0.10.6

Sources/Shared/Models/ChatTimelineEntry.swift

@@ -0,0 +1,28 @@
+import Foundation
+
+/// A cached presentation row for the selected chat. Building day boundaries
+/// once per message mutation avoids walking the full history during every
+/// scroll-position or composer-state update.
+struct ChatTimelineEntry: Identifiable, Hashable, Sendable {
+    let message: ChatMessage
+    let startsNewDay: Bool
+
+    var id: String { message.id }
+
+    static func make(
+        from messages: [ChatMessage],
+        calendar: Calendar = .autoupdatingCurrent
+    ) -> [ChatTimelineEntry] {
+        var previousTimestamp: Date?
+        return messages.map { message in
+            let startsNewDay = previousTimestamp.map {
+                !calendar.isDate($0, inSameDayAs: message.timestamp)
+            } ?? true
+            previousTimestamp = message.timestamp
+            return ChatTimelineEntry(
+                message: message,
+                startsNewDay: startsNewDay
+            )
+        }
+    }
+}