From c6b1413b7862812999d54607c202efcaedd4a34e Mon Sep 17 00:00:00 2001
From: Diogo <diogofncunha@gmail.com>
Date: Tue, 8 Oct 2024 15:26:55 +0100
Subject: [PATCH] simplify and pass direction

---
 apps/ios/Shared/Views/Chat/ChatView.swift    | 13 ++++++++-----
 apps/ios/Shared/Views/Chat/ReverseList.swift | 15 ++-------------
 2 files changed, 10 insertions(+), 18 deletions(-)

diff --git a/apps/ios/Shared/Views/Chat/ChatView.swift b/apps/ios/Shared/Views/Chat/ChatView.swift
index 7f6b61c1ea..85b3935502 100644
--- a/apps/ios/Shared/Views/Chat/ChatView.swift
+++ b/apps/ios/Shared/Views/Chat/ChatView.swift
@@ -179,7 +179,7 @@ struct ChatView: View {
             if !isLoading,
                im.reversedChatItems.count <= loadItemsPerPage,
                filtered(im.reversedChatItems).count < 10 {
-                loadChatItems(chat.chatInfo)
+                loadChatItems(chat.chatInfo, .toOldest)
             }
         }
         .environmentObject(scrollModel)
@@ -433,8 +433,8 @@ struct ChatView: View {
                     forwardedChatItems: $forwardedChatItems
                 )
                 .id(ci.id) // Required to trigger `onAppear` on iOS15
-            } loadPage: {
-                loadChatItems(cInfo)
+            } loadPage: { direction in
+                loadChatItems(cInfo, direction)
             }
             .opacity(ItemsModel.shared.isLoading ? 0 : 1)
             .padding(.vertical, -InvertedTableView.inset)
@@ -834,7 +834,7 @@ struct ChatView: View {
         }
     }
 
-    private func loadChatItems(_ cInfo: ChatInfo) {
+    private func loadChatItems(_ cInfo: ChatInfo, _ direction: ChatScrollDirection) {
         Task {
             if loadingItems || firstPage { return }
             loadingItems = true
@@ -844,8 +844,11 @@ struct ChatView: View {
                 // Load additional items until the page is +50 large after merging
                 while chatItemsAvailable && filtered(reversedPage).count < loadItemsPerPage {
                     let pagination: ChatPagination =
-                        if let lastItem = reversedPage.last ?? im.reversedChatItems.last {
+                        if direction == .toOldest, let lastItem = reversedPage.last ?? im.reversedChatItems.last {
                             .before(chatItemId: lastItem.id, count: loadItemsPerPage)
+                        } else if direction == .toLatest, let firstItem = reversedPage.first ?? im.reversedChatItems.first {
+                            // TODO: Replace with anchor.
+                            .after(chatItemId: firstItem.id, count: loadItemsPerPage)
                         } else {
                             .last(count: loadItemsPerPage)
                         }
diff --git a/apps/ios/Shared/Views/Chat/ReverseList.swift b/apps/ios/Shared/Views/Chat/ReverseList.swift
index 29a09a9429..b6cf500b84 100644
--- a/apps/ios/Shared/Views/Chat/ReverseList.swift
+++ b/apps/ios/Shared/Views/Chat/ReverseList.swift
@@ -25,7 +25,7 @@ struct ReverseList<Content: View>: UIViewControllerRepresentable {
     /// Closure, that returns user interface for a given item
     let content: (ChatItem) -> Content
 
-    let loadPage: () -> Void
+    let loadPage: (ChatScrollDirection) -> Void
 
     func makeUIViewController(context: Context) -> Controller {
         Controller(representer: self)
@@ -56,8 +56,6 @@ struct ReverseList<Content: View>: UIViewControllerRepresentable {
         private var itemCount: Int = 0
         private let updateFloatingButtons = PassthroughSubject<Void, Never>()
         private var bag = Set<AnyCancellable>()
-        private var lastContentOffset: CGFloat = 0
-        private var scrollDirection: ChatScrollDirection = .none
 
         init(representer: ReverseList) {
             self.representer = representer
@@ -87,7 +85,7 @@ struct ReverseList<Content: View>: UIViewControllerRepresentable {
                 tableView: tableView
             ) { (tableView, indexPath, item) -> UITableViewCell? in
                 if indexPath.item > self.itemCount - 8, self.itemCount > 8 {
-                    self.representer.loadPage()
+                    self.representer.loadPage(.toOldest)
                 }
                 let cell = tableView.dequeueReusableCell(withIdentifier: cellReuseId, for: indexPath)
                 if #available(iOS 16.0, *) {
@@ -213,15 +211,6 @@ struct ReverseList<Content: View>: UIViewControllerRepresentable {
         }
 
         override func scrollViewDidScroll(_ scrollView: UIScrollView) {
-            let currentOffset = scrollView.contentOffset.y
-            if currentOffset > lastContentOffset {
-                scrollDirection = .toOldest
-            } else if currentOffset < lastContentOffset {
-                scrollDirection = .toLatest
-            } else {
-                scrollDirection = .none
-            }
-            lastContentOffset = currentOffset
             updateFloatingButtons.send()
         }