using System.Collections.Generic;

namespace PKHeX.Core;

public static partial class Extensions
{
    public static IReadOnlyList<PKM> GetAllPKM(this SaveFile sav)
    {
        var result = new List<PKM>();
        if (sav.HasBox)
            result.AddRange(sav.BoxData);
        if (sav.HasParty)
            result.AddRange(sav.PartyData);

        var extra = sav.GetExtraPKM();
        result.AddRange(extra);
        result.RemoveAll(z => z.Species == 0);
        return result;
    }

    public static PKM[] GetExtraPKM(this SaveFile sav) => sav.GetExtraPKM(sav.GetExtraSlots());

    public static PKM[] GetExtraPKM(this SaveFile sav, IList<SlotInfoMisc> slots)
    {
        var arr = new PKM[slots.Count];
        for (int i = 0; i < slots.Count; i++)
            arr[i] = slots[i].Read(sav);
        return arr;
    }

    public static List<SlotInfoMisc> GetExtraSlots(this SaveFile sav, bool all = false)
    {
        var slots = GetExtraSlotsUnsafe(sav, all);
        for (int i = 0; i < slots.Count;)
        {
            if (slots[i].Offset < 0)
                slots.RemoveAt(i);
            else
                ++i;
        }
        return slots;
    }

    private static readonly List<SlotInfoMisc> None = new();

    private static List<SlotInfoMisc> GetExtraSlotsUnsafe(SaveFile sav, bool all) => sav switch
    {
        SAV2 sav2 => GetExtraSlots2(sav2),
        SAV3 sav3 => GetExtraSlots3(sav3),
        SAV4 sav4 => GetExtraSlots4(sav4),
        SAV5 sav5 => GetExtraSlots5(sav5),
        SAV6XY xy => GetExtraSlots6XY(xy),
        SAV6AO xy => GetExtraSlots6AO(xy),
        SAV7 sav7 => GetExtraSlots7(sav7, all),
        SAV7b lgpe => GetExtraSlots7b(lgpe),
        SAV8SWSH ss => GetExtraSlots8(ss),
        SAV8BS bs => GetExtraSlots8b(bs),
        SAV8LA la => GetExtraSlots8a(la),
        _ => None,
    };

    private static List<SlotInfoMisc> GetExtraSlots2(SAV2 sav)
    {
        return new List<SlotInfoMisc>
        {
            new(sav.Data, 0, sav.GetDaycareSlotOffset(0, 2)) {Type = StorageSlotType.Daycare }, // egg
        };
    }

    private static List<SlotInfoMisc> GetExtraSlots3(SAV3 sav)
    {
        if (sav is not SAV3FRLG)
            return None;
        return new List<SlotInfoMisc>
        {
            new(sav.Large, 0, 0x3C98) {Type = StorageSlotType.Daycare},
        };
    }

    private static List<SlotInfoMisc> GetExtraSlots4(SAV4 sav)
    {
        var list = new List<SlotInfoMisc>
        {
            new(sav.General, 0, sav.GTS) {Type = StorageSlotType.GTS},
        };
        if (sav is SAV4HGSS)
            list.Add(new SlotInfoMisc(sav.General, 1, SAV4HGSS.WalkerPair) {Type = StorageSlotType.Misc});
        return list;
    }

    private static List<SlotInfoMisc> GetExtraSlots5(SAV5 sav)
    {
        return new List<SlotInfoMisc>
        {
            new(sav.Data, 0, sav.GTS) {Type = StorageSlotType.GTS},
            new(sav.Data, 0, sav.Fused) {Type = StorageSlotType.Fused},
            new(sav.Data, 0, sav.PGL) { Type = StorageSlotType.Misc },

            new(sav.Data, 0, sav.GetBattleBoxSlot(0)) {Type = StorageSlotType.BattleBox},
            new(sav.Data, 1, sav.GetBattleBoxSlot(1)) {Type = StorageSlotType.BattleBox},
            new(sav.Data, 2, sav.GetBattleBoxSlot(2)) {Type = StorageSlotType.BattleBox},
            new(sav.Data, 3, sav.GetBattleBoxSlot(3)) {Type = StorageSlotType.BattleBox},
            new(sav.Data, 4, sav.GetBattleBoxSlot(4)) {Type = StorageSlotType.BattleBox},
            new(sav.Data, 5, sav.GetBattleBoxSlot(5)) {Type = StorageSlotType.BattleBox},
        };
    }

    private static List<SlotInfoMisc> GetExtraSlots6XY(SAV6XY sav)
    {
        return new List<SlotInfoMisc>
        {
            new(sav.Data, 0, sav.GTS) {Type = StorageSlotType.GTS},
            new(sav.Data, 0, sav.Fused) {Type = StorageSlotType.Fused},
            new(sav.Data, 0, sav.SUBE.Give) {Type = StorageSlotType.Misc}, // Old Man

            new(sav.Data, 0, sav.GetBattleBoxSlot(0)) {Type = StorageSlotType.BattleBox},
            new(sav.Data, 1, sav.GetBattleBoxSlot(1)) {Type = StorageSlotType.BattleBox},
            new(sav.Data, 2, sav.GetBattleBoxSlot(2)) {Type = StorageSlotType.BattleBox},
            new(sav.Data, 3, sav.GetBattleBoxSlot(3)) {Type = StorageSlotType.BattleBox},
            new(sav.Data, 4, sav.GetBattleBoxSlot(4)) {Type = StorageSlotType.BattleBox},
            new(sav.Data, 5, sav.GetBattleBoxSlot(5)) {Type = StorageSlotType.BattleBox},
        };
    }

    private static List<SlotInfoMisc> GetExtraSlots6AO(SAV6AO sav)
    {
        return new List<SlotInfoMisc>
        {
            new(sav.Data, 0, SAV6AO.GTS) {Type = StorageSlotType.GTS},
            new(sav.Data, 0, SAV6AO.Fused) {Type = StorageSlotType.Fused},
            new(sav.Data, 0, sav.SUBE.Give) {Type = StorageSlotType.Misc},

            new(sav.Data, 0, sav.GetBattleBoxSlot(0)) {Type = StorageSlotType.BattleBox},
            new(sav.Data, 1, sav.GetBattleBoxSlot(1)) {Type = StorageSlotType.BattleBox},
            new(sav.Data, 2, sav.GetBattleBoxSlot(2)) {Type = StorageSlotType.BattleBox},
            new(sav.Data, 3, sav.GetBattleBoxSlot(3)) {Type = StorageSlotType.BattleBox},
            new(sav.Data, 4, sav.GetBattleBoxSlot(4)) {Type = StorageSlotType.BattleBox},
            new(sav.Data, 5, sav.GetBattleBoxSlot(5)) {Type = StorageSlotType.BattleBox},
        };
    }

    private static List<SlotInfoMisc> GetExtraSlots7(SAV7 sav, bool all)
    {
        var list = new List<SlotInfoMisc>
        {
            new(sav.Data, 0, sav.AllBlocks[07].Offset) {Type = StorageSlotType.GTS},
            new(sav.Data, 0, sav.GetFusedSlotOffset(0)) {Type = StorageSlotType.Fused},
        };
        if (sav is SAV7USUM uu)
        {
            list.AddRange(new[]
            {
                new SlotInfoMisc(uu.Data, 1, uu.GetFusedSlotOffset(1)) {Type = StorageSlotType.Fused},
                new SlotInfoMisc(uu.Data, 2, uu.GetFusedSlotOffset(2)) {Type = StorageSlotType.Fused},
            });
            var ba = uu.BattleAgency;
            list.AddRange(new[]
            {
                new SlotInfoMisc(uu.Data, 0, ba.GetSlotOffset(0)) {Type = StorageSlotType.Misc},
                new SlotInfoMisc(uu.Data, 1, ba.GetSlotOffset(1)) {Type = StorageSlotType.Misc},
                new SlotInfoMisc(uu.Data, 2, ba.GetSlotOffset(2)) {Type = StorageSlotType.Misc},
            });
        }

        if (!all)
            return list;

        for (int i = 0; i < ResortSave7.ResortCount; i++)
            list.Add(new SlotInfoMisc(sav.Data, i, sav.ResortSave.GetResortSlotOffset(i)) { Type = StorageSlotType.Resort });
        return list;
    }

    private static List<SlotInfoMisc> GetExtraSlots7b(SAV7b sav)
    {
        return new List<SlotInfoMisc>
        {
            new(sav.Data, 0, sav.Blocks.GetBlockOffset(BelugaBlockIndex.Daycare) + 8, true) {Type = StorageSlotType.Daycare},
        };
    }

    private static List<SlotInfoMisc> GetExtraSlots8(ISaveBlock8Main sav)
    {
        var fused = sav.Fused;
        var dc = sav.Daycare;
        var list = new List<SlotInfoMisc>
        {
            new(fused.Data, 0, Fused8.GetFusedSlotOffset(0), true) {Type = StorageSlotType.Fused},
            new(fused.Data, 1, Fused8.GetFusedSlotOffset(1), true) {Type = StorageSlotType.Fused},
            new(fused.Data, 2, Fused8.GetFusedSlotOffset(2), true) {Type = StorageSlotType.Fused},

            new(dc.Data, 0, Daycare8.GetDaycareSlotOffset(0, 0)) {Type = StorageSlotType.Daycare},
            new(dc.Data, 0, Daycare8.GetDaycareSlotOffset(0, 1)) {Type = StorageSlotType.Daycare},
            new(dc.Data, 0, Daycare8.GetDaycareSlotOffset(1, 0)) {Type = StorageSlotType.Daycare},
            new(dc.Data, 0, Daycare8.GetDaycareSlotOffset(1, 1)) {Type = StorageSlotType.Daycare},
        };

        if (sav is SAV8SWSH {SaveRevision: >= 2} s8)
        {
            var block = s8.Blocks.GetBlockSafe(SaveBlockAccessor8SWSH.KFusedCalyrex);
            var c = new SlotInfoMisc(block.Data, 3, 0, true) {Type = StorageSlotType.Fused};
            list.Insert(3, c);
        }

        return list;
    }

    private static List<SlotInfoMisc> GetExtraSlots8b(SAV8BS sav)
    {
        return new List<SlotInfoMisc>
        {
            new(sav.Data, 0, sav.UgSaveData.GetSlotOffset(0), true) { Type = StorageSlotType.Misc },
            new(sav.Data, 1, sav.UgSaveData.GetSlotOffset(1), true) { Type = StorageSlotType.Misc },
            new(sav.Data, 2, sav.UgSaveData.GetSlotOffset(2), true) { Type = StorageSlotType.Misc },
            new(sav.Data, 3, sav.UgSaveData.GetSlotOffset(3), true) { Type = StorageSlotType.Misc },
            new(sav.Data, 4, sav.UgSaveData.GetSlotOffset(4), true) { Type = StorageSlotType.Misc },
            new(sav.Data, 5, sav.UgSaveData.GetSlotOffset(5), true) { Type = StorageSlotType.Misc },
            new(sav.Data, 6, sav.UgSaveData.GetSlotOffset(6), true) { Type = StorageSlotType.Misc },
            new(sav.Data, 7, sav.UgSaveData.GetSlotOffset(7), true) { Type = StorageSlotType.Misc },
            new(sav.Data, 8, sav.UgSaveData.GetSlotOffset(8), true) { Type = StorageSlotType.Misc },
        };
    }

    private static List<SlotInfoMisc> GetExtraSlots8a(SAV8LA sav)
    {
        return new List<SlotInfoMisc>();
    }
}