using System;
using static System.Buffers.Binary.BinaryPrimitives;

namespace PKHeX.Core
{
    public sealed class Mail3 : Mail
    {
        public const int SIZE = 0x24;
        private readonly bool JP;

        public Mail3() : base(new byte[SIZE], -1) => ResetData();
        public Mail3(byte[] data, int ofs, bool japanese) : base(data, ofs) => JP = japanese;

        private void ResetData()
        {
            for (int y = 0; y < 3; y++)
            {
                for (int x = 0; x < 3; x++)
                    SetMessage(y, x, 0xFFFF);
            }

            AuthorName = string.Empty;
            AuthorTID = 0;
            AuthorTID = 0;
            AppearPKM = 1;
            MailType = 0;
        }

        public override ushort GetMessage(int index1, int index2) => ReadUInt16LittleEndian(Data.AsSpan(((index1 * 3) + index2) * 2));
        public override void SetMessage(int index1, int index2, ushort value) => WriteUInt16LittleEndian(Data.AsSpan(((index1 * 3) + index2) * 2), value);
        public override void CopyTo(SaveFile sav) => sav.SetData(((SAV3)sav).Large, DataOffset);

        public override string AuthorName
        {
            get => StringConverter3.GetString(Data.AsSpan(0x12, 7), JP);
            set
            {
                var span = Data.AsSpan(0x12, 8);
                StringConverter3.SetString(span, value.AsSpan(), 7, JP, StringConverterOption.ClearFF);
            }
        }

        public override ushort AuthorTID { get => ReadUInt16LittleEndian(Data.AsSpan(0x1A)); set => WriteUInt16LittleEndian(Data.AsSpan(0x1A), value); }
        public override ushort AuthorSID { get => ReadUInt16LittleEndian(Data.AsSpan(0x1C)); set => WriteUInt16LittleEndian(Data.AsSpan(0x1C), value); }
        public override int AppearPKM { get => ReadUInt16LittleEndian(Data.AsSpan(0x1E)); set => WriteUInt16LittleEndian(Data.AsSpan(0x1E), (ushort)(value == 0 ? 1 : value)); }
        public override int MailType { get => ReadUInt16LittleEndian(Data.AsSpan(0x20)); set => WriteUInt16LittleEndian(Data.AsSpan(0x20), (ushort)value); }

        public override bool? IsEmpty => MailType switch
        {
            0 => true,
            >= 0x79 and <= 0x84 => false,
            _ => null,
        };

        public override void SetBlank() => (new Mail3()).Data.CopyTo(Data, 0);
    }
}