using UnityEngine;
using System.Collections;
using System.Collections.Generic;
using System.Linq;

public class TableCurve : Curve {
	private readonly List<float> _args;
	private readonly List<float> _vals;

	public float[] Args{
		get{return _args.ToArray();}
	}

	public float[] Vals{
		get{return _vals.ToArray();}
	}
	public TableCurve(){
		_args = new List<float>();
		_vals = new List<float>();
	}
	public TableCurve(IList<float> args, IList<float> vals){
		if((args == null) || (vals == null)){
			_args = new List<float>();
			_vals = new List<float>();
			return;
		}

		_args = args.ToList();
		_vals = vals.ToList();

	}

	public void AddArg(float arg){
		_args.Add(arg);
	}
	public void AddVal(float val){
		_vals.Add(val);
	}

    public override float Sample(float arg) {
        arg = Mathf.Clamp(arg, _args[0], _args[_args.Count - 1]);
        for (int i = 0; i < (_args.Count - 1); ++i) {
            if (_args[i] == arg) {
                return _vals[i];
            }
            var a = _args[i];
            var b = _args[i + 1];
            //args decreasing
            if (b < a) {
                if (arg < a && arg > b) {
                    return Mathf.Lerp(_vals[i], _vals[i + 1], (arg - a) / (b - a));
                }
            } else {
                if (arg > a && arg < b) {
                    return Mathf.Lerp(_vals[i], _vals[i + 1], (arg - a) / (b - a));
                }
            }
        }
        return float.NaN;
    }


}