using FinalFactory.Rendezvous.Contracts;

namespace FinalFactory.Rendezvous.Tests.Contracts;

public sealed class ContractLimitTests
{
    [Fact]
    public void RequiredPlayerFacingTextRejectsEmptyOrWhitespaceValues()
    {
        Assert.False(ContractValidation.IsBuildVersionValid(string.Empty));
        Assert.False(ContractValidation.IsBuildVersionValid("   "));
        Assert.False(ContractValidation.IsDisplayNameValid(string.Empty));
        Assert.False(ContractValidation.IsDisplayNameValid("   "));
    }

    [Fact]
    public void ByteAndCollectionLimitsAcceptTheBoundaryOnly()
    {
        Assert.True(ContractValidation.IsHttpRequestSizeValid(ContractLimits.HttpRequestMaxBytes));
        Assert.False(ContractValidation.IsHttpRequestSizeValid(ContractLimits.HttpRequestMaxBytes + 1));
        Assert.True(ContractValidation.IsBrowserResponseSizeValid(ContractLimits.BrowserResponseMaxBytes));
        Assert.False(ContractValidation.IsBrowserResponseSizeValid(ContractLimits.BrowserResponseMaxBytes + 1));
        Assert.True(ContractValidation.IsPageSizeValid(ContractLimits.BrowserPageMaxItems));
        Assert.False(ContractValidation.IsPageSizeValid(ContractLimits.BrowserPageMaxItems + 1));
        Assert.False(ContractValidation.IsPageSizeValid(0));
    }

    [Fact]
    public void Utf8LimitsCountBytesInsteadOfCharacters()
    {
        string atLimit = new('é', ContractLimits.DisplayNameMaxBytes / 2);
        string overLimit = atLimit + "é";

        Assert.True(ContractValidation.IsDisplayNameValid(atLimit));
        Assert.False(ContractValidation.IsDisplayNameValid(overLimit));
        Assert.True(ContractValidation.IsBuildVersionValid(
            new string('a', ContractLimits.BuildVersionMaxBytes)));
        Assert.False(ContractValidation.IsBuildVersionValid(
            new string('a', ContractLimits.BuildVersionMaxBytes + 1)));
    }

    [Fact]
    public void CapabilityLimitStaysBelowLiteNetLibTokenLimit()
    {
        Assert.True(ContractValidation.IsCapabilityValid(
            new string('a', ContractLimits.UdpCapabilityMaxCharacters - 1)));
        Assert.True(ContractValidation.IsCapabilityValid(
            new string('a', ContractLimits.UdpCapabilityMaxCharacters)));
        Assert.False(ContractValidation.IsCapabilityValid(
            new string('a', ContractLimits.UdpCapabilityMaxCharacters + 1)));
        Assert.False(ContractValidation.IsCapabilityValid("not+base64url"));
        Assert.True(
            ContractLimits.UdpCapabilityMaxCharacters
            < ContractLimits.LiteNetLibNatTokenMaxCharacters);
    }

    [Fact]
    public void CapacityAndMetadataLimitsAreBounded()
    {
        Assert.True(ContractValidation.IsCapacityValid(new SessionCapacity
        {
            CurrentPlayers = ContractLimits.SessionCapacityMaxPlayers,
            MaximumPlayers = ContractLimits.SessionCapacityMaxPlayers,
        }));
        Assert.False(ContractValidation.IsCapacityValid(new SessionCapacity
        {
            CurrentPlayers = 0,
            MaximumPlayers = ContractLimits.SessionCapacityMaxPlayers + 1,
        }));

        Dictionary<string, string> maximumKeys = Enumerable
            .Range(0, ContractLimits.MetadataMaxKeys)
            .ToDictionary(index => $"key-{index}", _ => "value", StringComparer.Ordinal);
        Dictionary<string, string> tooManyKeys = new(maximumKeys, StringComparer.Ordinal)
        {
            ["overflow"] = "value",
        };

        Assert.True(ContractValidation.IsMetadataValid(maximumKeys));
        Assert.False(ContractValidation.IsMetadataValid(tooManyKeys));
        Assert.False(ContractValidation.IsMetadataValid(new Dictionary<string, string>
        {
            [new string('k', ContractLimits.MetadataKeyMaxBytes + 1)] = "value",
        }));
        Assert.False(ContractValidation.IsMetadataValid(new Dictionary<string, string>
        {
            ["key"] = new string('v', ContractLimits.MetadataValueMaxBytes + 1),
        }));
    }

    [Fact]
    public void MetadataDocumentLimitAcceptsExactlyFourKibibytes()
    {
        Dictionary<string, string> atLimit = Enumerable
            .Range(0, ContractLimits.MetadataMaxKeys)
            .ToDictionary(index => $"k{index:00}", _ => string.Empty, StringComparer.Ordinal);
        for (int index = 0; index < 14; index++)
        {
            atLimit[$"k{index:00}"] = new string('v', ContractLimits.MetadataValueMaxBytes);
        }

        atLimit["k14"] = new string('v', 223);
        Dictionary<string, string> overLimit = new(atLimit, StringComparer.Ordinal)
        {
            ["k14"] = new string('v', 224),
        };

        Assert.True(ContractValidation.IsMetadataValid(atLimit));
        Assert.False(ContractValidation.IsMetadataValid(overLimit));
    }

    [Fact]
    public void EndpointValidationIsAddressFamilyAware()
    {
        Assert.True(ContractValidation.IsNetworkEndpointValid(new NetworkEndpoint
        {
            AddressFamily = AddressFamilyKind.Ipv4,
            Address = "192.0.2.10",
            Port = 9050,
        }));
        Assert.True(ContractValidation.IsNetworkEndpointValid(new NetworkEndpoint
        {
            AddressFamily = AddressFamilyKind.Ipv6,
            Address = "2001:db8::10",
            Port = 9050,
        }));
        Assert.False(ContractValidation.IsNetworkEndpointValid(new NetworkEndpoint
        {
            AddressFamily = AddressFamilyKind.Ipv4,
            Address = "2001:db8::10",
            Port = 9050,
        }));
    }

    [Fact]
    public void ScopeAndOpaqueTextBoundariesAreEnforced()
    {
        Assert.True(GameId.TryParse(new string('a', ContractLimits.GameIdMaxCharacters), out _));
        Assert.False(GameId.TryParse(
            new string('a', ContractLimits.GameIdMaxCharacters + 1),
            out _));
        Assert.True(ContractValidation.IsIdempotencyKeyValid(
            new string('i', ContractLimits.IdempotencyKeyMaxCharacters)));
        Assert.False(ContractValidation.IsIdempotencyKeyValid(
            new string('i', ContractLimits.IdempotencyKeyMaxCharacters + 1)));
        Assert.True(ContractValidation.IsCursorValid(null));
        Assert.False(ContractValidation.IsCursorValid("contains whitespace"));
    }
}