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osu-lazer/osu.Game/Screens/Select/DifficultyRecommender.cs
2020-05-12 11:14:51 +09:00

93 lines
3.0 KiB
C#

// 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.Linq;
using osu.Framework.Allocation;
using osu.Framework.Bindables;
using osu.Framework.Extensions.IEnumerableExtensions;
using osu.Framework.Graphics;
using osu.Game.Beatmaps;
using osu.Game.Online.API;
using osu.Game.Online.API.Requests;
using osu.Game.Rulesets;
namespace osu.Game.Screens.Select
{
public class DifficultyRecommender : Component, IOnlineComponent
{
[Resolved]
private IAPIProvider api { get; set; }
[Resolved]
private RulesetStore rulesets { get; set; }
[Resolved]
private Bindable<RulesetInfo> ruleset { get; set; }
private readonly Dictionary<RulesetInfo, double> recommendedStarDifficulty = new Dictionary<RulesetInfo, double>();
[BackgroundDependencyLoader]
private void load()
{
api.Register(this);
}
/// <summary>
/// Find the recommended difficulty from a selection of available difficulties for the current local user.
/// </summary>
/// <remarks>
/// This requires the user to be online for now.
/// </remarks>
/// <param name="beatmaps">A collection of beatmaps to select a difficulty from.</param>
/// <returns>The recommended difficulty, or null if a recommendation could not be provided.</returns>
public BeatmapInfo GetRecommendedBeatmap(IEnumerable<BeatmapInfo> beatmaps)
{
if (recommendedStarDifficulty.TryGetValue(ruleset.Value, out var stars))
{
return beatmaps.OrderBy(b =>
{
var difference = b.StarDifficulty - stars;
return difference >= 0 ? difference * 2 : difference * -1; // prefer easier over harder
}).FirstOrDefault();
}
return null;
}
private void calculateRecommendedDifficulties()
{
rulesets.AvailableRulesets.ForEach(rulesetInfo =>
{
var req = new GetUserRequest(api.LocalUser.Value.Id, rulesetInfo);
req.Success += result =>
{
// algorithm taken from https://github.com/ppy/osu-web/blob/e6e2825516449e3d0f3f5e1852c6bdd3428c3437/app/Models/User.php#L1505
recommendedStarDifficulty[rulesetInfo] = Math.Pow((double)(result.Statistics.PP ?? 0), 0.4) * 0.195;
};
api.Queue(req);
});
}
public void APIStateChanged(IAPIProvider api, APIState state)
{
switch (state)
{
case APIState.Online:
calculateRecommendedDifficulties();
break;
}
}
protected override void Dispose(bool isDisposing)
{
base.Dispose(isDisposing);
api?.Unregister(this);
}
}
}