//
// 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) 2022 Jellyfin & Jellyfin Contributors
//

import JellyfinAPI
import SwiftUI

struct EpisodesRowView<RowManager>: View where RowManager: EpisodesRowManager {

	@EnvironmentObject
	var itemRouter: ItemCoordinator.Router
	@ObservedObject
	var viewModel: RowManager
    let onlyCurrentSeason: Bool

	var body: some View {
		VStack(alignment: .leading, spacing: 0) {

			HStack {
                
                if onlyCurrentSeason {
                    if let currentSeason = Array(viewModel.seasonsEpisodes.keys).first(where: { $0.id == viewModel.item.id }) {
                        Text(currentSeason.name ?? L10n.noTitle)
                    }
                } else {
                    Menu {
                        ForEach(Array(viewModel.seasonsEpisodes.keys).sorted(by: { $0.name ?? "" < $1.name ?? "" }), id: \.self) { season in
                            Button {
                                viewModel.select(season: season)
                            } label: {
                                if season.id == viewModel.selectedSeason?.id {
                                    Label(season.name ?? L10n.season, systemImage: "checkmark")
                                } else {
                                    Text(season.name ?? L10n.season)
                                }
                            }
                        }
                    } label: {
                        HStack(spacing: 5) {
                            Text(viewModel.selectedSeason?.name ?? L10n.unknown)
                                .fontWeight(.semibold)
                                .fixedSize()
                            Image(systemName: "chevron.down")
                        }
                    }
                }

				Spacer()
			}
			.padding()

			ScrollView(.horizontal, showsIndicators: false) {
				ScrollViewReader { reader in
					HStack(alignment: .top, spacing: 15) {
						if viewModel.isLoading {
							VStack(alignment: .leading) {

								ZStack {
									Color.gray.ignoresSafeArea()

									ProgressView()
								}
								.mask(Rectangle().frame(width: 200, height: 112).cornerRadius(10))
								.frame(width: 200, height: 112)

								VStack(alignment: .leading) {
									Text("S-:E-")
										.font(.footnote)
										.foregroundColor(.secondary)
									Text("--")
										.font(.body)
										.padding(.bottom, 1)
										.lineLimit(2)
								}

								Spacer()
							}
							.frame(width: 200)
							.shadow(radius: 4, y: 2)
						} else if let selectedSeason = viewModel.selectedSeason {
                            if let seasonEpisodes = viewModel.seasonsEpisodes[selectedSeason] {
                                if seasonEpisodes.isEmpty {
                                    VStack(alignment: .leading) {

                                        Color.gray.ignoresSafeArea()
                                            .mask(Rectangle().frame(width: 200, height: 112).cornerRadius(10))
                                            .frame(width: 200, height: 112)

                                        VStack(alignment: .leading) {
                                            Text("--")
                                                .font(.footnote)
                                                .foregroundColor(.secondary)

                                            L10n.noEpisodesAvailable.text
                                                .font(.body)
                                                .padding(.bottom, 1)
                                                .lineLimit(2)
                                        }

                                        Spacer()
                                    }
                                    .frame(width: 200)
                                    .shadow(radius: 4, y: 2)
                                } else {
                                    ForEach(seasonEpisodes, id: \.self) { episode in
                                        EpisodeRowCard(viewModel: viewModel, episode: episode)
                                            .id(episode.id)
                                    }
                                }
                            }
						}
					}
					.padding(.horizontal)
					.onChange(of: viewModel.selectedSeason) { _ in
						if viewModel.selectedSeason?.id == viewModel.item.seasonId {
							reader.scrollTo(viewModel.item.id)
						}
					}
					.onChange(of: viewModel.seasonsEpisodes) { _ in
						if viewModel.selectedSeason?.id == viewModel.item.seasonId {
							reader.scrollTo(viewModel.item.id)
						}
					}
				}
				.edgesIgnoringSafeArea(.horizontal)
			}
		}
	}
}