import SwiftUI

struct CategoryPillBar: View {
    @Binding var selected: AppSection
    var streamCount: Int = 0
    var totalGames: Int = 0
    var liveGames: Int = 0

    @Namespace private var selectionNamespace

    private var primarySections: [AppSection] {
        AppSection.allCases.filter { $0 != .settings }
    }

    var body: some View {
        ViewThatFits {
            expandedBar
            compactBar
        }
    }

    private var expandedBar: some View {
        HStack(spacing: 24) {
            brandLockup

            HStack(spacing: 10) {
                ForEach(primarySections) { section in
                    sectionButton(section)
                }
            }

            Spacer(minLength: 12)

            HStack(spacing: 10) {
                statusChip(value: "\(liveGames)", label: "Live", systemImage: "dot.radiowaves.left.and.right", tint: DS.Colors.live)
                statusChip(value: "\(totalGames)", label: "Games", systemImage: "sportscourt", tint: DS.Colors.media)
                statusChip(value: "\(streamCount)", label: "Tiles", systemImage: "rectangle.split.2x2", tint: DS.Colors.positive)
                settingsButton
            }
        }
        .padding(.horizontal, containerPadH)
        .padding(.vertical, containerPadV)
        .background(shellBackground)
    }

    private var compactBar: some View {
        VStack(alignment: .leading, spacing: 16) {
            HStack(spacing: 16) {
                brandLockup
                Spacer()
                settingsButton
            }

            ScrollView(.horizontal, showsIndicators: false) {
                HStack(spacing: 10) {
                    ForEach(primarySections) { section in
                        sectionButton(section)
                    }
                    statusChip(value: "\(liveGames)", label: "Live", systemImage: "dot.radiowaves.left.and.right", tint: DS.Colors.live)
                    statusChip(value: "\(totalGames)", label: "Games", systemImage: "sportscourt", tint: DS.Colors.media)
                    statusChip(value: "\(streamCount)", label: "Tiles", systemImage: "rectangle.split.2x2", tint: DS.Colors.positive)
                }
            }
            .scrollClipDisabled()
        }
        .padding(.horizontal, containerPadH)
        .padding(.vertical, containerPadV)
        .background(shellBackground)
    }

    private var brandLockup: some View {
        VStack(alignment: .leading, spacing: 3) {
            Text("MLB")
                .font(brandPrimaryFont)
                .foregroundStyle(DS.Colors.textPrimary)

            Text("CONTROL ROOM")
                .font(brandSecondaryFont)
                .foregroundStyle(DS.Colors.textTertiary)
                .tracking(brandTracking)
        }
    }

    private func sectionButton(_ section: AppSection) -> some View {
        Button {
            withAnimation(.spring(response: 0.36, dampingFraction: 0.82)) {
                selected = section
            }
        } label: {
            HStack(spacing: 10) {
                Image(systemName: section.systemImage)
                    .font(.system(size: iconSize, weight: .bold))

                Text(section.title)
                    .font(pillFont)
            }
            .foregroundStyle(selected == section ? Color.black.opacity(0.86) : DS.Colors.textSecondary)
            .padding(.horizontal, pillPadH)
            .padding(.vertical, pillPadV)
            .background {
                if selected == section {
                    Capsule()
                        .fill(
                            LinearGradient(
                                colors: [
                                    DS.Colors.interactive,
                                    DS.Colors.warning,
                                ],
                                startPoint: .topLeading,
                                endPoint: .bottomTrailing
                            )
                        )
                        .matchedGeometryEffect(id: "selected-section", in: selectionNamespace)
                } else {
                    Capsule()
                        .fill(DS.Colors.panelFillMuted)
                }
            }
        }
        .platformCardStyle()
    }

    private var settingsButton: some View {
        Button {
            selected = .settings
        } label: {
            Image(systemName: "gearshape.fill")
                .font(.system(size: iconSize, weight: .bold))
                .foregroundStyle(selected == .settings ? Color.black.opacity(0.86) : DS.Colors.textSecondary)
                .padding(.horizontal, pillPadH)
                .padding(.vertical, pillPadV)
                .background {
                    if selected == .settings {
                        Capsule()
                            .fill(
                                LinearGradient(
                                    colors: [
                                        DS.Colors.interactive,
                                        DS.Colors.warning,
                                    ],
                                    startPoint: .topLeading,
                                    endPoint: .bottomTrailing
                                )
                            )
                    } else {
                        Capsule()
                            .fill(DS.Colors.panelFillMuted)
                    }
                }
        }
        .platformCardStyle()
    }

    private func statusChip(value: String, label: String, systemImage: String, tint: Color) -> some View {
        HStack(spacing: 9) {
            Image(systemName: systemImage)
                .font(.system(size: statIconSize, weight: .bold))
                .foregroundStyle(tint)

            Text(value)
                .font(statValueFont)
                .foregroundStyle(DS.Colors.textPrimary)
                .monospacedDigit()

            Text(label)
                .font(statLabelFont)
                .foregroundStyle(DS.Colors.textTertiary)
        }
        .padding(.horizontal, statPadH)
        .padding(.vertical, statPadV)
        .background(
            Capsule()
                .fill(DS.Colors.panelFillMuted)
                .overlay {
                    Capsule()
                        .strokeBorder(DS.Colors.panelStroke, lineWidth: 1)
                }
        )
    }

    private var shellBackground: some View {
        RoundedRectangle(cornerRadius: shellRadius, style: .continuous)
            .fill(DS.Colors.navFill)
            .overlay {
                RoundedRectangle(cornerRadius: shellRadius, style: .continuous)
                    .strokeBorder(DS.Colors.panelStroke, lineWidth: 1)
            }
            .shadow(color: DS.Shadows.card, radius: DS.Shadows.cardRadius, y: DS.Shadows.cardY)
    }

    #if os(tvOS)
    private var shellRadius: CGFloat { 28 }
    private var containerPadH: CGFloat { 28 }
    private var containerPadV: CGFloat { 22 }
    private var pillPadH: CGFloat { 24 }
    private var pillPadV: CGFloat { 16 }
    private var statPadH: CGFloat { 18 }
    private var statPadV: CGFloat { 14 }
    private var pillFont: Font { .system(size: 23, weight: .bold, design: .rounded) }
    private var statValueFont: Font { .system(size: 22, weight: .black, design: .rounded) }
    private var statLabelFont: Font { .system(size: 16, weight: .bold, design: .rounded) }
    private var brandPrimaryFont: Font { .system(size: 34, weight: .black, design: .rounded) }
    private var brandSecondaryFont: Font { .system(size: 14, weight: .black, design: .rounded) }
    private var brandTracking: CGFloat { 2.6 }
    private var iconSize: CGFloat { 20 }
    private var statIconSize: CGFloat { 13 }
    #else
    private var shellRadius: CGFloat { 22 }
    private var containerPadH: CGFloat { 18 }
    private var containerPadV: CGFloat { 16 }
    private var pillPadH: CGFloat { 18 }
    private var pillPadV: CGFloat { 10 }
    private var statPadH: CGFloat { 12 }
    private var statPadV: CGFloat { 10 }
    private var pillFont: Font { .system(size: 15, weight: .bold, design: .rounded) }
    private var statValueFont: Font { .system(size: 15, weight: .black, design: .rounded) }
    private var statLabelFont: Font { .system(size: 11, weight: .bold, design: .rounded) }
    private var brandPrimaryFont: Font { .system(size: 20, weight: .black, design: .rounded) }
    private var brandSecondaryFont: Font { .system(size: 10, weight: .black, design: .rounded) }
    private var brandTracking: CGFloat { 1.8 }
    private var iconSize: CGFloat { 15 }
    private var statIconSize: CGFloat { 11 }
    #endif
}

enum AppSection: String, CaseIterable, Identifiable {
    case today
    case intel
    case highlights
    case multiView
    case settings

    var id: String { rawValue }

    var title: String {
        switch self {
        case .today: "Dashboard"
        case .intel: "League"
        case .highlights: "Highlights"
        case .multiView: "Multi-View"
        case .settings: "Settings"
        }
    }

    var systemImage: String {
        switch self {
        case .today: "rectangle.3.group.fill"
        case .intel: "chart.xyaxis.line"
        case .highlights: "play.rectangle.on.rectangle.fill"
        case .multiView: "rectangle.split.2x2.fill"
        case .settings: "gearshape.fill"
        }
    }
}