import SwiftUI

struct Toast: Identifiable {
    enum Style {
        case success, error, warning, info, git
        var icon: String {
            switch self {
            case .success: return "checkmark.circle.fill"
            case .error:   return "xmark.circle.fill"
            case .warning: return "exclamationmark.triangle.fill"
            case .info:    return "info.circle.fill"
            case .git:     return "arrow.triangle.branch"
            }
        }
        var color: Color {
            switch self {
            case .success: return .green; case .error: return .red
            case .warning: return .orange; case .info: return Color.accentColor; case .git: return .purple
            }
        }
    }
    let id       = UUID()
    let message:  String
    let style:    Style
    let duration: TimeInterval
    init(_ message: String, style: Style = .info, duration: TimeInterval = 3) {
        self.message = message; self.style = style; self.duration = duration
    }
}

@MainActor
final class ToastStore: ObservableObject {
    static let shared = ToastStore()
    @Published var toasts: [Toast] = []

    func show(_ toast: Toast) {
        toasts.append(toast)
        Task {
            try? await Task.sleep(for: .seconds(toast.duration))
            toasts.removeAll { $0.id == toast.id }
        }
    }
    func show(_ message: String, style: Toast.Style = .info, duration: TimeInterval = 3) {
        show(Toast(message, style: style, duration: duration))
    }
}

struct ToastOverlay: ViewModifier {
    @ObservedObject var store: ToastStore
    func body(content: Content) -> some View {
        content.overlay(alignment: .bottom) {
            VStack(spacing: 8) {
                ForEach(store.toasts) { toast in
                    HStack(spacing: 10) {
                        Image(systemName: toast.style.icon).foregroundStyle(toast.style.color)
                        Text(toast.message).font(.subheadline).lineLimit(2)
                        Spacer()
                        Button { store.toasts.removeAll { $0.id == toast.id } }
                            label: { Image(systemName: "xmark").font(.caption.bold()).foregroundStyle(.secondary) }
                            .buttonStyle(.plain)
                    }
                    .padding(.horizontal, 14).padding(.vertical, 10)
                    .background(.regularMaterial, in: RoundedRectangle(cornerRadius: 12))
                    .shadow(color: .black.opacity(0.15), radius: 8, x: 0, y: 4)
                    .padding(.horizontal, 16)
                    .transition(.move(edge: .bottom).combined(with: .opacity))
                }
            }
            .padding(.bottom, 60)
            .animation(.spring(response: 0.3), value: store.toasts.count)
        }
    }
}

extension View {
    func toastOverlay() -> some View { modifier(ToastOverlay(store: ToastStore.shared)) }
}