import SwiftUI
import FlixyDesign
import FlixyDownloads
import FlixyPlayback
import PlexKit

/// Die Einstellungen.
///
/// In Phase 1 bewusst schmal: Serverangaben und Abmelden. Akzentfarbe,
/// Qualitätsregler und Download-Einstellungen kommen mit den Phasen, in denen
/// es das Geregelte auch gibt.
struct SettingsView: View {
    @Environment(FlixySession.self) private var session
    @Environment(\.flixyAccent) private var accent
    @Environment(PlaybackSettings.self) private var settings
    @Environment(DownloadCoordinator.self) private var downloads
    @State private var showsSignOutConfirmation = false

    var body: some View {
        Form {
            if let server = session.server {
                Section("settings.server") {
                    LabeledContent("settings.serverName", value: server.name)
                    LabeledContent("settings.connection", value: connectionLabel(server.connection))
                    LabeledContent("settings.address", value: server.connection.uri)
                        .font(.flixyCaption)
                        .textSelection(.enabled)
                }

                Section("settings.libraries") {
                    ForEach(session.libraries) { library in
                        LabeledContent(library.title, value: library.type.capitalized)
                    }
                }
            }

            Section {
                Picker("settings.qualityWifi", selection: Bindable(settings).wifiQuality) {
                    ForEach(PlaybackSettings.Quality.allCases) { quality in
                        Text(quality.label).tag(quality)
                    }
                }
                Picker("settings.qualityCellular", selection: Bindable(settings).cellularQuality) {
                    ForEach(PlaybackSettings.Quality.allCases) { quality in
                        Text(quality.label).tag(quality)
                    }
                }
            } header: {
                Text("settings.quality")
            } footer: {
                Text("settings.qualityExplanation")
            }

            Section("settings.playback") {
                Toggle("settings.autoSkipIntro", isOn: Bindable(settings).autoSkipIntro)
                Toggle("settings.autoSkipCredits", isOn: Bindable(settings).autoSkipCredits)
                Toggle("settings.autoPlayNext", isOn: Bindable(settings).autoPlayNext)
            }

            Section {
                NavigationLink {
                    AppearanceView()
                } label: {
                    Label("appearance.title", systemImage: "paintpalette")
                }

                NavigationLink {
                    HomeLayoutView()
                } label: {
                    Label("homeLayout.title", systemImage: "rectangle.stack")
                }

                NavigationLink {
                    DiagnosticsView()
                } label: {
                    Label("diagnostics.title", systemImage: "stethoscope")
                }
            }

            downloadSection

            Section("settings.app") {
                LabeledContent("settings.version", value: Branding.version)
                LabeledContent("settings.build", value: Branding.buildStamp)
            }

            Section {
                Button("action.signOut", role: .destructive) {
                    showsSignOutConfirmation = true
                }
            }
        }
        // Ausdrücklich, nicht nur geerbt.
        //
        // Listen und Formulare zeichnen ihre Zeilen teilweise in einem
        // eigenen Darstellungskontext, in dem eigene Umgebungswerte verloren
        // gehen können — sichtbar an Picker-Werten, die in der Standardfarbe
        // leuchteten, während die Schalter daneben schon die gewählte trugen.
        .tint(accent)
        .scrollContentBackground(.hidden)
        .background(Color.flixyCanvas)
        .navigationTitle(Text("sidebar.settings"))
        .navigationBarTitleDisplayMode(.inline)
        .confirmationDialog(
            Text("settings.signOutConfirm"),
            isPresented: $showsSignOutConfirmation,
            titleVisibility: .visible
        ) {
            Button("action.signOut", role: .destructive) { session.signOut() }
            Button("action.cancel", role: .cancel) {}
        } message: {
            Text("settings.signOutExplanation")
        }
    }

    /// Die Download-Einstellungen.
    ///
    /// Die Löschfrist steht bewusst mit ausgeschriebenen Fristen da statt mit
    /// einem Schieberegler: „Nach 7 Tagen" ist eine Entscheidung, die man
    /// bewusst trifft — beim Löschen von Filmen soll niemand versehentlich
    /// auf „sofort" rutschen.
    @ViewBuilder
    private var downloadSection: some View {
        @Bindable var downloads = downloads

        Section {
            Picker("settings.storageLimit", selection: storageLimitBinding) {
                Text("settings.storageUnlimited").tag(Int64(0))
                ForEach([Int64(5), 10, 20, 30, 50, 100], id: \.self) { gigabytes in
                    Text("\(gigabytes) GB").tag(gigabytes * 1_000_000_000)
                }
            }

            Picker("settings.deleteWatched", selection: deleteAfterBinding) {
                Text("settings.deleteNever").tag(Double(-1))
                Text("settings.deleteImmediately").tag(Double(0))
                Text("settings.deleteAfterDay").tag(Duration.afterOneDay.seconds)
                Text("settings.deleteAfterWeek").tag(Duration.afterOneWeek.seconds)
            }

            Picker("settings.keepUnwatched", selection: keepUnwatchedBinding) {
                Text("settings.keepOff").tag(0)
                ForEach([1, 2, 3, 5], id: \.self) { count in
                    Text("settings.keepCount \(count)").tag(count)
                }
            }

            Toggle("downloads.wifiOnly", isOn: $downloads.isWiFiOnly)
        } header: {
            Text("sidebar.downloads")
        } footer: {
            Text("settings.downloadsExplanation")
        }
    }

    private var storageLimitBinding: Binding<Int64> {
        Binding(
            get: { downloads.storageLimitBytes ?? 0 },
            set: { downloads.storageLimitBytes = $0 > 0 ? $0 : nil }
        )
    }

    private var deleteAfterBinding: Binding<Double> {
        Binding(
            get: { downloads.rules.deleteWatchedAfter?.seconds ?? -1 },
            set: { downloads.rules.deleteWatchedAfter = $0 >= 0 ? .seconds($0) : nil }
        )
    }

    private var keepUnwatchedBinding: Binding<Int> {
        Binding(
            get: { downloads.rules.keepUnwatchedEpisodes ?? 0 },
            set: { downloads.rules.keepUnwatchedEpisodes = $0 > 0 ? $0 : nil }
        )
    }

    /// Zeigt, über welchen Weg die Verbindung läuft — beim Suchen nach
    /// Ruckeln ist das die erste Frage.
    private func connectionLabel(_ connection: PlexConnection) -> String {
        if connection.local { return String(localized: "settings.connectionLocal") }
        if connection.relay { return String(localized: "settings.connectionRelay") }
        return String(localized: "settings.connectionRemote")
    }
}

extension PlaybackSettings.Quality {
    var label: LocalizedStringKey {
        switch self {
        case .original: "quality.original"
        case .high: "quality.high"
        case .medium: "quality.medium"
        case .low: "quality.low"
        case .minimal: "quality.minimal"
        }
    }
}