import SwiftUI

struct PinLockView: View {
    let onUnlocked: () -> Void
    @State private var pin = ""
    @State private var error: String?

    var body: some View {
        PinPadView(title: "Enter PIN", pin: $pin, error: $error) {
            if PinStore.shared.verifyPin(pin) {
                onUnlocked()
            } else {
                error = "Incorrect PIN. Try again."
                pin = ""
            }
        }
    }
}

struct PinLockOverlay: View {
    let onUnlocked: () -> Void
    @State private var pin = ""
    @State private var error: String?

    var body: some View {
        ZStack {
            LadillColors.page.ignoresSafeArea()
            PinPadView(title: "Enter PIN", pin: $pin, error: $error) {
                if PinStore.shared.verifyPin(pin) {
                    onUnlocked()
                } else {
                    error = "Incorrect PIN. Try again."
                    pin = ""
                }
            }
        }
    }
}

struct PinSetupView: View {
    let onPinSet: () -> Void
    @State private var pin = ""
    @State private var confirm = ""
    @State private var step = 0
    @State private var error: String?

    var body: some View {
        PinPadView(title: step == 0 ? "Set a PIN" : "Confirm PIN", pin: step == 0 ? $pin : $confirm, error: $error) {
            if step == 0 {
                step = 1
            } else if pin == confirm {
                PinStore.shared.savePin(pin)
                onPinSet()
            } else {
                error = "PINs don't match."
                confirm = ""
                step = 0
                pin = ""
            }
        }
    }
}

private struct PinPadView: View {
    let title: String
    @Binding var pin: String
    @Binding var error: String?
    let onComplete: () -> Void

    var body: some View {
        VStack(spacing: 24) {
            Spacer()
            Image(systemName: "lock.fill")
                .font(.system(size: 32))
                .foregroundStyle(LadillColors.indigo)
            Text(title)
                .font(.ladill(size: 22, weight: .semibold))
                .foregroundStyle(LadillColors.ink)

            HStack(spacing: 12) {
                ForEach(0..<4, id: \.self) { i in
                    Circle()
                        .fill(i < pin.count ? LadillColors.indigo : LadillColors.border)
                        .frame(width: 14, height: 14)
                }
            }

            if let error {
                Text(error)
                    .font(.ladill(size: 13))
                    .foregroundStyle(LadillColors.red)
            }

            let keys = ["1", "2", "3", "4", "5", "6", "7", "8", "9", "", "0", "⌫"]
            LazyVGrid(columns: Array(repeating: GridItem(.flexible()), count: 3), spacing: 16) {
                ForEach(keys, id: \.self) { key in
                    if key.isEmpty {
                        Color.clear.frame(height: 56)
                    } else {
                        Button {
                            if key == "⌫" {
                                if !pin.isEmpty { pin.removeLast() }
                            } else if pin.count < 4 {
                                pin.append(key)
                                if pin.count == 4 { onComplete() }
                            }
                        } label: {
                            Text(key)
                                .font(.ladill(size: 24, weight: .medium))
                                .frame(maxWidth: .infinity)
                                .frame(height: 56)
                                .background(LadillColors.surface)
                                .clipShape(Circle())
                        }
                        .buttonStyle(.plain)
                    }
                }
            }
            .padding(.horizontal, 40)

            Spacer()
        }
        .background(LadillColors.page)
    }
}