import SwiftUI
import FlixyDesign
import PlexKit

/// Reihen der Startseite ein- und ausblenden und umsortieren.
struct HomeLayoutView: View {
    @Environment(FlixySession.self) private var session
    @Environment(HomeLayoutSettings.self) private var layout

    @State private var rows: [HomeRow] = []
    @State private var isLoading = true

    var body: some View {
        Group {
            if isLoading {
                ProgressView().frame(maxWidth: .infinity, maxHeight: .infinity)
            } else if rows.isEmpty {
                ContentUnavailableView {
                    Label("home.empty.title", systemImage: "rectangle.stack")
                } description: {
                    Text("homeLayout.empty")
                }
            } else {
                list
            }
        }
        .background(Color.flixyCanvas)
        .navigationTitle(Text("homeLayout.title"))
        .navigationBarTitleDisplayMode(.inline)
        .toolbar { EditButton() }
        .task { await load() }
    }

    private var list: some View {
        List {
            Section {
                ForEach($rows) { $row in
                    Toggle(isOn: Binding(
                        get: { !row.isHidden },
                        set: {
                            row.isHidden = !$0
                            layout.setHidden(!$0, for: row.id)
                        }
                    )) {
                        Text(row.title)
                            .foregroundStyle(Color.flixyTextPrimary)
                    }
                    .listRowBackground(Color.flixySurface)
                }
                .onMove { indices, destination in
                    rows.move(fromOffsets: indices, toOffset: destination)
                    layout.setOrder(rows.map(\.id))
                }
            } footer: {
                Text("homeLayout.explanation")
            }
        }
        .scrollContentBackground(.hidden)
    }

    private func load() async {
        defer { isLoading = false }
        guard let server = session.server else { return }
        // Die Reihen kommen vom Server — es gibt keine feste Liste, die sich
        // vorweg anzeigen ließe. Was hier steht, hängt davon ab, welche
        // Mediatheken und Sammlungen angelegt sind.
        let hubs = (try? await server.homeHubs()) ?? []
        rows = layout.rows(from: hubs)
    }
}