using TestApp.Configuration;
using TestApp.Driver;

namespace TestApp
{
    internal class CurrentLimitter
    {
        private readonly ConfigurationManager _ConfigurationManager;
        private readonly EnergyManager _EnergyManager;

        public CurrentLimitter(ConfigurationManager configurationManager, EnergyManager energyManager)
        {
            _ConfigurationManager = configurationManager;
            _EnergyManager = energyManager;
        }

        public double GetLimitedCurrent(IChargerDriver chargerDriver, double current) {
            var maxCurrent = _ConfigurationManager.Settings.MaxCurrent ?? Settings.DEFAULT_MAX_CURRENT;

            var wallBoxCurrents = chargerDriver.GetCurrents();
            var measuredCurrents = _EnergyManager.GetCurrents();

            var maxWithoutCharger = GetMaximumCurrentWithoutWallBox(measuredCurrents, wallBoxCurrents);
            var freeCurrent = maxCurrent - maxWithoutCharger;

            if (freeCurrent < current) {
                return freeCurrent;
            } else
            {
                return current;
            }
        }

        private static double GetMaximumCurrentWithoutWallBox((double I1, double I2, double I3) measuredCurrent, (double I1, double I2, double I3) wallBoxCurrent)
        {
            return GetPermutations(wallBoxCurrent)
                .Where(wbc => IsValidCombinition(measuredCurrent, wbc))
                .Select(wbc => GetDifference(measuredCurrent, wbc))
                .Select(c => GetMax(c))
                .Max();
        }

        private static IEnumerable<(double I1, double I2, double I3)> GetPermutations((double I1, double I2, double I3) current) {
            yield return (current.I1, current.I2, current.I3);
            yield return (current.I1, current.I3, current.I2);
            yield return (current.I2, current.I3, current.I1);
            yield return (current.I2, current.I1, current.I3);
            yield return (current.I3, current.I1, current.I2);
            yield return (current.I3, current.I2, current.I1);
        } 

        private static bool IsValidCombinition((double I1, double I2, double I3) measuredCurrent, (double I1, double I2, double I3) wallBoxCurrent) {
            if (measuredCurrent.I1 < wallBoxCurrent.I1) { return false; } // even this is not correct if a PV is generating power !
            if (measuredCurrent.I2 < wallBoxCurrent.I2) { return false; }
            if (measuredCurrent.I3 < wallBoxCurrent.I3) { return false; }
            return true;
        }

        private static (double I1, double I2, double I3) GetDifference((double I1, double I2, double I3) x, (double I1, double I2, double I3) y) {
            return (x.I1 - y.I1, x.I2 - y.I2, x.I3 - y.I3);
        }

        private static double GetMax((double I1, double I2, double I3) currents) {
            return Math.Max(Math.Max(currents.I1, currents.I2), currents.I3);
        }
    }
}