PKHeX/PKHeX.Core/Legality/Verifiers/ContestStatVerifier.cs

namespace PKHeX.Core
{
    /// <summary>
    /// Verifies the Contest stat details.
    /// </summary>
    public class ContestStatVerifier : Verifier
    {
        protected override CheckIdentifier Identifier => CheckIdentifier.Memory;
        public override void Verify(LegalityAnalysis data)
        {
            var pkm = data.pkm;
            if (pkm.Format <= 4)
                return; // legal || not present

            if (pkm is IContestStats s && s.HasContestStats() && !CanHaveContestStats(pkm, data.Info.Generation))
                data.AddLine(GetInvalid(LegalityCheckStrings.LContestZero));
            
            // some encounters have contest stats built in. they're already checked by the initial encounter match.
        }

        private static bool CanHaveContestStats(PKM pkm, int origin)
        {
            return origin switch
            {
                1 => false,
                2 => false,
                3 => true,
                4 => true,
                5 => (pkm.Format >= 6), // ORAS Contests
                6 => (!pkm.IsUntraded || pkm.AO),
                7 => false,
                _ => false
            };
        }
    }
}