using System;
using System.Collections.Generic;
using static PKHeX.Core.Legal;
using static PKHeX.Core.GameVersion;
using static PKHeX.Core.Species;
namespace PKHeX.Core;
///
/// Miscellaneous GB Era restriction logic for legality checking
///
internal static class GBRestrictions
{
private static readonly HashSet Stadium_GiftSpecies = new()
{
(int)Bulbasaur,
(int)Charmander,
(int)Squirtle,
(int)Psyduck,
(int)Hitmonlee,
(int)Hitmonchan,
(int)Eevee,
(int)Omanyte,
(int)Kabuto,
};
///
/// Checks if the type matches any of the type IDs extracted from the Personal Table used for R/G/B/Y games.
///
/// Valid values: 0, 1, 2, 3, 4, 5, 7, 8, 20, 21, 22, 23, 24, 25, 26
internal static bool TypeIDExists(int type) => (uint)type < 32 && (0b111111100000000000110111111 & (1 << type)) != 0;
///
/// Species that have a catch rate value that is different from their pre-evolutions, and cannot be obtained directly.
///
internal static readonly HashSet Species_NotAvailable_CatchRate = new()
{
(int)Butterfree,
(int)Pidgeot,
(int)Nidoqueen,
(int)Nidoking,
(int)Ninetales,
(int)Vileplume,
(int)Persian,
(int)Arcanine,
(int)Poliwrath,
(int)Alakazam,
(int)Machamp,
(int)Victreebel,
(int)Rapidash,
(int)Cloyster,
(int)Exeggutor,
(int)Starmie,
(int)Dragonite,
};
internal static readonly HashSet Trade_Evolution1 = new()
{
(int)Kadabra,
(int)Machoke,
(int)Graveler,
(int)Haunter,
};
public static bool RateMatchesEncounter(ushort species, GameVersion version, byte rate)
{
if (version.Contains(YW))
{
if (rate == PersonalTable.Y[species].CatchRate)
return true;
if (version == YW) // no RB
return false;
}
return rate == PersonalTable.RB[species].CatchRate;
}
private static bool GetCatchRateMatchesPreEvolution(PK1 pk, byte catch_rate)
{
// For species catch rate, discard any species that has no valid encounters and a different catch rate than their pre-evolutions
var table = EvolutionTree.Evolves1;
var chain = table.GetValidPreEvolutions(pk, levelMax: (byte)pk.CurrentLevel);
foreach (var entry in chain)
{
var s = entry.Species;
if (Species_NotAvailable_CatchRate.Contains((byte)s))
continue;
if (catch_rate == PersonalTable.RB[s].CatchRate || catch_rate == PersonalTable.Y[s].CatchRate)
return true;
}
// Krabby encounter trade special catch rate
ushort species = pk.Species;
if (catch_rate == 204 && (species is (int)Krabby or (int)Kingler))
return true;
if (catch_rate is (167 or 168) && Stadium_GiftSpecies.Contains((byte)species))
return true;
return false;
}
///
/// Checks if the can inhabit
///
/// Data to check
/// true if can inhabit, false if not.
private static bool CanInhabitGen1(this PKM pk)
{
// Korean Gen2 games can't trade-back because there are no Gen1 Korean games released
if (pk.Korean || pk.IsEgg)
return false;
// Gen2 format with met data can't receive Gen1 moves, unless Stadium 2 is used (Oak's PC).
// If you put a Pokemon in the N64 box, the met info is retained, even if you switch over to a Gen I game to teach it TMs
// You can use rare candies from within the lab, so level-up moves from RBY context can be learned this way as well
// Stadium 2 is GB Cart Era only (not 3DS Virtual Console).
if (pk is ICaughtData2 {CaughtData: not 0} && !ParseSettings.AllowGBCartEra)
return false;
// Sanity check species, if it could have existed as a pre-evolution.
ushort species = pk.Species;
if (species <= MaxSpeciesID_1)
return true;
return EvolutionLegality.FutureEvolutionsGen1.Contains(species);
}
///
/// Gets the Tradeback status depending on various values.
///
/// Pokémon to guess the tradeback status from.
internal static PotentialGBOrigin GetTradebackStatusInitial(PKM pk)
{
if (pk is PK1 pk1)
return GetTradebackStatusRBY(pk1);
if (pk.Format == 2 || pk.VC2) // Check for impossible tradeback scenarios
return !pk.CanInhabitGen1() ? PotentialGBOrigin.Gen2Only : PotentialGBOrigin.Either;
// VC2 is released, we can assume it will be TradebackType.Any.
// Is impossible to differentiate a VC1 pokemon traded to Gen7 after VC2 is available.
// Met Date cannot be used definitively as the player can change their system clock.
return PotentialGBOrigin.Either;
}
///
/// Gets the Tradeback status depending on the
///
/// Pokémon to guess the tradeback status from.
private static PotentialGBOrigin GetTradebackStatusRBY(PK1 pk)
{
if (!ParseSettings.AllowGen1Tradeback)
return PotentialGBOrigin.Gen1Only;
// Detect tradeback status by comparing the catch rate(Gen1)/held item(Gen2) to the species in the pk's evolution chain.
var catch_rate = pk.Catch_Rate;
if (catch_rate == 0)
return PotentialGBOrigin.Either;
bool matchAny = GetCatchRateMatchesPreEvolution(pk, catch_rate);
if (!matchAny)
return PotentialGBOrigin.Either;
if (IsTradebackCatchRate(catch_rate))
return PotentialGBOrigin.Either;
return PotentialGBOrigin.Gen1Only;
}
public static TimeCapsuleEvaluation IsTimeCapsuleTransferred(PKM pk, ReadOnlySpan moves, IEncounterTemplate enc)
{
foreach (var z in moves)
{
if (z.Generation == enc.Generation || z.Generation > 2)
continue;
if (pk is PK1 {Catch_Rate: not 0} g1 && !IsTradebackCatchRate(g1.Catch_Rate))
return TimeCapsuleEvaluation.BadCatchRate;
return enc.Generation == 2 ? TimeCapsuleEvaluation.Transferred21 : TimeCapsuleEvaluation.Transferred12;
}
if (pk is not GBPKM gb)
{
return enc.Generation switch
{
2 when pk.VC2 => TimeCapsuleEvaluation.Transferred21,
1 when pk.VC1 => TimeCapsuleEvaluation.Transferred12,
_ => TimeCapsuleEvaluation.NotTransferred,
};
}
if (gb is ICaughtData2 pk2)
{
if (enc.Generation == 1)
return TimeCapsuleEvaluation.Transferred12;
if (pk2.CaughtData != 0)
return TimeCapsuleEvaluation.NotTransferred;
if (enc.Version == C)
return TimeCapsuleEvaluation.Transferred21;
return TimeCapsuleEvaluation.Indeterminate;
}
if (gb is PK1 pk1)
{
var rate = pk1.Catch_Rate;
if (rate == 0)
return TimeCapsuleEvaluation.Transferred12;
bool isTradebackItem = IsTradebackCatchRate(rate);
if (IsCatchRateMatchEncounter(enc, pk1))
return isTradebackItem ? TimeCapsuleEvaluation.Indeterminate : TimeCapsuleEvaluation.NotTransferred;
return isTradebackItem ? TimeCapsuleEvaluation.Transferred12 : TimeCapsuleEvaluation.BadCatchRate;
}
return TimeCapsuleEvaluation.Indeterminate;
}
private static bool IsCatchRateMatchEncounter(IEncounterTemplate enc, PK1 pk1) => enc switch
{
EncounterStatic1 s when s.GetMatchRating(pk1) != EncounterMatchRating.PartialMatch => true,
EncounterTrade1 => true,
_ => RateMatchesEncounter(enc.Species, enc.Version, pk1.Catch_Rate),
};
public static bool IsTradebackCatchRate(byte rate) => Array.IndexOf(HeldItems_GSC, rate) != -1;
}
public enum PotentialGBOrigin
{
Either,
Gen1Only,
Gen2Only,
}
public enum TimeCapsuleEvaluation
{
Indeterminate,
Transferred21,
Transferred12,
NotTransferred,
BadCatchRate,
}
public static class TimeCapsuleEvlautationExtensions
{
public static bool WasTimeCapsuleTransferred(this TimeCapsuleEvaluation eval) => eval is not (TimeCapsuleEvaluation.Indeterminate or TimeCapsuleEvaluation.NotTransferred or TimeCapsuleEvaluation.BadCatchRate);
}