using QVPN.Core;

internal static class SystemTunnelProbeTests
{
    public static async Task RunAsync(Func<string, Action, Task> test)
    {
        await test("An Up VPN adapter cannot hide a physical IPv4 route", () =>
        {
            var state = SystemTunnelProbe.Evaluate(true, 14, 14, new(0, 9), new(0, 14));
            Check(state.AdapterAvailable && !state.Ipv4RoutedThroughTunnel && !state.Healthy);
        });
        await test("IPv6 bypass is rejected even when IPv4 uses the VPN", () =>
        {
            var state = SystemTunnelProbe.Evaluate(true, 14, 14, new(0, 14), new(0, 9));
            Check(state.Ipv4RoutedThroughTunnel && state.Ipv6RoutedThroughTunnel == false && !state.Healthy);
        });
        await test("A missing IPv6 route permits a verified IPv4-only network", () =>
        {
            foreach (uint error in new uint[] {1168, 1231})
            {
                var state = SystemTunnelProbe.Evaluate(true, 14, 0, new(0, 14), new(error, 0));
                Check(state.Healthy && state.Ipv6RoutedThroughTunnel is null);
            }
            Check(SystemTunnelProbe.Evaluate(true, 14, 0, new(0, 14), null).Healthy);
        });
        await test("Unknown route errors and a missing adapter never report a healthy VPN", () =>
        {
            Check(!SystemTunnelProbe.Evaluate(true, 14, 14, new(0, 14), new(5, 0)).Healthy);
            Check(!SystemTunnelProbe.Evaluate(true, 14, 14, new(0, 14), new(232, 0)).Healthy);
            Check(!SystemTunnelProbe.Evaluate(true, 14, 14, new(0, 14), new(1232, 0)).Healthy);
            Check(!SystemTunnelProbe.Evaluate(true, 14, 14, new(5, 0), new(0, 14)).Healthy);
            Check(!SystemTunnelProbe.Evaluate(false, 14, 14, new(0, 14), new(0, 14)).Healthy);
            Check(!SystemTunnelProbe.Evaluate(true, 0, 0, new(0, 0), new(0, 0)).Healthy);
        });
        await test("Both Windows route families can belong to the verified VPN", () =>
        {
            Check(SystemTunnelProbe.Evaluate(true, 14, 14, new(0, 14), new(0, 14)).Healthy);
        });
    }

    private static void Check(bool condition)
    {
        if (!condition) throw new InvalidOperationException("System tunnel route verification failed.");
    }
}