#pragma once
#include "FastSIMD/InlInclude.h"
#include <climits>

namespace FastNoise
{    
    namespace Primes
    {
        static constexpr int X = 501125321;
        static constexpr int Y = 1136930381;
        static constexpr int Z = 1720413743;
        static constexpr int W = 1066037191;

        static constexpr int Lookup[] = { X,Y,Z,W };
    }

    template<typename FS>
    struct Utils
    {
        using float32v = typename FS::float32v;
        using int32v = typename FS::int32v;
        using mask32v = typename FS::mask32v;

        static constexpr float ROOT2 = 1.4142135623730950488f;
        static constexpr float ROOT3 = 1.7320508075688772935f;

        template<typename SIMD = FS, std::enable_if_t<SIMD::SIMD_Level < FastSIMD::Level_AVX2>* = nullptr>
        FS_INLINE static float32v GetGradientDotFancy( int32v hash, float32v fX, float32v fY )
        {
            int32v index = FS_Convertf32_i32( FS_Converti32_f32( hash & int32v( 0x3FFFFF ) ) * float32v( 1.3333333333333333f ) );

            // Bit-4 = Choose X Y ordering
            mask32v xy;

            if constexpr( FS::SIMD_Level == FastSIMD::Level_Scalar )
            {
                xy = int32_t( index & int32v( 1 << 2 ) ) != 0;
            }
            else
            {
                xy = index << 29;

                if constexpr( FS::SIMD_Level < FastSIMD::Level_SSE41 )
                {
                    xy >>= 31;
                }
            }

            float32v a = FS_Select_f32( xy, fY, fX );
            float32v b = FS_Select_f32( xy, fX, fY );

            // Bit-1 = b flip sign
            b ^= FS_Casti32_f32( index << 31 );

            // Bit-2 = Mul a by 2 or Root3
            mask32v aMul2;

            if constexpr( FS::SIMD_Level == FastSIMD::Level_Scalar )
            {
                aMul2 = int32_t( index & int32v( 1 << 1 ) ) != 0;
            }
            else
            {
                aMul2 = (index << 30) >> 31;
            }

            a *= FS_Select_f32( aMul2, float32v( 2 ), float32v( ROOT3 ) );
            // b zero value if a mul 2
            b = FS_NMask_f32( b, aMul2 );

            // Bit-8 = Flip sign of a + b
            return ( a + b ) ^ FS_Casti32_f32( (index >> 3) << 31 );
        }
        template<typename SIMD = FS, std::enable_if_t<SIMD::SIMD_Level == FastSIMD::Level_NEON>* = nullptr>
        FS_INLINE static float32v GetGradientDotFancy( int32v hash, float32v fX, float32v fY )
        {
            int32v index = FS_Convertf32_i32( FS_Converti32_f32( hash & int32v( 0x3FFFFF ) ) * float32v( 1.3333333333333333f ) );

            // Bit-4 = Choose X Y ordering
            mask32v xy;

//             if constexpr( FS::SIMD_Level == FastSIMD::Level_Scalar )
//             {
//                 xy = int32_t( index & int32v( 1 << 2 ) ) != 0;
//             }
//             else
//             {
                xy = index << 29;

//                 if constexpr( FS::SIMD_Level < FastSIMD::Level_SSE41 )
//                 {
                    xy >>= 31;
//                 }
//             }

            float32v a = FS_Select_f32( xy, fY, fX );
            float32v b = FS_Select_f32( xy, fX, fY );

            // Bit-1 = b flip sign
            b ^= FS_Casti32_f32( index << 31 );

            // Bit-2 = Mul a by 2 or Root3
            mask32v aMul2;

//             if constexpr( FS::SIMD_Level == FastSIMD::Level_Scalar )
//             {
//                 aMul2 = int32_t( index & int32v( 1 << 1 ) ) != 0;
//             }
//             else
//             {
                aMul2 = (index << 30) >> 31;
//             }

            a *= FS_Select_f32( aMul2, float32v( 2 ), float32v( ROOT3 ) );
            // b zero value if a mul 2
            b = FS_NMask_f32( b, aMul2 );

            // Bit-8 = Flip sign of a + b
            return ( a + b ) ^ FS_Casti32_f32( (index >> 3) << 31 );
        }

        template<typename SIMD = FS, std::enable_if_t<SIMD::SIMD_Level == FastSIMD::Level_AVX2>* = nullptr>
        FS_INLINE static float32v GetGradientDotFancy( int32v hash, float32v fX, float32v fY )
        {
            int32v index = FS_Convertf32_i32( FS_Converti32_f32( hash & int32v( 0x3FFFFF ) ) * float32v( 1.3333333333333333f ) );

            float32v gX = _mm256_permutevar8x32_ps( float32v( ROOT3, ROOT3, 2, 2, 1, -1, 0, 0 ), index );
            float32v gY = _mm256_permutevar8x32_ps( float32v( 1, -1, 0, 0, ROOT3, ROOT3, 2, 2 ), index );

            // Bit-8 = Flip sign of a + b
            return FS_FMulAdd_f32( gX, fX, fY * gY ) ^ FS_Casti32_f32( (index >> 3) << 31 );
        }

        template<typename SIMD = FS, std::enable_if_t<(SIMD::SIMD_Level == FastSIMD::Level_AVX512)>* = nullptr>
        FS_INLINE static float32v GetGradientDotFancy( int32v hash, float32v fX, float32v fY )
        {
            int32v index = FS_Convertf32_i32( FS_Converti32_f32( hash & int32v( 0x3FFFFF ) ) * float32v( 1.3333333333333333f ) );

            float32v gX = _mm512_permutexvar_ps( index, float32v( ROOT3, ROOT3, 2, 2, 1, -1, 0, 0, -ROOT3, -ROOT3, -2, -2, -1, 1, 0, 0 ) );
            float32v gY = _mm512_permutexvar_ps( index, float32v( 1, -1, 0, 0, ROOT3, ROOT3, 2, 2, -1, 1, 0, 0, -ROOT3, -ROOT3, -2, -2 ) );

            return FS_FMulAdd_f32( gX, fX, fY * gY );
        }


        template<typename SIMD = FS, std::enable_if_t<SIMD::SIMD_Level < FastSIMD::Level_AVX2>* = nullptr>
        FS_INLINE static float32v GetGradientDot( int32v hash, float32v fX, float32v fY )
        {
            // ( 1+R2, 1 ) ( -1-R2, 1 ) ( 1+R2, -1 ) ( -1-R2, -1 )
            // ( 1, 1+R2 ) ( 1, -1-R2 ) ( -1, 1+R2 ) ( -1, -1-R2 )

            int32v  bit1 = (hash << 31);
            int32v  bit2 = (hash >> 1) << 31;
            mask32v bit4;

            if constexpr( FS::SIMD_Level == FastSIMD::Level_Scalar )
            {
                bit4 = int32_t( hash & int32v( 1 << 2 ) ) != 0;
            }
            else
            {
                bit4 = hash << 29;

                if constexpr( FS::SIMD_Level < FastSIMD::Level_SSE41 )
                {
                    bit4 >>= 31;
                }
            }

            fX ^= FS_Casti32_f32( bit1 );
            fY ^= FS_Casti32_f32( bit2 );
            
            float32v a = FS_Select_f32( bit4, fY, fX );
            float32v b = FS_Select_f32( bit4, fX, fY );
            
            return FS_FMulAdd_f32( float32v( 1.0f + ROOT2 ), a, b );
        }
        template<typename SIMD = FS, std::enable_if_t<SIMD::SIMD_Level == FastSIMD::Level_NEON> * = nullptr>
         FS_INLINE static float32v GetGradientDot( int32v hash, float32v fX, float32v fY )
        {
            // ( 1+R2, 1 ) ( -1-R2, 1 ) ( 1+R2, -1 ) ( -1-R2, -1 )
            // ( 1, 1+R2 ) ( 1, -1-R2 ) ( -1, 1+R2 ) ( -1, -1-R2 )

            int32v  bit1 = (hash << 31);
            int32v  bit2 = (hash >> 1) << 31;
            mask32v bit4;

//             if constexpr( FS::SIMD_Level == FastSIMD::Level_Scalar )
//             {
//                 bit4 = int32_t( hash & int32v( 1 << 2 ) ) != 0;
//             }
//             else
//             {
                bit4 = hash << 29;
// 
//                 if constexpr( FS::SIMD_Level < FastSIMD::Level_SSE41 )
//                 {
                    bit4 >>= 31;
//                 }
//             }

            fX ^= FS_Casti32_f32( bit1 );
            fY ^= FS_Casti32_f32( bit2 );
            
            float32v a = FS_Select_f32( bit4, fY, fX );
            float32v b = FS_Select_f32( bit4, fX, fY );
            
            return FS_FMulAdd_f32( float32v( 1.0f + ROOT2 ), a, b );
        }

        template<typename SIMD = FS, std::enable_if_t<SIMD::SIMD_Level == FastSIMD::Level_AVX2>* = nullptr>
        FS_INLINE static float32v GetGradientDot( int32v hash, float32v fX, float32v fY )
        {
            float32v gX = _mm256_permutevar8x32_ps( float32v( 1 + ROOT2, -1 - ROOT2, 1 + ROOT2, -1 - ROOT2, 1, -1, 1, -1 ), hash );
            float32v gY = _mm256_permutevar8x32_ps( float32v( 1, 1, -1, -1, 1 + ROOT2, 1 + ROOT2, -1 - ROOT2, -1 - ROOT2 ), hash );

            return FS_FMulAdd_f32( gX, fX, fY * gY );
        }

        template<typename SIMD = FS, std::enable_if_t<SIMD::SIMD_Level == FastSIMD::Level_AVX512> * = nullptr>
         FS_INLINE static float32v GetGradientDot( int32v hash, float32v fX, float32v fY )
        {
            float32v gX = _mm512_permutexvar_ps( hash, float32v( 1 + ROOT2, -1 - ROOT2, 1 + ROOT2, -1 - ROOT2, 1, -1, 1, -1, 1 + ROOT2, -1 - ROOT2, 1 + ROOT2, -1 - ROOT2, 1, -1, 1, -1 ) );
            float32v gY = _mm512_permutexvar_ps( hash, float32v( 1, 1, -1, -1, 1 + ROOT2, 1 + ROOT2, -1 - ROOT2, -1 - ROOT2, 1, 1, -1, -1, 1 + ROOT2, 1 + ROOT2, -1 - ROOT2, -1 - ROOT2 ) );

            return FS_FMulAdd_f32( gX, fX, fY * gY );
        }

        template<typename SIMD = FS, std::enable_if_t<SIMD::SIMD_Level != FastSIMD::Level_AVX512 > * = nullptr >
        FS_INLINE static float32v GetGradientDot( int32v hash, float32v fX, float32v fY, float32v fZ )
        {
            int32v hasha13 = hash & int32v( 13 );

            //if h < 8 then x, else y
            float32v u = FS_Select_f32( hasha13 < int32v( 8 ), fX, fY );

            //if h < 4 then y else if h is 12 or 14 then x else z
            float32v v = FS_Select_f32( hasha13 == int32v( 12 ), fX, fZ );
            v = FS_Select_f32( hasha13 < int32v( 2 ), fY, v );

            //if h1 then -u else u
            //if h2 then -v else v
            float32v h1 = FS_Casti32_f32( hash << 31 );
            float32v h2 = FS_Casti32_f32( (hash & int32v( 2 )) << 30 );
            //then add them
            return ( u ^ h1 ) + ( v ^ h2 );
        }

        template<typename SIMD = FS, std::enable_if_t<SIMD::SIMD_Level == FastSIMD::Level_AVX512>* = nullptr>
        FS_INLINE static float32v GetGradientDot( int32v hash, float32v fX, float32v fY, float32v fZ )
        {
            float32v gX = _mm512_permutexvar_ps( hash, float32v( 1, -1, 1, -1, 1, -1, 1, -1, 0, 0, 0, 0, 1, 0, -1, 0 ) );
            float32v gY = _mm512_permutexvar_ps( hash, float32v( 1, 1, -1, -1, 0, 0, 0, 0, 1, -1, 1, -1, 1, -1, 1, -1 ) );
            float32v gZ = _mm512_permutexvar_ps( hash, float32v( 0, 0, 0, 0, 1, 1, -1, -1, 1, 1, -1, -1, 0, 1, 0, -1 ) );

            return FS_FMulAdd_f32( gX, fX, FS_FMulAdd_f32( fY, gY, fZ * gZ ));
        }

        template<typename SIMD = FS, std::enable_if_t<SIMD::SIMD_Level != FastSIMD::Level_AVX512>* = nullptr >
        FS_INLINE static float32v GetGradientDot( int32v hash, float32v fX, float32v fY, float32v fZ, float32v fW )
        {
            int32v p = hash & int32v( 3 << 3 );

            float32v a = FS_Select_f32( p > int32v( 0 ), fX, fY );
            float32v b;
            if constexpr( FS::SIMD_Level <= FastSIMD::Level_SSE2 )
            {
                b = FS_Select_f32( p > int32v( 1 << 3 ), fY, fZ );        
            }
            else
            {
                b = FS_Select_f32( hash << 27, fY, fZ );
            }
            float32v c = FS_Select_f32( p > int32v( 2 << 3 ), fZ, fW );

            float32v aSign = FS_Casti32_f32( hash << 31 );
            float32v bSign = FS_Casti32_f32( (hash << 30) & int32v( 0x80000000 ) );
            float32v cSign = FS_Casti32_f32( (hash << 29) & int32v( 0x80000000 ) );

            return ( a ^ aSign ) + ( b ^ bSign ) + ( c ^ cSign );
        }

        template<typename SIMD = FS, std::enable_if_t<SIMD::SIMD_Level == FastSIMD::Level_AVX512>* = nullptr>
        FS_INLINE static float32v GetGradientDot( int32v hash, float32v fX, float32v fY, float32v fZ, float32v fW )
        {
            float32v gX = _mm512_permutex2var_ps( float32v( 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 1, -1, 1, -1, 1, -1 ), hash, float32v( 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1 ) );
            float32v gY = _mm512_permutex2var_ps( float32v( 1, -1, 1, -1, 1, -1, 1, -1, 0, 0, 0, 0, 0, 0, 0, 0 ), hash, float32v( 1, 1, -1, -1, 1, 1, -1, -1, 1, 1, -1, -1, 1, 1, -1, -1 ) );
            float32v gZ = _mm512_permutex2var_ps( float32v( 1, 1, -1, -1, 1, 1, -1, -1, 1, 1, -1, -1, 1, 1, -1, -1 ), hash, float32v( 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, -1, -1, -1, -1 ) );
            float32v gW = _mm512_permutex2var_ps( float32v( 1, 1, 1, 1, -1, -1, -1, -1, 1, 1, 1, 1, -1, -1, -1, -1 ), hash, float32v( 1, 1, 1, 1, -1, -1, -1, -1, 0, 0, 0, 0, 0, 0, 0, 0 ) );

            return FS_FMulAdd_f32( gX, fX, FS_FMulAdd_f32( fY, gY, FS_FMulAdd_f32( fZ, gZ, fW * gW ) ));
        }

        template<typename SIMD = FS, typename... P>
        FS_INLINE static int32v HashPrimes( int32v seed, P... primedPos )
        {
            int32v hash = seed;
            hash ^= (primedPos ^ ...);

            hash *= int32v( 0x27d4eb2d );
            return (hash >> 15) ^ hash;
        }

        template<typename SIMD = FS, typename... P>
        FS_INLINE static int32v HashPrimesHB( int32v seed, P... primedPos )
        {
            int32v hash = seed;
            hash ^= (primedPos ^ ...);
            
            hash *= int32v( 0x27d4eb2d );
            return hash;
        }  

        template<typename SIMD = FS, typename... P>
         FS_INLINE static float32v GetValueCoord( int32v seed, P... primedPos )
        {
            int32v hash = seed;
            hash ^= (primedPos ^ ...);
            
            hash *= hash * int32v( 0x27d4eb2d );
            return FS_Converti32_f32( hash ) * float32v( 1.0f / (float)INT_MAX );
        }

        template<typename SIMD = FS>
        FS_INLINE static float32v Lerp( float32v a, float32v b, float32v t )
        {
            return FS_FMulAdd_f32( t, b - a, a );
        }

        template<typename SIMD = FS>
         FS_INLINE static float32v InterpHermite( float32v t )
        {
            return t * t * FS_FNMulAdd_f32( t, float32v( 2 ), float32v( 3 ));
        }

        template<typename SIMD = FS>
         FS_INLINE static float32v InterpQuintic( float32v t )
        {
            return t * t * t * FS_FMulAdd_f32( t, FS_FMulAdd_f32( t, float32v( 6 ), float32v( -15 )), float32v( 10 ) );
        }

        template<typename SIMD = FS, typename... P>
        FS_INLINE static float32v CalcDistance( DistanceFunction distFunc, float32v dX, P... d )
        {
            switch( distFunc )
            {
                default:
                case DistanceFunction::Euclidean:
                {
                    float32v distSqr = dX * dX;
                    ((distSqr = FS_FMulAdd_f32( d, d, distSqr )), ...);

                    return FS_InvSqrt_f32( distSqr ) * distSqr;
                }

                case DistanceFunction::EuclideanSquared:
                {
                    float32v distSqr = dX * dX;
                    ((distSqr = FS_FMulAdd_f32( d, d, distSqr )), ...);

                    return distSqr;
                }

                case DistanceFunction::Manhattan:
                {
                    float32v dist = FS_Abs_f32( dX );
                    dist += (FS_Abs_f32( d ) + ...);

                    return dist;
                }

                case DistanceFunction::Hybrid:
                {
                    float32v both = FS_FMulAdd_f32( dX, dX, FS_Abs_f32( dX ) );
                    ((both += FS_FMulAdd_f32( d, d, FS_Abs_f32( d ) )), ...);

                    return both;
                }

                case DistanceFunction::MaxAxis:
                {
                    float32v max = FS_Abs_f32( dX );
                    ((max = FS_Max_f32( FS_Abs_f32(d), max )), ...);

                    return max;
                }
            }
        }
    };
}

using FnUtils = FastNoise::Utils<FS_SIMD_CLASS>;
namespace FnPrimes = FastNoise::Primes;