feat(chat): render a group conversation

apps/flipcash/core/src/main/kotlin/com/flipcash/app/core/chat/ChatStep.kt

@@ -45,4 +45,16 @@ sealed interface ChatStep : FlowStep, Parcelable {
     @Parcelize
     @Serializable
     data class Profile(val contact: ChatParticipant): ChatStep
+
+    /**
+     * The group's own profile — the counterpart of [Profile] for a chat that has no counterparty.
+     *
+     * Carries nothing, because there is nothing a group can be identified by that the flow does
+     * not already hold: the screen reads the group off the conversation's view model, the same
+     * way the transcript does. [Profile] has to carry its participant because a member's profile
+     * is opened from a bubble rather than from the chat the flow was opened on.
+     */
+    @Parcelize
+    @Serializable
+    data object GroupProfile : ChatStep
 }

apps/flipcash/core/src/main/res/values/strings.xml

@@ -250,6 +250,12 @@
         <item quantity="other">%1$s members</item>
     </plurals>
 
+    <plurals name="subtitle_chatMemberCount">
+        <item quantity="zero">0 people</item>
+        <item quantity="one">1 person</item>
+        <item quantity="other">%1$s people</item>
+    </plurals>
+
     <string name="action_addCash">Add Cash</string>
     <string name="title_selectMethod">Select Method</string>
     <string name="title_amountToAdd">Amount to Add</string>
@@ -885,6 +891,19 @@
 
     <string name="label_fromYourContacts">From Your Contacts</string>
     <string name="label_addContact">Add Contact</string>
+    <string name="label_chat_balanceRequirement">Balance Requirement: %1$s of $%2$s</string>
+    <string name="label_chat_balanceRequirement_anyToken">Balance Requirement: %1$s</string>
+    <string name="subtitle_chatGate_minimumBalance">Minimum Balance: %1$s of $%2$s</string>
+    <string name="subtitle_chatGate_minimumBalance_anyToken">Minimum Balance: %1$s</string>
+    <string name="subtitle_chatGate_staffOnly">This chat is open to Flipcash staff only.</string>
+    <string name="action_buyMoreToken">Buy More $%1$s</string>
+    <string name="action_joinChat">Join Chat</string>
+    <string name="title_leaveChat">Leave Chat</string>
+    <string name="action_leaveChat">Leave</string>
+    <string name="prompt_title_leaveChat">Leave %1$s?</string>
+    <string name="prompt_description_leaveChat">You won’t receive new messages from this chat. You can join it again if it still lets you in</string>
+    <string name="error_title_failedToLeave">Something Went Wrong</string>
+    <string name="error_description_failedToLeave">We were unable to leave the chat. Please try again</string>
 
     <string name="prompt_title_cancelCashLinkPostShare">Are You Sure?</string>
     <string name="prompt_description_cancelCashLinkPostShare">Anyone you sent the link to won\'t be able to collect the cash</string>
@@ -898,6 +917,9 @@
     <string name="label_chat_preview_tippedCash">You tipped %1$s</string>
     <string name="label_chat_preview_receivedTip">Someone tipped you %1$s</string>
     <string name="label_chat_preview_sentMessage">You: %1$s</string>
+    <string name="label_chat_preview_senderMessage">%1$s: %2$s</string>
+    <string name="label_chat_preview_sentCash_bySender">%1$s sent %2$s</string>
+    <string name="label_chat_preview_tippedCash_bySender">%1$s tipped %2$s</string>
     <string name="label_isTyping">Is Typing…</string>
 
     <string name="label_edited">Edited</string>

apps/flipcash/features/messenger/src/main/kotlin/com/flipcash/app/messenger/ChatFlowScreen.kt

@@ -24,6 +24,7 @@ import com.flipcash.app.messenger.internal.screens.cash.ChatAmountEntryContent
 import com.flipcash.app.messenger.internal.screens.cash.ChatInitPaymentSheet
 import com.flipcash.app.messenger.internal.screens.profile.ChatProfileScreen
 import com.flipcash.app.messenger.internal.screens.profile.ChatProfileViewModel
+import com.flipcash.app.messenger.internal.screens.profile.GroupProfileScreen
 import com.getcode.navigation.annotatedEntry
 import com.getcode.navigation.core.LocalCodeNavigator
 import com.getcode.navigation.flow.FlowHost
@@ -89,6 +90,9 @@ private fun chatEntryProvider(
     annotatedEntry<ChatStep.Profile> { step ->
         FlowChatProfileScreen(step.contact)
     }
+    annotatedEntry<ChatStep.GroupProfile> {
+        FlowGroupProfileScreen()
+    }
 }
 
 @Composable
@@ -230,3 +234,14 @@ private fun FlowChatProfileScreen(participant: ChatParticipant) {
             }.launchIn(this)
     }
 }
+
+/**
+ * The group's profile, on the conversation's own view model.
+ *
+ * No [LaunchedEffect] seeding it the way [FlowChatProfileScreen] seeds a participant: the shared
+ * view model is already open on this group, so there is nothing to hand it.
+ */
+@Composable
+private fun FlowGroupProfileScreen() {
+    GroupProfileScreen(flowSharedViewModel<ChatViewModel>())
+}

apps/flipcash/features/messenger/src/main/kotlin/com/flipcash/app/messenger/internal/ChatSubject.kt

@@ -0,0 +1,121 @@
+package com.flipcash.app.messenger.internal
+
+import com.flipcash.app.core.chat.ChatParticipant
+import com.flipcash.services.models.chat.ChatId
+import com.flipcash.services.models.chat.ChatRuleRequirement
+import com.flipcash.services.models.chat.ChatRules
+import com.flipcash.services.models.chat.MediaItem
+
+/**
+ * What the messenger screen is a conversation *with*.
+ *
+ * [ChatParticipant] answers this for a DM and is unchanged — [Contact] and [TipUser] wrap it
+ * rather than restating it, so DM rendering keeps reading the same fields off the same type. What
+ * the subject adds is a [Group] arm and, with it, exhaustiveness: the title bar, the info card and
+ * the profile route each become a `when` over three arms, so a fourth chat type is a compile error
+ * at every site that has to decide something rather than a blank render at one of them.
+ *
+ * Deliberately not `Parcelable`. Nothing bundles a subject —
+ * [com.flipcash.app.messenger.internal.screens.ChatStep.Profile] takes a [ChatParticipant], which
+ * is why [asParticipant] exists — and parcelling one would mean parcelling [ChatRules].
+ */
+sealed interface ChatSubject {
+
+    /** What to call this conversation. Never null; a nameless subject reads as empty, not absent. */
+    val title: String
+
+    /**
+     * The line under the title, or `null` when there is none.
+     *
+     * [Group] answers `null` even though it has one to show: "3 people" is a plural resource and
+     * resolving it needs a `Context` this type has no business holding. The title bar renders it
+     * from [Group.memberCount] instead.
+     */
+    val subtitle: String?
+
+    /** Whether tapping the title or the info card's chevron opens a profile. */
+    val canViewProfile: Boolean
+
+    /**
+     * The [ChatParticipant] behind this subject, or `null` for a [Group].
+     *
+     * The bridge to code that predates the subject: the profile route, the tip recipient flow and
+     * the payment paths all still speak `ChatParticipant`, and none of them can be reached from a
+     * group.
+     */
+    fun asParticipant(): ChatParticipant?
+
+    /**
+     * A `CONTACT_DM`. Carried, not extended: contact DMs are end-of-life, and this arm exists so
+     * their phone line and add-to-contacts pill keep rendering exactly as they did.
+     */
+    data class Contact(val participant: ChatParticipant.Contact) : ChatSubject {
+        override val title: String get() = participant.name.orEmpty()
+        override val subtitle: String? get() = null
+        override val canViewProfile: Boolean get() = false
+        override fun asParticipant(): ChatParticipant = participant
+    }
+
+    /** A `TIP_DM`. Blocking is reached through its profile. */
+    data class TipUser(val participant: ChatParticipant.TipUser) : ChatSubject {
+        override val title: String get() = participant.name.orEmpty()
+        // `handle` already carries the leading `@` (see `String.asHandle`), so this is the raw
+        // value rather than one this type prefixes again.
+        override val subtitle: String? get() = participant.handle
+        override val canViewProfile: Boolean get() = true
+        override fun asParticipant(): ChatParticipant = participant
+    }
+
+    /**
+     * A `GROUP`. Everything here comes off the chat's own row rather than off a counterparty,
+     * because a group has none.
+     *
+     * [isMember] rides along because the access gate reads it in the same breath as [rules], and
+     * splitting them would let the screen blur a chat it had just joined for one frame.
+     */
+    data class Group(
+        val chatId: ChatId,
+        val groupTitle: String?,
+        val picture: MediaItem?,
+        val memberCount: Long,
+        val rules: ChatRules?,
+        val isMember: Boolean,
+    ) : ChatSubject {
+        override val title: String get() = groupTitle.orEmpty()
+        override val subtitle: String? get() = null
+        // The group's own profile, not a counterparty's — which is why this is true while
+        // [asParticipant] stays null. The route the tap takes is decided per arm, in
+        // MessengerScreen's ChatAction.ViewProfile handler.
+        override val canViewProfile: Boolean get() = true
+        override fun asParticipant(): ChatParticipant? = null
+    }
+}
+
+/**
+ * The subject for a DM counterparty.
+ *
+ * The bridge in the other direction from [ChatSubject.asParticipant]: the profile route still
+ * carries a [ChatParticipant] through navigation, and its header renders the same avatar the
+ * conversation bar does. A group has no participant to arrive here with, so `null` in is `null` out.
+ */
+internal fun ChatParticipant?.asSubject(): ChatSubject? = when (this) {
+    is ChatParticipant.Contact -> ChatSubject.Contact(this)
+    is ChatParticipant.TipUser -> ChatSubject.TipUser(this)
+    null -> null
+}
+
+/**
+ * The balance requirement to show the user, or `null` when there is nothing actionable to show.
+ *
+ * Listener rules gate reading and joining, speaker rules gate sending, and speaker rules apply on
+ * top of listener rules — so the first thing standing between the viewer and the chat is the
+ * listener requirement when there is one.
+ *
+ * [ChatRuleRequirement.Staff] deliberately produces nothing: it is not a bar a user can clear by
+ * doing something, and rendering it as a requirement would read as an instruction.
+ */
+internal fun ChatRules?.balanceRequirement(): ChatRuleRequirement.MinimumBalance? {
+    val rules = this ?: return null
+    return rules.listener.filterIsInstance<ChatRuleRequirement.MinimumBalance>().firstOrNull()
+        ?: rules.speaker.filterIsInstance<ChatRuleRequirement.MinimumBalance>().firstOrNull()
+}