import Foundation
import SwiftUI

struct CartView: View {
    @Binding var appState: AppState

    var body: some View {
        VStack(spacing: 14) {
            Text("Carrinho")
                .font(AppTypography.heading1)
                .frame(maxWidth: .infinity, alignment: .leading)
                .padding(.horizontal, 20)
                .padding(.top, 20)

            if appState.cart.items.isEmpty {
                VStack(spacing: 10) {
                    Text("Seu carrinho está vazio")
                        .font(AppTypography.heading3)
                        .foregroundStyle(AppColors.textPrimary)
                    Text("Adicione produtos para continuar.")
                        .font(AppTypography.body)
                        .foregroundStyle(AppColors.textMuted)
                }
                .frame(maxWidth: .infinity, maxHeight: .infinity, alignment: .center)
            } else {
                ScrollView(showsIndicators: false) {
                    VStack(spacing: 12) {
                        if let storeName = appState.cart.storeName, storeName.isEmpty == false {
                            Text(storeName)
                                .font(AppTypography.heading3)
                                .foregroundStyle(AppColors.textPrimary)
                                .frame(maxWidth: .infinity, alignment: .leading)
                                .padding(.horizontal, 20)
                        }

                        ForEach(appState.cart.items) { item in
                            cartItemRow(item)
                        }
                    }
                    .padding(.bottom, 120)
                }
            }
        }
        .frame(maxWidth: .infinity, maxHeight: .infinity)
        .background(AppColors.backgroundLight)
        .safeAreaInset(edge: .bottom) {
            if appState.cart.items.isEmpty == false {
                VStack(spacing: 10) {
                    HStack {
                        Text("Total")
                            .font(AppTypography.heading3)
                            .foregroundStyle(AppColors.textPrimary)
                        Spacer()
                        Text(formatCurrency(appState.cart.total))
                            .font(AppTypography.heading2)
                            .foregroundStyle(AppColors.primary)
                    }
                    .padding(.horizontal, 20)

                    PrimaryButton(title: "Finalizar pedido", action: {})
                        .padding(.horizontal, 20)
                }
                .padding(.top, 10)
                .padding(.bottom, 12)
                .background(.ultraThinMaterial)
            }
        }
    }

    private func cartItemRow(_ item: CartItemState) -> some View {
        HStack(spacing: 12) {
            VStack(alignment: .leading, spacing: 4) {
                Text(item.name)
                    .font(AppTypography.heading3)
                    .foregroundStyle(AppColors.textPrimary)
                    .lineLimit(1)
                if let details = item.details, details.isEmpty == false {
                    Text(details)
                        .font(.caption)
                        .foregroundStyle(AppColors.textMuted)
                        .lineLimit(2)
                }
                Text(formatCurrency(item.unitPrice))
                    .font(AppTypography.body)
                    .foregroundStyle(AppColors.textMuted)
            }

            Spacer()

            HStack(spacing: 8) {
                Button(action: { appState.cart.decrement(itemId: item.id) }) {
                    Image(systemName: "minus")
                        .font(.system(size: 13, weight: .bold))
                        .foregroundStyle(AppColors.textPrimary)
                        .frame(width: 28, height: 28)
                        .background(AppColors.brandSoft)
                        .clipShape(Circle())
                }
                .buttonStyle(.plain)

                Text("\(item.quantity)")
                    .font(AppTypography.heading3)
                    .foregroundStyle(AppColors.textPrimary)
                    .frame(minWidth: 18)

                Button(action: { appState.cart.increment(itemId: item.id) }) {
                    Image(systemName: "plus")
                        .font(.system(size: 13, weight: .bold))
                        .foregroundStyle(AppColors.textPrimary)
                        .frame(width: 28, height: 28)
                        .background(AppColors.tertiary)
                        .clipShape(Circle())
                }
                .buttonStyle(.plain)
            }
        }
        .padding(.horizontal, 14)
        .padding(.vertical, 12)
        .background(AppColors.surface)
        .clipShape(RoundedRectangle(cornerRadius: AppLayout.radiusLG, style: .continuous))
        .padding(.horizontal, 20)
    }

    private func formatCurrency(_ value: Double) -> String {
        String(format: "R$ %.2f", value).replacingOccurrences(of: ".", with: ",")
    }
}