namespace PKHeX.Core
{
    /// <summary>
    /// Minimal Trainer Information necessary for generating a <see cref="PKM"/>.
    /// </summary>
    public interface ITrainerInfo : ITrainerID
    {
        string OT { get; }
        int Gender { get; }
        int Game { get; }
        int Language { get; }

        int Generation { get; }
        EntityContext Context { get; }
    }

    public static class TrainerInfoExtensions
    {
        public static void ApplyTo(this ITrainerInfo info, PKM pk)
        {
            pk.OT_Name = info.OT;
            pk.TID = info.TID;
            pk.SID = pk.Format < 3 || pk.VC ? 0 : info.SID;
            pk.OT_Gender = info.Gender;
            pk.Language = info.Language;
            pk.Version = info.Game;

            if (pk is not IRegionOrigin tr)
                return;

            if (info is not IRegionOrigin o)
                return;
            tr.Country = o.Country;
            tr.Region = o.Region;
            tr.ConsoleRegion = o.ConsoleRegion;
        }

        public static void ApplyHandlingTrainerInfo(this ITrainerInfo sav, PKM pk, bool force = false)
        {
            if (pk.Format == sav.Generation && !force)
                return;

            pk.HT_Name = sav.OT;
            pk.HT_Gender = sav.Gender;
            pk.HT_Friendship = pk.OT_Friendship;
            pk.CurrentHandler = 1;

            if (pk is PK6 pk6 && sav is IRegionOrigin o)
            {
                pk6.Geo1_Country = o.Country;
                pk6.Geo1_Region = o.Region;
                pk6.SetTradeMemoryHT6(true);
            }
            else if (pk is PK8 pk8)
            {
                pk8.SetTradeMemoryHT8();
            }
        }

        public static bool IsFromTrainer(this ITrainerInfo tr, PKM pk)
        {
            if (tr.Game == (int)GameVersion.Any)
                return true;

            if (tr.TID != pk.TID)
                return false;
            if (tr.OT != pk.OT_Name)
                return false;
            if (pk.Format <= 2)
                return false;

            if (tr.SID != pk.SID)
                return false;
            if (pk.Format == 3)
                return false;

            if (tr.Gender != pk.OT_Gender)
                return false;

            return IsMatchVersion(tr, pk);
        }

        private static bool IsMatchVersion(ITrainerInfo tr, PKM pk)
        {
            if (tr.Game == pk.Version)
                return true;
            if (pk.GO_LGPE)
                return tr.Game is (int)GameVersion.GP or (int)GameVersion.GE;
            return false;
        }
    }
}