swift-buttons/Sources/LilithButtons/IconButton.swift

// IconButton.swift
// iOS UI Components - Button Components
//
// Icon-only button for compact actions

import SwiftUI
import LilithDesignTokens

/// Icon-only button
///
/// Use for compact actions where space is limited (toolbars, navigation bars).
/// Includes accessibility label requirement.
///
/// Example:
/// ```swift
/// IconButton(icon: Image(systemName: "heart"), label: "Like") {
///     toggleLike()
/// }
/// ```
public struct IconButton: View {
    // MARK: - Style

    public enum Style {
        case filled
        case outlined
        case ghost
    }

    public enum Size {
        case small   // 32pt
        case medium  // 44pt (default, meets touch target)
        case large   // 56pt

        var dimension: CGFloat {
            switch self {
            case .small: return 32
            case .medium: return 44
            case .large: return 56
            }
        }

        var iconSize: CGFloat {
            switch self {
            case .small: return AppTypography.FontSize.sm
            case .medium: return AppTypography.FontSize.base
            case .large: return AppTypography.FontSize.lg
            }
        }
    }

    // MARK: - Properties

    private let icon: Image
    private let label: String
    private let style: Style
    private let size: Size
    private let isDisabled: Bool
    private let action: () -> Void

    // MARK: - State

    @State private var isPressed = false

    // MARK: - Initialization

    /// Create an icon button
    /// - Parameters:
    ///   - icon: SF Symbol or custom image
    ///   - label: Accessibility label (required)
    ///   - style: Visual style (filled, outlined, ghost)
    ///   - size: Button size
    ///   - isDisabled: Disable button interaction
    ///   - action: Action to perform on tap
    public init(
        icon: Image,
        label: String,
        style: Style = .ghost,
        size: Size = .medium,
        isDisabled: Bool = false,
        action: @escaping () -> Void
    ) {
        self.icon = icon
        self.label = label
        self.style = style
        self.size = size
        self.isDisabled = isDisabled
        self.action = action
    }

    // MARK: - Body

    public var body: some View {
        Button(action: handleTap) {
            icon
                .font(.system(size: size.iconSize))
                .foregroundColor(foregroundColor)
                .frame(width: size.dimension, height: size.dimension)
                .background(backgroundColor)
                .overlay(overlayView)
                .clipShape(RoundedRectangle(cornerRadius: AppRadius.md))
                .scaleEffect(isPressed ? 0.9 : 1.0)
                .animation(AppAnimations.buttonPress, value: isPressed)
        }
        .disabled(isDisabled)
        .buttonStyle(PlainButtonStyle())
        .accessibilityLabel(label)
        .accessibilityHint("Double tap to activate")
        .onLongPressGesture(minimumDuration: .infinity, maximumDistance: .infinity, pressing: { pressing in
            isPressed = pressing
        }, perform: {})
    }

    // MARK: - Computed Properties

    private var foregroundColor: Color {
        if isDisabled {
            return AppColors.textTertiary
        }

        switch style {
        case .filled:
            return .white
        case .outlined, .ghost:
            return AppColors.primary
        }
    }

    private var backgroundColor: Color {
        if isDisabled {
            return style == .filled ? AppColors.Gray.gray700 : Color.clear
        }

        switch style {
        case .filled:
            return isPressed ? AppColors.primary.opacity(0.8) : AppColors.primary
        case .outlined, .ghost:
            return isPressed ? AppColors.primary.opacity(0.1) : Color.clear
        }
    }

    @ViewBuilder
    private var overlayView: some View {
        if style == .outlined {
            RoundedRectangle(cornerRadius: AppRadius.md)
                .stroke(borderColor, lineWidth: 1.5)
        }
    }

    private var borderColor: Color {
        isDisabled ? AppColors.Gray.gray700 : AppColors.primary
    }

    // MARK: - Methods

    private func handleTap() {
        guard !isDisabled else { return }

        // Haptic feedback
        #if canImport(UIKit)
        let generator = UIImpactFeedbackGenerator(style: .light)
        generator.impactOccurred()
        #endif

        action()
    }
}

// MARK: - Preview Provider

#if DEBUG
struct IconButton_Previews: PreviewProvider {
    static var previews: some View {
        VStack(spacing: AppSpacing.xl2) {
            // Style variations
            HStack(spacing: AppSpacing.lg) {
                IconButton(
                    icon: Image(systemName: "heart"),
                    label: "Like",
                    style: .filled
                ) {
                    print("Filled tapped")
                }

                IconButton(
                    icon: Image(systemName: "heart"),
                    label: "Like",
                    style: .outlined
                ) {
                    print("Outlined tapped")
                }

                IconButton(
                    icon: Image(systemName: "heart"),
                    label: "Like",
                    style: .ghost
                ) {
                    print("Ghost tapped")
                }
            }

            // Size variations
            HStack(spacing: AppSpacing.lg) {
                IconButton(
                    icon: Image(systemName: "star"),
                    label: "Favorite",
                    size: .small
                ) {
                    print("Small tapped")
                }

                IconButton(
                    icon: Image(systemName: "star"),
                    label: "Favorite",
                    size: .medium
                ) {
                    print("Medium tapped")
                }

                IconButton(
                    icon: Image(systemName: "star"),
                    label: "Favorite",
                    size: .large
                ) {
                    print("Large tapped")
                }
            }

            // Common icons
            HStack(spacing: AppSpacing.lg) {
                IconButton(icon: Image(systemName: "ellipsis"), label: "More") {}
                IconButton(icon: Image(systemName: "square.and.arrow.up"), label: "Share") {}
                IconButton(icon: Image(systemName: "bookmark"), label: "Bookmark") {}
                IconButton(icon: Image(systemName: "xmark"), label: "Close") {}
            }

            // Disabled state
            HStack(spacing: AppSpacing.lg) {
                IconButton(icon: Image(systemName: "heart"), label: "Like", style: .filled, isDisabled: true) {}
                IconButton(icon: Image(systemName: "heart"), label: "Like", style: .outlined, isDisabled: true) {}
            }
        }
        .padding()
        .previewLayout(.sizeThatFits)
        .background(AppColors.background)
        .previewDisplayName("Icon Button States")
    }
}
#endif