using Shouldly;
using Xunit;
using ZB.MOM.WW.LmxOpcUa.Host.OpcUa;

namespace ZB.MOM.WW.LmxOpcUa.Tests.Redundancy
{
    public class ServiceLevelCalculatorTests
    {
        private readonly ServiceLevelCalculator _calculator = new ServiceLevelCalculator();

        [Fact]
        public void FullyHealthy_Primary_ReturnsBase()
        {
            _calculator.Calculate(200, mxAccessConnected: true, dbConnected: true).ShouldBe((byte)200);
        }

        [Fact]
        public void FullyHealthy_Secondary_ReturnsBaseMinusFifty()
        {
            _calculator.Calculate(150, mxAccessConnected: true, dbConnected: true).ShouldBe((byte)150);
        }

        [Fact]
        public void MxAccessDown_ReducesServiceLevel()
        {
            _calculator.Calculate(200, mxAccessConnected: false, dbConnected: true).ShouldBe((byte)100);
        }

        [Fact]
        public void DbDown_ReducesServiceLevel()
        {
            _calculator.Calculate(200, mxAccessConnected: true, dbConnected: false).ShouldBe((byte)150);
        }

        [Fact]
        public void BothDown_ReturnsZero()
        {
            _calculator.Calculate(200, mxAccessConnected: false, dbConnected: false).ShouldBe((byte)0);
        }

        [Fact]
        public void ClampedTo255()
        {
            _calculator.Calculate(255, mxAccessConnected: true, dbConnected: true).ShouldBe((byte)255);
        }

        [Fact]
        public void ClampedToZero()
        {
            _calculator.Calculate(50, mxAccessConnected: false, dbConnected: true).ShouldBe((byte)0);
        }

        [Fact]
        public void ZeroBase_BothHealthy_ReturnsZero()
        {
            _calculator.Calculate(0, mxAccessConnected: true, dbConnected: true).ShouldBe((byte)0);
        }
    }
}