//
//  LockScreenLiveActivityOverlay.swift
//  DynamicIsland
//
//  Mirrors the closed-notch live activity layout on the macOS lock screen.
//

import SwiftUI

enum LockLiveActivityState: Equatable {
    case locked
    case unlocking
}

struct LockScreenLiveActivityOverlay: View {
    let state: LockLiveActivityState
    let notchSize: CGSize

    private var indicatorSize: CGFloat {
        max(0, notchSize.height - 12)
    }

    private var horizontalPadding: CGFloat {
        cornerRadiusInsets.closed.bottom
    }

    private var baseWidth: CGFloat {
        notchSize.width + (indicatorSize * 2)
    }

    private var totalWidth: CGFloat {
        baseWidth + (horizontalPadding * 2)
    }

    private var iconName: String {
        state == .locked ? "lock.fill" : "lock.open.fill"
    }

    private var iconColor: Color {
        state == .locked ? .blue : .green
    }

    private var glowColor: Color {
        state == .locked ? Color.blue.opacity(0.15) : Color.green.opacity(0.2)
    }

    var body: some View {
        HStack(spacing: 0) {
            Color.clear
                .background {
                    HStack {
                        ZStack {
                            RoundedRectangle(cornerRadius: 6)
                                .fill(glowColor)

                            Image(systemName: iconName)
                                .font(.system(size: 12, weight: .semibold))
                                .foregroundColor(iconColor)
                                .modifier(LockPulsingModifier(isUnlocking: state == .unlocking))
                        }
                        .frame(width: indicatorSize, height: indicatorSize)
                    }
                    .frame(maxWidth: .infinity, maxHeight: .infinity, alignment: .leading)
                }
                .frame(width: indicatorSize, height: notchSize.height)

            Color.clear
                .frame(width: notchSize.width, height: notchSize.height)

            Color.clear
                .frame(width: indicatorSize, height: notchSize.height)
        }
        .frame(width: baseWidth, height: notchSize.height)
        .padding(.horizontal, horizontalPadding)
        .background(Color.black)
        .clipShape(
            NotchShape(
                topCornerRadius: cornerRadiusInsets.closed.top,
                bottomCornerRadius: cornerRadiusInsets.closed.bottom
            )
        )
        .frame(width: totalWidth, height: notchSize.height)
        .animation(.spring(response: 0.45, dampingFraction: 0.85), value: state)
        .drawingGroup()
    }
}

#Preview {
    VStack(spacing: 24) {
        LockScreenLiveActivityOverlay(state: .locked, notchSize: CGSize(width: 220, height: 32))
        LockScreenLiveActivityOverlay(state: .unlocking, notchSize: CGSize(width: 220, height: 32))
    }
    .padding()
    .background(Color.gray.opacity(0.2))
}