using UnityEngine;
using System.Runtime.InteropServices;
using Random = UnityEngine.Random;

public class Tests : MonoBehaviour
{
    System.Text.StringBuilder sb = new System.Text.StringBuilder();

    // Start is called before the first frame update
    void Start()
    {
        UnityEngine.Random.InitState(1234);
        XORShift128.InitSeed(1234);

        // Print some ranged integers
        // 0 to max
        IntegerTests(0, int.MaxValue);
        // 0 to min
        IntegerTests(0, int.MinValue);
        // Min to max
        IntegerTests(int.MinValue, int.MaxValue);
        // Max to min
        IntegerTests(int.MaxValue, int.MinValue);
        // Min to min (error)
        IntegerTests(int.MinValue, int.MinValue);

        // Print some floating points
        for (int i = 0; i < 5; i++) AppendTestFloat(Random.value, XORShift128.NextFloat());

        // Print some ranged floating points
        // 0 to 100
        FloatingPointTests(0f, 100f);
        // 0 to 100000
        FloatingPointTests(0f, 100000f);
        // 0 to max (not accurate)
        FloatingPointTests(0f, float.MaxValue);
        // 0 to min (not accurate)
        FloatingPointTests(0f, float.MinValue);
        // Min to max
        FloatingPointTests(float.MinValue, float.MaxValue);
        // Max to min
        FloatingPointTests(float.MaxValue, float.MinValue);
        // Min to min
        FloatingPointTests(float.MinValue, float.MinValue);

        Debug.Log(sb.ToString());
    }

    void IntegerTests(int min, int max)
    {
        sb.AppendLine("--- " + min + " to " + max + " ---");

        for (int i = 0; i < 5; i++)
        {
            int ur = UnityEngine.Random.Range(min, max);
            int xr = XORShift128.NextIntRange(min, max);
            AppendTestInt(ur, xr);
        }
    }

    void FloatingPointTests(float min, float max)
    {
        sb.AppendLine("--- " + min + " to " + max + " ---");
        for (int i = 0; i < 5; i++)
        {
            float ur = UnityEngine.Random.Range(min, max);
            float xr = XORShift128.NextFloatRange(min, max);
            AppendTestFloat(ur, xr);
        }
    }

    void AppendTest(string a, string b)
    {
        var state = (RandomStateWrapper)UnityEngine.Random.state;
        sb.AppendLine(state.v3.ToString().PadRight(15) + XORShift128.w.ToString().PadRight(15) + a.PadRight(15) + b.PadRight(15));
    }

    void AppendTestInt(int a, int b)
    {
        AppendTest(a.ToString(), b.ToString());
    }

    void AppendTestFloat(float a, float b)
    {
        AppendTest(a.ToString(), b.ToString());
    }
}

[StructLayout(LayoutKind.Explicit)]
public struct RandomStateWrapper
{
    [FieldOffset(0)] public Random.State state;
    [FieldOffset(0)] public uint v0;
    [FieldOffset(4)] public uint v1;
    [FieldOffset(8)] public uint v2;
    [FieldOffset(12)] public uint v3;

    public static implicit operator RandomStateWrapper(Random.State aState)
    {
        return new RandomStateWrapper { state = aState };
    }
    public static implicit operator Random.State(RandomStateWrapper aState)
    {
        return aState.state;
    }

    public override string ToString()
    {
        return v0 + ", " + v1 + ", " + v2 + ", " + v3;
    }
}