using System;
using System.Runtime.InteropServices;
using static PKHeX.Core.Move;
using static PKHeX.Core.Species;
using static System.Buffers.Binary.BinaryPrimitives;

namespace PKHeX.Core
{
    [StructLayout(LayoutKind.Sequential, Pack = 4, Size = SIZE)]
    public sealed class Swarm3
    {
        public const int SIZE = 0x14;
        public readonly byte[] Data;

        private Span<byte> Raw => Data.AsSpan();

        public ushort Gen3Species { get => ReadUInt16LittleEndian(Raw); set => WriteUInt16LittleEndian(Raw, value); }
        public byte MapNum    { get => Raw[2]; set => Raw[2] = value; }
        public byte MapGroup  { get => Raw[3]; set => Raw[3] = value; }
        public byte Level     { get => Raw[4]; set => Raw[4] = value; }
        public byte Unused1   { get => Raw[5]; set => Raw[5] = value; }
        public ushort Unused2 { get => ReadUInt16LittleEndian(Raw[0x6..]); set => WriteUInt16LittleEndian(Raw[0x6..], value); }
        public ushort Move1   { get => ReadUInt16LittleEndian(Raw[0x8..]); set => WriteUInt16LittleEndian(Raw[0x8..], value); }
        public ushort Move2   { get => ReadUInt16LittleEndian(Raw[0xA..]); set => WriteUInt16LittleEndian(Raw[0xA..], value); }
        public ushort Move3   { get => ReadUInt16LittleEndian(Raw[0xC..]); set => WriteUInt16LittleEndian(Raw[0xC..], value); }
        public ushort Move4   { get => ReadUInt16LittleEndian(Raw[0xE..]); set => WriteUInt16LittleEndian(Raw[0xE..], value); }
        public byte Unused3 { get => Raw[0x10]; set => Raw[0x10] = value; }
        public byte EncounterProbability { get => Raw[0x11]; set => Raw[0x11] = value; }
        public ushort DaysLeft { get => ReadUInt16LittleEndian(Raw[0x12..]); set => WriteUInt16LittleEndian(Raw[0x12..], value); }

        public Swarm3(byte[] data) => Data = data;

        public Swarm3(Species species, byte level, byte map, Move m1, Move m2 = 0, Move m3 = 0, Move m4 = 0) : this(new byte[SIZE])
        {
            Gen3Species = (ushort)SpeciesConverter.GetG3Species((int)species);
            Level = level;
            MapNum = map;
            Move1 = (ushort)m1;
            Move2 = (ushort)m2;
            Move3 = (ushort)m3;
            Move4 = (ushort)m4;
            EncounterProbability = 50;
            DaysLeft = 1337;
        }
    }

    public static class Swarm3Details
    {
        public static readonly Swarm3[] Swarms_RS =
        {
            new(Surskit, 03, 0x11, Bubble, QuickAttack), // Route 102
            new(Surskit, 15, 0x1D, Bubble, QuickAttack), // Route 114
            new(Surskit, 15, 0x20, Bubble, QuickAttack), // Route 117
            new(Surskit, 28, 0x23, Bubble, QuickAttack), // Route 120
            new(Skitty,  15, 0x1F, Growl,  Tackle),      // Route 116
        };

        public static readonly Swarm3[] Swarms_E =
        {
            new(Seedot,  03, 0x11, Bide,      Harden,      LeechSeed),              // Route 102
            new(Nuzleaf, 15, 0x1D, Harden,    Growth,      NaturePower, LeechSeed), // Route 114
            new(Seedot,  13, 0x20, Harden,    Growth,      NaturePower, LeechSeed), // Route 117
            new(Seedot,  25, 0x23, GigaDrain, Frustration, SolarBeam,   LeechSeed), // Route 120
            new(Skitty,  08, 0x1F, Growl,     Tackle,      TailWhip,    Attract),   // Route 116
        };
    }
}