import SwiftUI

struct RootView: View {
    @EnvironmentObject private var session: Session
    @EnvironmentObject private var router: Router
    @EnvironmentObject private var display: DisplaySettings

    var body: some View {
        Group {
            if session.isLoggedIn {
                HomeView()
            } else {
                LoginView()
            }
        }
        // Anzeigeeinstellungen (Datumsformat) gehoeren dem Server.
        .task(id: session.isLoggedIn) {
            if session.isLoggedIn { await display.load() }
        }
        // Shortcut/URL öffnet den passenden Scan-Bildschirm direkt.
        .fullScreenCover(item: $router.route) { route in
            NavigationStack {
                switch route {
                case .checkin: CheckInView()
                case .checkout: CheckOutView()
                }
            }
        }
    }
}

extension Route: Identifiable {
    var id: String { rawValue }
}

struct HomeView: View {
    @EnvironmentObject private var session: Session
    @EnvironmentObject private var router: Router

    var body: some View {
        NavigationStack {
            VStack(spacing: 16) {
                Button {
                    router.route = .checkin
                } label: {
                    ActionTile(title: "Einlagern", subtitle: "Barcode scannen und Bestand erfassen",
                               systemImage: "arrow.down.to.line")
                }
                Button {
                    router.route = .checkout
                } label: {
                    // "arrow.up.from.line" gibt es als SF Symbol nicht - das Icon
                    // blieb dadurch leer und es war nur die Kachelflaeche zu sehen.
                    ActionTile(title: "Auslagern", subtitle: "Barcode scannen und Menge entnehmen",
                               systemImage: "arrow.up.to.line")
                }
                NavigationLink {
                    ShoppingListView()
                } label: {
                    ActionTile(title: "Einkaufsliste", subtitle: "Was unter dem Mindestbestand liegt",
                               systemImage: "cart")
                }
                NavigationLink {
                    ExpiringView()
                } label: {
                    ActionTile(title: "Bald ablaufend", subtitle: "Chargen mit knappem MHD",
                               systemImage: "clock")
                }
                NavigationLink {
                    ProductListView()
                } label: {
                    ActionTile(title: "Produkte", subtitle: "Suchen, ansehen und bearbeiten",
                               systemImage: "list.bullet")
                }
                Spacer()
            }
            .padding()
            .navigationTitle("Project-Good")
            .toolbar {
                ToolbarItem(placement: .topBarTrailing) {
                    Menu {
                        Text("Angemeldet als \(session.username)")
                        Button("Abmelden", role: .destructive) { session.logout() }
                    } label: {
                        Image(systemName: "person.circle")
                    }
                }
            }
        }
    }
}

struct ActionTile: View {
    let title: String
    let subtitle: String
    let systemImage: String

    var body: some View {
        HStack(spacing: 14) {
            Image(systemName: systemImage)
                .font(.title2)
                .frame(width: 44, height: 44)
                .background(Color.accentColor.opacity(0.15))
                .clipShape(RoundedRectangle(cornerRadius: 10))
            VStack(alignment: .leading, spacing: 2) {
                Text(title).font(.headline)
                Text(subtitle).font(.caption).foregroundStyle(.secondary)
                    .multilineTextAlignment(.leading)
            }
            Spacer()
            Image(systemName: "chevron.right").foregroundStyle(.tertiary)
        }
        .padding()
        .background(Color(.secondarySystemBackground))
        .clipShape(RoundedRectangle(cornerRadius: 12))
        .foregroundStyle(.primary)
    }
}