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

namespace PKHeX.Core;

public static partial class Legal
{
    /// <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<ushort> 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,
        (int)Koraidon, (int)Miraidon,
    };

    /// <summary>
    /// Species that are from Mythical Distributions (disallowed species for competitive rulesets)
    /// </summary>
    public static readonly HashSet<ushort> 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>
    /// <remarks>Previous games may have included Mythicals in this species list, but that list should be considered separately.</remarks>
    public static readonly HashSet<ushort> Legends = new()
    {
        (int)Mewtwo,
        (int)Lugia, (int)HoOh,
        (int)Kyogre, (int)Groudon, (int)Rayquaza,
        (int)Dialga, (int)Palkia, (int)Giratina,
        (int)Reshiram, (int)Zekrom, (int)Kyurem,
        (int)Xerneas, (int)Yveltal, (int)Zygarde,
        (int)Cosmog, (int)Cosmoem, (int)Solgaleo, (int)Lunala, (int)Necrozma,
        (int)Zacian, (int)Zamazenta, (int)Eternatus, (int)Calyrex,
        (int)Koraidon, (int)Miraidon,
    };

    /// <summary>
    /// Species classified as "SubLegend" by the game code.
    /// </summary>
    public static readonly HashSet<ushort> 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)Kubfu, (int)Urshifu, (int)Regieleki, (int)Regidrago, (int)Glastrier, (int)Spectrier, (int)Enamorus,
        (int)TingLu, (int)ChienPao, (int)WoChien, (int)ChiYu,
    };

    /// <summary>
    /// Checks if the <see cref="species"/> is an Ultra Beast Pokémon.
    /// </summary>
    public static bool IsUltraBeast(ushort species) => species is
        (int)Nihilego or (int)Buzzwole or (int)Pheromosa or (int)Xurkitree or (int)Celesteela or (int)Kartana or (int)Guzzlord or
        (int)Poipole or (int)Naganadel or (int)Stakataka or (int)Blacephalon;

    /// <summary>
    /// Checks if the <see cref="species"/> is a Paradox Pokémon.
    /// </summary>
    public static bool IsParadox(ushort species) => species is (>= (int)GreatTusk and <= (int)IronThorns) or (int)RoaringMoon or (int)IronValiant;

    /// <summary>
    /// Species that evolve from a Bi-Gendered species into a Single-Gender.
    /// </summary>
    public static readonly HashSet<ushort> 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

        (int)Lechonk,
        (int)Oinkologne, // (M/F) form specific
    };

    /// <summary>
    /// Gets a permit list with the permitted indexes, then un-flags the indexes that are not permitted.
    /// </summary>
    /// <param name="max">Maximum index expected to allow</param>
    /// <param name="allowed">Allowed indexes</param>
    private static bool[] GetPermitList(int max, ReadOnlySpan<ushort> allowed)
    {
        var result = new bool[max + 1];
        foreach (var index in allowed)
            result[index] = true;
        return result;
    }

    /// <summary>
    /// Gets a permit list with the permitted indexes, then un-flags the indexes that are not permitted.
    /// </summary>
    /// <param name="max">Maximum index expected to allow</param>
    /// <param name="allowed">Allowed indexes (may have some disallowed)</param>
    /// <param name="disallow">Disallowed indexes</param>
    private static bool[] GetPermitList(int max, ReadOnlySpan<ushort> allowed, ReadOnlySpan<ushort> disallow)
    {
        var result = GetPermitList(max, allowed);
        foreach (var index in disallow)
            result[index] = false;
        return result;
    }
}