// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
// See the LICENCE file in the repository root for full licence text.
using System;
using System.Collections.Generic;
using System.Diagnostics.CodeAnalysis;
using System.Linq;
using osu.Framework.Extensions.LocalisationExtensions;
using osu.Framework.Localisation;
using osu.Game.Online.API;
using osu.Game.Rulesets;
using osu.Game.Rulesets.Mods;
namespace osu.Game.Utils
{
/// <summary>
/// A set of utilities to handle <see cref="Mod"/> combinations.
/// </summary>
public static class ModUtils
{
/// <summary>
/// Checks that all <see cref="Mod"/>s are compatible with each-other, and that all appear within a set of allowed types.
/// </summary>
/// <remarks>
/// The allowed types must contain exact <see cref="Mod"/> types for the respective <see cref="Mod"/>s to be allowed.
/// </remarks>
/// <param name="combination">The <see cref="Mod"/>s to check.</param>
/// <param name="allowedTypes">The set of allowed <see cref="Mod"/> types.</param>
/// <returns>Whether all <see cref="Mod"/>s are compatible with each-other and appear in the set of allowed types.</returns>
public static bool CheckCompatibleSetAndAllowed(IEnumerable<Mod> combination, IEnumerable<Type> allowedTypes)
{
// Prevent multiple-enumeration.
var combinationList = combination as ICollection<Mod> ?? combination.ToArray();
return CheckCompatibleSet(combinationList, out _) && CheckAllowed(combinationList, allowedTypes);
}
/// <summary>
/// Checks that all <see cref="Mod"/>s in a combination are compatible with each-other.
/// </summary>
/// <param name="combination">The <see cref="Mod"/> combination to check.</param>
/// <returns>Whether all <see cref="Mod"/>s in the combination are compatible with each-other.</returns>
public static bool CheckCompatibleSet(IEnumerable<Mod> combination)
=> CheckCompatibleSet(combination, out _);
/// <summary>
/// Checks that all <see cref="Mod"/>s in a combination are compatible with each-other.
/// </summary>
/// <param name="combination">The <see cref="Mod"/> combination to check.</param>
/// <param name="invalidMods">Any invalid mods in the set.</param>
/// <returns>Whether all <see cref="Mod"/>s in the combination are compatible with each-other.</returns>
public static bool CheckCompatibleSet(IEnumerable<Mod> combination, [NotNullWhen(false)] out List<Mod>? invalidMods)
{
var mods = FlattenMods(combination).ToArray();
invalidMods = null;
// ensure there are no duplicate mod definitions.
for (int i = 0; i < mods.Length; i++)
{
var candidate = mods[i];
for (int j = i + 1; j < mods.Length; j++)
{
var m = mods[j];
if (candidate.Equals(m))
{
invalidMods ??= new List<Mod>();
invalidMods.Add(m);
}
}
}
foreach (var mod in mods)
{
foreach (var type in mod.IncompatibleMods)
{
foreach (var invalid in mods.Where(m => type.IsInstanceOfType(m)))
{
if (invalid == mod)
continue;
invalidMods ??= new List<Mod>();
invalidMods.Add(invalid);
}
}
}
return invalidMods == null;
}
/// <summary>
/// Checks that all <see cref="Mod"/>s in a combination appear within a set of allowed types.
/// </summary>
/// <remarks>
/// The set of allowed types must contain exact <see cref="Mod"/> types for the respective <see cref="Mod"/>s to be allowed.
/// </remarks>
/// <param name="combination">The <see cref="Mod"/> combination to check.</param>
/// <param name="allowedTypes">The set of allowed <see cref="Mod"/> types.</param>
/// <returns>Whether all <see cref="Mod"/>s in the combination are allowed.</returns>
public static bool CheckAllowed(IEnumerable<Mod> combination, IEnumerable<Type> allowedTypes)
{
var allowedSet = new HashSet<Type>(allowedTypes);
return combination.SelectMany(FlattenMod)
.All(m => allowedSet.Contains(m.GetType()));
}
/// <summary>
/// Checks that all <see cref="Mod"/>s in a combination are valid for a local gameplay session.
/// </summary>
/// <param name="mods">The mods to check.</param>
/// <param name="invalidMods">Invalid mods, if any were found. Will be null if all mods were valid.</param>
/// <returns>Whether the input mods were all valid. If false, <paramref name="invalidMods"/> will contain all invalid entries.</returns>
public static bool CheckValidForGameplay(IEnumerable<Mod> mods, [NotNullWhen(false)] out List<Mod>? invalidMods)
{
mods = mods.ToArray();
// checking compatibility of multi mods would try to flatten them and return incompatible mods.
// in gameplay context, we never want MultiMod selected in the first place, therefore check against it first.
if (!checkValid(mods, m => !(m is MultiMod), out invalidMods))
return false;
if (!CheckCompatibleSet(mods, out invalidMods))
return false;
return checkValid(mods, m => m.HasImplementation, out invalidMods);
}
/// <summary>
/// Checks that all <see cref="Mod"/>s in a combination are valid as "required mods" in a multiplayer match session.
/// </summary>
/// <param name="mods">The mods to check.</param>
/// <param name="invalidMods">Invalid mods, if any were found. Will be null if all mods were valid.</param>
/// <returns>Whether the input mods were all valid. If false, <paramref name="invalidMods"/> will contain all invalid entries.</returns>
public static bool CheckValidRequiredModsForMultiplayer(IEnumerable<Mod> mods, [NotNullWhen(false)] out List<Mod>? invalidMods)
{
mods = mods.ToArray();
// checking compatibility of multi mods would try to flatten them and return incompatible mods.
// in gameplay context, we never want MultiMod selected in the first place, therefore check against it first.
if (!checkValid(mods, m => !(m is MultiMod), out invalidMods))
return false;
if (!CheckCompatibleSet(mods, out invalidMods))
return false;
return checkValid(mods, m => m.Type != ModType.System && m.HasImplementation && m.ValidForMultiplayer, out invalidMods);
}
/// <summary>
/// Checks that all <see cref="Mod"/>s in a combination are valid as "free mods" in a multiplayer match session.
/// </summary>
/// <remarks>
/// Note that this does not check compatibility between mods,
/// given that the passed mods are expected to be the ones to be allowed for the multiplayer match,
/// not to be confused with the list of mods the user currently has selected for the multiplayer match.
/// </remarks>
/// <param name="mods">The mods to check.</param>
/// <param name="invalidMods">Invalid mods, if any were found. Will be null if all mods were valid.</param>
/// <returns>Whether the input mods were all valid. If false, <paramref name="invalidMods"/> will contain all invalid entries.</returns>
public static bool CheckValidFreeModsForMultiplayer(IEnumerable<Mod> mods, [NotNullWhen(false)] out List<Mod>? invalidMods)
=> checkValid(mods, m => m.Type != ModType.System && m.HasImplementation && m.ValidForMultiplayerAsFreeMod && !(m is MultiMod), out invalidMods);
private static bool checkValid(IEnumerable<Mod> mods, Predicate<Mod> valid, [NotNullWhen(false)] out List<Mod>? invalidMods)
{
mods = mods.ToArray();
invalidMods = null;
foreach (var mod in mods)
{
if (!valid(mod))
{
invalidMods ??= new List<Mod>();
invalidMods.Add(mod);
}
}
return invalidMods == null;
}
/// <summary>
/// Flattens a set of <see cref="Mod"/>s, returning a new set with all <see cref="MultiMod"/>s removed.
/// </summary>
/// <param name="mods">The set of <see cref="Mod"/>s to flatten.</param>
/// <returns>The new set, containing all <see cref="Mod"/>s in <paramref name="mods"/> recursively with all <see cref="MultiMod"/>s removed.</returns>
public static IEnumerable<Mod> FlattenMods(IEnumerable<Mod> mods) => mods.SelectMany(FlattenMod);
/// <summary>
/// Flattens a <see cref="Mod"/>, returning a set of <see cref="Mod"/>s in-place of any <see cref="MultiMod"/>s.
/// </summary>
/// <param name="mod">The <see cref="Mod"/> to flatten.</param>
/// <returns>A set of singular "flattened" <see cref="Mod"/>s</returns>
public static IEnumerable<Mod> FlattenMod(Mod mod)
{
if (mod is MultiMod multi)
{
foreach (var m in multi.Mods.SelectMany(FlattenMod))
yield return m;
}
else
yield return mod;
}
/// <summary>
/// Verifies all proposed mods are valid for a given ruleset and returns instantiated <see cref="Mod"/>s for further processing.
/// </summary>
/// <param name="ruleset">The ruleset to verify mods against.</param>
/// <param name="proposedMods">The proposed mods.</param>
/// <param name="valid">Mods instantiated from <paramref name="proposedMods"/> which were valid for the given <paramref name="ruleset"/>.</param>
/// <returns>Whether all <paramref name="proposedMods"/> were valid for the given <paramref name="ruleset"/>.</returns>
public static bool InstantiateValidModsForRuleset(Ruleset ruleset, IEnumerable<APIMod> proposedMods, out List<Mod> valid)
{
valid = new List<Mod>();
bool proposedWereValid = true;
foreach (var apiMod in proposedMods)
{
var mod = apiMod.ToMod(ruleset);
if (mod is UnknownMod)
{
proposedWereValid = false;
continue;
}
valid.Add(mod);
}
return proposedWereValid;
}
/// <summary>
/// Verifies all mods provided belong to the given ruleset.
/// </summary>
/// <param name="ruleset">The ruleset to check the proposed mods against.</param>
/// <param name="proposedMods">The mods proposed for checking.</param>
/// <returns>Whether all <paramref name="proposedMods"/> belong to the given <paramref name="ruleset"/>.</returns>
public static bool CheckModsBelongToRuleset(Ruleset ruleset, IEnumerable<Mod> proposedMods)
{
var rulesetModsTypes = ruleset.AllMods.Select(m => m.GetType()).ToList();
foreach (var proposedMod in proposedMods)
{
bool found = false;
var proposedModType = proposedMod.GetType();
foreach (var rulesetModType in rulesetModsTypes)
{
if (rulesetModType.IsAssignableFrom(proposedModType))
{
found = true;
break;
}
}
if (!found)
return false;
}
return true;
}
/// <summary>
/// Given a value of a score multiplier, returns a string version with special handling for a value near 1.00x.
/// </summary>
/// <param name="scoreMultiplier">The value of the score multiplier.</param>
/// <returns>A formatted score multiplier with a trailing "x" symbol</returns>
public static LocalisableString FormatScoreMultiplier(double scoreMultiplier)
{
// Round multiplier values away from 1.00x to two significant digits.
if (scoreMultiplier > 1)
scoreMultiplier = Math.Ceiling(Math.Round(scoreMultiplier * 100, 12)) / 100;
else
scoreMultiplier = Math.Floor(Math.Round(scoreMultiplier * 100, 12)) / 100;
return scoreMultiplier.ToLocalisableString("0.00x");
}
/// <summary>
/// Calculate the rate for the song with the selected mods.
/// </summary>
/// <param name="mods">The list of selected mods.</param>
/// <returns>The rate with mods.</returns>
public static double CalculateRateWithMods(IEnumerable<Mod> mods)
{
double rate = 1;
// TODO: This doesn't consider mods which apply variable rates, yet.
foreach (var mod in mods.OfType<IApplicableToRate>())
rate = mod.ApplyToRate(0, rate);
return rate;
}
}
}