using System;
using System.Collections.Generic;
using static PKHeX.Core.Species;
using static PKHeX.Core.Move;

namespace PKHeX.Core
{
    public static partial class Legal
    {
        /// <summary>
        /// Species that can change between their forms and get access to form-specific moves.
        /// </summary>
        public static readonly HashSet<int> FormChangeMovesRetain = new()
        {
            (int)Deoxys,
            (int)Giratina,
            (int)Shaymin,
            (int)Hoopa,
        };

        /// <summary>
        /// Species that can change between their forms and get access to form-specific moves.
        /// </summary>
        public static readonly Dictionary<int, Func<int, int, bool>> FormChangeMoves = new()
        {
            {(int)Deoxys,   (g, _) => g >= 6},
            {(int)Giratina, (g, _) => g >= 6},
            {(int)Shaymin,  (g, _) => g >= 6},
            {(int)Rotom,    (g, _) => g >= 6},
            {(int)Hoopa,    (g, _) => g >= 6},
            {(int)Tornadus, (g, _) => g >= 6},
            {(int)Thundurus,(g, _) => g >= 6},
            {(int)Landorus, (g, _) => g >= 6},
            {(int)Urshifu,  (g, _) => g >= 8},
            {(int)Enamorus, (g, _) => g >= 8},

            // Fused
            {(int)Kyurem,   (g, _) => g >= 6},
            {(int)Necrozma, (g, _) => g >= 8},
            {(int)Calyrex,  (g, _) => g >= 8},

            {(int)Pikachu,  (g, f) => g == 6 && f != 0},
        };

        /// <summary>
        /// Generation 3 &amp; 4 Battle Frontier Species banlist. When referencing this in context to generation 4, be sure to disallow <see cref="Pichu"/> with Form 1 (Spiky).
        /// </summary>
        public static readonly HashSet<int> BattleFrontierBanlist = new()
        {
            (int)Mewtwo, (int)Mew,
            (int)Lugia, (int)HoOh, (int)Celebi,
            (int)Kyogre, (int)Groudon, (int)Rayquaza, (int)Jirachi, (int)Deoxys,
            (int)Dialga, (int)Palkia, (int)Giratina, (int)Phione, (int)Manaphy, (int)Darkrai, (int)Shaymin, (int)Arceus,
            (int)Victini, (int)Reshiram, (int)Zekrom, (int)Kyurem, (int)Keldeo, (int)Meloetta, (int)Genesect,
            (int)Xerneas, (int)Yveltal, (int)Zygarde, (int)Diancie, (int)Hoopa, (int)Volcanion,
            (int)Cosmog, (int)Cosmoem, (int)Solgaleo, (int)Lunala, (int)Necrozma, (int)Magearna, (int)Marshadow, (int)Zeraora,
            (int)Meltan, (int)Melmetal,
        };

        /// <summary>
        /// Checks if Sketch can obtain the <see cref="move"/> in the requested <see cref="generation"/>
        /// </summary>
        /// <remarks>Doesn't bounds check the <see cref="generation"/> for max move ID.</remarks>
        /// <param name="move">Move ID</param>
        /// <param name="generation">Generation to check</param>
        /// <returns>True if can be sketched, false if not available.</returns>
        public static bool IsValidSketch(int move, int generation)
        {
            if (MoveInfo.InvalidSketch.Contains(move))
                return false;
            if (generation is 6 && move is ((int)ThousandArrows or (int)ThousandWaves))
                return false;
            if (generation is 8) // can't Sketch unusable moves in BDSP, no Sketch in PLA
            {
                if (DummiedMoves_BDSP.Contains(move))
                    return false;
                if (move > MaxMoveID_8)
                    return false;
            }

            return move <= GetMaxMoveID(generation);
        }

        /// <summary>
        /// Species that are from Mythical Distributions (disallowed species for competitive rulesets)
        /// </summary>
        public static readonly HashSet<int> Mythicals = new()
        {
            (int)Mew,
            (int)Celebi,
            (int)Jirachi, (int)Deoxys,
            (int)Phione, (int)Manaphy, (int)Darkrai, (int)Shaymin, (int)Arceus,
            (int)Victini, (int)Keldeo, (int)Meloetta, (int)Genesect,
            (int)Diancie, (int)Hoopa, (int)Volcanion,
            (int)Magearna, (int)Marshadow,
            (int)Zeraora, (int)Meltan, (int)Melmetal,
            (int)Zarude,
        };

        /// <summary>
        /// Species classified as "Legend" by the game code.
        /// </summary>
        public static readonly HashSet<int> Legends = new()
        {
            (int)Mewtwo, (int)Mew,
            (int)Lugia, (int)HoOh, (int)Celebi,
            (int)Kyogre, (int)Groudon, (int)Rayquaza, (int)Jirachi, (int)Deoxys,
            (int)Dialga, (int)Palkia, (int)Giratina, (int)Phione, (int)Manaphy, (int)Darkrai, (int)Shaymin, (int)Arceus,
            (int)Victini, (int)Reshiram, (int)Zekrom, (int)Kyurem, (int)Keldeo, (int)Meloetta, (int)Genesect,
            (int)Xerneas, (int)Yveltal, (int)Zygarde, (int)Diancie, (int)Hoopa, (int)Volcanion,
            (int)Cosmog, (int)Cosmoem, (int)Solgaleo, (int)Lunala, (int)Necrozma, (int)Magearna, (int)Marshadow, (int)Zeraora,
            (int)Meltan, (int)Melmetal,
            (int)Zacian, (int)Zamazenta, (int)Eternatus, (int)Zarude, (int)Calyrex,
        };

        /// <summary>
        /// Species classified as "SubLegend" by the game code.
        /// </summary>
        public static readonly HashSet<int> SubLegends = new()
        {
            (int)Articuno, (int)Zapdos, (int)Moltres,
            (int)Raikou, (int)Entei, (int)Suicune,
            (int)Regirock, (int)Regice, (int)Registeel, (int)Latias, (int)Latios,
            (int)Uxie, (int)Mesprit, (int)Azelf, (int)Heatran, (int)Regigigas, (int)Cresselia,
            (int)Cobalion, (int)Terrakion, (int)Virizion, (int)Tornadus, (int)Thundurus, (int)Landorus,
            (int)TypeNull, (int)Silvally, (int)TapuKoko, (int)TapuLele, (int)TapuBulu, (int)TapuFini,
            (int)Nihilego, (int)Buzzwole, (int)Pheromosa, (int)Xurkitree, (int)Celesteela, (int)Kartana, (int)Guzzlord,
            (int)Poipole, (int)Naganadel, (int)Stakataka, (int)Blacephalon,
            (int)Kubfu, (int)Urshifu, (int)Regieleki, (int)Regidrago, (int)Glastrier, (int)Spectrier, (int)Enamorus,
        };

        /// <summary>
        /// Species that evolve from a Bi-Gendered species into a Single-Gender.
        /// </summary>
        public static readonly HashSet<int> FixedGenderFromBiGender = new()
        {
            (int)Nincada,
            (int)Shedinja, // (G)

            (int)Burmy,
            (int)Wormadam, //(F)
            (int)Mothim, // (M)

            (int)Ralts,
            (int)Gallade, // (M)

            (int)Snorunt,
            (int)Froslass, // (F)

            (int)Espurr,
            (int)Meowstic, // (M/F) form specific
        };

        private static bool[] GetPermitList(int max, IEnumerable<ushort> held)
        {
            var result = new bool[max + 1];
            foreach (var item in held)
                result[item] = true;
            return result;
        }

        private static bool[] GetPermitList(int max, IEnumerable<ushort> held, IEnumerable<ushort> unreleased)
        {
            var result = GetPermitList(max, held);
            foreach (var u in unreleased)
                result[u] = false;
            return result;
        }
    }
}