using System;


namespace SymulacjaCyfrowa
{
    internal class Generator
    {
        private int a = 16807;
         private int q = 127773;
         private int r = 2836;
       /* private int a = 69621;
        private int q = 30845;
        private int r = 23902;*/
        private int max = 2147483647;

        public enum Operator
        {
            NormalOrder,
            PatientAppearance,
            Transfusion,
            EmergencyOrder,
            DonorAppearance,
            PassBlood
        }

       /* public Generator(Operator op)
        {
            switch (op)
            {
                case Operator.NormalOrder:
                    Output = 123;
                    break;
                case Operator.PatientAppearance:
                    Output = 30;
                    break;
                case Operator.Transfusion:
                    Output = 3;
                    break;
                case Operator.EmergencyOrder:
                    Output = Convert.ToInt32 (Normal(300,0.1));
                    break;
                case Operator.DonorAppearance:
                    Output = 40;
                    break;
                case Operator.PassBlood:
                    Output = UniformAB(5,10);
                    break;
                default:
                    throw new InvalidOperationException("Nieprawidłowe zapytanie do generatora: " + op);
            }
        }*/


        private double Uniform(ref int seed)
        {
            int h;
            //via ivocom
            h = seed / q;
            seed = a * (seed - q * h) - r * h;
            if (seed < 0) { seed = seed + max; }
            return seed;
        }
        public double UniformZO(ref int seed) { return (Uniform(ref seed) / max); } //rozkład równomierny (0,1)
        public double UniformAB(int A, int B,ref int seed) { return (A +UniformZO(ref seed) * (B - A)); } //rozkład równomierny w przedziale (A,B)

       public double Normal(double s, double w, ref int seed)
        {
            double x = 0.0;
            for (int i = 0; i < 12; i++)
            {
                x += UniformZO(ref seed);
            }
            x -= 6;
            return x * w + s;
        }
        public double Geometric(double lambda, ref int seed)
        {
            //return Math.Floor(-Math.Log(UniformZO(ref seed))/lambda);
            //return (Math.Log(Uniform(ref seed)) / Math.Log(lambda));
            int i = 0;
            while (UniformZO(ref seed) > 1 * lambda) {
                i++;
            }
            return i + 1;

        }

        public double Exponential(double lambda, ref int seed)
        {
            return -lambda*Math.Log(UniformZO(ref seed));
        }

        //public double Output { get; set; }
    }
}