import SwiftUI

#if canImport(UIKit)
import UIKit
#endif

/// Vier Rating-Buttons unten am Bildschirm. Tap → onRate(rating)
/// plus Haptic-Feedback.
struct RatingBar: View {
    let onRate: (Rating) -> Void

    var body: some View {
        HStack(spacing: 8) {
            ForEach(Rating.allCases, id: \.self) { rating in
                Button {
                    triggerHaptic(for: rating)
                    onRate(rating)
                } label: {
                    VStack(spacing: 2) {
                        Text(rating.label)
                            .font(.subheadline.weight(.semibold))
                        Text(rating.shortcut)
                            .font(.caption2)
                            .foregroundStyle(.secondary)
                    }
                    .frame(maxWidth: .infinity)
                    .padding(.vertical, 14)
                    .background(background(for: rating), in: RoundedRectangle(cornerRadius: 10))
                    .foregroundStyle(foreground(for: rating))
                }
                .buttonStyle(.plain)
            }
        }
        .padding(.horizontal, 16)
    }

    private func background(for rating: Rating) -> Color {
        switch rating {
        case .again: CardsTheme.error.opacity(0.12)
        case .hard: CardsTheme.warning.opacity(0.12)
        case .good: CardsTheme.primary.opacity(0.12)
        case .easy: CardsTheme.success.opacity(0.12)
        }
    }

    private func foreground(for rating: Rating) -> Color {
        switch rating {
        case .again: CardsTheme.error
        case .hard: CardsTheme.warning
        case .good: CardsTheme.primary
        case .easy: CardsTheme.success
        }
    }

    private func triggerHaptic(for rating: Rating) {
        #if canImport(UIKit)
        let generator = UIImpactFeedbackGenerator(
            style: rating == .easy ? .heavy : .medium
        )
        generator.impactOccurred()
        #endif
    }
}