_TEXT)
     }
 
     @Test
     fun `identity and address without a display name`() {
         val account = Account("uuid").apply {
             identities += Identity(name = null, email = IDENTITY_ADDRESS)
+            identities += Identity(name = "Another identity", email = "irrelevant@domain.example")
         }
 
         val displayName = participantFormatter.getDisplayName(Address(IDENTITY_ADDRESS), account)
 
-        assertThat(displayName).isNull()
+        assertThat(displayName).isEqualTo(ME_TEXT)
     }
 
     @Test
@@ -118,6 +132,7 @@ class MessageDetailsParticipantFormatterTest : RobolectricTest() {
             contactNameProvider = contactNameProvider,
             showContactNames = showContactNames,
             contactNameColor = contactNameColor,
+            meText = ME_TEXT,
         )
     }
 }