using System;

namespace Science.Mathematics.VectorCalculus
{
    public class GaussDivergenceTheorem
    {
        private Function.ToLastType<double[], double[]> vf;
        private Surface s;
        private Volume v;
        public GaussDivergenceTheorem()
        {
        }
        public GaussDivergenceTheorem(Volume V,
            Function.ToLastType<double[], double[]> F, Surface D)
        {
            v = V;
            vf = F;
            s = D;
        }
        public Function.ToLastType<double[], double[]> VectorField
        {
            set { vf = value; }
        }
        public Surface Boundary
        {
            set { s = value; }
        }
        public Volume Domain
        {
            set { v = value; }
        }
        public void Compute()
        {
            Function.ToLastType<double[],double> ff
                = new Function.ToLastType<double[],double>(divF);
            IntegrationMultiD md = new IntegrationMultiD(ff,v.From,v.To);
            md.NumberOfCall = nc;
            md.Compute();
            ltgral = md.BestEstimation;
            lsd = md.StandardDeviation;
            lchi2 = md.ChiSQUARE; 
           
            SurfaceIntegral obj = new SurfaceIntegral(vf, s);
            obj.NumberOfCall = nc;
            obj.Compute();
            tgral = obj.BestEstimation;
            sd = obj.StandardDeviation;
            chi2 = obj.ChiSQUARE; 
        }
        private double divF(double[] x)
        {
            Divergence obj = new Divergence(vf,x);
            obj.Compute();  
            if (v.IsInVolumeQ(x)) return obj.Result;
            else return 0.0; 
        }
        public double LeftHandSideBestEstimation
        {
            get { return ltgral; }
        }
        public double LeftHandSideStandardDeviation
        {
            get { return lsd; }
        }
        public double LeftHandSideChiSQUARE
        {
            get { return lchi2; }
        }
        private double ltgral, lsd, lchi2;
        private double tgral, sd, chi2;
        private ulong nc = 100000;
        public double RightHandSideBestEstimation
        {
            get { return tgral; }
        }
        public double RightHandSideStandardDeviation
        {
            get { return sd; }
        }
        public double RightHandSideChiSQUARE
        {
            get { return chi2; }
        }
        public ulong NumberOfCall
        {
            set { nc = value; }
        }

        public override string ToString()
        {
            string res = "";
            res += this.LeftHandSideBestEstimation.ToString() + " +/- " +
                this.LeftHandSideStandardDeviation.ToString() + "  =  ";
            res += this.RightHandSideBestEstimation.ToString() + " +/- " +
                this.RightHandSideStandardDeviation.ToString(); 
            res += "\r\n";
            return res;
        }  
    }
}