import SwiftUI

struct TopNav: View {
    @EnvironmentObject private var app: AppModel
    @State private var now = Date()

    private let clockTimer = Timer.publish(every: 30, on: .main, in: .common).autoconnect()

    var body: some View {
        HStack(spacing: 8) {
            BrandLogo(size: 34)
                .padding(.trailing, 20)

            HStack(spacing: 10) {
                ForEach(visibleTabs) { tab in
                    if tab == .search || tab == .settings {
                        navIconButton(tab)
                    } else {
                        navTextButton(tab)
                    }
                }
            }
            .focusSection()

            Spacer(minLength: 16)

            Text(timeString)
                .font(.system(size: 22, weight: .semibold, design: .rounded))
                .foregroundStyle(TvColors.textDim)
                .monospacedDigit()
                .padding(.trailing, 12)

            Button {
                app.tab = .settings
            } label: {
                FocusAwareProfileBadge(avatarId: app.store.profileAvatarId)
            }
            .buttonStyle(NavTabButtonStyle())
        }
        .padding(.horizontal, 48)
        .padding(.vertical, 18)
        .background {
            Rectangle()
                .fill(.ultraThinMaterial)
                .overlay(
                    LinearGradient(
                        colors: [Color.black.opacity(0.55), Color.black.opacity(0.15)],
                        startPoint: .top,
                        endPoint: .bottom
                    )
                )
                .ignoresSafeArea(edges: .top)
        }
        .onReceive(clockTimer) { now = $0 }
    }

    private var timeString: String {
        let f = DateFormatter()
        f.locale = Locale(identifier: "nl_NL")
        f.dateFormat = "HH:mm"
        return f.string(from: now)
    }

    private var visibleTabs: [AppModel.MainTab] {
        AppModel.MainTab.allCases.filter { tab in
            if tab == .tv { return app.iptvEnabled }
            return true
        }
    }

    private func navTextButton(_ tab: AppModel.MainTab) -> some View {
        Button {
            withAnimation(.easeOut(duration: 0.2)) { app.tab = tab }
        } label: {
            FocusAwareNavLabel(title: tab.title, selected: app.tab == tab)
        }
        .buttonStyle(NavTabButtonStyle())
    }

    private func navIconButton(_ tab: AppModel.MainTab) -> some View {
        Button {
            withAnimation(.easeOut(duration: 0.2)) { app.tab = tab }
        } label: {
            FocusAwareNavIcon(systemName: tab.icon, selected: app.tab == tab)
        }
        .buttonStyle(NavTabButtonStyle())
        .accessibilityLabel(tab.title)
    }
}

private struct FocusAwareNavLabel: View {
    let title: String
    let selected: Bool
    @Environment(\.isFocused) private var isFocused

    var body: some View {
        Text(title)
            .font(TvFonts.nav)
            .foregroundStyle(isFocused || selected ? TvColors.text : TvColors.textDim)
            .padding(.horizontal, 20)
            .padding(.vertical, 12)
            .background(
                Capsule().fill(backgroundFill)
            )
            .overlay {
                Capsule()
                    .strokeBorder(borderColor, lineWidth: isFocused ? 3 : (selected ? 1.5 : 0))
            }
    }

    private var backgroundFill: Color {
        if isFocused { return Color.white.opacity(0.18) }
        if selected { return TvColors.accent.opacity(0.28) }
        return .clear
    }

    private var borderColor: Color {
        if isFocused { return Color.white }
        if selected { return TvColors.accent.opacity(0.7) }
        return .clear
    }
}

private struct FocusAwareNavIcon: View {
    let systemName: String
    let selected: Bool
    @Environment(\.isFocused) private var isFocused

    var body: some View {
        Image(systemName: systemName)
            .font(.system(size: 24, weight: .semibold))
            .foregroundStyle(isFocused || selected ? Color.white : TvColors.textDim)
            .frame(width: 54, height: 54)
            .background(Circle().fill(backgroundFill))
            .overlay {
                Circle()
                    .strokeBorder(borderColor, lineWidth: isFocused ? 3 : (selected ? 1.5 : 0))
            }
    }

    private var backgroundFill: Color {
        if isFocused { return Color.white.opacity(0.18) }
        if selected { return TvColors.accent.opacity(0.28) }
        return .clear
    }

    private var borderColor: Color {
        if isFocused { return Color.white }
        if selected { return TvColors.accent.opacity(0.7) }
        return .clear
    }
}

private struct FocusAwareProfileBadge: View {
    let avatarId: String?
    @Environment(\.isFocused) private var isFocused

    var body: some View {
        Text(ProfileAvatars.emoji(for: avatarId))
            .font(.system(size: 32))
            .frame(width: 56, height: 56)
            .background(.ultraThinMaterial, in: Circle())
            .overlay(
                Circle().strokeBorder(
                    isFocused ? Color.white : TvColors.accent.opacity(0.45),
                    lineWidth: isFocused ? 3 : 1.5
                )
            )
    }
}