using System;
using System.Linq;

namespace PKHeX.Core
{
    /// <summary>
    /// Contains extension logic for modifying <see cref="PKM"/> data.
    /// </summary>
    public static class CommonEdits
    {
        /// <summary>
        /// Setting which enables/disables automatic manipulation of <see cref="PKM.Markings"/> when importing from a <see cref="IBattleTemplate"/>.
        /// </summary>
        public static bool ShowdownSetIVMarkings { get; set; } = true;

        /// <summary>
        /// Setting which causes the <see cref="PKM.StatNature"/> to the <see cref="PKM.Nature"/> in Gen8+ formats.
        /// </summary>
        public static bool ShowdownSetBehaviorNature { get; set; }

        /// <summary>
        /// Sets the <see cref="PKM.Nickname"/> to the provided value.
        /// </summary>
        /// <param name="pk">Pokémon to modify.</param>
        /// <param name="nick"><see cref="PKM.Nickname"/> to set. If no nickname is provided, the <see cref="PKM.Nickname"/> is set to the default value for its current language and format.</param>
        public static void SetNickname(this PKM pk, string nick)
        {
            if (string.IsNullOrWhiteSpace(nick))
            {
                pk.ClearNickname();
                return;
            }
            pk.IsNicknamed = true;
            pk.Nickname = nick;
        }

        /// <summary>
        /// Clears the <see cref="PKM.Nickname"/> to the default value.
        /// </summary>
        /// <param name="pk"></param>
        public static string ClearNickname(this PKM pk)
        {
            pk.IsNicknamed = false;
            string nick = SpeciesName.GetSpeciesNameGeneration(pk.Species, pk.Language, pk.Format);
            pk.Nickname = nick;
            if (pk is GBPKM pk12)
                pk12.SetNotNicknamed();
            return nick;
        }

        /// <summary>
        /// Sets the <see cref="PKM.Form"/> value, with special consideration for <see cref="PKM.Format"/> values which derive the <see cref="PKM.Form"/> value.
        /// </summary>
        /// <param name="pk">Pokémon to modify.</param>
        /// <param name="form">Desired <see cref="PKM.Form"/> value to set.</param>
        public static void SetForm(this PKM pk, int form)
        {
            switch (pk.Format)
            {
                case 2:
                    while (pk.Form != form)
                        pk.SetRandomIVs();
                    break;
                case 3:
                    pk.SetPIDUnown3(form);
                    break;
                default:
                    pk.Form = form;
                    break;
            }
        }

        /// <summary>
        /// Sets the <see cref="PKM.Ability"/> value by sanity checking the provided <see cref="PKM.Ability"/> against the possible pool of abilities.
        /// </summary>
        /// <param name="pk">Pokémon to modify.</param>
        /// <param name="abil">Desired <see cref="PKM.Ability"/> to set.</param>
        public static void SetAbility(this PKM pk, int abil)
        {
            if (abil < 0)
                return;
            var index = pk.PersonalInfo.GetAbilityIndex(abil);
            index = Math.Max(0, index);
            pk.SetAbilityIndex(index);
        }

        /// <summary>
        /// Sets the <see cref="PKM.Ability"/> value based on the provided ability index (0-2)
        /// </summary>
        /// <param name="pk">Pokémon to modify.</param>
        /// <param name="index">Desired <see cref="PKM.AbilityNumber"/> (shifted by 1) to set.</param>
        public static void SetAbilityIndex(this PKM pk, int index)
        {
            if (pk is PK5 pk5 && index == 2)
                pk5.HiddenAbility = true;
            else if (pk.Format <= 5)
                pk.PID = PKX.GetRandomPID(Util.Rand, pk.Species, pk.Gender, pk.Version, pk.Nature, pk.Form, (uint)(index * 0x10001));
            pk.RefreshAbility(index);
        }

        /// <summary>
        /// Sets a Random <see cref="PKM.EncryptionConstant"/> value. The <see cref="PKM.EncryptionConstant"/> is not updated if the value should match the <see cref="PKM.PID"/> instead.
        /// </summary>
        /// <remarks>Accounts for Wurmple evolutions.</remarks>
        /// <param name="pk">Pokémon to modify.</param>
        public static void SetRandomEC(this PKM pk)
        {
            int gen = pk.Generation;
            if (gen is 3 or 4 or 5)
            {
                pk.EncryptionConstant = pk.PID;
                return;
            }

            int wIndex = WurmpleUtil.GetWurmpleEvoGroup(pk.Species);
            if (wIndex != -1)
            {
                pk.EncryptionConstant = WurmpleUtil.GetWurmpleEncryptionConstant(wIndex);
                return;
            }
            pk.EncryptionConstant = Util.Rand32();
        }

        /// <summary>
        /// Sets the <see cref="PKM.IsShiny"/> derived value.
        /// </summary>
        /// <param name="pk">Pokémon to modify.</param>
        /// <param name="shiny">Desired <see cref="PKM.IsShiny"/> state to set.</param>
        /// <returns></returns>
        public static bool SetIsShiny(this PKM pk, bool shiny) => shiny ? SetShiny(pk) : pk.SetUnshiny();

        /// <summary>
        /// Makes a <see cref="PKM"/> shiny.
        /// </summary>
        /// <param name="pk">Pokémon to modify.</param>
        /// <param name="type">Shiny type to force. Only use Always* or Random</param>
        /// <returns>Returns true if the <see cref="PKM"/> data was modified.</returns>
        public static bool SetShiny(PKM pk, Shiny type = Shiny.Random)
        {
            if (pk.IsShiny && type.IsValid(pk))
                return false;

            if (type == Shiny.Random || pk.FatefulEncounter || pk.Version == (int)GameVersion.GO || pk.Format <= 2)
            {
                pk.SetShiny();
                return true;
            }

            do { pk.SetShiny(); }
            while (!type.IsValid(pk));

            return true;
        }

        /// <summary>
        /// Makes a <see cref="PKM"/> not-shiny.
        /// </summary>
        /// <param name="pk">Pokémon to modify.</param>
        /// <returns>Returns true if the <see cref="PKM"/> data was modified.</returns>
        public static bool SetUnshiny(this PKM pk)
        {
            if (!pk.IsShiny)
                return false;

            pk.SetPIDGender(pk.Gender);
            return true;
        }

        /// <summary>
        /// Sets the <see cref="PKM.Nature"/> value, with special consideration for the <see cref="PKM.Format"/> values which derive the <see cref="PKM.Nature"/> value.
        /// </summary>
        /// <param name="pk">Pokémon to modify.</param>
        /// <param name="nature">Desired <see cref="PKM.Nature"/> value to set.</param>
        public static void SetNature(this PKM pk, int nature)
        {
            var value = Math.Min((int)Nature.Quirky, Math.Max((int)Nature.Hardy, nature));
            var format = pk.Format;
            if (format >= 8)
                pk.StatNature = value;
            else if (format is 3 or 4)
                pk.SetPIDNature(value);
            else
                pk.Nature = value;
        }

        /// <summary>
        /// Copies <see cref="IBattleTemplate"/> details to the <see cref="PKM"/>.
        /// </summary>
        /// <param name="pk">Pokémon to modify.</param>
        /// <param name="Set"><see cref="IBattleTemplate"/> details to copy from.</param>
        public static void ApplySetDetails(this PKM pk, IBattleTemplate Set)
        {
            pk.Species = Math.Min(pk.MaxSpeciesID, Set.Species);
            pk.SetMoves(Set.Moves, true);
            pk.ApplyHeldItem(Set.HeldItem, Set.Format);
            pk.CurrentLevel = Set.Level;
            pk.CurrentFriendship = Set.Friendship;
            pk.IVs = Set.IVs;

            if (pk is GBPKM gb)
            {
                // In Generation 1/2 Format sets, when IVs are not specified with a Hidden Power set, we might not have the hidden power type.
                // Under this scenario, just force the Hidden Power type.
                if (Set.Moves.Contains(237) && pk.HPType != Set.HiddenPowerType && Set.IVs.Any(z => z >= 30))
                    pk.SetHiddenPower(Set.HiddenPowerType);

                // In Generation 1/2 Format sets, when EVs are not specified at all, it implies maximum EVs instead!
                // Under this scenario, just apply maximum EVs (65535).
                if (Set.EVs.All(z => z == 0))
                    gb.MaxEVs();
                else
                    pk.EVs = Set.EVs;
            }
            else
            {
                pk.EVs = Set.EVs;
            }

            // IVs have no side effects such as hidden power type in gen 8
            // therefore all specified IVs are deliberate and should not be Hyper Trained for pokemon met in gen 8
            if (!pk.Gen8)
                pk.SetSuggestedHyperTrainingData(Set.IVs);

            if (ShowdownSetIVMarkings)
                pk.SetMarkings();

            pk.SetNickname(Set.Nickname);
            pk.SetForm(Set.Form);
            pk.SetSaneGender(Set.Gender);
            pk.SetMaximumPPUps(Set.Moves);

            if (pk.Format >= 3)
            {
                pk.SetAbility(Set.Ability);
                pk.SetNature(Set.Nature);
            }

            pk.SetIsShiny(Set.Shiny);
            pk.SetRandomEC();

            if (pk is IAwakened a)
            {
                a.SetSuggestedAwakenedValues(pk);
                if (pk is PB7 b)
                {
                    for (int i = 0; i < 6; i++)
                        b.SetEV(i, 0);
                    b.ResetCalculatedValues();
                }
            }

            if (pk is IGigantamax c)
                c.CanGigantamax = Set.CanGigantamax;
            if (pk is IDynamaxLevel d)
                d.DynamaxLevel = d.CanHaveDynamaxLevel(pk) ? (byte)10 : (byte)0;

            pk.ClearRecordFlags();
            pk.SetRecordFlags(Set.Moves);

            if (ShowdownSetBehaviorNature && pk.Format >= 8)
                pk.Nature = pk.StatNature;

            var legal = new LegalityAnalysis(pk);
            if (legal.Parsed && legal.Info.Relearn.Any(z => !z.Valid))
                pk.SetRelearnMoves(legal.GetSuggestedRelearnMoves());
            pk.ResetPartyStats();
            pk.RefreshChecksum();
        }

        /// <summary>
        /// Sets the <see cref="PKM.HeldItem"/> value depending on the current format and the provided item index &amp; format.
        /// </summary>
        /// <param name="pk">Pokémon to modify.</param>
        /// <param name="item">Held Item to apply</param>
        /// <param name="format">Format required for importing</param>
        public static void ApplyHeldItem(this PKM pk, int item, int format)
        {
            item = ItemConverter.GetItemForFormat(item, format, pk.Format);
            pk.HeldItem = ((uint)item > pk.MaxItemID) ? 0 : item;
        }

        /// <summary>
        /// Sets one of the <see cref="PKM.EVs"/> based on its index within the array.
        /// </summary>
        /// <param name="pk">Pokémon to modify.</param>
        /// <param name="index">Index to set to</param>
        /// <param name="value">Value to set</param>
        public static int SetEV(this PKM pk, int index, int value) => index switch
        {
            0 => pk.EV_HP = value,
            1 => pk.EV_ATK = value,
            2 => pk.EV_DEF = value,
            3 => pk.EV_SPE = value,
            4 => pk.EV_SPA = value,
            5 => pk.EV_SPD = value,
            _ => throw new ArgumentOutOfRangeException(nameof(index)),
        };

        /// <summary>
        /// Sets one of the <see cref="PKM.IVs"/> based on its index within the array.
        /// </summary>
        /// <param name="pk">Pokémon to modify.</param>
        /// <param name="index">Index to set to</param>
        /// <param name="value">Value to set</param>
        public static int SetIV(this PKM pk, int index, int value) => index switch
        {
            0 => pk.IV_HP = value,
            1 => pk.IV_ATK = value,
            2 => pk.IV_DEF = value,
            3 => pk.IV_SPE = value,
            4 => pk.IV_SPA = value,
            5 => pk.IV_SPD = value,
            _ => throw new ArgumentOutOfRangeException(nameof(index)),
        };

        /// <summary>
        /// Fetches the highest value the provided <see cref="PKM.EVs"/> index can be while considering others.
        /// </summary>
        /// <param name="pk">Pokémon to modify.</param>
        /// <param name="index">Index to fetch for</param>
        /// <returns>Highest value the value can be.</returns>
        public static int GetMaximumEV(this PKM pk, int index)
        {
            if (pk.Format < 3)
                return ushort.MaxValue;

            var sum = pk.EVTotal - pk.GetEV(index);
            int remaining = 510 - sum;
            return Math.Min(Math.Max(remaining, 0), 252);
        }

        /// <summary>
        /// Fetches the highest value the provided <see cref="PKM.IVs"/>.
        /// </summary>
        /// <param name="pk">Pokémon to modify.</param>
        /// <param name="index">Index to fetch for</param>
        /// <param name="allow30">Causes the returned value to be dropped down -1 if the value is already at a maximum.</param>
        /// <returns>Highest value the value can be.</returns>
        public static int GetMaximumIV(this PKM pk, int index, bool allow30 = false)
        {
            if (pk.GetIV(index) == pk.MaxIV && allow30)
                return pk.MaxIV - 1;
            return pk.MaxIV;
        }

        /// <summary>
        /// Force hatches a PKM by applying the current species name and a valid Met Location from the origin game.
        /// </summary>
        /// <param name="pk">PKM to apply hatch details to</param>
        /// <param name="reHatch">Re-hatch already hatched <see cref="PKM"/> inputs</param>
        public static void ForceHatchPKM(this PKM pk, bool reHatch = false)
        {
            if (!pk.IsEgg && !reHatch)
                return;
            pk.IsEgg = false;
            pk.ClearNickname();
            pk.CurrentFriendship = pk.PersonalInfo.BaseFriendship;
            if (pk.IsTradedEgg)
                pk.Egg_Location = pk.Met_Location;
            var loc = EncounterSuggestion.GetSuggestedEggMetLocation(pk);
            if (loc >= 0)
                pk.Met_Location = loc;
            pk.MetDate = DateTime.Today;
            if (pk.Gen6)
                pk.SetHatchMemory6();
        }

        /// <summary>
        /// Force hatches a PKM by applying the current species name and a valid Met Location from the origin game.
        /// </summary>
        /// <param name="pk">PKM to apply hatch details to</param>
        /// <param name="origin">Game the egg originated from</param>
        /// <param name="dest">Game the egg is currently present on</param>
        public static void SetEggMetData(this PKM pk, GameVersion origin, GameVersion dest)
        {
            bool traded = origin == dest;
            var today = pk.MetDate = DateTime.Today;
            pk.Egg_Location = EncounterSuggestion.GetSuggestedEncounterEggLocationEgg(pk.Generation, origin, traded);
            pk.EggMetDate = today;
        }

        /// <summary>
        /// Maximizes the <see cref="PKM.CurrentFriendship"/>. If the <see cref="PKM.IsEgg"/>, the hatch counter is set to 1.
        /// </summary>
        /// <param name="pk">PKM to apply hatch details to</param>
        public static void MaximizeFriendship(this PKM pk)
        {
            if (pk.IsEgg)
                pk.OT_Friendship = 1;
            else
                pk.CurrentFriendship = byte.MaxValue;
            if (pk is PB7 pb)
                pb.ResetCP();
        }

        /// <summary>
        /// Maximizes the <see cref="PKM.CurrentLevel"/>. If the <see cref="PKM.IsEgg"/>, the <see cref="PKM"/> is ignored.
        /// </summary>
        /// <param name="pk">PKM to apply hatch details to</param>
        public static void MaximizeLevel(this PKM pk)
        {
            if (pk.IsEgg)
                return;
            pk.CurrentLevel = 100;
            if (pk is PB7 pb)
                pb.ResetCP();
        }

        /// <summary>
        /// Sets the <see cref="PKM.Nickname"/> to its default value.
        /// </summary>
        /// <param name="pk">Pokémon to modify.</param>
        /// <param name="la">Precomputed optional</param>
        public static void SetDefaultNickname(this PKM pk, LegalityAnalysis la)
        {
            if (la.Parsed && la.EncounterOriginal is EncounterTrade {HasNickname: true} t)
                pk.SetNickname(t.GetNickname(pk.Language));
            else
                pk.ClearNickname();
        }

        /// <summary>
        /// Sets the <see cref="PKM.Nickname"/> to its default value.
        /// </summary>
        /// <param name="pk">Pokémon to modify.</param>
        public static void SetDefaultNickname(this PKM pk) => pk.SetDefaultNickname(new LegalityAnalysis(pk));

        private static readonly string[] PotentialUnicode = { "★☆☆☆", "★★☆☆", "★★★☆", "★★★★" };
        private static readonly string[] PotentialNoUnicode = { "+", "++", "+++", "++++" };

        /// <summary>
        /// Gets the Potential evaluation of the input <see cref="pk"/>.
        /// </summary>
        /// <param name="pk">Pokémon to analyze.</param>
        /// <param name="unicode">Returned value is unicode or not</param>
        /// <returns>Potential string</returns>
        public static string GetPotentialString(this PKM pk, bool unicode = true)
        {
            var arr = unicode ? PotentialUnicode : PotentialNoUnicode;
            return arr[pk.PotentialRating];
        }

        // Extensions
        /// <summary>
        /// Gets the Location Name for the <see cref="PKM"/>
        /// </summary>
        /// <param name="pk">PKM to fetch data for</param>
        /// <param name="eggmet">Location requested is the egg obtained location, not met location.</param>
        /// <returns>Location string</returns>
        public static string GetLocationString(this PKM pk, bool eggmet)
        {
            if (pk.Format < 2)
                return string.Empty;

            int location = eggmet ? pk.Egg_Location : pk.Met_Location;
            return GameInfo.GetLocationName(eggmet, location, pk.Format, pk.Generation, (GameVersion)pk.Version);
        }
    }
}