using System;

namespace PKHeX.Core;

public sealed class MysteryBlock6 : SaveBlock<SAV6>
{
    private const int FlagStart = 0;
    private const int MaxReceivedFlag = 2048;
    private const int MaxCardsPresent = 24;
    // private const int FlagRegionSize = (MaxReceivedFlag / 8); // 0x100
    private const int CardStart = FlagStart + (MaxReceivedFlag / 8);

    public MysteryBlock6(SAV6XY sav, int offset) : base(sav) => Offset = offset;
    public MysteryBlock6(SAV6AO sav, int offset) : base(sav) => Offset = offset;

    public bool[] GetReceivedFlags() => FlagUtil.GitBitFlagArray(Data.AsSpan(Offset + FlagStart), MaxReceivedFlag);

    public void SetReceivedFlags(ReadOnlySpan<bool> value)
    {
        if (value.Length != MaxReceivedFlag)
            return;
        FlagUtil.SetBitFlagArray(Data.AsSpan(Offset + FlagStart), value);
        SAV.State.Edited = true;
    }

    public DataMysteryGift[] GetGifts()
    {
        var cards = new DataMysteryGift[MaxCardsPresent];
        for (int i = 0; i < cards.Length; i++)
            cards[i] = GetGift(i);
        return cards;
    }

    public void SetGifts(DataMysteryGift[] value)
    {
        int count = Math.Min(MaxCardsPresent, value.Length);
        for (int i = 0; i < count; i++)
            SetGift(value[i], i);
        for (int i = value.Length; i < MaxCardsPresent; i++)
            SetGift(new WC6(), i);
    }

    public DataMysteryGift GetGift(int index)
    {
        if ((uint)index > MaxCardsPresent)
            throw new ArgumentOutOfRangeException(nameof(index));

        var offset = GetGiftOffset(index);
        var data = SAV.Data.AsSpan(offset, WC6.Size).ToArray();
        return new WC6(data);
    }

    private int GetGiftOffset(int index) => Offset + CardStart + (index * WC6.Size);

    public void SetGift(DataMysteryGift wc6, int index)
    {
        if ((uint)index > MaxCardsPresent)
            throw new ArgumentOutOfRangeException(nameof(index));
        if (wc6.Data.Length != WC6.Size)
            throw new InvalidCastException(nameof(wc6));

        if (wc6 is { CardID: 2048, ItemID: 726 }) // Eon Ticket (OR/AS)
        {
            if (SAV is not SAV6AO ao)
                return;
            // Set the special received data
            var info = ao.Blocks.Sango;
            info.ReceiveEon();
            info.EnableSendEon();
        }

        SAV.SetData(wc6.Data, GetGiftOffset(index));
    }
}