import SwiftUI

struct GateView: View {
    @EnvironmentObject private var router: Router
    @State private var isNavigated = false
    @State private var isLoading = true
    @State private var errorMessage: String? = nil

    var body: some View {
        ZStack {
            Color.themeTextWhiteSecondary.ignoresSafeArea()

            if isLoading {
                VStack(spacing: 16) {
                    ProgressView()
                    Text("Loading...")
                        .font(Typography.font(for: .body))
                        .foregroundColor(.themeTextMessage)
                }
            } else if let error = errorMessage {
                // Briefly inform the user, then auto-navigate to avatar page
                VStack(spacing: 12) {
                    Text("Network error, going to Avatar setup...")
                        .font(Typography.font(for: .subtitle, family: .quicksandBold))
                        .foregroundColor(.themeTextMessageMain)
                    Text(error)
                        .font(.caption)
                        .foregroundColor(.themeTextMessage)
                        .multilineTextAlignment(.center)
                        .padding(.horizontal)
                }
            } else {
                // Should not be seen because we auto-route when done
                EmptyView()
            }
        }
        .onAppear(perform: queryAndRoute)
        .navigationBarBackButtonHidden(true)
    }

    private func queryAndRoute() {
        guard !isNavigated else { return }
        isLoading = true
        errorMessage = nil
        print("[Gate] Start queryAndRoute")

        NetworkService.shared.get(
            path: "/blind_boxs/query",
            parameters: nil
        ) { (result: Result<APIResponse<[BlindList]>, NetworkError>) in
            print("Query result: \(result)")
            DispatchQueue.main.async {
                isLoading = false
                switch result {
                case .success(let response):
                    let list = response.data ?? []
                    print("[Gate] Success, list count: \(list.count)")
                    let lowered = list.map { ($0.boxType).lowercased() }
                    let hasFirst = lowered.contains(where: { $0 == "first" })
                    let hasSecond = lowered.contains(where: { $0 == "second" })
                    let hasRetrieval = lowered.contains(where: { $0 == "retrievalgeneration" })

                    print("hasFirst: \(hasFirst), hasSecond: \(hasSecond), hasRetrieval: \(hasRetrieval)")
                    // Routing rules (updated):
                    // - If has 'second' OR 'retrievalgeneration' -> normal home
                    // - Else if only 'first' exists -> second onboarding page
                    // - Else -> avatar upload page
                    if hasSecond || hasRetrieval {
                        print("[Gate] Route -> BlindBox .all")
                        navigateOnce(to: .blindBox(mediaType: .all))
                    } else if hasFirst {
                        print("[Gate] Route -> SecondOnboardingView")
                        navigateOnce(to: .secondOnboarding)
                    } else {
                        print("[Gate] Route -> UserInfo (no first/second/retrieval)")
                        navigateOnce(to: .userInfo)
                    }

                    // Defensive fallback: if for any reason not navigated, push avatar after small delay
                    DispatchQueue.main.asyncAfter(deadline: .now() + 1.0) {
                        if !isNavigated {
                            print("[Gate] Fallback routing -> UserInfo")
                            navigateOnce(to: .userInfo)
                        }
                    }

                case .failure(let error):
                    // Show an error briefly, then route to avatar page automatically
                    errorMessage = error.localizedDescription
                    print("Error: \(error.localizedDescription)")
                    DispatchQueue.main.asyncAfter(deadline: .now() + 0.8) {
                        navigateOnce(to: .userInfo)
                    }
                }
            }
        }
    }

    private func navigateOnce(to destination: AppRoute) {
        guard !isNavigated else { return }
        isNavigated = true
        router.navigate(to: destination)
    }
}

#Preview {
    GateView().environmentObject(Router.shared)
}