import SwiftUI

struct SettingsView: View {
    @EnvironmentObject var appState: AppState
    @Environment(\.dismiss) var dismiss
    @State private var showLegal = false
    @State private var showDeleteConfirm = false
    @State private var showDeleteFinal = false
    @State private var deletePassword = ""
    @State private var isDeleting = false
    @State private var deleteError: String?
    @State private var notificationsEnabled = false

    var body: some View {
        NavigationStack {
            ZStack {
                Color.nightBase.ignoresSafeArea()

                List {
                    // Account
                    Section {
                        if let user = appState.currentUser {
                            HStack(spacing: 12) {
                                AvatarView(user: user, size: 44)
                                VStack(alignment: .leading, spacing: 2) {
                                    Text(user.displayName)
                                        .font(.nightLabel(15, weight: .semibold))
                                        .foregroundColor(.nightPrimary)
                                    Text("@\(user.username)")
                                        .font(.nightLabel(13))
                                        .foregroundColor(.nightSecondary)
                                }
                            }
                            .padding(.vertical, 4)
                        }
                    }
                    .listRowBackground(Color.nightSurface)

                    // Benachrichtigungen
                    Section("benachrichtigungen") {
                        HStack {
                            VStack(alignment: .leading, spacing: 2) {
                                Text("nightly ping")
                                    .font(.nightLabel(15))
                                    .foregroundColor(.nightPrimary)
                                Text("Wenn das Fenster öffnet")
                                    .font(.nightLabel(12))
                                    .foregroundColor(.nightSecondary)
                            }
                            Spacer()
                            Toggle("", isOn: $notificationsEnabled)
                                .tint(.nightPurple)
                        }

                        // APNs-Hinweis
                        HStack(spacing: 8) {
                            Image(systemName: "info.circle")
                                .foregroundColor(.nightSecondary)
                                .font(.system(size: 13))
                            Text("Push-Benachrichtigungen benötigen einen bezahlten Apple Developer Account ($99/Jahr).")
                                .font(.nightLabel(12))
                                .foregroundColor(.nightSecondary)
                                .lineSpacing(3)
                        }
                        .padding(.vertical, 2)
                    }
                    .listRowBackground(Color.nightSurface)

                    // Rechtliches
                    Section("rechtliches") {
                        Button {
                            showLegal = true
                        } label: {
                            HStack {
                                Text("Impressum & Datenschutz")
                                    .font(.nightLabel(15))
                                    .foregroundColor(.nightPrimary)
                                Spacer()
                                Image(systemName: "chevron.right")
                                    .font(.system(size: 12))
                                    .foregroundColor(.nightSecondary)
                            }
                        }

                        HStack {
                            Text("Version")
                                .font(.nightLabel(15))
                                .foregroundColor(.nightPrimary)
                            Spacer()
                            Text(appVersion)
                                .font(.nightMono(13))
                                .foregroundColor(.nightSecondary)
                        }
                    }
                    .listRowBackground(Color.nightSurface)

                    // Account-Aktionen
                    Section("account") {
                        Button {
                            appState.signOut()
                            dismiss()
                        } label: {
                            Text("abmelden")
                                .font(.nightLabel(15))
                                .foregroundColor(.nightPrimary)
                        }

                        Button(role: .destructive) {
                            showDeleteConfirm = true
                        } label: {
                            Text("account löschen")
                                .font(.nightLabel(15))
                                .foregroundColor(.nightRed)
                        }
                    }
                    .listRowBackground(Color.nightSurface)
                }
                .scrollContentBackground(.hidden)
                .listStyle(.insetGrouped)
            }
            .navigationBarTitleDisplayMode(.inline)
            .toolbar {
                ToolbarItem(placement: .principal) {
                    Text("einstellungen")
                        .font(.nightTitle(17))
                        .foregroundColor(.nightPrimary)
                }
                ToolbarItem(placement: .navigationBarLeading) {
                    Button("Fertig") { dismiss() }
                        .foregroundColor(.nightSecondary)
                }
            }
            .sheet(isPresented: $showLegal) { LegalView() }
        }
        .preferredColorScheme(.dark)
        // Schritt 1: Erklärung
        .confirmationDialog(
            "Account wirklich löschen?",
            isPresented: $showDeleteConfirm,
            titleVisibility: .visible
        ) {
            Button("Ja, Account löschen", role: .destructive) {
                showDeleteFinal = true
            }
        } message: {
            Text("Alle deine Posts, Reaktionen und Daten werden sofort und dauerhaft gelöscht. Dieser Vorgang kann nicht rückgängig gemacht werden.")
        }
        // Schritt 2: Passwort bestätigen
        .sheet(isPresented: $showDeleteFinal) {
            DeleteAccountSheet(
                password: $deletePassword,
                isDeleting: isDeleting,
                error: deleteError,
                onDelete: { Task { await deleteAccount() } }
            )
        }
        .onAppear { checkNotificationStatus() }
    }

    var appVersion: String {
        Bundle.main.infoDictionary?["CFBundleShortVersionString"] as? String ?? "1.0"
    }

    func checkNotificationStatus() {
        Task {
            let settings = await UNUserNotificationCenter.current().notificationSettings()
            notificationsEnabled = settings.authorizationStatus == .authorized
        }
    }

    func deleteAccount() async {
        isDeleting = true
        deleteError = nil
        defer { isDeleting = false }
        do {
            try await appState.deleteAccount()
            showDeleteFinal = false
            dismiss()
        } catch {
            deleteError = error.localizedDescription
        }
    }
}

struct DeleteAccountSheet: View {
    @Binding var password: String
    let isDeleting: Bool
    let error: String?
    let onDelete: () -> Void
    @Environment(\.dismiss) var dismiss

    var body: some View {
        NavigationStack {
            ZStack {
                Color.nightBase.ignoresSafeArea()
                VStack(spacing: 24) {
                    Image(systemName: "trash.circle.fill")
                        .font(.system(size: 52))
                        .foregroundColor(.nightRed)

                    VStack(spacing: 8) {
                        Text("Account löschen")
                            .font(.nightTitle(22))
                            .foregroundColor(.nightPrimary)
                        Text("Diese Aktion löscht alle deine Daten dauerhaft. Kein Weg zurück.")
                            .font(.nightBody(15))
                            .foregroundColor(.nightSecondary)
                            .multilineTextAlignment(.center)
                    }

                    NightlyField(text: $password, placeholder: "passwort bestätigen", icon: "lock", isSecure: true)
                        .padding(.horizontal, 24)

                    if let err = error {
                        Text(err).font(.nightLabel(13)).foregroundColor(.nightRed)
                    }

                    Button {
                        onDelete()
                    } label: {
                        Group {
                            if isDeleting { ProgressView().tint(.white) }
                            else { Text("endgültig löschen").font(.nightLabel(16, weight: .semibold)).foregroundColor(.white) }
                        }
                        .frame(maxWidth: .infinity).frame(height: 50)
                        .background(Color.nightRed)
                        .clipShape(RoundedRectangle(cornerRadius: 14))
                    }
                    .disabled(password.isEmpty || isDeleting)
                    .padding(.horizontal, 24)
                }
                .padding(.top, 32)
            }
            .toolbar {
                ToolbarItem(placement: .navigationBarLeading) {
                    Button("Abbrechen") { dismiss() }.foregroundColor(.nightSecondary)
                }
            }
        }
        .preferredColorScheme(.dark)
        .presentationDetents([.medium])
    }
}