From 746b56bc7763fbbaa9ca28a67bc7ee4b712eea5b Mon Sep 17 00:00:00 2001
From: Trey t <treytartt@fastmail.com>
Date: Mon, 12 Jan 2026 19:07:54 -0600
Subject: [PATCH] perf: add pagination to schedule list

Loads 50 games at a time to fix lag with large datasets.

- Add pagination state (displayedGames, currentPage, allFilteredGames)
- Add loadInitialGames() and loadMoreGames() methods
- Update gamesBySport to use displayedGames
- Add infinite scroll trigger via onAppear on last game
- Add ProgressView indicator when more games available
- Reset pagination when search text changes

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
---
 .../ViewModels/ScheduleViewModel.swift        | 44 ++++++++++++++++++-
 .../Schedule/Views/ScheduleListView.swift     | 25 ++++++++++-
 2 files changed, 66 insertions(+), 3 deletions(-)

diff --git a/SportsTime/Features/Schedule/ViewModels/ScheduleViewModel.swift b/SportsTime/Features/Schedule/ViewModels/ScheduleViewModel.swift
index 8a505b1..7be2438 100644
--- a/SportsTime/Features/Schedule/ViewModels/ScheduleViewModel.swift
+++ b/SportsTime/Features/Schedule/ViewModels/ScheduleViewModel.swift
@@ -26,6 +26,22 @@ final class ScheduleViewModel {
 
     private let dataProvider = AppDataProvider.shared
 
+    // MARK: - Pagination
+
+    private let pageSize = 50
+    private(set) var displayedGames: [RichGame] = []
+    private var currentPage = 0
+    private var allFilteredGames: [RichGame] = []
+
+    var hasMoreGames: Bool {
+        displayedGames.count < allFilteredGames.count
+    }
+
+    /// The last game in the displayed list, used for infinite scroll detection
+    var lastDisplayedGame: RichGame? {
+        displayedGames.last
+    }
+
     // MARK: - Computed Properties
 
     var filteredGames: [RichGame] {
@@ -51,7 +67,7 @@ final class ScheduleViewModel {
     }
 
     var gamesBySport: [(sport: Sport, games: [RichGame])] {
-        let grouped = Dictionary(grouping: filteredGames) { game in
+        let grouped = Dictionary(grouping: displayedGames) { game in
             game.game.sport
         }
         // Sort by sport order (use allCases index for consistent ordering)
@@ -69,11 +85,35 @@ final class ScheduleViewModel {
         selectedSports.count < Sport.supported.count || !searchText.isEmpty
     }
 
+    // MARK: - Pagination Actions
+
+    /// Updates filtered games list based on current search text and resets pagination
+    func updateFilteredGames() {
+        allFilteredGames = filteredGames
+        loadInitialGames()
+    }
+
+    /// Loads the first page of games
+    func loadInitialGames() {
+        currentPage = 0
+        displayedGames = Array(allFilteredGames.prefix(pageSize))
+    }
+
+    /// Loads more games when scrolling to the bottom
+    func loadMoreGames() {
+        guard hasMoreGames else { return }
+        currentPage += 1
+        let start = currentPage * pageSize
+        let end = min(start + pageSize, allFilteredGames.count)
+        displayedGames.append(contentsOf: allFilteredGames[start..<end])
+    }
+
     // MARK: - Actions
 
     func loadGames() async {
         guard !selectedSports.isEmpty else {
             games = []
+            updateFilteredGames()
             return
         }
 
@@ -92,6 +132,7 @@ final class ScheduleViewModel {
                 self.errorMessage = providerError
                 self.error = dataProvider.error
                 isLoading = false
+                updateFilteredGames()
                 return
             }
 
@@ -109,6 +150,7 @@ final class ScheduleViewModel {
         }
 
         isLoading = false
+        updateFilteredGames()
     }
 
     func clearError() {
diff --git a/SportsTime/Features/Schedule/Views/ScheduleListView.swift b/SportsTime/Features/Schedule/Views/ScheduleListView.swift
index c34eaaa..4706a89 100644
--- a/SportsTime/Features/Schedule/Views/ScheduleListView.swift
+++ b/SportsTime/Features/Schedule/Views/ScheduleListView.swift
@@ -12,11 +12,11 @@ struct ScheduleListView: View {
 
     var body: some View {
         Group {
-            if viewModel.isLoading && viewModel.games.isEmpty {
+            if viewModel.isLoading && viewModel.displayedGames.isEmpty {
                 loadingView
             } else if let errorMessage = viewModel.errorMessage {
                 errorView(message: errorMessage)
-            } else if viewModel.games.isEmpty {
+            } else if viewModel.displayedGames.isEmpty {
                 emptyView
             } else {
                 gamesList
@@ -58,6 +58,9 @@ struct ScheduleListView: View {
         .task {
             await viewModel.loadGames()
         }
+        .onChange(of: viewModel.searchText) {
+            viewModel.updateFilteredGames()
+        }
     }
 
     // MARK: - Sport Filter
@@ -93,6 +96,12 @@ struct ScheduleListView: View {
                 Section {
                     ForEach(sportGroup.games) { richGame in
                         GameRowView(game: richGame, showDate: true, showLocation: true)
+                            .onAppear {
+                                // Trigger load more when the last game appears
+                                if richGame.id == viewModel.lastDisplayedGame?.id {
+                                    viewModel.loadMoreGames()
+                                }
+                            }
                     }
                 } header: {
                     HStack(spacing: 8) {
@@ -103,6 +112,18 @@ struct ScheduleListView: View {
                 }
                 .listRowBackground(Theme.cardBackground(colorScheme))
             }
+
+            // Show loading indicator when more games are available
+            if viewModel.hasMoreGames {
+                Section {
+                    HStack {
+                        Spacer()
+                        ProgressView()
+                        Spacer()
+                    }
+                    .listRowBackground(Color.clear)
+                }
+            }
         }
         .listStyle(.plain)
         .scrollContentBackground(.hidden)