import SwiftUI

struct SettingsView: View {
  @EnvironmentObject private var model: AppModel
  @Environment(\.dismiss) private var dismiss
  @State private var showDeleteConfirm = false

  private let currencies = ["USD", "MYR", "JPY"]

  var body: some View {
    ScrollView {
      VStack(alignment: .leading, spacing: 18) {
        ScreenHeader(title: "Settings", subtitle: "Security and device options", onBack: { dismiss() })

        Card {
          VStack(alignment: .leading, spacing: 10) {
            Text("Currency")
              .font(.system(size: 13, weight: .semibold))
              .foregroundStyle(Theme.muted)

            LazyVGrid(columns: [GridItem(.adaptive(minimum: 64), spacing: 8)], spacing: 8) {
              ForEach(currencies, id: \.self) { currency in
                let selected = model.fiatCurrency == currency
                Button {
                  model.fiatCurrency = currency
                } label: {
                  Text(currency)
                    .font(.system(size: 13, weight: .medium))
                    .frame(maxWidth: .infinity)
                    .padding(.vertical, 8)
                    .background(selected ? Theme.accent : Theme.surfaceAlt)
                    .foregroundStyle(selected ? Color.black : Theme.text)
                    .clipShape(RoundedRectangle(cornerRadius: 10, style: .continuous))
                }
              }
            }

            Text("Prices come from CoinGecko (with a Kraken fallback for USD and EUR) and refresh about once a minute.")
              .font(.system(size: 11))
              .foregroundStyle(Theme.muted)
              .padding(.top, 4)
          }
        }

        Card {
          Toggle(isOn: Binding(get: { model.faceIDEnabled },
                               set: { model.faceIDEnabled = $0 })) {
            VStack(alignment: .leading, spacing: 3) {
              Text("Unlock with \(Biometrics.label)")
                .font(.system(size: 15, weight: .semibold))
                .foregroundStyle(Theme.text)
              Text("Require \(Biometrics.label) to open the app, reveal the recovery phrase, and send payments.")
                .font(.system(size: 11))
                .foregroundStyle(Theme.muted)
            }
          }
          .tint(Theme.accent)
          .disabled(!Biometrics.isAvailable)

          if !Biometrics.isAvailable {
            Text("This device has no biometric sensor configured.")
              .font(.system(size: 11))
              .foregroundStyle(Theme.muted)
          }
        }

        Card {
          VStack(alignment: .leading, spacing: 10) {
            Text("Danger zone")
              .font(.system(size: 13, weight: .semibold))
              .foregroundStyle(Theme.muted)
            Button {
              showDeleteConfirm = true
            } label: {
              Text("Delete this wallet")
                .font(.system(size: 15, weight: .semibold))
                .foregroundStyle(Theme.danger)
                .frame(maxWidth: .infinity)
                .padding(.vertical, 14)
                .background(Theme.danger.opacity(0.12))
                .clipShape(RoundedRectangle(cornerRadius: 14, style: .continuous))
            }
            Text("Removes the wallet from this device. Your recovery phrase is the only way to get it back.")
              .font(.system(size: 11))
              .foregroundStyle(Theme.muted)
          }
        }

        Spacer(minLength: 0)
      }
      .padding(.horizontal, 20)
      .padding(.top, 12)
    }
    .preferredColorScheme(.dark)
    .confirmationDialog("Delete this wallet?",
                        isPresented: $showDeleteConfirm,
                        titleVisibility: .visible) {
      Button("Delete wallet", role: .destructive) {
        Task {
          await model.deleteWallet()
          dismiss()
        }
      }
      Button("Cancel", role: .cancel) {}
    } message: {
      Text("The keys stored on this device are removed. Make sure your recovery phrase is backed up.")
    }
  }
}