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

namespace PKHeX.Core
{
    /// <summary>
    /// Generation 8 <see cref="SaveFile"/> object for <see cref="GameVersion.BDSP"/> games.
    /// </summary>
    public sealed class SAV8BS : SaveFile, ISaveFileRevision, ITrainerStatRecord
    {
        // Save Data Attributes
        protected internal override string ShortSummary => $"{OT} ({Version}) - {System.LastSavedTime}";
        public override string Extension => string.Empty;

        public override IReadOnlyList<string> PKMExtensions => Array.FindAll(PKM.Extensions, f =>
        {
            int gen = f[^1] - 0x30;
            return gen <= 8;
        });

        public SAV8BS(byte[] data, bool exportable = true) : base(data, exportable)
        {
            Work = new FlagWork8b(this, 0x00004);
            Items = new MyItem8b(this, 0x0563C);
            Underground = new UndergroundItemList8b(this, 0x111BC);
            SelectBoundItems = new SaveItemShortcut8b(this, 0x14090); // size: 0x8
            PartyInfo = new Party8b(this, 0x14098);
            BoxLayout = new BoxLayout8b(this, 0x148AA); // size: 0x64A
            // 0x14EF4 - Box[40]

            // PLAYER_DATA:
            Config = new ConfigSave8b(this, 0x79B74); // size: 0x40
            MyStatus = new MyStatus8b(this, 0x79BB4); // size: 0x50
            Played = new PlayTime8b(this, 0x79C04); // size: 0x04
            Contest = new Contest8b(this, 0x79C08); // size: 0x720

            Zukan = new Zukan8b(this, 0x7A328); // size: 0x30B8
            BattleTrainer = new BattleTrainerStatus8b(this, 0x7D3E0); // size: 0x1618
            MenuSelection = new MenuSelect8b(this, 0x7E9F8); // size: 0x44
            FieldObjects = new FieldObjectSave8b(this, 0x7EA3C); // size: 0x109A0 (1000 * 0x44)
            Records = new Record8b(this, 0x8F3DC); // size: 0x78 * 12
            Encounter = new EncounterSave8b(this, 0x8F97C); // size: 0x188
            Player = new PlayerData8b(this, 0x8FB04); // 0x80
            SealDeco = new SealBallDecoData8b(this, 0x8FB84); // size: 0x4288
            SealList = new SealList8b(this, 0x93E0C); // size: 0x960 SaveSealData[200]
            Random = new RandomGroup8b(this, 0x9476C); // size: 0x630
            FieldGimmick = new FieldGimmickSave8b(this, 0x94D9C); // FieldGimmickSaveData; int[3] gearRotate
            BerryTrees = new BerryTreeGrowSave8b(this, 0x94DA8); // size: 0x808
            Poffins = new PoffinSaveData8b(this, 0x955B0); // size: 0x644
            BattleTower = new BattleTowerWork8b(this, 0x95BF4); // size: 0x1B8
            System = new SystemData8b(this, 0x95DAC); // size: 0x138
            Poketch = new Poketch8b(this, 0x95EE4); // todo
            Daycare = new Daycare8b(this, 0x96080); // 0x2C0
            // 0x96340 - _DENDOU_SAVEDATA; DENDOU_RECORD[30], POKEMON_DATA_INSIDE[6], ushort[4] ?
            // BadgeSaveData; byte[8]
            // BoukenNote; byte[24]
            // TV_DATA (int[48], TV_STR_DATA[42]), (int[37], bool[37])*2, (int[8], int[8]), TV_STR_DATA[10]; 144 128bit zeroed (900 bytes?)? 
            UgSaveData = new UgSaveData8b(this, 0x9A89C); // size: 0x27A0
            // 0x9D03C - GMS_DATA // size: 0x31304, (GMS_POINT_DATA[650], ushort, ushort, byte)?; substructure GMS_POINT_HISTORY_DATA[5]
            // 0xCE340 - PLAYER_NETWORK_DATA; bcatFlagArray byte[1300]
            UnionSave = new UnionSaveData8b(this, 0xCEA10); // size: 0xC
            ContestPhotoLanguage = new ContestPhotoLanguage8b(this, 0xCEA1C); // size: 0x18
            ZukanExtra = new ZukanSpinda8b(this, 0xCEA34); // size: 0x64 (100)
            // CON_PHOTO_EXT_DATA[5]
            // GMS_POINT_HISTORY_EXT_DATA[3250]
            UgCount = new UgCountRecord8b(this, 0xE8178); // size: 0x20
            // 0xE8198 - ReBuffnameData; RE_DENDOU_RECORD[30], RE_DENDOU_POKEMON_DATA_INSIDE[6] (0x20) = 0x1680
            // 0xE9818 -- 0x10 byte[] MD5 hash of all savedata;

            // v1.1 additions
            RecordAdd = new RecordAddData8b(this, 0xE9828); // size: 0x3C0
            MysteryRecords = new MysteryBlock8b(this, 0xE9BE8); // size: ???
            // POKETCH_POKETORE_COUNT_ARRAY -- (u16 species, u16 unused, i32 count, i32 reserved, i32 reserved)[3] = 0x10bytes
            // PLAYREPORT_DATA -- reporting player progress online? 248 bytes?
            // MT_DATA mtData; -- 0x400 bytes
            // DENDOU_SAVE_ADD -- language tracking of members (hall of fame?); ADD_POKE_MEMBER[30], ADD_POKE[6]

            // v1.2 additions
            // ReBuffnameData reBuffNameDat -- RE_DENDOU_RECORD[], RE_DENDOU_RECORD is an RE_DENDOU_POKEMON_DATA_INSIDE[] with nicknames
            // PLAYREPORT_DATA playReportData    sizeof(0xF8)
            // PLAYREPORT_DATA playReportDataRef sizeof(0xF8)

        Initialize();
        }

        public SAV8BS() : this(new byte[SaveUtil.SIZE_G8BDSP_2], false) => SaveRevision = (int)Gem8Version.V1_2;

        private void Initialize()
        {
            Box = 0x14EF4;
            Party = PartyInfo.Offset;
            PokeDex = Zukan.PokeDex;
            DaycareOffset = Daycare.Offset;

            ReloadBattleTeams();
            TeamSlots = BoxLayout.TeamSlots;
        }

        public override bool HasEvents => true;

        // Configuration
        protected override int SIZE_STORED => PokeCrypto.SIZE_8STORED;
        protected override int SIZE_PARTY => PokeCrypto.SIZE_8PARTY;
        public override int SIZE_BOXSLOT => PokeCrypto.SIZE_8PARTY;
        public override PKM BlankPKM => new PB8();
        public override Type PKMType => typeof(PB8);

        public override int BoxCount => BoxLayout8b.BoxCount;
        public override int MaxEV => 252;

        public override int Generation => 8;
        protected override int EventConstMax => 500;
        public override PersonalTable Personal => PersonalTable.BDSP;
        public override int OTLength => 12;
        public override int NickLength => 12;
        public override int MaxMoveID => Legal.MaxMoveID_8b;
        public override int MaxSpeciesID => Legal.MaxSpeciesID_8b;
        public override int MaxItemID => Legal.MaxItemID_8b;
        public override int MaxBallID => Legal.MaxBallID_8b;
        public override int MaxGameID => Legal.MaxGameID_8b;
        public override int MaxAbilityID => Legal.MaxAbilityID_8b;

        public bool HasFirstSaveFileExpansion => (Gem8Version)SaveRevision >= Gem8Version.V1_1;
        public bool HasSecondSaveFileExpansion => (Gem8Version)SaveRevision >= Gem8Version.V1_2;

        public int SaveRevision
        {
            get => ReadInt32LittleEndian(Data.AsSpan(0));
            init => WriteInt32LittleEndian(Data.AsSpan(0), value);
        }

        public string SaveRevisionString => ((Gem8Version)SaveRevision).GetSuffixString();

        public override IReadOnlyList<ushort> HeldItems => Legal.HeldItems_BS;
        protected override SaveFile CloneInternal() => new SAV8BS((byte[])(Data.Clone()));

        protected override byte[] GetFinalData()
        {
            BoxLayout.SaveBattleTeams();
            return base.GetFinalData();
        }

        private void ReloadBattleTeams()
        {
            if (!State.Exportable)
                BoxLayout.ClearBattleTeams();
            else // Valid slot locking info present
                BoxLayout.LoadBattleTeams();
        }

        public override StorageSlotFlag GetSlotFlags(int index)
        {
            int team = Array.IndexOf(TeamSlots, index);
            if (team < 0)
                return StorageSlotFlag.None;

            team /= 6;
            var result = (StorageSlotFlag)((int)StorageSlotFlag.BattleTeam1 << team);
            if (BoxLayout.GetIsTeamLocked(team))
                result |= StorageSlotFlag.Locked;
            return result;
        }

        #region Checksums

        private const int HashOffset = SaveUtil.SIZE_G8BDSP - 0x10;
        private Span<byte> CurrentHash => Data.AsSpan(SaveUtil.SIZE_G8BDSP - 0x10, 0x10);

        private byte[] ComputeHash()
        {
            CurrentHash.Fill(0);
            using var md5 = new MD5CryptoServiceProvider();
            return md5.ComputeHash(Data);
        }

        protected override void SetChecksums() => ComputeHash().CopyTo(Data, HashOffset);
        public override string ChecksumInfo => !ChecksumsValid ? "MD5 Hash Invalid" : string.Empty;

        public override bool ChecksumsValid
        {
            get
            {
                // Cache hash and restore it after computation
                var original = CurrentHash.ToArray();
                var newHash = ComputeHash();
                var result = newHash.AsSpan().SequenceEqual(original);
                original.AsSpan().CopyTo(CurrentHash);
                return result;
            }
        }

        #endregion

        protected override PKM GetPKM(byte[] data) => new PB8(data);
        protected override byte[] DecryptPKM(byte[] data) => PokeCrypto.DecryptArray8(data);

        #region Blocks
        // public Box8 BoxInfo { get; }
        public FlagWork8b Work { get; }
        public MyItem8b Items { get; }
        public UndergroundItemList8b Underground { get; }
        public SaveItemShortcut8b SelectBoundItems { get; }
        public Party8b PartyInfo { get; }
        // public MyItem Items { get; }
        public BoxLayout8b BoxLayout { get; }
        public ConfigSave8b Config { get; }
        public MyStatus8b MyStatus { get; }
        public PlayTime8b Played { get; }
        public Contest8b Contest { get; }
        // public Misc8 Misc { get; }
        public Zukan8b Zukan { get; }
        public BattleTrainerStatus8b BattleTrainer { get; }
        public MenuSelect8b MenuSelection { get; }
        public FieldObjectSave8b FieldObjects { get; }
        public Record8b Records { get; }
        public EncounterSave8b Encounter { get; }
        public PlayerData8b Player { get; }
        public SealBallDecoData8b SealDeco { get; }
        public SealList8b SealList { get; }
        public RandomGroup8b Random { get; }
        public FieldGimmickSave8b FieldGimmick { get; }
        public BerryTreeGrowSave8b BerryTrees { get; }
        public PoffinSaveData8b Poffins { get; }
        public BattleTowerWork8b BattleTower { get; }
        public SystemData8b System { get; }
        public Poketch8b Poketch { get; }
        public Daycare8b Daycare { get; }
        public UgSaveData8b UgSaveData { get; }
        public UnionSaveData8b UnionSave { get; }
        public ContestPhotoLanguage8b ContestPhotoLanguage { get; }
        public ZukanSpinda8b ZukanExtra { get; }
        public UgCountRecord8b UgCount { get; }

        // First Savedata Expansion!
        public RecordAddData8b RecordAdd { get; }
        public MysteryBlock8b MysteryRecords { get; }
        #endregion

        public override GameVersion Version => Game switch
        {
            (int)GameVersion.BD => GameVersion.BD,
            (int)GameVersion.SP => GameVersion.SP,
            _ => GameVersion.Invalid,
        };

        public override string GetString(ReadOnlySpan<byte> data) => StringConverter8.GetString(data);

        public override int SetString(Span<byte> destBuffer, ReadOnlySpan<char> value, int maxLength, StringConverterOption option)
        {
            return StringConverter8.SetString(destBuffer, value, maxLength, option);
        }

        public override bool GetEventFlag(int flagNumber) => Work.GetFlag(flagNumber);
        public override void SetEventFlag(int flagNumber, bool value) => Work.SetFlag(flagNumber, value);

        // Player Information
        public override int TID { get => MyStatus.TID; set => MyStatus.TID = value; }
        public override int SID { get => MyStatus.SID; set => MyStatus.SID = value; }
        public override int Game { get => MyStatus.Game; set => MyStatus.Game = value; }
        public override int Gender { get => MyStatus.Male ? 0 : 1; set => MyStatus.Male = value == 0; }
        public override int Language { get => Config.Language; set => Config.Language = value; }
        public override string OT { get => MyStatus.OT; set => MyStatus.OT = value; }
        public override uint Money { get => MyStatus.Money; set => MyStatus.Money = value; }

        public override int PlayedHours { get => Played.PlayedHours; set => Played.PlayedHours = (ushort)value; }
        public override int PlayedMinutes { get => Played.PlayedMinutes; set => Played.PlayedMinutes = (byte)value; }
        public override int PlayedSeconds { get => Played.PlayedSeconds; set => Played.PlayedSeconds = (byte)value; }

        // Inventory
        public override IReadOnlyList<InventoryPouch> Inventory { get => Items.Inventory; set => Items.Inventory = value; }

        // Storage
        public override int GetPartyOffset(int slot) => Party + (SIZE_PARTY * slot);
        public override int GetBoxOffset(int box) => Box + (SIZE_PARTY * box * 30);
        protected override int GetBoxWallpaperOffset(int box) => BoxLayout.GetBoxWallpaperOffset(box);
        public override int GetBoxWallpaper(int box) => BoxLayout.GetBoxWallpaper(box);
        public override void SetBoxWallpaper(int box, int value) => BoxLayout.SetBoxWallpaper(box, value);
        public override string GetBoxName(int box) => BoxLayout[box];
        public override void SetBoxName(int box, string value) => BoxLayout[box] = value;
        public override byte[] GetDataForBox(PKM pkm) => pkm.EncryptedPartyData;
        public override int CurrentBox { get => BoxLayout.CurrentBox; set => BoxLayout.CurrentBox = (byte)value; }
        public override int BoxesUnlocked { get => BoxLayout.BoxesUnlocked; set => BoxLayout.BoxesUnlocked = (byte)value; }

        public string Rival
        {
            get => GetString(0x55F4, 0x1A);
            set => SetString(Data.AsSpan(0x55F4, 0x1A), value.AsSpan(), OTLength, StringConverterOption.ClearZero);
        }

        public short ZoneID // map
        {
            get => ReadInt16LittleEndian(Data.AsSpan(0x5634));
            set => WriteInt16LittleEndian(Data.AsSpan(0x5634), value);
        }

        public float TimeScale // default 1440.0f
        {
            get => ReadSingleLittleEndian(Data.AsSpan(0x5638));
            set => WriteSingleLittleEndian(Data.AsSpan(0x5638), value);
        }

        public uint UnionRoomPenaltyTime // move this into the UnionSaveData block once reversed.
        {
            get => ReadUInt32LittleEndian(Data.AsSpan(0xCEA14));
            set => WriteSingleLittleEndian(Data.AsSpan(0xCEA14), value);
        }

        protected override void SetPKM(PKM pkm, bool isParty = false)
        {
            var pk = (PB8)pkm;
            // Apply to this Save File
            DateTime Date = DateTime.Now;
            pk.Trade(this, Date.Day, Date.Month, Date.Year);

            pkm.RefreshChecksum();
            AddCountAcquired(pkm);
        }

        private void AddCountAcquired(PKM pkm)
        {
            // There aren't many records, and they only track Capture/Fish/Hatch/Defeat.
            Records.AddRecord(pkm.WasEgg ? 004 : 002); // egg, capture
        }

        protected override void SetDex(PKM pkm) => Zukan.SetDex(pkm);
        public override bool GetCaught(int species) => Zukan.GetCaught(species);
        public override bool GetSeen(int species) => Zukan.GetSeen(species);

        public override int PartyCount
        {
            get => PartyInfo.PartyCount;
            protected set => PartyInfo.PartyCount = value;
        }

        public override PKM GetDecryptedPKM(byte[] data) => GetPKM(DecryptPKM(data));
        public override PKM GetBoxSlot(int offset) => GetDecryptedPKM(GetData(Data, offset, SIZE_PARTY)); // party format in boxes!

        public enum TopMenuItemType
        {
            Zukan = 0,
            Pokemon = 1,
            Bag = 2,
            Card = 3,
            Map = 4,
            Seal = 5,
            Setting = 6,
            Gift = 7,
        }

        public int RecordCount => Record8b.RecordCount;
        public int GetRecord(int recordID) => Records.GetRecord(recordID);
        public int GetRecordOffset(int recordID) => Records.GetRecordOffset(recordID);
        public int GetRecordMax(int recordID) => Record8b.GetMax(recordID);
        public void SetRecord(int recordID, int value) => Records.SetRecord(recordID, value);

        #region Daycare
        public override int DaycareSeedSize => 16; // 8byte
        public override int GetDaycareSlotOffset(int loc, int slot) => Daycare.GetParentSlotOffset(slot);
        public override uint? GetDaycareEXP(int loc, int slot) => 0;
        public override bool? IsDaycareOccupied(int loc, int slot) => Daycare.GetDaycareSlotOccupied(slot);
        public override bool? IsDaycareHasEgg(int loc) => Daycare.IsEggAvailable;
        public override void SetDaycareEXP(int loc, int slot, uint EXP) { }
        public override void SetDaycareOccupied(int loc, int slot, bool occupied) { }
        public override void SetDaycareHasEgg(int loc, bool hasEgg) => Daycare.IsEggAvailable = hasEgg;
        public override string GetDaycareRNGSeed(int loc) => Daycare.DaycareSeed.ToString("X16");
        public override void SetDaycareRNGSeed(int loc, string seed) => Daycare.DaycareSeed = Util.GetHexValue64(seed);
        #endregion
    }
}