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

namespace PKHeX.Core
{
    /// <summary>
    /// <see cref="SaveFile"/> format for <see cref="GameVersion.Pt"/>
    /// </summary>
    public sealed class SAV4Pt : SAV4Sinnoh
    {
        public SAV4Pt() : base(GeneralSize, StorageSize)
        {
            Initialize();
            Dex = new Zukan4(this, PokeDex);
        }

        public SAV4Pt(byte[] data) : base(data, GeneralSize, StorageSize, GeneralSize)
        {
            Initialize();
            Dex = new Zukan4(this, PokeDex);
        }

        public override Zukan4 Dex { get; }
        protected override SAV4 CloneInternal4() => State.Exportable ? new SAV4Pt((byte[])Data.Clone()) : new SAV4Pt();
        public override PersonalTable Personal => PersonalTable.Pt;
        public override IReadOnlyList<ushort> HeldItems => Legal.HeldItems_Pt;
        public override int MaxItemID => Legal.MaxItemID_4_Pt;

        private const int GeneralSize = 0xCF2C;
        private const int StorageSize = 0x121E4; // Start 0xCF2C, +4 starts box data
        protected override int StorageStart => GeneralSize;

        private void Initialize()
        {
            Version = GameVersion.Pt;
            GetSAVOffsets();
        }

        private void GetSAVOffsets()
        {
            AdventureInfo = 0;
            Trainer1 = 0x68;
            Party = 0xA0;
            PokeDex = 0x1328;
            WondercardFlags = 0xB4C0;
            WondercardData = 0xB5C0;

            EventConst = 0xDAC;
            EventFlag = 0xFEC;
            DaycareOffset = 0x1654;
            OFS_HONEY = 0x7F38;

            OFS_UG_Stats = 0x3CB4;
            OFS_UG_Items = 0x4538;

            PoketchStart = 0x1160;

            OFS_PoffinCase = 0x52E8;
            Seal = 0x6494;

            Box = 4;
        }

        #region Storage
        private static int AdjustWallpaper(int value, int shift)
        {
            // Pt's  Special Wallpapers 1-8 are shifted by +0x8
            // HG/SS Special Wallpapers 1-8 (Primo Phrases) are shifted by +0x10
            if (value >= 0x10) // special
                return value + shift;
            return value;
        }

        public override int GetBoxWallpaper(int box)
        {
            if ((uint)box > 18)
                return 0;
            int value = Storage[GetBoxWallpaperOffset(box)];
            return AdjustWallpaper(value, -0x08);
        }

        public override void SetBoxWallpaper(int box, int value)
        {
            if ((uint)box >= 18)
                return;
            value = AdjustWallpaper(value, 0x08);
            Storage[GetBoxWallpaperOffset(box)] = (byte)value;
        }
        #endregion

        public override IReadOnlyList<InventoryPouch> Inventory
        {
            get
            {
                InventoryPouch[] pouch =
                {
                    new InventoryPouch4(InventoryType.Items, Legal.Pouch_Items_Pt, 999, 0x630),
                    new InventoryPouch4(InventoryType.KeyItems, Legal.Pouch_Key_Pt, 1, 0x8C4),
                    new InventoryPouch4(InventoryType.TMHMs, Legal.Pouch_TMHM_Pt, 99, 0x98C),
                    new InventoryPouch4(InventoryType.MailItems, Legal.Pouch_Mail_Pt, 999, 0xB1C),
                    new InventoryPouch4(InventoryType.Medicine, Legal.Pouch_Medicine_Pt, 999, 0xB4C),
                    new InventoryPouch4(InventoryType.Berries, Legal.Pouch_Berries_Pt, 999, 0xBEC),
                    new InventoryPouch4(InventoryType.Balls, Legal.Pouch_Ball_Pt, 999, 0xCEC),
                    new InventoryPouch4(InventoryType.BattleItems, Legal.Pouch_Battle_Pt, 999, 0xD28),
                };
                return pouch.LoadAll(General);
            }
            set => value.SaveAll(General);
        }

        public override int M { get => ReadUInt16LittleEndian(General.AsSpan(0x1280)); set => WriteUInt16LittleEndian(General.AsSpan(0x1280), (ushort)value); }
        public override int X { get => ReadUInt16LittleEndian(General.AsSpan(0x1288)); set => WriteUInt16LittleEndian(General.AsSpan(0x1288), (ushort)(X2 = value)); }
        public override int Y { get => ReadUInt16LittleEndian(General.AsSpan(0x128C)); set => WriteUInt16LittleEndian(General.AsSpan(0x128C), (ushort)(Y2 = value)); }

        public override Span<byte> Rival_Trash
        {
            get => General.AsSpan(0x27E8, OTLength * 2);
            set { if (value.Length == OTLength * 2) value.CopyTo(General.AsSpan(0x27E8)); }
        }

        public override int X2 { get => ReadUInt16LittleEndian(General.AsSpan(0x287E)); set => WriteUInt16LittleEndian(General.AsSpan(0x287E), (ushort)value); }
        public override int Y2 { get => ReadUInt16LittleEndian(General.AsSpan(0x2882)); set => WriteUInt16LittleEndian(General.AsSpan(0x2882), (ushort)value); }
        public override int Z { get => ReadUInt16LittleEndian(General.AsSpan(0x2886)); set => WriteUInt16LittleEndian(General.AsSpan(0x2886), (ushort)value); }

        public override uint SafariSeed { get => ReadUInt32LittleEndian(General.AsSpan(0x5660)); set => WriteUInt32LittleEndian(General.AsSpan(0x5660), value); }
        public override uint SwarmSeed { get => ReadUInt32LittleEndian(General.AsSpan(0x5664)); set => WriteUInt32LittleEndian(General.AsSpan(0x5664), value); }
        public override uint SwarmMaxCountModulo => 22;
    }
}