using System;

namespace ZB.MOM.WW.OtOpcUa.Host.OpcUa
{
    /// <summary>
    ///     Computes the OPC UA ServiceLevel byte from a baseline and runtime health inputs.
    /// </summary>
    public sealed class ServiceLevelCalculator
    {
        /// <summary>
        ///     Calculates the current ServiceLevel from a role-adjusted baseline and health state.
        /// </summary>
        /// <param name="baseLevel">The role-adjusted baseline (e.g., 200 for primary, 150 for secondary).</param>
        /// <param name="mxAccessConnected">Whether the MXAccess runtime connection is healthy.</param>
        /// <param name="dbConnected">Whether the Galaxy repository database is reachable.</param>
        /// <returns>A ServiceLevel byte between 0 and 255.</returns>
        public byte Calculate(int baseLevel, bool mxAccessConnected, bool dbConnected)
        {
            if (!mxAccessConnected && !dbConnected)
                return 0;

            var level = baseLevel;

            if (!mxAccessConnected)
                level -= 100;

            if (!dbConnected)
                level -= 50;

            return (byte)Math.Max(0, Math.Min(level, 255));
        }
    }
}