jellyflood/Shared/ViewModels/ItemViewModel.swift

//
 /* 
  * 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 2021 Aiden Vigue & Jellyfin Contributors
  */

import Combine
import Foundation
import JellyfinAPI
import UIKit

class ItemViewModel: ViewModel {

    @Published var item: BaseItemDto
    @Published var playButtonItem: BaseItemDto? {
        didSet {
            playButtonItem?.createVideoPlayerViewModel()
                .sink { completion in
                    self.handleAPIRequestError(completion: completion)
                } receiveValue: { videoPlayerViewModel in
                    self.itemVideoPlayerViewModel = videoPlayerViewModel
                    self.mediaItems = videoPlayerViewModel.item.createMediaItems()
                }
                .store(in: &cancellables)
        }
    }
    @Published var similarItems: [BaseItemDto] = []
    @Published var isWatched = false
    @Published var isFavorited = false
    @Published var informationItems: [BaseItemDto.ItemDetail]
    @Published var mediaItems: [BaseItemDto.ItemDetail]
    var itemVideoPlayerViewModel: VideoPlayerViewModel?

    init(item: BaseItemDto) {
        self.item = item

        switch item.itemType {
        case .episode, .movie:
            self.playButtonItem = item
        default: ()
        }
        
        informationItems = item.createInformationItems()
        mediaItems = item.createMediaItems()

        isFavorited = item.userData?.isFavorite ?? false
        isWatched = item.userData?.played ?? false
        super.init()

        getSimilarItems()
        
        item.createVideoPlayerViewModel()
            .sink { completion in
                self.handleAPIRequestError(completion: completion)
            } receiveValue: { videoPlayerViewModel in
                self.itemVideoPlayerViewModel = videoPlayerViewModel
                self.mediaItems = videoPlayerViewModel.item.createMediaItems()
            }
            .store(in: &cancellables)
    }

    func playButtonText() -> String {
        if let itemProgressString = item.getItemProgressString() {
            return itemProgressString
        }
        
        return L10n.play
    }

    func getItemDisplayName() -> String {
        return item.name ?? ""
    }

    func shouldDisplayRuntime() -> Bool {
        return true
    }

    func getSimilarItems() {
        LibraryAPI.getSimilarItems(itemId: item.id!, userId: SessionManager.main.currentLogin.user.id, limit: 20, fields: [.primaryImageAspectRatio, .seriesPrimaryImage, .seasonUserData, .overview, .genres, .people])
            .trackActivity(loading)
            .sink(receiveCompletion: { [weak self] completion in
                self?.handleAPIRequestError(completion: completion)
            }, receiveValue: { [weak self] response in
                self?.similarItems = response.items ?? []
            })
            .store(in: &cancellables)
    }

    func updateWatchState() {
        if isWatched {
            PlaystateAPI.markUnplayedItem(userId: SessionManager.main.currentLogin.user.id, itemId: item.id!)
                .trackActivity(loading)
                .sink(receiveCompletion: { [weak self] completion in
                    self?.handleAPIRequestError(completion: completion)
                }, receiveValue: { [weak self] _ in
                    self?.isWatched = false
                })
                .store(in: &cancellables)
        } else {
            PlaystateAPI.markPlayedItem(userId: SessionManager.main.currentLogin.user.id, itemId: item.id!)
                .trackActivity(loading)
                .sink(receiveCompletion: { [weak self] completion in
                    self?.handleAPIRequestError(completion: completion)
                }, receiveValue: { [weak self] _ in
                    self?.isWatched = true
                })
                .store(in: &cancellables)
        }
    }

    func updateFavoriteState() {
        if isFavorited {
            UserLibraryAPI.unmarkFavoriteItem(userId: SessionManager.main.currentLogin.user.id, itemId: item.id!)
                .trackActivity(loading)
                .sink(receiveCompletion: { [weak self] completion in
                    self?.handleAPIRequestError(completion: completion)
                }, receiveValue: { [weak self] _ in
                    self?.isFavorited = false
                })
                .store(in: &cancellables)
        } else {
            UserLibraryAPI.markFavoriteItem(userId: SessionManager.main.currentLogin.user.id, itemId: item.id!)
                .trackActivity(loading)
                .sink(receiveCompletion: { [weak self] completion in
                    self?.handleAPIRequestError(completion: completion)
                }, receiveValue: { [weak self] _ in
                    self?.isFavorited = true
                })
                .store(in: &cancellables)
        }
    }
}