using System;
using System.Collections.Generic;
using System.Runtime.CompilerServices;
using static System.Buffers.Binary.BinaryPrimitives;

namespace PKHeX.Core
{
    /// <summary> Generation 7 <see cref="PKM"/> format used for <see cref="GameVersion.GG"/>. </summary>
    public sealed class PB7 : G6PKM, IHyperTrain, IAwakened, IScaledSizeValue, ICombatPower, IFavorite, IFormArgument
    {
        public static readonly ushort[] Unused =
        {
            0x2A, // Old Marking Value (PelagoEventStatus)
            0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, // Unused Ribbons
            0x58, 0x59, // Nickname Terminator
            0x73,
            0x90, 0x91, // HT Terminator
            0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9A, 0x9B, 0x9C, 0x9D, 0x9E, 0x9F, 0xA0, 0xA1, // Old Geolocation/memories
            0xA7, 0xAA, 0xAB,
            0xAC, 0xAD, // Fatigue, no GUI editing
            0xC8, 0xC9, // OT Terminator
        };

        public override IReadOnlyList<ushort> ExtraBytes => Unused;

        public override int SIZE_PARTY => SIZE;
        public override int SIZE_STORED => SIZE;
        private const int SIZE = 260;
        public override int Format => 7;
        public override PersonalInfo PersonalInfo => PersonalTable.GG.GetFormEntry(Species, Form);

        public PB7() : base(SIZE) { }
        public PB7(byte[] data) : base(DecryptParty(data)) { }

        private static byte[] DecryptParty(byte[] data)
        {
            PokeCrypto.DecryptIfEncrypted67(ref data);
            if (data.Length != SIZE)
                Array.Resize(ref data, SIZE);
            return data;
        }

        public override PKM Clone() => new PB7((byte[])Data.Clone());

        // Structure
        #region Block A
        public override uint EncryptionConstant
        {
            get => ReadUInt32LittleEndian(Data.AsSpan(0x00));
            set => WriteUInt32LittleEndian(Data.AsSpan(0x00), value);
        }

        public override ushort Sanity
        {
            get => ReadUInt16LittleEndian(Data.AsSpan(0x04));
            set => WriteUInt16LittleEndian(Data.AsSpan(0x04), value);
        }

        public override ushort Checksum
        {
            get => ReadUInt16LittleEndian(Data.AsSpan(0x06));
            set => WriteUInt16LittleEndian(Data.AsSpan(0x06), value);
        }

        public override int Species
        {
            get => ReadUInt16LittleEndian(Data.AsSpan(0x08));
            set => WriteUInt16LittleEndian(Data.AsSpan(0x08), (ushort)value);
        }

        public override int HeldItem
        {
            get => ReadUInt16LittleEndian(Data.AsSpan(0x0A));
            set => WriteUInt16LittleEndian(Data.AsSpan(0x0A), (ushort)value);
        }

        public override int TID
        {
            get => ReadUInt16LittleEndian(Data.AsSpan(0x0C));
            set => WriteUInt16LittleEndian(Data.AsSpan(0x0C), (ushort)value);
        }

        public override int SID
        {
            get => ReadUInt16LittleEndian(Data.AsSpan(0x0E));
            set => WriteUInt16LittleEndian(Data.AsSpan(0x0E), (ushort)value);
        }

        public override uint EXP
        {
            get => ReadUInt32LittleEndian(Data.AsSpan(0x10));
            set => WriteUInt32LittleEndian(Data.AsSpan(0x10), value);
        }

        public override int Ability { get => Data[0x14]; set => Data[0x14] = (byte)value; }
        public override int AbilityNumber { get => Data[0x15] & 7; set => Data[0x15] = (byte)((Data[0x15] & ~7) | (value & 7)); }
        public bool Favorite { get => (Data[0x15] & 8) != 0; set => Data[0x15] = (byte)((Data[0x15] & ~8) | ((value ? 1 : 0) << 3)); }
        public override int MarkValue { get => ReadUInt16LittleEndian(Data.AsSpan(0x16)); protected set => WriteUInt16LittleEndian(Data.AsSpan(0x16), (ushort)value); }

        public override uint PID
        {
            get => ReadUInt32LittleEndian(Data.AsSpan(0x18));
            set => WriteUInt32LittleEndian(Data.AsSpan(0x18), value);
        }

        public override int Nature { get => Data[0x1C]; set => Data[0x1C] = (byte)value; }
        public override bool FatefulEncounter { get => (Data[0x1D] & 1) == 1; set => Data[0x1D] = (byte)((Data[0x1D] & ~0x01) | (value ? 1 : 0)); }
        public override int Gender { get => (Data[0x1D] >> 1) & 0x3; set => Data[0x1D] = (byte)((Data[0x1D] & ~0x06) | (value << 1)); }
        public override int Form { get => Data[0x1D] >> 3; set => Data[0x1D] = (byte)((Data[0x1D] & 0x07) | (value << 3)); }
        public override int EV_HP { get => Data[0x1E]; set => Data[0x1E] = (byte)value; }
        public override int EV_ATK { get => Data[0x1F]; set => Data[0x1F] = (byte)value; }
        public override int EV_DEF { get => Data[0x20]; set => Data[0x20] = (byte)value; }
        public override int EV_SPE { get => Data[0x21]; set => Data[0x21] = (byte)value; }
        public override int EV_SPA { get => Data[0x22]; set => Data[0x22] = (byte)value; }
        public override int EV_SPD { get => Data[0x23]; set => Data[0x23] = (byte)value; }
        public int AV_HP { get => Data[0x24]; set => Data[0x24] = (byte)value; }
        public int AV_ATK { get => Data[0x25]; set => Data[0x25] = (byte)value; }
        public int AV_DEF { get => Data[0x26]; set => Data[0x26] = (byte)value; }
        public int AV_SPE { get => Data[0x27]; set => Data[0x27] = (byte)value; }
        public int AV_SPA { get => Data[0x28]; set => Data[0x28] = (byte)value; }
        public int AV_SPD { get => Data[0x29]; set => Data[0x29] = (byte)value; }
        // 0x2A Unused
        private byte PKRS { get => Data[0x2B]; set => Data[0x2B] = value; }
        public override int PKRS_Days { get => PKRS & 0xF; set => PKRS = (byte)((PKRS & ~0xF) | value); }
        public override int PKRS_Strain { get => PKRS >> 4; set => PKRS = (byte)((PKRS & 0xF) | value << 4); }
        public float HeightAbsolute { get => ReadSingleLittleEndian(Data.AsSpan(0x2C)); set => WriteSingleLittleEndian(Data.AsSpan(0x2C), value); }
        // 0x38 Unused
        // 0x39 Unused
        public int HeightScalar { get => Data[0x3A]; set => Data[0x3A] = (byte)value; }
        public int WeightScalar { get => Data[0x3B]; set => Data[0x3B] = (byte)value; }
        public uint FormArgument { get => ReadUInt32LittleEndian(Data.AsSpan(0x3C)); set => WriteUInt32LittleEndian(Data.AsSpan(0x3C), value); }
        public byte FormArgumentRemain { get => (byte)FormArgument; set => FormArgument = (FormArgument & ~0xFFu) | value; }
        public byte FormArgumentElapsed { get => (byte)(FormArgument >> 8); set => FormArgument = (FormArgument & ~0xFF00u) | (uint)(value << 8); }
        public byte FormArgumentMaximum { get => (byte)(FormArgument >> 16); set => FormArgument = (FormArgument & ~0xFF0000u) | (uint)(value << 16); }

        #endregion
        #region Block B
        public override string Nickname
        {
            get => StringConverter8.GetString(Nickname_Trash);
            set => StringConverter8.SetString(Nickname_Trash, value.AsSpan(), 12, StringConverterOption.None);
        }

        public override int Move1
        {
            get => ReadUInt16LittleEndian(Data.AsSpan(0x5A));
            set => WriteUInt16LittleEndian(Data.AsSpan(0x5A), (ushort)value);
        }

        public override int Move2
        {
            get => ReadUInt16LittleEndian(Data.AsSpan(0x5C));
            set => WriteUInt16LittleEndian(Data.AsSpan(0x5C), (ushort)value);
        }

        public override int Move3
        {
            get => ReadUInt16LittleEndian(Data.AsSpan(0x5E));
            set => WriteUInt16LittleEndian(Data.AsSpan(0x5E), (ushort)value);
        }

        public override int Move4
        {
            get => ReadUInt16LittleEndian(Data.AsSpan(0x60));
            set => WriteUInt16LittleEndian(Data.AsSpan(0x60), (ushort)value);
        }

        public override int Move1_PP { get => Data[0x62]; set => Data[0x62] = (byte)value; }
        public override int Move2_PP { get => Data[0x63]; set => Data[0x63] = (byte)value; }
        public override int Move3_PP { get => Data[0x64]; set => Data[0x64] = (byte)value; }
        public override int Move4_PP { get => Data[0x65]; set => Data[0x65] = (byte)value; }
        public override int Move1_PPUps { get => Data[0x66]; set => Data[0x66] = (byte)value; }
        public override int Move2_PPUps { get => Data[0x67]; set => Data[0x67] = (byte)value; }
        public override int Move3_PPUps { get => Data[0x68]; set => Data[0x68] = (byte)value; }
        public override int Move4_PPUps { get => Data[0x69]; set => Data[0x69] = (byte)value; }

        public override int RelearnMove1
        {
            get => ReadUInt16LittleEndian(Data.AsSpan(0x6A));
            set => WriteUInt16LittleEndian(Data.AsSpan(0x6A), (ushort)value);
        }

        public override int RelearnMove2
        {
            get => ReadUInt16LittleEndian(Data.AsSpan(0x6C));
            set => WriteUInt16LittleEndian(Data.AsSpan(0x6C), (ushort)value);
        }

        public override int RelearnMove3
        {
            get => ReadUInt16LittleEndian(Data.AsSpan(0x6E));
            set => WriteUInt16LittleEndian(Data.AsSpan(0x6E), (ushort)value);
        }

        public override int RelearnMove4
        {
            get => ReadUInt16LittleEndian(Data.AsSpan(0x70));
            set => WriteUInt16LittleEndian(Data.AsSpan(0x70), (ushort)value);
        }

        // 0x72 Unused
        // 0x73 Unused
        private uint IV32 { get => ReadUInt32LittleEndian(Data.AsSpan(0x74)); set => WriteUInt32LittleEndian(Data.AsSpan(0x74), value); }
        public override int IV_HP { get => (int)(IV32 >> 00) & 0x1F; set => IV32 = (IV32 & ~(0x1Fu << 00)) | ((value > 31 ? 31u : (uint)value) << 00); }
        public override int IV_ATK { get => (int)(IV32 >> 05) & 0x1F; set => IV32 = (IV32 & ~(0x1Fu << 05)) | ((value > 31 ? 31u : (uint)value) << 05); }
        public override int IV_DEF { get => (int)(IV32 >> 10) & 0x1F; set => IV32 = (IV32 & ~(0x1Fu << 10)) | ((value > 31 ? 31u : (uint)value) << 10); }
        public override int IV_SPE { get => (int)(IV32 >> 15) & 0x1F; set => IV32 = (IV32 & ~(0x1Fu << 15)) | ((value > 31 ? 31u : (uint)value) << 15); }
        public override int IV_SPA { get => (int)(IV32 >> 20) & 0x1F; set => IV32 = (IV32 & ~(0x1Fu << 20)) | ((value > 31 ? 31u : (uint)value) << 20); }
        public override int IV_SPD { get => (int)(IV32 >> 25) & 0x1F; set => IV32 = (IV32 & ~(0x1Fu << 25)) | ((value > 31 ? 31u : (uint)value) << 25); }
        public override bool IsEgg { get => ((IV32 >> 30) & 1) == 1; set => IV32 = (IV32 & ~0x40000000u) | (value ? 0x40000000u : 0u); }
        public override bool IsNicknamed { get => ((IV32 >> 31) & 1) == 1; set => IV32 = (IV32 & 0x7FFFFFFFu) | (value ? 0x80000000u : 0u); }
        #endregion
        #region Block C
        public override string HT_Name
        {
            get => StringConverter8.GetString(HT_Trash);
            set => StringConverter8.SetString(HT_Trash, value.AsSpan(), 12, StringConverterOption.None);
        }

        public override int HT_Gender { get => Data[0x92]; set => Data[0x92] = (byte)value; }
        public override int CurrentHandler { get => Data[0x93]; set => Data[0x93] = (byte)value; }
        // 0x94 Unused
        // 0x95 Unused
        // 0x96 Unused
        // 0x97 Unused
        // 0x98 Unused
        // 0x99 Unused
        // 0x9A Unused
        // 0x9B Unused
        // 0x9C Unused
        // 0x9D Unused
        // 0x9E Unused
        // 0x9F Unused
        // 0xA0 Unused
        // 0xA1 Unused
        public override int HT_Friendship { get => Data[0xA2]; set => Data[0xA2] = (byte)value; }
        // 0xA1 HT_Affection Unused
        public int HT_Intensity { get => Data[0xA4]; set => Data[0xA4] = (byte)value; }
        public int HT_Memory { get => Data[0xA5]; set => Data[0xA5] = (byte)value; }
        public int HT_Feeling { get => Data[0xA6]; set => Data[0xA6] = (byte)value; }
        // 0xA7 Unused
        public int HT_TextVar { get => ReadUInt16LittleEndian(Data.AsSpan(0xA8)); set => WriteUInt16LittleEndian(Data.AsSpan(0xA8), (ushort)value); }
        // 0xAA Unused
        // 0xAB Unused
        public byte FieldEventFatigue1 { get => Data[0xAC]; set => Data[0xAC] = value; }
        public byte FieldEventFatigue2 { get => Data[0xAD]; set => Data[0xAD] = value; }
        public override byte Fullness { get => Data[0xAE]; set => Data[0xAE] = value; }
        public override byte Enjoyment { get => Data[0xAF]; set => Data[0xAF] = value; }
        #endregion
        #region Block D
        public override string OT_Name
        {
            get => StringConverter8.GetString(OT_Trash);
            set => StringConverter8.SetString(OT_Trash, value.AsSpan(), 12, StringConverterOption.None);
        }

        public override int OT_Friendship { get => Data[0xCA]; set => Data[0xCA] = (byte)value; }
        // 0xCB Unused
        // 0xCC Unused
        // 0xCD Unused
        // 0xCE Unused
        // 0xCF Unused
        // 0xD0 Unused
        public override int Egg_Year { get => Data[0xD1]; set => Data[0xD1] = (byte)value; }
        public override int Egg_Month { get => Data[0xD2]; set => Data[0xD2] = (byte)value; }
        public override int Egg_Day { get => Data[0xD3]; set => Data[0xD3] = (byte)value; }
        public override int Met_Year { get => Data[0xD4]; set => Data[0xD4] = (byte)value; }
        public override int Met_Month { get => Data[0xD5]; set => Data[0xD5] = (byte)value; }
        public override int Met_Day { get => Data[0xD6]; set => Data[0xD6] = (byte)value; }
        public int Rank { get => Data[0xD7]; set => Data[0xD7] = (byte)value; } // unused but fetched for stat calcs, and set for trpoke data?
        public override int Egg_Location { get => ReadUInt16LittleEndian(Data.AsSpan(0xD8)); set => WriteUInt16LittleEndian(Data.AsSpan(0xD8), (ushort)value); }
        public override int Met_Location { get => ReadUInt16LittleEndian(Data.AsSpan(0xDA)); set => WriteUInt16LittleEndian(Data.AsSpan(0xDA), (ushort)value); }
        public override int Ball { get => Data[0xDC]; set => Data[0xDC] = (byte)value; }
        public override int Met_Level { get => Data[0xDD] & ~0x80; set => Data[0xDD] = (byte)((Data[0xDD] & 0x80) | value); }
        public override int OT_Gender { get => Data[0xDD] >> 7; set => Data[0xDD] = (byte)((Data[0xDD] & ~0x80) | (value << 7)); }
        public int HyperTrainFlags { get => Data[0xDE]; set => Data[0xDE] = (byte)value; }
        public bool HT_HP { get => ((HyperTrainFlags >> 0) & 1) == 1; set => HyperTrainFlags = (HyperTrainFlags & ~(1 << 0)) | ((value ? 1 : 0) << 0); }
        public bool HT_ATK { get => ((HyperTrainFlags >> 1) & 1) == 1; set => HyperTrainFlags = (HyperTrainFlags & ~(1 << 1)) | ((value ? 1 : 0) << 1); }
        public bool HT_DEF { get => ((HyperTrainFlags >> 2) & 1) == 1; set => HyperTrainFlags = (HyperTrainFlags & ~(1 << 2)) | ((value ? 1 : 0) << 2); }
        public bool HT_SPA { get => ((HyperTrainFlags >> 3) & 1) == 1; set => HyperTrainFlags = (HyperTrainFlags & ~(1 << 3)) | ((value ? 1 : 0) << 3); }
        public bool HT_SPD { get => ((HyperTrainFlags >> 4) & 1) == 1; set => HyperTrainFlags = (HyperTrainFlags & ~(1 << 4)) | ((value ? 1 : 0) << 4); }
        public bool HT_SPE { get => ((HyperTrainFlags >> 5) & 1) == 1; set => HyperTrainFlags = (HyperTrainFlags & ~(1 << 5)) | ((value ? 1 : 0) << 5); }
        public override int Version { get => Data[0xDF]; set => Data[0xDF] = (byte)value; }
        // 0xE0 Unused
        // 0xE1 Unused
        // 0xE2 Unused
        public override int Language { get => Data[0xE3]; set => Data[0xE3] = (byte)value; }
        public float WeightAbsolute { get => ReadSingleLittleEndian(Data.AsSpan(0xE4)); set => WriteSingleLittleEndian(Data.AsSpan(0xE4), value); }
        #endregion
        #region Battle Stats
        public override int Status_Condition { get => ReadInt32LittleEndian(Data.AsSpan(0xE8)); set => WriteInt32LittleEndian(Data.AsSpan(0xE8), value); }
        public override int Stat_Level { get => Data[0xEC]; set => Data[0xEC] = (byte)value; }
        public byte DirtType { get => Data[0xED]; set => Data[0xED] = value; }
        public byte DirtLocation { get => Data[0xEE]; set => Data[0xEE] = value; }
        // 0xEF unused
        public override int Stat_HPCurrent { get => ReadUInt16LittleEndian(Data.AsSpan(0xF0)); set => WriteUInt16LittleEndian(Data.AsSpan(0xF0), (ushort)value); }
        public override int Stat_HPMax { get => ReadUInt16LittleEndian(Data.AsSpan(0xF2)); set => WriteUInt16LittleEndian(Data.AsSpan(0xF2), (ushort)value); }
        public override int Stat_ATK { get => ReadUInt16LittleEndian(Data.AsSpan(0xF4)); set => WriteUInt16LittleEndian(Data.AsSpan(0xF4), (ushort)value); }
        public override int Stat_DEF { get => ReadUInt16LittleEndian(Data.AsSpan(0xF6)); set => WriteUInt16LittleEndian(Data.AsSpan(0xF6), (ushort)value); }
        public override int Stat_SPE { get => ReadUInt16LittleEndian(Data.AsSpan(0xF8)); set => WriteUInt16LittleEndian(Data.AsSpan(0xF8), (ushort)value); }
        public override int Stat_SPA { get => ReadUInt16LittleEndian(Data.AsSpan(0xFA)); set => WriteUInt16LittleEndian(Data.AsSpan(0xFA), (ushort)value); }
        public override int Stat_SPD { get => ReadUInt16LittleEndian(Data.AsSpan(0xFC)); set => WriteUInt16LittleEndian(Data.AsSpan(0xFC), (ushort)value); }
        public int Stat_CP { get => ReadUInt16LittleEndian(Data.AsSpan(0xFE)); set => WriteUInt16LittleEndian(Data.AsSpan(0xFE), (ushort)value); }
        public bool Stat_Mega { get => Data[0x100] != 0; set => Data[0x100] = value ? (byte)1 : (byte)0; }
        public int Stat_MegaForm { get => Data[0x101]; set => Data[0x101] = (byte)value; }
        // 102/103 unused
        #endregion

        public override int[] Markings
        {
            get
            {
                int[] marks = new int[8];
                int val = MarkValue;
                for (int i = 0; i < marks.Length; i++)
                    marks[i] = ((val >> (i * 2)) & 3) % 3;
                return marks;
            }
            set => SetMarkings(value);
        }

        public override void SetMarkings(ReadOnlySpan<int> value)
        {
            if (value.Length > 8)
                return;
            int v = 0;
            for (int i = 0; i < value.Length; i++)
                v |= (value[i] % 3) << (i * 2);
            MarkValue = v;
        }

        protected override bool TradeOT(ITrainerInfo tr)
        {
            // Check to see if the OT matches the SAV's OT info.
            if (!(tr.OT == OT_Name && tr.TID == TID && tr.SID == SID && tr.Gender == OT_Gender))
                return false;

            CurrentHandler = 0;
            return true;
        }

        protected override void TradeHT(ITrainerInfo tr)
        {
            if (HT_Name != tr.OT)
            {
                HT_Friendship = CurrentFriendship; // copy friendship instead of resetting (don't alter CP)
                HT_Name = tr.OT;
            }
            CurrentHandler = 1;
            HT_Gender = tr.Gender;
        }

        public void FixMemories()
        {
            if (IsUntraded)
                HT_Friendship = HT_TextVar = HT_Memory = HT_Intensity = HT_Feeling = 0;
        }

        // Maximums
        public override int MaxMoveID => Legal.MaxMoveID_7b;
        public override int MaxSpeciesID => Legal.MaxSpeciesID_7b;
        public override int MaxAbilityID => Legal.MaxAbilityID_7_USUM;
        public override int MaxItemID => Legal.MaxItemID_7_USUM;
        public override int MaxBallID => Legal.MaxBallID_7;
        public override int MaxGameID => Legal.MaxGameID_7b;

        public override ushort[] GetStats(PersonalInfo p) => CalculateStatsBeluga(p);

        public ushort[] CalculateStatsBeluga(PersonalInfo p)
        {
            int level = CurrentLevel;
            int nature = Nature;
            int friend = CurrentFriendship; // stats +10% depending on friendship!
            int scalar = (int)(((friend / 255.0f / 10.0f) + 1.0f) * 100.0f);
            return new[]
            {
                (ushort)(AV_HP  + GetStat(p.HP,  HT_HP  ? 31 : IV_HP,  level) + 10 + level),
                (ushort)(AV_ATK + (scalar * GetStat(p.ATK, HT_ATK ? 31 : IV_ATK, level, nature, 0) / 100)),
                (ushort)(AV_DEF + (scalar * GetStat(p.DEF, HT_DEF ? 31 : IV_DEF, level, nature, 1) / 100)),
                (ushort)(AV_SPE + (scalar * GetStat(p.SPE, HT_SPE ? 31 : IV_SPE, level, nature, 4) / 100)),
                (ushort)(AV_SPA + (scalar * GetStat(p.SPA, HT_SPA ? 31 : IV_SPA, level, nature, 2) / 100)),
                (ushort)(AV_SPD + (scalar * GetStat(p.SPD, HT_SPD ? 31 : IV_SPD, level, nature, 3) / 100)),
            };
        }

        /// <summary>
        /// Gets the initial stat value based on the base stat value, IV, and current level.
        /// </summary>
        /// <param name="baseStat"><see cref="PersonalInfo"/> stat.</param>
        /// <param name="iv">Current IV, already accounted for Hyper Training</param>
        /// <param name="level">Current Level</param>
        /// <returns>Initial Stat</returns>
        private static int GetStat(int baseStat, int iv, int level) => (iv + (2 * baseStat)) * level / 100;

        /// <summary>
        /// Gets the initial stat value with nature amplification applied. Used for all stats except HP.
        /// </summary>
        /// <param name="baseStat"><see cref="PersonalInfo"/> stat.</param>
        /// <param name="iv">Current IV, already accounted for Hyper Training</param>
        /// <param name="level">Current Level</param>
        /// <param name="nature"><see cref="PKM.Nature"/></param>
        /// <param name="statIndex">Stat amp index in the nature amp table</param>
        /// <returns>Initial Stat with nature amplification applied.</returns>
        private static int GetStat(int baseStat, int iv, int level, int nature, int statIndex)
        {
            int initial = GetStat(baseStat, iv, level) + 5;
            return AmplifyStat(nature, statIndex, initial);
        }

        private static int AmplifyStat(int nature, int index, int initial) => GetNatureAmp(nature, index) switch
        {
            1 => 110 * initial / 100, // 110%
            -1 => 90 * initial / 100, // 90%
            _ => initial,
        };

        private static sbyte GetNatureAmp(int nature, int index)
        {
            if ((uint)nature >= 25)
                return -1;
            return NatureAmpTable[(5 * nature) + index];
        }

        private static readonly sbyte[] NatureAmpTable =
        {
            0, 0, 0, 0, 0, // Hardy
            1,-1, 0, 0, 0, // Lonely
            1, 0, 0, 0,-1, // Brave
            1, 0,-1, 0, 0, // Adamant
            1, 0, 0,-1, 0, // Naughty
           -1, 1, 0, 0, 0, // Bold
            0, 0, 0, 0, 0, // Docile
            0, 1, 0, 0,-1, // Relaxed
            0, 1,-1, 0, 0, // Impish
            0, 1, 0,-1, 0, // Lax
           -1, 0, 0, 0, 1, // Timid
            0,-1, 0, 0, 1, // Hasty
            0, 0, 0, 0, 0, // Serious
            0, 0,-1, 0, 1, // Jolly
            0, 0, 0,-1, 1, // Naive
           -1, 0, 1, 0, 0, // Modest
            0,-1, 1, 0, 0, // Mild
            0, 0, 1, 0,-1, // Quiet
            0, 0, 0, 0, 0, // Bashful
            0, 0, 1,-1, 0, // Rash
           -1, 0, 0, 1, 0, // Calm
            0,-1, 0, 1, 0, // Gentle
            0, 0, 0, 1,-1, // Sassy
            0, 0,-1, 1, 0, // Careful
            0, 0, 0, 0, 0, // Quirky
        };

        public int CalcCP => Math.Min(10000, AwakeCP + BaseCP);

        public int BaseCP
        {
            get
            {
                var p = PersonalInfo;
                int level = CurrentLevel;
                int nature = Nature;
                int scalar = CPScalar;

                // Calculate stats for all, then sum together.
                // HP is not overriden to 1 like a regular stat calc for Shedinja.
                var statSum =
                    (ushort)GetStat(p.HP, HT_HP ? 31 : IV_HP, level) + 10 + level
                    + (ushort)(GetStat(p.ATK, HT_ATK ? 31 : IV_ATK, level, nature, 0) * scalar / 100)
                    + (ushort)(GetStat(p.DEF, HT_DEF ? 31 : IV_DEF, level, nature, 1) * scalar / 100)
                    + (ushort)(GetStat(p.SPE, HT_SPE ? 31 : IV_SPE, level, nature, 4) * scalar / 100)
                    + (ushort)(GetStat(p.SPA, HT_SPA ? 31 : IV_SPA, level, nature, 2) * scalar / 100)
                    + (ushort)(GetStat(p.SPD, HT_SPD ? 31 : IV_SPD, level, nature, 3) * scalar / 100);

                float result = statSum * 6f;
                result *= level;
                result /= 100f;
                return (int)result;
            }
        }

        public int CPScalar
        {
            get
            {
                int friend = CurrentFriendship; // stats +10% depending on friendship!
                float scalar = friend / 255f;
                scalar /= 10f;
                scalar++;
                scalar *= 100f;
                return (int)scalar;
            }
        }

        public int AwakeCP
        {
            get
            {
                var sum = this.AwakeningSum();
                if (sum == 0)
                    return 0;
                var lvl = CurrentLevel;
                float scalar = lvl * 4f;
                scalar /= 100f;
                scalar += 2f;
                float result = sum * scalar;
                return (int)result;
            }
        }

        public void ResetCP() => Stat_CP = CalcCP;

        public void ResetCalculatedValues()
        {
            ResetCP();
            ResetHeight();
            ResetWeight();
        }

        // Casts are as per the game code; they may seem redundant but every bit of precision matters?
        // This still doesn't precisely match :( -- just use a tolerance check when updating.
        // If anyone can figure out how to get all precision to match, feel free to update :)
        public float HeightRatio => GetHeightRatio(HeightScalar);
        public float WeightRatio => GetWeightRatio(WeightScalar);

        public float CalcHeightAbsolute => GetHeightAbsolute(PersonalInfo, HeightScalar);
        public float CalcWeightAbsolute => GetWeightAbsolute(PersonalInfo, HeightScalar, WeightScalar);

        public void ResetHeight()
        {
            var current = HeightAbsolute;
            var updated = CalcHeightAbsolute;
            if (Math.Abs(current - updated) > 0.0001f)
                HeightAbsolute = updated;
        }

        public void ResetWeight()
        {
            var current = WeightAbsolute;
            var updated = CalcWeightAbsolute;
            if (Math.Abs(current - updated) > 0.0001f)
                WeightAbsolute = updated;
        }

        [MethodImpl(MethodImplOptions.NoOptimization | MethodImplOptions.NoInlining)]
        private static float GetHeightRatio(int heightScalar)
        {
            // +/- 40%
            float result = (byte)heightScalar / 255f;
            result *= 0.8f;
            result += 0.6f;
            return result;
        }

        [MethodImpl(MethodImplOptions.NoOptimization | MethodImplOptions.NoInlining)]
        private static float GetWeightRatio(int weightScalar)
        {
            // +/- 20%
            float result = (byte)weightScalar / 255f;
            result *= 0.4f;
            result += 0.8f;
            return result;
        }

        [MethodImpl(MethodImplOptions.NoOptimization | MethodImplOptions.NoInlining)]
        public static float GetHeightAbsolute(PersonalInfo p, int heightScalar)
        {
            float HeightRatio = GetHeightRatio(heightScalar);
            return HeightRatio * p.Height;
        }

        [MethodImpl(MethodImplOptions.NoOptimization | MethodImplOptions.NoInlining)]
        public static float GetWeightAbsolute(PersonalInfo p, int heightScalar, int weightScalar)
        {
            float HeightRatio = GetHeightRatio(heightScalar);
            float WeightRatio = GetWeightRatio(weightScalar);

            float weight = WeightRatio * p.Weight;
            return HeightRatio * weight;
        }

        [MethodImpl(MethodImplOptions.NoOptimization | MethodImplOptions.NoInlining)]
        public static byte GetHeightScalar(float height, int avgHeight)
        {
            // height is already *100
            float biasH = avgHeight * -0.6f;
            float biasL = avgHeight * 0.8f;
            float numerator = biasH + height;
            float result = numerator / biasL;
            result *= 255f;
            int value = (int)result;
            int unsigned = value & ~(value >> 31);
            return (byte)Math.Min(255, unsigned);
        }

        [MethodImpl(MethodImplOptions.NoOptimization | MethodImplOptions.NoInlining)]
        public static byte GetWeightScalar(float height, float weight, int avgHeight, int avgWeight)
        {
            // height is already *100
            // weight is already *10
            float heightRatio = height / avgHeight;
            float weightComponent = heightRatio * weight;
            float top = avgWeight * -0.8f;
            top += weightComponent;
            float bot = avgWeight * 0.4f;
            float result = top / bot;
            result *= 255f;
            int value = (int)result;
            int unsigned = value & ~(value >> 31);
            return (byte)Math.Min(255, unsigned);
        }

        public PK8 ConvertToPK8()
        {
            var pk8 = new PK8
            {
                EncryptionConstant = EncryptionConstant,
                Species = Species,
                TID = TID,
                SID = SID,
                EXP = EXP,
                PID = PID,
                Ability = Ability,
                AbilityNumber = AbilityNumber,
                Markings = Markings,
                Language = Language,
                EV_HP = EV_HP,
                EV_ATK = EV_ATK,
                EV_DEF = EV_DEF,
                EV_SPA = EV_SPA,
                EV_SPD = EV_SPD,
                EV_SPE = EV_SPE,
                Move1 = Move1,
                Move2 = Move2,
                Move3 = Move3,
                Move4 = Move4,
                Move1_PPUps = Move1_PPUps,
                Move2_PPUps = Move2_PPUps,
                Move3_PPUps = Move3_PPUps,
                Move4_PPUps = Move4_PPUps,
                RelearnMove1 = RelearnMove1,
                RelearnMove2 = RelearnMove2,
                RelearnMove3 = RelearnMove3,
                RelearnMove4 = RelearnMove4,
                IV_HP = IV_HP,
                IV_ATK = IV_ATK,
                IV_DEF = IV_DEF,
                IV_SPA = IV_SPA,
                IV_SPD = IV_SPD,
                IV_SPE = IV_SPE,
                IsNicknamed = IsNicknamed,
                FatefulEncounter = FatefulEncounter,
                Gender = Gender,
                Form = Form,
                Nature = Nature,
                Nickname = Nickname,
                Version = Version,
                OT_Name = OT_Name,
                MetDate = MetDate,
                Met_Location = Met_Location,
                Ball = Ball,
                Met_Level = Met_Level,
                OT_Gender = OT_Gender,
                HyperTrainFlags = HyperTrainFlags,

                // Memories don't exist in LGPE, and no memories are set on transfer.

                OT_Friendship = OT_Friendship,

                // No Ribbons or Markings on transfer.

                StatNature = Nature,
                HeightScalar = HeightScalar,
                WeightScalar = WeightScalar,
            };

            // Fix PP and Stats
            pk8.Heal();

            // Fix Checksum
            pk8.RefreshChecksum();

            return pk8; // Done!
        }
    }
}