[iOS & tvOS] ItemLibraryViewModel - Cleanup (#1411)

* Move ItemType to Filter

* Init but normally...

* filter on people?

* Default to easiest / least change solution.

* Reset `.collectionFolder`, `.folder`, and `.BaseItemPerson` in `PagingLibraryView` to have the default filters. This was originally in place. This Commit just ensures that iOS and tvOS have the same implementation.

* wip

* Update ItemLibraryViewModel.swift

* Update ItemLibraryViewModel.swift

---------

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

Shared/Coordinators/MainCoordinator/tvOSMainTabCoordinator.swift

@@ -48,9 +48,8 @@ final class MainTabCoordinator: TabCoordinatable {
     }
 
     func makeTVShows() -> NavigationViewCoordinator<LibraryCoordinator<BaseItemDto>> {
-        let viewModel = ItemTypeLibraryViewModel(
-            itemTypes: [.series],
-            filters: .default
+        let viewModel = ItemLibraryViewModel(
+            filters: .init(itemTypes: [.series])
         )
         return NavigationViewCoordinator(LibraryCoordinator(viewModel: viewModel))
     }
@@ -65,9 +64,8 @@ final class MainTabCoordinator: TabCoordinatable {
     }
 
     func makeMovies() -> NavigationViewCoordinator<LibraryCoordinator<BaseItemDto>> {
-        let viewModel = ItemTypeLibraryViewModel(
-            itemTypes: [.movie],
-            filters: .default
+        let viewModel = ItemLibraryViewModel(
+            filters: .init(itemTypes: [.movie])
         )
         return NavigationViewCoordinator(LibraryCoordinator(viewModel: viewModel))
     }

Shared/Extensions/JellyfinAPI/BaseItemDto/BaseItemDto.swift

@@ -22,6 +22,7 @@ extension BaseItemDto: Displayable {
 }
 
 extension BaseItemDto: LibraryParent {
+
     var libraryType: BaseItemKind? {
         type
     }

Shared/Extensions/JellyfinAPI/BaseItemKind.swift

@@ -0,0 +1,31 @@
+//
+// Swiftfin is subject to the terms of the Mozilla Public
+// License, v2.0. If a copy of the MPL was not distributed with this
+// file, you can obtain one at https://mozilla.org/MPL/2.0/.
+//
+// Copyright (c) 2025 Jellyfin & Jellyfin Contributors
+//
+
+import JellyfinAPI
+
+extension BaseItemKind: SupportedCaseIterable {
+
+    /// The base supported cases for media navigation.
+    /// This differs from media viewing, which may include
+    /// `.episode`.
+    ///
+    /// These is the *base* supported cases and other objects
+    /// like `LibararyParent` may have additional supported
+    /// cases for querying a library.
+    static var supportedCases: [BaseItemKind] {
+        [.movie, .series, .boxSet]
+    }
+}
+
+extension BaseItemKind: ItemFilter {
+
+    // TODO: localize
+    var displayTitle: String {
+        rawValue
+    }
+}

Shared/Extensions/JellyfinAPI/BaseItemPerson/BaseItemPerson.swift

@@ -17,6 +17,7 @@ extension BaseItemPerson: Displayable {
 }
 
 extension BaseItemPerson: LibraryParent {
+
     var libraryType: BaseItemKind? {
         .person
     }

Shared/Objects/ItemFilter/ItemFilterCollection.swift

@@ -14,6 +14,7 @@ import JellyfinAPI
 struct ItemFilterCollection: Codable, Defaults.Serializable, Hashable {
 
     var genres: [ItemGenre] = []
+    var itemTypes: [BaseItemKind] = []
     var letter: [ItemLetter] = []
     var sortBy: [ItemSortBy] = [ItemSortBy.name]
     var sortOrder: [ItemSortOrder] = [ItemSortOrder.ascending]
@@ -32,7 +33,10 @@ struct ItemFilterCollection: Codable, Defaults.Serializable, Hashable {
         sortOrder: [ItemSortOrder.descending]
     )
 
-    /// A collection that has all statically available values
+    /// A collection that has all statically available values.
+    ///
+    /// These may be altered when used to better represent all
+    /// available values within the current context.
     static let all: ItemFilterCollection = .init(
         letter: ItemLetter.allCases,
         sortBy: ItemSortBy.allCases,

Shared/Objects/LibraryParent/LibraryParent.swift

@@ -6,17 +6,58 @@
 // Copyright (c) 2025 Jellyfin & Jellyfin Contributors
 //
 
-import Foundation
 import JellyfinAPI
 
 protocol LibraryParent: Displayable, Hashable, Identifiable<String?> {
 
-    // Only called `libraryType` because `BaseItemPerson` has
-    // a different `type` property. However, people should have
-    // different views so this can be renamed when they do, or
-    // this protocol to be removed entirely and replace just with
-    // a concrete `BaseItemDto`
-    //
-    // edit: studios also implement `LibraryParent` - reconsider above comment
+    /// The type of the library, reusing `BaseItemKind` for some
+    /// ease of provided variety like `folder` and `userView`.
     var libraryType: BaseItemKind? { get }
+
+    /// The `BaseItemKind` types that this library parent
+    /// support. Mainly used for `.folder` support.
+    ///
+    /// When using filters, this is used to determine the initial
+    /// set of supported types and then
+    var supportedItemTypes: [BaseItemKind] { get }
+
+    /// Modifies the parameters for the items request per this library parent.
+    func setParentParameters(_ parameters: Paths.GetItemsByUserIDParameters) -> Paths.GetItemsByUserIDParameters
+}
+
+extension LibraryParent {
+
+    var supportedItemTypes: [BaseItemKind] {
+        switch libraryType {
+        case .folder:
+            BaseItemKind.supportedCases
+                .appending([.folder, .collectionFolder])
+        default:
+            BaseItemKind.supportedCases
+        }
+    }
+
+    func setParentParameters(_ parameters: Paths.GetItemsByUserIDParameters) -> Paths.GetItemsByUserIDParameters {
+
+        guard let id else { return parameters }
+
+        var parameters = parameters
+        parameters.isRecursive = true
+        parameters.includeItemTypes = supportedItemTypes
+
+        switch libraryType {
+        case .collectionFolder, .userView:
+            parameters.parentID = id
+        case .folder:
+            parameters.parentID = id
+            parameters.isRecursive = nil
+        case .person:
+            parameters.personIDs = [id]
+        case .studio:
+            parameters.studioIDs = [id]
+        default: ()
+        }
+
+        return parameters
+    }
 }

Shared/ViewModels/FilterViewModel.swift

@@ -19,26 +19,18 @@ 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()
+        if let parent {
+            self.allFilters.itemTypes = parent.supportedItemTypes
+        }
     }
 
     /// Sets the query filters from the parent
@@ -53,10 +45,10 @@ 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,
-            includeItemTypes: itemTypes
+            parentID: parent?.id
         )
 
         let request = Paths.getQueryFiltersLegacy(parameters: parameters)

Shared/ViewModels/LibraryViewModel/ItemLibraryViewModel.swift

@@ -48,42 +48,23 @@ final class ItemLibraryViewModel: PagingLibraryViewModel<BaseItemDto> {
 
     // MARK: item parameters
 
-    func itemParameters(for page: Int?) -> Paths.GetItemsByUserIDParameters {
-
-        var libraryID: String?
-        var personIDs: [String]?
-        var studioIDs: [String]?
-        var includeItemTypes: [BaseItemKind] = [.movie, .series, .boxSet]
-        var isRecursive: Bool? = true
-
-        // TODO: this logic should be moved to a `LibraryParent` function
-        //       that transforms a `GetItemsByUserIDParameters` struct, instead
-        //       of having to do this case-by-case.
-
-        if let libraryType = parent?.libraryType, let id = parent?.id {
-            switch libraryType {
-            case .collectionFolder, .userView:
-                libraryID = id
-            case .folder:
-                libraryID = id
-                isRecursive = nil
-                includeItemTypes = [.movie, .series, .boxSet, .folder, .collectionFolder]
-            case .person:
-                personIDs = [id]
-            case .studio:
-                studioIDs = [id]
-            default: ()
-            }
-        }
+    private func itemParameters(for page: Int?) -> Paths.GetItemsByUserIDParameters {
 
         var parameters = Paths.GetItemsByUserIDParameters()
+
         parameters.enableUserData = true
         parameters.fields = .MinimumFields
-        parameters.includeItemTypes = includeItemTypes
-        parameters.isRecursive = isRecursive
-        parameters.parentID = libraryID
-        parameters.personIDs = personIDs
-        parameters.studioIDs = studioIDs
+
+        // Default values, expected to be overridden
+        // by parent or filters
+        parameters.includeItemTypes = BaseItemKind.supportedCases
+        parameters.sortOrder = [.ascending]
+        parameters.sortBy = [ItemSortBy.name.rawValue]
+
+        // Parent
+        if let parent {
+            parameters = parent.setParentParameters(parameters)
+        }
 
         // Page size
         if let page {
@@ -101,6 +82,12 @@ final class ItemLibraryViewModel: PagingLibraryViewModel<BaseItemDto> {
             parameters.tags = filters.tags.map(\.value)
             parameters.years = filters.years.compactMap { Int($0.value) }
 
+            // Only set filtering on item types if selected, where
+            // supported values should have been set by the parent.
+            if filters.itemTypes.isNotEmpty {
+                parameters.includeItemTypes = filters.itemTypes
+            }
+
             if filters.letter.first?.value == "#" {
                 parameters.nameLessThan = "A"
             } else {