using System;
using System.Collections;
using System.Collections.Generic;
using System.Runtime.CompilerServices;

using UnityEngine;
using UnityEngine.Windows;

namespace XericLibrary.Runtime.MacroLibrary
{
	/// <summary>
	/// 数学库
	/// </summary>
    public static partial class MacroMath
    {
		#region 随机

		/// <summary>
		/// 获取一个被特定随机数填充的矩阵，这通常是无意义的
		/// </summary>
		/// <param name="vec"></param>
		/// <returns></returns>
		public static Matrix4x4 RandomMatrix4(float range)
		{
			return new Matrix4x4(
				RandomVector4(range), 
				RandomVector4(range), 
				RandomVector4(range), 
				RandomVector4(range));
		}

		/// <summary>
		/// 获取一个在指定坐标范围内的随机矢量(矩形范围)
		/// </summary>
		/// <param name="vec"></param>
		/// <returns></returns>
		public static Vector4 RandomVector4(float range)
		{
			var rand = new System.Random();
			range *= 100;
			Func<float> GetNextRand = () =>
			{
				return rand.Next((int)-range, (int)range) * 0.01f;
			};

			return new Vector4(GetNextRand(), GetNextRand(), GetNextRand(), GetNextRand());
		}

		/// <summary>
		/// 获取一个在指定坐标范围内的随机矢量(矩形范围)
		/// </summary>
		/// <param name="vec"></param>
		/// <returns></returns>
		public static Vector3 RandomVector3(float range)
		{
			var rand = new System.Random();
			range *= 100;
			Func<float> GetNextRand = () =>
			{
				return rand.Next((int)-range, (int)range) * 0.01f;
			};

			return new Vector3(GetNextRand(), GetNextRand(), GetNextRand());
		}

		/// <summary>
		/// 获取一个在指定坐标范围内的随机矢量(矩形范围)
		/// </summary>
		/// <param name="vec"></param>
		/// <returns></returns>
		public static Vector2 RandomVector2(float range)
		{
			var rand = new System.Random();
			range *= 100;
			Func<float> GetNextRand = () =>
			{
				return rand.Next((int)-range, (int)range) * 0.01f;
			};

			return new Vector2(GetNextRand(), GetNextRand());
		}

		/// <summary>
		/// 哈希后处理
		/// </summary>
		/// <param name="index"></param>
		/// <returns></returns>
		[MethodImpl(MethodImplOptions.AggressiveInlining)]
		public static ulong MurmurFinalize(ulong index)
		{
			index ^= index >> 33;
			index *= 0xff51afd7ed558ccd;
			index ^= index >> 33;
			index *= 0xc4ceb9fe1a85ec53;
			index ^= index >> 33;
			return index;
		}

		/// <summary>
		/// 大范围随机
		/// </summary>
		/// <param name="index"></param>
		/// <returns></returns>
		[MethodImpl(MethodImplOptions.AggressiveInlining)]
		public static ulong RandomNumber(ulong index)
		{
			index *= 1103515245;
			index += 12345;
			index *= 6364136223846793005UL;
			index += 1442695040888963407UL;
			index %= 18446744073709551615UL;
			return index;
		}


		#endregion

		#region 数学

		/// <summary>
		/// pmod
		/// </summary>
		/// <param name="a"></param>
		/// <param name="b"></param>
		/// <returns></returns>
		[MethodImpl(MethodImplOptions.AggressiveInlining)]
		public static int PMod(int a, int b)
		{
			if(b <= 0)
				return 0;
			var mod = a % b;
			return a < 0 ? (b + mod) % b : mod;
		}

		/// <summary>
		/// pmod
		/// </summary>
		/// <param name="a"></param>
		/// <param name="b"></param>
		/// <returns></returns>
		[MethodImpl(MethodImplOptions.AggressiveInlining)]
		public static double PMod(double a, double b)
		{
			double z = a % b;
			double w = (z < 0) ? -1 : 1;
			z = (z < 0) ? -z : z;
			if(w < 0)
				return b - z;
			else
				return z;
		}

		/// <summary>
		/// 获取两者的最小值，但不包括负数；
		/// </summary>
		/// <param name="a"></param>
		/// <param name="b"></param>
		/// <returns></returns>
		[MethodImpl(MethodImplOptions.AggressiveInlining)]
		public static float MinPositive(float a, float b)
			=> Math.Min(Math.Max(0, a), Math.Max(0, b));

		/// <summary>
		/// 获取两者的最小值，但不包括负数；
		/// </summary>
		/// <param name="a"></param>
		/// <param name="b"></param>
		/// <returns></returns>
		[MethodImpl(MethodImplOptions.AggressiveInlining)]
		public static int MinPositive(int a, int b)
			=> Math.Min(Math.Max(0, a), Math.Max(0, b));

		#endregion

		#region 字节控制

		/// <summary>
		/// 设置字
		/// </summary>
		[MethodImpl(MethodImplOptions.AggressiveInlining)]
		public static void SetByteState(ref int target, int site, bool state)
		{
			if(state)
				target |= 1 << site;

			else
				target &= 0xff - (1 << site);
		}

		/// <summary>
		/// 设置字
		/// </summary>
		[MethodImpl(MethodImplOptions.AggressiveInlining)]
		public static void SetByteState(ref int target, Enum site, bool state)
		{
			SetByteState(ref target, Convert.ToInt32(site), state);
		}

		/// <summary>
		/// 检查字
		/// </summary>
		[MethodImpl(MethodImplOptions.AggressiveInlining)]
		public static bool GetByteState(int target, int site)
		{
			return (target >> site & 0x01) > 0;
		}

		/// <summary>
		/// 检查字
		/// </summary>
		[MethodImpl(MethodImplOptions.AggressiveInlining)]
		public static bool GetByteState(int target, Enum site)
		{
			return GetByteState(target, Convert.ToInt32(site));
		}

		#endregion

		#region 填充

		/// <summary>
		/// 获取被从A到B的值填充的列表
		/// </summary>
		/// <param name="a"></param>
		/// <param name="b"></param>
		/// <returns></returns>
		public static List<int> GetListFormAToB(int a, int b)
		{
			var list = new List<int>();
			bool way = a > b;
			var step = way ? -1 : 1;

			for(int i = a; (!way && i <= b) || (way && i >= b); i += step)
				list.Add(i);

			return list;
		}

		#endregion

	}
}