Refactor ChatListUI

submodules/ChatListUI/Sources/ChatListSelection.swift

@@ -0,0 +1,57 @@
+import Foundation
+import UIKit
+import SwiftSignalKit
+import Postbox
+import TelegramCore
+
+enum ChatListSelectionReadOption: Equatable {
+    case all(enabled: Bool)
+    case selective(enabled: Bool)
+}
+
+struct ChatListSelectionOptions: Equatable {
+    let read: ChatListSelectionReadOption
+    let delete: Bool
+}
+
+func chatListSelectionOptions(postbox: Postbox, peerIds: Set<PeerId>) -> Signal<ChatListSelectionOptions, NoError> {
+    if peerIds.isEmpty {
+        let key = PostboxViewKey.unreadCounts(items: [.total(nil)])
+        return postbox.combinedView(keys: [key])
+        |> map { view -> ChatListSelectionOptions in
+            var hasUnread = false
+            if let unreadCounts = view.views[key] as? UnreadMessageCountsView, let total = unreadCounts.total() {
+                for (_, counter) in total.1.absoluteCounters {
+                    if counter.messageCount != 0 {
+                        hasUnread = true
+                        break
+                    }
+                }
+            }
+            return ChatListSelectionOptions(read: .all(enabled: hasUnread), delete: false)
+        }
+        |> distinctUntilChanged
+    } else {
+        let items: [UnreadMessageCountsItem] = peerIds.map(UnreadMessageCountsItem.peer)
+        let key = PostboxViewKey.unreadCounts(items: items)
+        return postbox.combinedView(keys: [key])
+        |> map { view -> ChatListSelectionOptions in
+            var hasUnread = false
+            if let unreadCounts = view.views[key] as? UnreadMessageCountsView {
+                loop: for entry in unreadCounts.entries {
+                    switch entry {
+                        case let .peer(_, state):
+                            if let state = state, state.isUnread {
+                                hasUnread = true
+                                break loop
+                            }
+                        default:
+                            break
+                    }
+                }
+            }
+            return ChatListSelectionOptions(read: .selective(enabled: hasUnread), delete: true)
+        }
+        |> distinctUntilChanged
+    }
+}