[tvOS] ItemTypeLibraryViewModel - Implement FilterViewModel (#1409)

* FilterViewModel only

* comments

---------

Co-authored-by: Ethan Pippin <ethanpippin2343@gmail.com>

Shared/Coordinators/MainCoordinator/tvOSMainTabCoordinator.swift

@@ -48,7 +48,10 @@ final class MainTabCoordinator: TabCoordinatable {
     }
 
     func makeTVShows() -> NavigationViewCoordinator<LibraryCoordinator<BaseItemDto>> {
-        let viewModel = ItemTypeLibraryViewModel(itemTypes: [.series])
+        let viewModel = ItemTypeLibraryViewModel(
+            itemTypes: [.series],
+            filters: .default
+        )
         return NavigationViewCoordinator(LibraryCoordinator(viewModel: viewModel))
     }
 
@@ -62,7 +65,10 @@ final class MainTabCoordinator: TabCoordinatable {
     }
 
     func makeMovies() -> NavigationViewCoordinator<LibraryCoordinator<BaseItemDto>> {
-        let viewModel = ItemTypeLibraryViewModel(itemTypes: [.movie])
+        let viewModel = ItemTypeLibraryViewModel(
+            itemTypes: [.movie],
+            filters: .default
+        )
         return NavigationViewCoordinator(LibraryCoordinator(viewModel: viewModel))
     }
 

Shared/ViewModels/FilterViewModel.swift

@@ -19,12 +19,24 @@ final class FilterViewModel: ViewModel {
     var allFilters: ItemFilterCollection = .all
 
     private let parent: (any LibraryParent)?
+    private let itemTypes: [BaseItemKind]?
 
     init(
         parent: (any LibraryParent)? = nil,
         currentFilters: ItemFilterCollection = .default
     ) {
         self.parent = parent
+        self.itemTypes = nil
+        self.currentFilters = currentFilters
+        super.init()
+    }
+
+    init(
+        itemTypes: [BaseItemKind],
+        currentFilters: ItemFilterCollection = .default
+    ) {
+        self.parent = nil
+        self.itemTypes = itemTypes
         self.currentFilters = currentFilters
         super.init()
     }
@@ -43,7 +55,8 @@ final class FilterViewModel: ViewModel {
     private func getQueryFilters() async -> (genres: [ItemGenre], tags: [ItemTag], years: [ItemYear]) {
         let parameters = Paths.GetQueryFiltersLegacyParameters(
             userID: userSession.user.id,
-            parentID: parent?.id as? String
+            parentID: parent?.id as? String,
+            includeItemTypes: itemTypes
         )
 
         let request = Paths.getQueryFiltersLegacy(parameters: parameters)

Shared/ViewModels/LibraryViewModel/ItemLibraryViewModel.swift

@@ -56,9 +56,9 @@ final class ItemLibraryViewModel: PagingLibraryViewModel<BaseItemDto> {
         var includeItemTypes: [BaseItemKind] = [.movie, .series, .boxSet]
         var isRecursive: Bool? = true
 
-        // TODO: determine `includeItemTypes` better
+        // TODO: this logic should be moved to a `LibraryParent` function
-        //       - look at parent collection type if necessary
+        //       that transforms a `GetItemsByUserIDParameters` struct, instead
-        //       - condense supported values
+        //       of having to do this case-by-case.
 
         if let libraryType = parent?.libraryType, let id = parent?.id {
             switch libraryType {

Shared/ViewModels/LibraryViewModel/ItemTypeLibraryViewModel.swift

@@ -11,17 +11,28 @@ import Foundation
 import Get
 import JellyfinAPI
 
-// TODO: atow, this is only really used for tvOS tabs
+// TODO: filtering on `itemTypes` should be moved to `ItemFilterCollection`,
+//       but there is additional logic based on the parent type, mainly `.folder`.
 final class ItemTypeLibraryViewModel: PagingLibraryViewModel<BaseItemDto> {
 
     let itemTypes: [BaseItemKind]
 
-    init(itemTypes: [BaseItemKind]) {
+    // MARK: Initializer
+
+    init(
+        itemTypes: [BaseItemKind],
+        filters: ItemFilterCollection? = nil
+    ) {
         self.itemTypes = itemTypes
 
-        super.init()
+        super.init(
+            itemTypes: itemTypes,
+            filters: filters
+        )
     }
 
+    // MARK: Get Page
+
     override func get(page: Int) async throws -> [BaseItemDto] {
 
         let parameters = itemParameters(for: page)
@@ -31,6 +42,8 @@ final class ItemTypeLibraryViewModel: PagingLibraryViewModel<BaseItemDto> {
         return response.value.items ?? []
     }
 
+    // MARK: Item Parameters
+
     func itemParameters(for page: Int?) -> Paths.GetItemsByUserIDParameters {
 
         var parameters = Paths.GetItemsByUserIDParameters()
@@ -38,8 +51,6 @@ final class ItemTypeLibraryViewModel: PagingLibraryViewModel<BaseItemDto> {
         parameters.fields = .MinimumFields
         parameters.includeItemTypes = itemTypes
         parameters.isRecursive = true
-        parameters.sortBy = [ItemSortBy.name.rawValue]
-        parameters.sortOrder = [.ascending]
 
         // Page size
         if let page {
@@ -47,6 +58,48 @@ final class ItemTypeLibraryViewModel: PagingLibraryViewModel<BaseItemDto> {
             parameters.startIndex = page * pageSize
         }
 
+        // Filters
+        if let filterViewModel {
+            let filters = filterViewModel.currentFilters
+            parameters.filters = filters.traits
+            parameters.genres = filters.genres.map(\.value)
+            parameters.sortBy = filters.sortBy.map(\.rawValue)
+            parameters.sortOrder = filters.sortOrder
+            parameters.tags = filters.tags.map(\.value)
+            parameters.years = filters.years.compactMap { Int($0.value) }
+
+            if filters.letter.first?.value == "#" {
+                parameters.nameLessThan = "A"
+            } else {
+                parameters.nameStartsWith = filters.letter
+                    .map(\.value)
+                    .filter { $0 != "#" }
+                    .first
+            }
+
+            // Random sort won't take into account previous items, so
+            // manual exclusion is necessary. This could possibly be
+            // a performance issue for loading pages after already loading
+            // many items, but there's nothing we can do about that.
+            if filters.sortBy.first == ItemSortBy.random {
+                parameters.excludeItemIDs = elements.compactMap(\.id)
+            }
+        }
+
         return parameters
     }
+
+    // MARK: Get Random Item
+
+    override func getRandomItem() async -> BaseItemDto? {
+
+        var parameters = itemParameters(for: nil)
+        parameters.limit = 1
+        parameters.sortBy = [ItemSortBy.random.rawValue]
+
+        let request = Paths.getItemsByUserID(userID: userSession.user.id, parameters: parameters)
+        let response = try? await userSession.client.send(request)
+
+        return response?.value.items?.first
+    }
 }

Shared/ViewModels/LibraryViewModel/PagingLibraryViewModel.swift

@@ -49,6 +49,8 @@ protocol LibraryIdentifiable: Identifiable {
 //       on refresh. Should make bidirectional/offset index start?
 //       - use startIndex/index ranges instead of pages
 //       - source of data doesn't guarantee that all items in 0 ..< startIndex exist
+// TODO: have `filterViewModel` be private to the parent and the `get_` overrides recieve the
+//       current filters as a parameter
 
 /*
  Note: if `rememberSort == true`, then will override given filters with stored sorts
@@ -218,6 +220,52 @@ class PagingLibraryViewModel<Element: Poster>: ViewModel, Eventful, Stateful {
         }
     }
 
+    // paging item type
+    init(
+        itemTypes: [BaseItemKind],
+        filters: ItemFilterCollection? = nil,
+        pageSize: Int = DefaultPageSize
+    ) {
+        self.elements = IdentifiedArray([], id: \.unwrappedIDHashOrZero, uniquingIDsWith: { x, _ in x })
+        self.isStatic = false
+        self.pageSize = pageSize
+
+        self.parent = nil
+
+        if let filters {
+            self.filterViewModel = .init(
+                itemTypes: itemTypes,
+                currentFilters: filters
+            )
+        } else {
+            self.filterViewModel = nil
+        }
+
+        super.init()
+
+        Notifications[.didDeleteItem]
+            .publisher
+            .sink { id in
+                self.elements.remove(id: id.hashValue)
+            }
+            .store(in: &cancellables)
+
+        if let filterViewModel {
+            filterViewModel.$currentFilters
+                .dropFirst()
+                .debounce(for: 1, scheduler: RunLoop.main)
+                .removeDuplicates()
+                .sink { [weak self] _ in
+                    guard let self else { return }
+
+                    Task { @MainActor in
+                        self.send(.refresh)
+                    }
+                }
+                .store(in: &cancellables)
+        }
+    }
+
     convenience init(
         title: String,
         id: String?,