#if os(iOS)
import SwiftUI

struct ContentView: View {
    @EnvironmentObject var importer: BundleImporter
    @EnvironmentObject var libraryVM: LibraryViewModel

    @State private var tab = 0

    var body: some View {
        TabView(selection: $tab) {
            NavigationStack {
                BookListView(importer: importer, vm: libraryVM)
            }
            .tabItem { Label("书库", systemImage: "books.vertical") }
            .tag(0)

            NavigationStack {
                if let index = importer.index {
                    StatsView(index: index)
                } else {
                    VStack(spacing: 16) {
                        Text("尚未导入数据包")
                        Button("导入 iPad 导出包") { importer.presentPicker() }
                    }.padding()
                }
            }
            .tabItem { Label("统计", systemImage: "chart.bar") }
            .tag(1)

            NavigationStack {
                ScrollView { VStack(alignment:.leading, spacing: 12) {
                    Text("关于").font(.title2).bold()
                    Text("离线阅读与统计查看器。加载 Python 导出的 iPad Bundle。")
                    Button("重新导入") { importer.presentPicker() }
                    if let p = importer.lastImportedURL {
                        Text("最近: \(p.lastPathComponent)").font(.footnote).foregroundColor(.secondary)
                    }
                }.padding() }
            }
            .tabItem { Label("关于", systemImage: "info.circle") }
            .tag(2)
        }
        .onReceive(importer.$bundleIndex) { newIndex in
            if let newIndex {
                libraryVM.attach(index: newIndex)
            }
        }
    }
}
#endif