PinnedBanner is now managed by the RoomScreenViewModel (#3163)

ElementX/Sources/Screens/RoomScreen/RoomScreenModels.swift

@@ -15,18 +15,119 @@
 //
 
 import Foundation
+import OrderedCollections
 
-enum RoomScreenViewModelAction { }
+enum RoomScreenViewModelAction {
+    case focusEvent(eventID: String)
+    case displayPinnedEventsTimeline
+}
 
-enum RoomScreenViewAction { }
+enum RoomScreenViewAction {
+    case tappedPinnedEventsBanner
+    case viewAllPins
+}
 
 struct RoomScreenViewState: BindableState {
+    var lastScrollDirection: ScrollDirection?
+    var isPinningEnabled = false
+    // This is used to control the banner
+    var pinnedEventsBannerState: PinnedEventsBannerState = .loading(numbersOfEvents: 0)
+    var shouldShowPinnedEventsBanner: Bool {
+        isPinningEnabled && !pinnedEventsBannerState.isEmpty && lastScrollDirection != .top
+    }
+    
     var bindings: RoomScreenViewStateBindings
 }
 
 struct RoomScreenViewStateBindings { }
 
-enum RoomScreenComposerAction {
-    case saveDraft
-    case loadDraft
+enum PinnedEventsBannerState: Equatable {
+    case loading(numbersOfEvents: Int)
+    case loaded(state: PinnedEventsState)
+    
+    var isEmpty: Bool {
+        switch self {
+        case .loaded(let state):
+            return state.pinnedEventContents.isEmpty
+        case .loading(let numberOfEvents):
+            return numberOfEvents == 0
+        }
+    }
+    
+    var isLoading: Bool {
+        switch self {
+        case .loading:
+            return true
+        default:
+            return false
+        }
+    }
+    
+    var selectedPinEventID: String? {
+        switch self {
+        case .loaded(let state):
+            return state.selectedPinEventID
+        default:
+            return nil
+        }
+    }
+    
+    var count: Int {
+        switch self {
+        case .loaded(let state):
+            return state.pinnedEventContents.count
+        case .loading(let numberOfEvents):
+            return numberOfEvents
+        }
+    }
+    
+    var selectedPinIndex: Int {
+        switch self {
+        case .loaded(let state):
+            return state.selectedPinIndex
+        case .loading(let numbersOfEvents):
+            // We always want the index to be the last one when loading, since is the default one.
+            return numbersOfEvents - 1
+        }
+    }
+    
+    var displayedMessage: AttributedString {
+        switch self {
+        case .loading:
+            return AttributedString(L10n.screenRoomPinnedBannerLoadingDescription)
+        case .loaded(let state):
+            return state.selectedPinContent
+        }
+    }
+    
+    var bannerIndicatorDescription: AttributedString {
+        let index = selectedPinIndex + 1
+        let boldPlaceholder = "{bold}"
+        var finalString = AttributedString(L10n.screenRoomPinnedBannerIndicatorDescription(boldPlaceholder))
+        var boldString = AttributedString(L10n.screenRoomPinnedBannerIndicator(index, count))
+        boldString.bold()
+        finalString.replace(boldPlaceholder, with: boldString)
+        return finalString
+    }
+    
+    mutating func previousPin() {
+        switch self {
+        case .loaded(var state):
+            state.previousPin()
+            self = .loaded(state: state)
+        default:
+            break
+        }
+    }
+    
+    mutating func setPinnedEventContents(_ pinnedEventContents: OrderedDictionary<String, AttributedString>) {
+        switch self {
+        case .loading:
+            // The default selected event should always be the last one.
+            self = .loaded(state: .init(pinnedEventContents: pinnedEventContents, selectedPinEventID: pinnedEventContents.keys.last))
+        case .loaded(var state):
+            state.pinnedEventContents = pinnedEventContents
+            self = .loaded(state: state)
+        }
+    }
 }