PKHeX/PKHeX.Core/Legality/Encounters/EncounterStatic/EncounterStatic3.cs

using System;
using System.Linq;

namespace PKHeX.Core;

/// <summary>
/// Generation 3 Static Encounter
/// </summary>
/// <inheritdoc cref="EncounterStatic"/>
public sealed record EncounterStatic3 : EncounterStatic
{
    public override int Generation => 3;
    public override EntityContext Context => EntityContext.Gen3;
    public bool Roaming { get; init; }

    public EncounterStatic3(ushort species, byte level, GameVersion game) : base(game)
    {
        Species = species;
        Level = level;
    }

    protected override bool IsMatchEggLocation(PKM pk)
    {
        if (pk.Format == 3)
            return !pk.IsEgg || EggLocation == 0 || EggLocation == pk.Met_Location;
        return base.IsMatchEggLocation(pk);
    }

    protected override bool IsMatchLevel(PKM pk, EvoCriteria evo)
    {
        if (pk.Format != 3) // Met Level lost on PK3=>PK4
            return Level <= evo.LevelMax;

        if (EggEncounter)
            return pk.Met_Level == 0 && pk.CurrentLevel >= 5; // met level 0, origin level 5

        return pk.Met_Level == Level;
    }

    protected override bool IsMatchLocation(PKM pk)
    {
        if (EggEncounter)
            return true;
        if (pk.Format != 3)
            return true; // transfer location verified later

        var met = pk.Met_Location;
        if (!Roaming)
            return Location == met;

        var table = Version <= GameVersion.E ? Roaming_MetLocation_RSE : Roaming_MetLocation_FRLG;
        return table.Contains(met);
    }

    protected override bool IsMatchPartial(PKM pk)
    {
        if (Gift && pk.Ball != Ball)
            return true;
        return base.IsMatchPartial(pk);
    }

    protected override void SetMetData(PKM pk, int level, DateTime today)
    {
        pk.Met_Level = level;
        pk.Met_Location = !Roaming ? Location : (Version <= GameVersion.E ? Roaming_MetLocation_RSE : Roaming_MetLocation_FRLG)[0];
    }

    private static readonly int[] Roaming_MetLocation_FRLG =
    {
        // Route 1-25 encounter is possible either in grass or on water
        101,102,103,104,105,106,107,108,109,110,
        111,112,113,114,115,116,117,118,119,120,
        121,122,123,124,125,
    };

    private static readonly int[] Roaming_MetLocation_RSE =
    {
        // Roaming encounter is possible in tall grass and on water
        // Route 101-138
        16, 17, 18, 19, 20, 21, 22, 23, 24, 25,
        26, 27, 28, 29, 30, 31, 32, 33, 34, 35,
        36, 37, 38, 39, 40, 41, 42, 43, 44, 45,
        46, 47, 48, 49,
    };
}