using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Weasels
{
    class Weasel : Organism, Asexual, Sexual
    {        
        public const string TARGET = "methinks it is like a weasel";
        public const int GENOME_LENGTH = 28;
        public const int MUATION_PERIOD = GENOME_LENGTH;

        public Char[] genome;

        public Weasel() : this(RandomGenome()) { }

        public Weasel(Char[] genome) : base()
        {
            this.genome = genome;
        }

        public static Char[] RandomGenome()
        {
            Char[] genome = new Char[GENOME_LENGTH];

            Random r = new Random();

            for(int i = 0; i < GENOME_LENGTH; i++)
            {
                int val = r.Next(95) + 32;
                genome[i] = (char)val;
            }

            return genome;
        }

        public override int Fitness()
        {
            int sim = 0;

            for(int i = 0; i < GENOME_LENGTH; i++)
            {
                sim += (genome[i] == TARGET[i]) ? 1 : 0;
            }

            return sim;
        }

        public override Organism Mutate()
        {
            Random r = new Random();
            double frequency = 1.0 / MUATION_PERIOD;

            char[] genome = this.genome.Select(
                c => (r.NextDouble() < frequency) ? (char)(r.Next(95) + 32) : c
                ).ToArray();

            return new Weasel(genome);
        }

        public Asexual Reproduce()
        {
            return (Asexual) Mutate();
        }

        public Sexual Reproduce(Sexual otherParent)
        {
            Random r = new Random();
            char[] childGenome = new char[GENOME_LENGTH];

            for(int i = 0; i < GENOME_LENGTH; i++)
            {
                childGenome[i] = (r.NextDouble() < 0.5) ? this.genome[i] : ((Weasel)otherParent).genome[i];
            }

            return (Sexual) new Weasel(childGenome).Mutate();
        }
    }
}