using System;
using System.Collections.Generic;
using System.Text;

namespace Sunweaver
{
    public class SystemVariables
    {
        private static string[] Variables;
        private static Dictionary<string, int> Indices;

        public bool Contains(string variable)
        {
            if (this[variable] != -1)
                return true;
            return false;
        }

        public string this[int index]
        {
            get
            {
                if (Variables == null)
                    Initialize();
                return Variables[Math.Abs(index)%Variables.Length];
            }
        }

        public int this[string variable]
        {
            get
            {
                if (Indices == null)
                    Initialize();
                if(Indices.ContainsKey(variable))
                    return Indices[variable];
                return -1;
            }
        }

        private static void Initialize()
        {
            Variables = new string[1000];
            Indices = new Dictionary<string, int>();

            AddUsedVariables();

            int count = 0;

            for (int i = 0; i < Variables.Length; i++)
            {
                if (Variables[i] == null)
                {
                    Variables[i] = "freemem" + count.ToString();
                    count++;
                }
                Indices.Add(Variables[i], i);
            }
        }

        private static void AddUsedVariables()
        {
            AddUsedVariable("mydir");
            AddUsedVariable("myvelx");
            AddUsedVariable("myvely");
            AddUsedVariable("mynrg");
            AddUsedVariable("myfat");
            AddUsedVariable("myleaf");
            AddUsedVariable("mymuscle");
        }

        private static void AddUsedVariable(string variable, int index)
        {
            if (Variables[index] == null)
            {
                Variables[index] = variable;
            }
        }

        private static void AddUsedVariable(string variable)
        {
            int i = Variables.Length-1;
            while(i>=0 && Variables[i]==null)
            {
                i--;
            }
            if (i >= 0)
            {
                AddUsedVariable(variable, i);
            }
        }
    }
}