import SwiftUI

struct SettingsView: View {
    @Environment(AuthSession.self) private var auth
    @AppStorage("autoPauseEnabled") private var autoPauseEnabled = true
    @AppStorage("healthKitSyncEnabled") private var healthKitSyncEnabled = false
    @State private var showHealthPermissionAlert = false

    var body: some View {
        NavigationStack {
            Form {
                Section {
                    HStack(spacing: 14) {
                        avatarView
                            .frame(width: 60, height: 60)
                            .clipShape(Circle())
                        VStack(alignment: .leading, spacing: 2) {
                            Text(displayName)
                                .font(.headline)
                            if let email = auth.profile?.email {
                                Text(email)
                                    .font(.footnote)
                                    .foregroundStyle(.secondary)
                            }
                        }
                    }
                    .padding(.vertical, 4)
                }

                Section("Hund & Alltag") {
                    NavigationLink {
                        DogsListView()
                    } label: {
                        Label("Meine Hunde", systemImage: "pawprint.fill")
                    }
                    NavigationLink {
                        TagebuchView()
                    } label: {
                        Label("Tagebuch", systemImage: "book.fill")
                    }
                    NavigationLink {
                        ErsteHilfeView()
                    } label: {
                        Label("Erste Hilfe", systemImage: "cross.case.fill")
                    }
                    NavigationLink {
                        WetterView()
                    } label: {
                        Label("Wetter", systemImage: "cloud.sun.fill")
                    }
                    NavigationLink {
                        GassiZeitenView()
                    } label: {
                        Label("Gassi-Zeiten", systemImage: "alarm.fill")
                    }
                    NavigationLink {
                        GiftkoederView()
                    } label: {
                        Label("Giftköder", systemImage: "exclamationmark.octagon.fill")
                    }
                    NavigationLink {
                        VerloreneHundeView()
                    } label: {
                        Label("Verlorene Hunde", systemImage: "magnifyingglass.circle.fill")
                    }
                    NavigationLink {
                        AusgabenView()
                    } label: {
                        Label("Ausgaben", systemImage: "eurosign.circle.fill")
                    }
                }

                Section("Account") {
                    LabeledContent("Rolle", value: rolleLabel)
                    if auth.profile?.isFounderFlag == true {
                        LabeledContent("Founder", value: founderLabel)
                    }
                    if auth.profile?.isPartnerFlag == true {
                        LabeledContent("Partner", value: "Ja")
                    }
                    if let tier = auth.profile?.subscriptionTier, !tier.isEmpty {
                        LabeledContent("Abo", value: tier.capitalized)
                    }
                    LabeledContent("Premium", value: premiumValue ? "Ja" : "Nein")
                }

                if let wohnort = auth.profile?.wohnort, !wohnort.isEmpty {
                    Section("Ort") {
                        Text(wohnort)
                    }
                }

                Section {
                    Toggle(isOn: $autoPauseEnabled) {
                        Label("Auto-Pause", systemImage: "pause.circle")
                    }
                    Toggle(isOn: $healthKitSyncEnabled) {
                        Label("Apple Health Sync", systemImage: "heart.fill")
                    }
                    .onChange(of: healthKitSyncEnabled) { _, newValue in
                        if newValue {
                            Task {
                                let granted = await WalkHealthSync.shared.requestAuthorization()
                                if !granted {
                                    healthKitSyncEnabled = false
                                    showHealthPermissionAlert = true
                                }
                            }
                        }
                    }
                } header: {
                    Text("Aufnahme")
                } footer: {
                    Text("Auto-Pause: pausiert die Aufnahme, wenn du 2 Minuten lang stehen bleibst.\nApple Health: schreibt jede gespeicherte Tour als Spaziergang-Workout mit Route in Health.")
                }

                Section("Mehr auf banyaro.app") {
                    pwaLink("Forum", systemImage: "bubble.left.and.bubble.right.fill", fragment: "forum")
                    pwaLink("Hunde-Profile bearbeiten", systemImage: "pawprint.fill", fragment: "dogs")
                    pwaLink("Gassi-Treffen", systemImage: "person.2.fill", fragment: "walks")
                    pwaLink("Profil & Einstellungen", systemImage: "gearshape.fill", fragment: "settings")
                }

                Section {
                    if let url = URL(string: "https://banyaro.app") {
                        Link(destination: url) {
                            Label("banyaro.app in Safari öffnen", systemImage: "safari.fill")
                                .foregroundStyle(.primary)
                        }
                    }
                } header: {
                    Text("banyaro.app als Web-App")
                } footer: {
                    VStack(alignment: .leading, spacing: 8) {
                        Text("Du kannst banyaro.app zusätzlich als Web-App auf deinem Home-Bildschirm ablegen — praktisch für alle Features, die diese App nicht abbildet.")
                        HStack(alignment: .firstTextBaseline, spacing: 4) {
                            Text("**1.**")
                            Text("Oben „in Safari öffnen“ tippen")
                        }
                        HStack(alignment: .firstTextBaseline, spacing: 4) {
                            Text("**2.**")
                            HStack(spacing: 4) {
                                Text("In Safari unten das Teilen-Icon")
                                Image(systemName: "square.and.arrow.up")
                                Text("antippen")
                            }
                        }
                        HStack(alignment: .firstTextBaseline, spacing: 4) {
                            Text("**3.**")
                            HStack(spacing: 4) {
                                Text("„Zum Home-Bildschirm“")
                                Image(systemName: "plus.square")
                                Text("auswählen")
                            }
                        }
                        Text("Eine native App kann eine Web-App leider nicht selbst installieren — Apple lässt das nur über Safari zu.")
                            .padding(.top, 4)
                            .foregroundStyle(.tertiary)
                    }
                }

                Section {
                    Button("Abmelden", role: .destructive) {
                        auth.logout()
                    }
                }

                Section("Über") {
                    Text("Ban Yaro Go ist die native iOS-Ergänzung zur banyaro.app PWA. Phase 1: deine Touren ansehen.")
                        .font(.footnote)
                        .foregroundStyle(.secondary)
                }
            }
            .navigationTitle("Mehr")
            .refreshable { await auth.loadProfile() }
            .alert("Apple Health hat den Zugriff verweigert", isPresented: $showHealthPermissionAlert) {
                Button("OK", role: .cancel) {}
            } message: {
                Text("Du kannst die Berechtigung in den iOS-Einstellungen unter Datenschutz & Sicherheit → Health → Ban Yaro Go nachträglich ändern.")
            }
        }
    }

    private var displayName: String {
        auth.profile?.name ?? auth.userName ?? "—"
    }

    private var premiumValue: Bool {
        auth.profile?.isPremium ?? auth.isPremium
    }

    private var rolleLabel: String {
        switch auth.profile?.rolle?.lowercased() {
        case "admin":     return "Admin"
        case "moderator": return "Moderator"
        case nil:         return "—"
        default:          return "Mitglied"
        }
    }

    private var founderLabel: String {
        if let n = auth.profile?.founderNumber { return "#\(n)" }
        return "Ja"
    }

    @ViewBuilder
    private var avatarView: some View {
        if let path = auth.profile?.avatarUrl, !path.isEmpty,
           let url = avatarURL(path) {
            AsyncImage(url: url) { phase in
                switch phase {
                case .success(let img): img.resizable().scaledToFill()
                default: avatarPlaceholder
                }
            }
        } else {
            avatarPlaceholder
        }
    }

    private var avatarPlaceholder: some View {
        ZStack {
            Color.accentColor.opacity(0.2)
            Image(systemName: "person.crop.circle.fill")
                .font(.system(size: 36))
                .foregroundStyle(Color.accentColor)
        }
    }

    private func avatarURL(_ path: String) -> URL? {
        if path.hasPrefix("http") { return URL(string: path) }
        return URL(string: "https://banyaro.app\(path)")
    }

    @ViewBuilder
    private func pwaLink(_ title: String, systemImage: String, fragment: String) -> some View {
        if let url = URL(string: "https://banyaro.app/#\(fragment)") {
            Link(destination: url) {
                HStack {
                    Label(title, systemImage: systemImage)
                        .foregroundStyle(.primary)
                    Spacer()
                    Image(systemName: "arrow.up.right.square")
                        .font(.caption)
                        .foregroundStyle(.tertiary)
                }
            }
        }
    }
}