//
//  OnboardingStyle.swift
//  Reflect
//
//  Created by Claude Code on 12/10/24.
//

import SwiftUI

struct OnboardingStyle: View {
    @ObservedObject var onboardingData: OnboardingData
    @State private var selectedTheme: AppTheme = .celestial

    var body: some View {
        ScrollView(showsIndicators: false) {
                VStack(spacing: 0) {
                    // Icon
                    ZStack {
                        Circle()
                            .fill(.white.opacity(0.15))
                            .frame(width: 100, height: 100)

                        Text(selectedTheme.emoji)
                            .font(.system(size: 44))
                    }
                    .padding(.top, 40)
                    .padding(.bottom, 20)

                    // Title
                    Text("Choose your vibe")
                        .font(.title.weight(.bold))
                        .foregroundColor(.white)
                        .shadow(color: .black.opacity(0.2), radius: 4, x: 0, y: 2)
                        .padding(.bottom, 8)

                    // Subtitle
                    Text("Each theme sets your colors, icons, and layouts")
                        .font(.body.weight(.medium))
                        .foregroundColor(.white.opacity(0.85))
                        .multilineTextAlignment(.center)
                        .padding(.horizontal, 32)
                        .padding(.bottom, 24)

                    // Theme Grid
                    LazyVGrid(columns: [
                        GridItem(.flexible(), spacing: 12),
                        GridItem(.flexible(), spacing: 12)
                    ], spacing: 14) {
                        ForEach(AppTheme.allCases) { theme in
                            OnboardingThemeCard(
                                theme: theme,
                                isSelected: selectedTheme == theme,
                                action: {
                                    let impactMed = UIImpactFeedbackGenerator(style: .medium)
                                    impactMed.impactOccurred()
                                    withAnimation(.easeInOut(duration: 0.3)) {
                                        selectedTheme = theme
                                    }
                                    // Apply the theme immediately
                                    theme.apply()
                                }
                            )
                        }
                    }
                    .padding(.horizontal, 20)

                    // Hint
                    HStack(spacing: 8) {
                        Image(systemName: "arrow.left.arrow.right")
                            .font(.subheadline)
                        Text("You can change this anytime in Customize")
                            .font(.caption.weight(.medium))
                    }
                    .foregroundColor(.white.opacity(0.7))
                    .padding(.top, 24)
                    .padding(.bottom, 80)
                }
        }
        .background(
            LinearGradient(
                colors: selectedTheme.previewColors,
                startPoint: .topLeading,
                endPoint: .bottomTrailing
            )
            .ignoresSafeArea()
            .animation(.easeInOut(duration: 0.4), value: selectedTheme)
        )
        .onAppear {
            // Apply default theme on appear
            selectedTheme.apply()
        }
        .accessibilityIdentifier(AccessibilityID.Onboarding.styleScreen)
    }
}

// MARK: - Onboarding Theme Card
struct OnboardingThemeCard: View {
    let theme: AppTheme
    let isSelected: Bool
    let action: () -> Void

    var body: some View {
        Button(action: action) {
            VStack(spacing: 0) {
                // Preview gradient with emoji
                ZStack {
                    LinearGradient(
                        colors: theme.previewColors,
                        startPoint: .topLeading,
                        endPoint: .bottomTrailing
                    )

                    Text(theme.emoji)
                        .font(.system(size: 32))
                        .shadow(color: .black.opacity(0.2), radius: 2, x: 0, y: 1)

                    // Selected checkmark
                    if isSelected {
                        VStack {
                            HStack {
                                Spacer()
                                Image(systemName: "checkmark.circle.fill")
                                    .font(.system(size: 20))
                                    .foregroundStyle(.white, .green)
                                    .padding(6)
                            }
                            Spacer()
                        }
                    }
                }
                .frame(height: 70)
                .clipShape(
                    UnevenRoundedRectangle(
                        topLeadingRadius: 14,
                        bottomLeadingRadius: 0,
                        bottomTrailingRadius: 0,
                        topTrailingRadius: 14
                    )
                )

                // Name and tagline
                VStack(alignment: .leading, spacing: 2) {
                    Text(theme.name)
                        .font(.subheadline.weight(.semibold))
                        .foregroundColor(Color(UIColor.darkText))
                        .lineLimit(1)

                    Text(theme.tagline)
                        .font(.caption2)
                        .foregroundColor(Color(UIColor.darkGray))
                        .lineLimit(1)
                }
                .frame(maxWidth: .infinity, alignment: .leading)
                .padding(.horizontal, 10)
                .padding(.vertical, 8)
                .background(Color.white)
                .clipShape(
                    UnevenRoundedRectangle(
                        topLeadingRadius: 0,
                        bottomLeadingRadius: 14,
                        bottomTrailingRadius: 14,
                        topTrailingRadius: 0
                    )
                )
            }
            .overlay(
                RoundedRectangle(cornerRadius: 14)
                    .stroke(isSelected ? Color.white : Color.clear, lineWidth: 3)
            )
            .shadow(
                color: .black.opacity(isSelected ? 0.25 : 0.15),
                radius: isSelected ? 8 : 4,
                x: 0,
                y: isSelected ? 4 : 2
            )
        }
        .buttonStyle(.plain)
    }
}

struct OnboardingStyle_Previews: PreviewProvider {
    static var previews: some View {
        OnboardingStyle(onboardingData: OnboardingData())
    }
}