import SwiftUI

@main
struct MultiSimAdminApp: App {
  @StateObject private var themeStore = ThemeStore.shared
  @State private var tab: AppTab

  init() {
    let arguments = ProcessInfo.processInfo.arguments
    if arguments.contains("--tab-messages") {
      _tab = State(initialValue: .messages)
    } else if arguments.contains("--tab-settings") {
      _tab = State(initialValue: .settings)
    } else {
      _tab = State(initialValue: .fleet)
    }
  }

  var body: some Scene {
    WindowGroup {
      Group {
        switch tab {
        case .fleet:
          NavigationStack { FleetView().aiInlineTitle() }
        case .messages:
          NavigationStack { MessagesView().aiInlineTitle() }
        case .settings:
          NavigationStack { SettingsView().aiInlineTitle() }
        }
      }
      .safeAreaInset(edge: .bottom, spacing: 0) {
        AITabBar(selection: $tab)
      }
      .tint(AITheme.primary)
      .preferredColorScheme(themeStore.mode.colorScheme)
      #if os(iOS)
        .toolbarBackground(.ultraThinMaterial, for: .navigationBar)
        .toolbarBackground(.visible, for: .navigationBar)
      #endif
    }
  }
}

#if os(iOS)
  extension View {
    fileprivate func aiInlineTitle() -> some View {
      navigationBarTitleDisplayMode(.inline)
    }
  }
#else
  extension View {
    fileprivate func aiInlineTitle() -> some View { self }
  }
#endif

enum AppTab: Hashable {
  case fleet
  case messages
  case settings
}

struct AITabBar: View {
  @Binding var selection: AppTab

  var body: some View {
    HStack(spacing: 0) {
      tab(.fleet, "节点", "server.rack")
      tab(.messages, "消息", "message")
      tab(.settings, "设置", "gearshape")
    }
    .frame(height: 62)
    .background {
      ZStack {
        Rectangle()
          .fill(.ultraThinMaterial)
        Rectangle()
          .fill(AITheme.chrome)
      }
      .ignoresSafeArea(edges: .bottom)
    }
    .overlay(alignment: .top) {
      Rectangle()
        .fill(AITheme.line)
        .frame(height: 1)
    }
  }

  private func tab(_ value: AppTab, _ title: String, _ systemImage: String) -> some View {
    let isSelected = selection == value
    return Button {
      selection = value
    } label: {
      VStack(spacing: 4) {
        Image(systemName: systemImage)
          .font(.system(size: 18, weight: .semibold))
        Text(title)
          .font(.caption2.weight(.semibold))
      }
      .foregroundStyle(isSelected ? AITheme.primary : AITheme.muted)
      .frame(maxWidth: .infinity, maxHeight: .infinity)
    }
    .buttonStyle(.plain)
    .accessibilityLabel(title)
    .accessibilityAddTraits(isSelected ? [.isSelected] : [])
  }
}