import SwiftUI

/// Root navigation — switches between Login, BusinessList, and Scan screens
struct RootView: View {
    @EnvironmentObject var appState: AppState

    var body: some View {
        ZStack {
            switch appState.currentScreen {
            case .login:
                LoginView()
                    .transition(.opacity)

            case .businessList:
                BusinessListView()
                    .transition(.move(edge: .trailing))

            case .scan(let business):
                ScanView(business: business)
                    .transition(.move(edge: .trailing))
            }
        }
        .animation(.easeInOut(duration: 0.3), value: screenKey)
        .overlay(alignment: .top) {
            if APIConfig.isDev {
                DevBanner()
            }
        }
    }

    /// Stable key for animation
    private var screenKey: String {
        switch appState.currentScreen {
        case .login: return "login"
        case .businessList: return "businesses"
        case .scan(let b): return "scan-\(b.id)"
        }
    }
}