namespace Qrakhen.Randomize;

public class Dice : IRandomizer<uint>
{
  public static uint MaxValue => uint.MaxValue;

  public static Dice? Global { get; private set; }

  private const uint P = 0x0100_0193; // prime
  private const uint Q = 0x811C_9DC5; // basis

  private uint _n;

  public readonly uint Seed;

  public int Count { get; private set; } = 0;

  public Dice() : this((int)((DateTime.UtcNow.Ticks & 0xFFFF_FFFF) ^ Q)) { }

  public Dice(int seed)
  {
    Seed = (uint)seed;
    _n = StrongHash(Q, Seed);
  }
  
  //public float ExpRange(float from, float to, float q = .5f)
  //{
  //  q = Mathf.Clamp(q, 0, 1);
  //  float linear = Range(0f, 1f);
  //  float exponent = Mathf.Pow(2f, (0.5f - q) * 4f);
  //  float curvedRandom = Mathf.Pow(linear, exponent);
  //  return Mathf.Lerp(from, to, curvedRandom);
  //}

  public uint Next()
  {
    unchecked
    {
      _n ^= Q;
      _n *= P;
      Count++;

      return (_n);
    }
  }

  public uint FastHash(uint v)
  {
    return (v ^ Q) * P;
  }

  public uint StrongHash(uint v, uint q)
  {
    uint r = v;
    r = (r ^ (q & 0xFF)) * P;
    r = (r ^ ((q >> 0x08) & 0xFF)) * P;
    r = (r ^ ((q >> 0x10) & 0xFF)) * P;
    r = (r ^ ((q >> 0x18) & 0xFF)) * P;

    return r;
  }

  public override string ToString()
  {
    return $"Dice <Seed: {Seed}, Count: {Count}, N: 0x{_n:x8}>";
  }

  public static void InitGlobal(int seed)
  {
    Global = new Dice(seed);
  }
}