using System.Collections.Generic;
using System.Linq;

namespace PKHeX.Core
{
    public class LegalInfo
    {
        /// <summary>The <see cref="PKM"/> object used for comparisons.</summary>
        private readonly PKM pkm;

        /// <summary>The generation of games the PKM originated from.</summary>
        public int Generation { get; set; }

        /// <summary> The Game the PPKM originated from.</summary>
        public GameVersion Game { get; set; }

        /// <summary>The matched Encounter details for the <see cref="PKM"/>. </summary>
        public IEncounterable EncounterMatch
        {
            get => _match;
            set
            {
                if (EncounterMatch != null && (value.LevelMin != EncounterMatch.LevelMin || value.Species != EncounterMatch.Species))
                    _evochains = null;
                _match = value;
                Parse.Clear();
            }
        }

        public bool WasXD => pkm?.Version == 15 && EncounterMatch != null && !Encounters3.Encounter_Colo.Contains(EncounterMatch);
        public int[] RelearnBase { get; set; }

        public readonly List<CheckResult> Parse = new List<CheckResult>();

        public CheckResult[] Relearn { get; set; } = new CheckResult[4];
        public CheckMoveResult[] Moves { get; set; } = new CheckMoveResult[4];

        public DexLevel[][] EvoChainsAllGens => _evochains ?? (_evochains = Legal.GetEvolutionChainsAllGens(pkm, EncounterMatch));
        public ValidEncounterMoves EncounterMoves { get; set; }

        private DexLevel[][] _evochains;
        private IEncounterable _match;
        public PIDIV PIDIV { get; set; }

        /// <summary>
        /// Indicates whether or not the <see cref="PIDIV"/> can originate from the <see cref="EncounterMatch"/>.
        /// </summary>
        /// <remarks>This boolean is true until all valid PIDIV encounters are tested, at which time it is false.</remarks>
        public bool PIDIVMatches { get; set; } = true;

        public LegalInfo(PKM pk)
        {
            pkm = pk;
            Game = (GameVersion) pkm.Version;
            Generation = pkm.GenNumber;
        }

        internal void Reject(CheckResult c)
        {
            if (InvalidMatches == null)
                InvalidMatches = new List<RejectedEncounter>();
            InvalidMatches.Add(new RejectedEncounter(EncounterMatch, c));
        }

        public class RejectedEncounter : IEncounterable
        {
            public readonly IEncounterable Encounter;
            public readonly CheckResult Check;
            public string Reason => Check.Comment;

            public int Species => Encounter.Species;
            public string Name => Encounter.Name;
            public bool EggEncounter => Encounter.EggEncounter;
            public int LevelMin => Encounter.LevelMin;
            public int LevelMax => Encounter.LevelMax;

            public RejectedEncounter(IEncounterable encounter, CheckResult check)
            {
                Encounter = encounter;
                Check = check;
            }
        }
        public List<RejectedEncounter> InvalidMatches;
    }
}