namespace ZB.MOM.WW.MxGateway.Client.Tests;

public sealed class MxGatewayClientOptionsTests
{
    /// <summary>
    /// The safe-unary budget covers every attempt's deadline plus the backoff between them, so a
    /// first attempt that hits its deadline does not consume the retry's time (#197).
    /// </summary>
    [Fact]
    public void SafeUnaryBudget_CoversEveryAttemptAndBackoff()
    {
        var options = new MxGatewayClientOptions
        {
            Endpoint = new Uri("http://localhost:5000"),
            ApiKey = "test-api-key",
            DefaultCallTimeout = TimeSpan.FromSeconds(30),
            Retry = new MxGatewayClientRetryOptions { MaxAttempts = 3, MaxDelay = TimeSpan.FromSeconds(2) },
        };

        Assert.Equal(TimeSpan.FromSeconds(94), MxGatewayClientRetryPolicy.SafeUnaryBudget(options));
    }

    /// <summary>A budget beyond what a cancellation timer accepts means no outer cap rather than a throw.</summary>
    [Fact]
    public void SafeUnaryBudget_WhenTooLargeForATimer_ReturnsNull()
    {
        var options = new MxGatewayClientOptions
        {
            Endpoint = new Uri("http://localhost:5000"),
            ApiKey = "test-api-key",
            DefaultCallTimeout = TimeSpan.FromDays(40),
            Retry = new MxGatewayClientRetryOptions { MaxAttempts = 2 },
        };

        Assert.Null(MxGatewayClientRetryPolicy.SafeUnaryBudget(options));
    }

    /// <summary>Verifies that options with valid endpoint and API key pass validation.</summary>
    [Fact]
    public void Validate_WithAbsoluteEndpointAndApiKey_Succeeds()
    {
        var options = new MxGatewayClientOptions
        {
            Endpoint = new Uri("http://localhost:5000"),
            ApiKey = "test-api-key",
        };

        options.Validate();
    }

    /// <summary>Verifies that empty API key causes validation to fail.</summary>
    [Fact]
    public void Validate_WithEmptyApiKey_Throws()
    {
        var options = new MxGatewayClientOptions
        {
            Endpoint = new Uri("http://localhost:5000"),
            ApiKey = "",
        };

        Assert.Throws<ArgumentException>(options.Validate);
    }

    /// <summary>Verifies that invalid retry options cause validation to fail.</summary>
    [Fact]
    public void Validate_WithInvalidRetryOptions_Throws()
    {
        var options = new MxGatewayClientOptions
        {
            Endpoint = new Uri("http://localhost:5000"),
            ApiKey = "test-api-key",
            Retry = new MxGatewayClientRetryOptions { MaxAttempts = 0 },
        };

        Assert.Throws<ArgumentOutOfRangeException>(options.Validate);
    }
}