using System.Net;
using System.Threading.Tasks;
using Server.Network;
using Xunit;

namespace Server.Tests;

public class FirewallTests
{
    [Fact]
    public void Firewall_BlocksIPAddress_WhenAdded()
    {
        var ip = IPAddress.Parse("192.168.1.1");
        var entry = new SingleIpFirewallEntry("192.168.1.1");

        Assert.False(Firewall.IsBlocked(ip));

        Firewall.Add(entry);

        Assert.True(Firewall.IsBlocked(ip));
    }

    [Fact]
    public void Firewall_DoesNotBlockIPAddress_WhenNotAdded()
    {
        var ip = IPAddress.Parse("192.168.1.2");
        Assert.False(Firewall.IsBlocked(ip));
    }

    [Fact]
    public void Firewall_StopsBlockingIPAddress_WhenRemoved()
    {
        var ip = IPAddress.Parse("192.168.1.3");
        var entry = new SingleIpFirewallEntry("192.168.1.3");

        Firewall.Add(entry);
        Assert.True(Firewall.IsBlocked(ip));

        Firewall.Remove(entry);
        Assert.False(Firewall.IsBlocked(ip));
    }

    [Fact]
    public void Firewall_BlocksIPRange()
    {
        var entry = new CidrFirewallEntry(IPAddress.Parse("10.0.0.1"), IPAddress.Parse("10.0.0.5"));

        Firewall.Add(entry);

        Assert.True(Firewall.IsBlocked(IPAddress.Parse("10.0.0.1")));
        Assert.True(Firewall.IsBlocked(IPAddress.Parse("10.0.0.3")));
        Assert.True(Firewall.IsBlocked(IPAddress.Parse("10.0.0.5")));

        Assert.False(Firewall.IsBlocked(IPAddress.Parse("10.0.0.6")));
    }

    [Fact]
    public void Firewall_CacheInvalidation_WorksOnUpdate()
    {
        var ip = IPAddress.Parse("192.168.1.10");
        var entry = new SingleIpFirewallEntry("192.168.1.10");

        Firewall.Add(entry);
        Assert.True(Firewall.IsBlocked(ip));

        Firewall.Remove(entry);
        Assert.False(Firewall.IsBlocked(ip));
    }

    [Fact]
    public void Firewall_ReadsFirewallSetCorrectly()
    {
        var entry = new SingleIpFirewallEntry("172.16.0.1");
        Firewall.Add(entry);

        var found = false;
        Firewall.ReadFirewallSet(set =>
        {
            found = set.Contains(entry);
        });

        Assert.True(found);
    }

    [Fact]
    public void Firewall_IsThreadSafe()
    {
        var testIps = new IPAddress[256];
        for (var i = 0; i <= 255; i++)
        {
            testIps[i] = IPAddress.Parse($"192.168.0.{i}");
        }

        var entry = new CidrFirewallEntry(IPAddress.Parse("192.168.0.1"), IPAddress.Parse("192.168.0.255"));
        Firewall.Add(entry);

        Parallel.ForEach(testIps, ip =>
        {
            var shouldBlock = int.Parse(ip.ToString().Split('.')[3]) is > 0;
            Assert.Equal(shouldBlock, Firewall.IsBlocked(ip));
        });

        Firewall.Remove(entry);

        Parallel.ForEach(testIps, ip =>
        {
            Assert.False(Firewall.IsBlocked(ip));
        });
    }

    [Fact]
    public void Firewall_DoesNotThrowWhenRemovingNonExistentEntry()
    {
        var entry = new SingleIpFirewallEntry("203.0.113.5");
        Assert.False(Firewall.Remove(entry));
    }

    [Fact]
    public void Firewall_CacheHandlesMultipleUpdates()
    {
        var ip = IPAddress.Parse("192.168.1.20");
        var entry = new SingleIpFirewallEntry("192.168.1.20");

        Firewall.Add(entry);
        Assert.True(Firewall.IsBlocked(ip));

        Firewall.Remove(entry);
        Assert.False(Firewall.IsBlocked(ip));

        Firewall.Add(entry);
        Assert.True(Firewall.IsBlocked(ip));

        Firewall.Remove(entry);
        Assert.False(Firewall.IsBlocked(ip));
    }
}