fix(notifications): show amount and title in payment request pushes

apps/flipcash/shared/notifications/src/main/kotlin/com/flipcash/app/notifications/NotificationService.kt

@@ -31,6 +31,7 @@ import com.flipcash.app.contacts.ContactResolver
 import com.flipcash.app.core.util.Linkify
 import com.flipcash.shared.chat.ChatArchiveStore
 import com.flipcash.shared.chat.ChatCoordinator
+import com.flipcash.shared.chat.PaymentRequests
 import com.flipcash.app.tokens.TokenCoordinator
 import com.flipcash.app.persistence.sources.ChatMetadataDataSource
 import com.flipcash.app.persistence.sources.UserProfileDataSource
@@ -48,6 +49,9 @@ import com.flipcash.services.models.PushChatMetadata
 import com.flipcash.services.models.Substitution
 import com.flipcash.services.models.chat.BlobAccessContext
 import com.flipcash.services.models.chat.ChatType
+import com.flipcash.services.models.chat.MessageContent
+import com.flipcash.services.models.chat.WidgetContent
+import com.flipcash.services.models.paymentrequest.PaymentRequest
 import com.flipcash.services.user.UserManager
 import com.flipcash.shared.notifications.R
 import com.getcode.utils.TraceType
@@ -92,6 +96,7 @@ class NotificationService : FirebaseMessagingService(),
         // bound only caps the cold-cache network fetch so the notification isn't
         // held back indefinitely.
         private const val AVATAR_FETCH_TIMEOUT_MS = 5_000L
+        private const val REQUEST_FETCH_TIMEOUT_MS = 5_000L
     }
 
     @Inject
@@ -121,6 +126,9 @@ class NotificationService : FirebaseMessagingService(),
     @Inject
     lateinit var chatCoordinator: ChatCoordinator
 
+    @Inject
+    lateinit var paymentRequests: PaymentRequests
+
     @Inject
     lateinit var profileController: ProfileController
 
@@ -481,7 +489,8 @@ class NotificationService : FirebaseMessagingService(),
         // The server can't read an end-to-end encrypted DM or private group, so its body is a
         // stand-in. The opened text is the message itself, with no sender prefix to strip; a group
         // line takes its sender from the Person. Unencrypted messages open to null and keep the body.
-        val opened = openPushedMessage(chatId, metadata)
+        // A payment request carries only its id, so its body comes from fetching the request.
+        val opened = openPushedMessage(chatId, metadata) ?: pushedRequestBody(chatId, metadata)
         style.addMessage(opened ?: planMessageBody(body, senderNames), System.currentTimeMillis(), senderPerson)
 
         // After the extract above, not before: a re-post rebuilds the style from the notification
@@ -512,6 +521,39 @@ class NotificationService : FirebaseMessagingService(),
         }
     }
 
+    /**
+     * What a payment-request push asks, from fetching the request, or `null` to keep the server's
+     * body: the message isn't a request, or the fetch failed or took longer than
+     * [REQUEST_FETCH_TIMEOUT_MS]. A sealed (private group) request's title is opened by the fetch.
+     */
+    private suspend fun pushedRequestBody(chatId: ChatId, metadata: PushChatMetadata?): String? {
+        if (metadata == null || (metadata.message == null && metadata.messageId == null)) return null
+        return try {
+            val widget = (metadata.message?.content?.singleOrNull() as? MessageContent.Widget)?.widget
+                ?: (chatCoordinator.openPushedChatMessage(chatId, metadata.message, metadata.messageId)
+                    ?.content?.singleOrNull() as? MessageContent.Widget)?.widget
+            val requestId = (widget as? WidgetContent.PaymentRequest)?.id ?: return null
+            val request: PaymentRequest? = withTimeoutOrNull(REQUEST_FETCH_TIMEOUT_MS.milliseconds) {
+                paymentRequests.fetch(requestId).getOrNull()?.paymentRequest
+            }
+            planPaymentRequestBody(
+                request = request,
+                chatId = chatId,
+                viewerId = userManager.accountId,
+                templates = PaymentRequestBodyTemplates(
+                    amountAndTitle = getString(R.string.notification_request_amountAndTitle),
+                    amountOnly = getString(R.string.notification_request_amountOnly),
+                    titleOnly = getString(R.string.notification_request_titleOnly),
+                ),
+            )
+        } catch (e: CancellationException) {
+            throw e
+        } catch (e: Exception) {
+            trace(tag = "NotificationService", message = "Couldn't build a payment request body", error = e)
+            null
+        }
+    }
+
     /** Who a chat push is attributed to: their id (for blob access) and their profile. */
     private data class Sender(val userId: ID, val profile: UserProfile)
 

apps/flipcash/shared/notifications/src/main/kotlin/com/flipcash/app/notifications/PaymentRequestBodyPlanner.kt

@@ -0,0 +1,62 @@
+package com.flipcash.app.notifications
+
+import com.flipcash.services.models.chat.ChatId
+import com.flipcash.services.models.paymentrequest.PaymentRequest
+import com.flipcash.services.models.paymentrequest.PaymentRequestText
+import com.getcode.opencode.model.core.ID
+import com.getcode.opencode.model.financial.Fiat
+
+/**
+ * The wording of a payment-request push, each a format string taking the amount and/or title as
+ * `%1$s` / `%2$s`. Kept apart from [planPaymentRequestBody] so the rule needs no `Context`.
+ *
+ * The sender is not named: `MessagingStyle` draws it above the line in a group and in the title of
+ * a DM, as it does for [planMessageBody].
+ */
+data class PaymentRequestBodyTemplates(
+    /** Takes the amount, then the title. */
+    val amountAndTitle: String,
+    /** Takes the amount. */
+    val amountOnly: String,
+    /** Takes the title. */
+    val titleOnly: String,
+)
+
+/**
+ * The body for a push whose message is a payment-request widget, from the request it points at.
+ *
+ * The server's body for a widget is generic, and in a private group a stand-in because the request's
+ * text is sealed. The fetched request carries the opened [PaymentRequestText.Plain] title and the
+ * amounts, so the notification can say what was asked.
+ *
+ * The amount is the viewer's own share when they owe one, since that is what the push asks of them,
+ * and otherwise the whole split. A blank or unopened title is left out.
+ *
+ * `null` when there is nothing worth saying (no request, one from another chat, or neither a title
+ * nor an amount), in which case the caller keeps the push's own body.
+ *
+ * @param request the fetched request, null when the fetch failed or timed out
+ * @param chatId the chat the push is for; a request made elsewhere is not shown here
+ * @param viewerId the signed-in user, to pick their share
+ */
+fun planPaymentRequestBody(
+    request: PaymentRequest?,
+    chatId: ChatId,
+    viewerId: ID?,
+    templates: PaymentRequestBodyTemplates,
+): String? {
+    val split = request?.split ?: return null
+    if (request.chatId != chatId) return null
+
+    val title = (split.text as? PaymentRequestText.Plain)?.title?.trim()?.takeIf { it.isNotEmpty() }
+    val amount = (viewerId?.let { split.shareOf(it)?.amount } ?: split.requested.takeIf { it.quarks > 0 })
+        ?.takeIf { it.quarks > 0 }
+        ?.formatted(Fiat.FormattingRule.Truncated)
+
+    return when {
+        amount != null && title != null -> templates.amountAndTitle.format(amount, title)
+        amount != null -> templates.amountOnly.format(amount)
+        title != null -> templates.titleOnly.format(title)
+        else -> null
+    }
+}

apps/flipcash/shared/notifications/src/main/res/values/strings.xml

@@ -26,4 +26,9 @@
     <!-- Channel group names -->
     <string name="notification_group_transactions">Transactions</string>
     <string name="notification_group_social">Social</string>
+
+    <!-- Payment-request push bodies; the sender is drawn by MessagingStyle, so it is not named here. -->
+    <string name="notification_request_amountAndTitle">Requested %1$s for %2$s</string>
+    <string name="notification_request_amountOnly">Requested %1$s</string>
+    <string name="notification_request_titleOnly">Sent request for %1$s</string>
 </resources>

apps/flipcash/shared/notifications/src/test/kotlin/com/flipcash/app/notifications/PaymentRequestBodyPlannerTest.kt

@@ -0,0 +1,99 @@
+package com.flipcash.app.notifications
+
+import com.flipcash.services.models.chat.ChatId
+import com.flipcash.services.models.paymentrequest.PaymentRequest
+import com.flipcash.services.models.paymentrequest.PaymentRequestStatus
+import com.flipcash.services.models.paymentrequest.PaymentRequestText
+import com.flipcash.services.models.paymentrequest.Share
+import com.flipcash.services.models.paymentrequest.Split
+import com.getcode.opencode.model.financial.CurrencyCode
+import com.getcode.opencode.model.financial.Fiat
+import org.junit.Before
+import org.junit.Test
+import java.util.Locale
+import kotlin.test.assertEquals
+import kotlin.test.assertNull
+import kotlin.time.Instant
+
+class PaymentRequestBodyPlannerTest {
+
+    private val chat = ChatId(ByteArray(32) { 3 })
+    private val viewer = List<Byte>(16) { 5 }
+    private val other = List<Byte>(16) { 6 }
+    private val templates = PaymentRequestBodyTemplates(
+        amountAndTitle = "Requested %1\$s for %2\$s",
+        amountOnly = "Requested %1\$s",
+        titleOnly = "Sent request for %1\$s",
+    )
+
+    @Before
+    fun locale() = Locale.setDefault(Locale.US)
+
+    private fun share(userId: List<Byte>, dollars: Double) =
+        Share(userId, Fiat(fiat = dollars, currencyCode = CurrencyCode.USD), paid = null)
+
+    private fun request(
+        text: PaymentRequestText = PaymentRequestText.Plain("Dinner", ""),
+        shares: List<Share> = listOf(share(viewer, 12.5), share(other, 20.0)),
+        chatId: ChatId = chat,
+    ) = PaymentRequest(
+        id = List(16) { 9 },
+        creator = List(16) { 1 },
+        createdAt = Instant.fromEpochSeconds(0),
+        status = PaymentRequestStatus.Open,
+        closedAt = null,
+        version = 1,
+        kind = PaymentRequest.Kind.GroupSplit(
+            chatId = chatId,
+            split = Split(text, CurrencyCode.USD, Instant.fromEpochSeconds(1_000), shares),
+        ),
+    )
+
+    private fun plan(request: PaymentRequest?, viewerId: List<Byte>? = viewer) =
+        planPaymentRequestBody(request, chat, viewerId, templates)
+
+    @Test
+    fun `a fetched request names the viewer's share and its title`() {
+        assertEquals("Requested \$12.50 for Dinner", plan(request()))
+    }
+
+    @Test
+    fun `a viewer with no share is told the whole split`() {
+        assertEquals("Requested \$32.50 for Dinner", plan(request(), viewerId = List(16) { 7 }))
+    }
+
+    @Test
+    fun `a whole-dollar amount drops its cents`() {
+        assertEquals("Requested \$20 for Dinner", plan(request(shares = listOf(share(viewer, 20.0)))))
+    }
+
+    @Test
+    fun `a request without a title still says the amount`() {
+        assertEquals("Requested \$12.50", plan(request(text = PaymentRequestText.Plain("  ", ""))))
+    }
+
+    @Test
+    fun `a title that stayed sealed is left out`() {
+        assertEquals("Requested \$12.50", plan(request(text = PaymentRequestText.Undecryptable)))
+    }
+
+    @Test
+    fun `a request with a title but no amount says the title`() {
+        assertEquals("Sent request for Dinner", plan(request(shares = emptyList())))
+    }
+
+    @Test
+    fun `a request with neither falls back`() {
+        assertNull(plan(request(text = PaymentRequestText.Undecryptable, shares = emptyList())))
+    }
+
+    @Test
+    fun `a failed or timed out fetch falls back`() {
+        assertNull(plan(null))
+    }
+
+    @Test
+    fun `a request made in another chat falls back`() {
+        assertNull(plan(request(chatId = ChatId(ByteArray(32) { 4 }))))
+    }
+}