using Shouldly;
using Xunit;

namespace ZB.MOM.WW.OtOpcUa.Driver.Historian.SqlServer.Tests;

public sealed class SqlServerHistorianRetentionOptionsTests
{
    private static SqlServerHistorianOptions Valid() => new() { ConnectionString = "Server=x" };

    [Fact]
    public void Retention_is_off_by_default_with_sane_defaults()
    {
        var o = Valid();
        o.RetentionDays.ShouldBeNull();
        o.PurgeInterval.ShouldBe(TimeSpan.FromHours(1));
        o.PurgeBatchSize.ShouldBe(4000);
        o.Validate().ShouldBeEmpty();
    }

    [Theory]
    [InlineData(0)]
    [InlineData(-5)]
    public void Non_positive_RetentionDays_is_rejected(int days)
    {
        var o = Valid();
        o.RetentionDays = days;
        o.Validate().ShouldContain(e => e.Contains("RetentionDays"));
    }

    [Fact]
    public void Positive_RetentionDays_is_valid()
    {
        var o = Valid();
        o.RetentionDays = 30;
        o.Validate().ShouldBeEmpty();
    }

    [Fact]
    public void Bad_interval_and_batch_are_rejected()
    {
        var o = Valid();
        o.PurgeInterval = TimeSpan.Zero;
        o.PurgeBatchSize = 0;
        var errors = o.Validate();
        errors.ShouldContain(e => e.Contains("PurgeInterval"));
        errors.ShouldContain(e => e.Contains("PurgeBatchSize"));
    }

    [Fact]
    public void Provider_creates_retention_only_when_RetentionDays_set()
    {
        var o = Valid();
        new SqlServerHistorianProvider(o).CreateRetention(new EmptyServices()).ShouldBeNull();
        o.RetentionDays = 7;
        new SqlServerHistorianProvider(o).CreateRetention(new EmptyServices()).ShouldNotBeNull();
    }

    private sealed class EmptyServices : IServiceProvider
    {
        public object? GetService(Type serviceType) => null;
    }
}