Add infinite scroll for search (fixes #5)

Shared/Defaults.swift

@@ -30,8 +30,7 @@ extension Defaults.Keys {
         .init(section: .channel("UC-lHJZR3Gqxm24_Vd_AJ5Yw", "PewDiePie")),
         .init(section: .channel("UCXuqSBlHAE6Xw-yeJA0Tunw", "Linus Tech Tips")),
         .init(section: .channel("UCBJycsmduvYEL83R_U4JriQ", "Marques Brownlee")),
-        .init(section: .channel("UCE_M8A5yxnLfW0KghEeajjw", "Apple")),
-        .init(section: .searchQuery("Apple Pie Recipes", "", "", ""))
+        .init(section: .channel("UCE_M8A5yxnLfW0KghEeajjw", "Apple"))
     ])
 
     #if !os(tvOS)

Shared/EnvironmentValues.swift

@@ -29,6 +29,12 @@ private struct CurrentPlaylistID: EnvironmentKey {
     static let defaultValue: String? = nil
 }
 
+private struct LoadMoreContentHandler: EnvironmentKey {
+    static let defaultValue: LoadMoreContentHandlerClosure = { print("infinite load") }
+}
+
+typealias LoadMoreContentHandlerClosure = () -> Void
+
 extension EnvironmentValues {
     var inNavigationView: Bool {
         get { self[InNavigationViewKey.self] }
@@ -59,4 +65,9 @@ extension EnvironmentValues {
         get { self[CurrentPlaylistID.self] }
         set { self[CurrentPlaylistID.self] = newValue }
     }
+
+    var loadMoreContentHandler: LoadMoreContentHandlerClosure {
+        get { self[LoadMoreContentHandler.self] }
+        set { self[LoadMoreContentHandler.self] = newValue }
+    }
 }

Shared/Favorites/FavoriteItemView.swift

@@ -113,12 +113,15 @@ struct FavoriteItemView: View {
             return accounts.api.playlist(id)
 
         case let .searchQuery(text, date, duration, order):
-            return accounts.api.search(.init(
-                query: text,
-                sortBy: SearchQuery.SortOrder(rawValue: order) ?? .uploadDate,
-                date: SearchQuery.Date(rawValue: date),
-                duration: SearchQuery.Duration(rawValue: duration)
-            ))
+            return accounts.api.search(
+                .init(
+                    query: text,
+                    sortBy: SearchQuery.SortOrder(rawValue: order) ?? .uploadDate,
+                    date: SearchQuery.Date(rawValue: date),
+                    duration: SearchQuery.Duration(rawValue: duration)
+                ),
+                page: nil
+            )
         }
 
         return nil

Shared/Search/SearchView.swift

@@ -199,10 +199,12 @@ struct SearchView: View {
                         }
 
                         HorizontalCells(items: items)
+                            .environment(\.loadMoreContentHandler) { state.loadNextPage() }
                     }
                     .edgesIgnoringSafeArea(.horizontal)
                 #else
                     VerticalCells(items: items)
+                        .environment(\.loadMoreContentHandler) { state.loadNextPage() }
                 #endif
 
                 if noResults {

Shared/Videos/HorizontalCells.swift

@@ -4,6 +4,8 @@ import SwiftUI
 struct HorizontalCells: View {
     var items = [ContentItem]()
 
+    @Environment(\.loadMoreContentHandler) private var loadMoreContentHandler
+
     @Default(.channelOnThumbnail) private var channelOnThumbnail
 
     var body: some View {
@@ -12,6 +14,7 @@ struct HorizontalCells: View {
                 ForEach(items) { item in
                     ContentItemView(item: item)
                         .environment(\.horizontalCells, true)
+                        .onAppear { loadMoreContentItemsIfNeeded(current: item) }
                     #if os(tvOS)
                         .frame(width: 580)
                         .padding(.trailing, 20)
@@ -33,6 +36,13 @@ struct HorizontalCells: View {
         .edgesIgnoringSafeArea(.horizontal)
     }
 
+    func loadMoreContentItemsIfNeeded(current item: ContentItem) {
+        let thresholdIndex = items.index(items.endIndex, offsetBy: -5)
+        if items.firstIndex(where: { $0.id == item.id }) == thresholdIndex {
+            loadMoreContentHandler()
+        }
+    }
+
     var cellHeight: Double {
         #if os(tvOS)
             560

Shared/Videos/VerticalCells.swift

@@ -6,6 +6,8 @@ struct VerticalCells: View {
         @Environment(\.verticalSizeClass) private var verticalSizeClass
     #endif
 
+    @Environment(\.loadMoreContentHandler) private var loadMoreContentHandler
+
     var items = [ContentItem]()
 
     var body: some View {
@@ -13,6 +15,7 @@ struct VerticalCells: View {
             LazyVGrid(columns: columns, alignment: .center) {
                 ForEach(items.sorted { $0 < $1 }) { item in
                     ContentItemView(item: item)
+                        .onAppear { loadMoreContentItemsIfNeeded(current: item) }
                 }
             }
             .padding()
@@ -24,6 +27,13 @@ struct VerticalCells: View {
         #endif
     }
 
+    func loadMoreContentItemsIfNeeded(current item: ContentItem) {
+        let thresholdIndex = items.index(items.endIndex, offsetBy: -5)
+        if items.firstIndex(where: { $0.id == item.id }) == thresholdIndex {
+            loadMoreContentHandler()
+        }
+    }
+
     var columns: [GridItem] {
         #if os(tvOS)
             items.count < 3 ? Array(repeating: GridItem(.fixed(500)), count: [items.count, 1].max()!) : adaptiveItem