Add json properties to difficulty attributes

osu.Game.Rulesets.Catch/Difficulty/CatchDifficultyAttributes.cs

@@ -1,12 +1,14 @@
 // 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 Newtonsoft.Json;
 using osu.Game.Rulesets.Difficulty;
 
 namespace osu.Game.Rulesets.Catch.Difficulty
 {
     public class CatchDifficultyAttributes : DifficultyAttributes
     {
+        [JsonProperty("approach_rate")]
         public double ApproachRate { get; set; }
     }
 }

osu.Game.Rulesets.Mania/Difficulty/ManiaDifficultyAttributes.cs

@@ -1,13 +1,17 @@
 // 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 Newtonsoft.Json;
 using osu.Game.Rulesets.Difficulty;
 
 namespace osu.Game.Rulesets.Mania.Difficulty
 {
     public class ManiaDifficultyAttributes : DifficultyAttributes
     {
+        [JsonProperty("great_hit_window")]
         public double GreatHitWindow { get; set; }
+
+        [JsonProperty("score_multiplier")]
         public double ScoreMultiplier { get; set; }
     }
 }

osu.Game.Rulesets.Osu/Difficulty/OsuDifficultyAttributes.cs

@@ -1,21 +1,41 @@
 // 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 Newtonsoft.Json;
 using osu.Game.Rulesets.Difficulty;
 
 namespace osu.Game.Rulesets.Osu.Difficulty
 {
     public class OsuDifficultyAttributes : DifficultyAttributes
     {
+        [JsonProperty("aim_strain")]
         public double AimStrain { get; set; }
+
+        [JsonProperty("speed_strain")]
         public double SpeedStrain { get; set; }
+
+        [JsonProperty("flashlight_rating")]
         public double FlashlightRating { get; set; }
+
+        [JsonProperty("slider_factor")]
         public double SliderFactor { get; set; }
+
+        [JsonProperty("approach_rate")]
         public double ApproachRate { get; set; }
+
+        [JsonProperty("overall_difficulty")]
         public double OverallDifficulty { get; set; }
+
+        [JsonProperty("drain_rate")]
         public double DrainRate { get; set; }
+
+        [JsonProperty("hit_circle_count")]
         public int HitCircleCount { get; set; }
+
+        [JsonProperty("slider_count")]
         public int SliderCount { get; set; }
+
+        [JsonProperty("spinner_count")]
         public int SpinnerCount { get; set; }
     }
 }

osu.Game.Rulesets.Taiko/Difficulty/TaikoDifficultyAttributes.cs

@@ -1,16 +1,26 @@
 // 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 Newtonsoft.Json;
 using osu.Game.Rulesets.Difficulty;
 
 namespace osu.Game.Rulesets.Taiko.Difficulty
 {
     public class TaikoDifficultyAttributes : DifficultyAttributes
     {
+        [JsonProperty("stamina_strain")]
         public double StaminaStrain { get; set; }
+
+        [JsonProperty("rhythm_strain")]
         public double RhythmStrain { get; set; }
+
+        [JsonProperty("colour_strain")]
         public double ColourStrain { get; set; }
+
+        [JsonProperty("approach_rate")]
         public double ApproachRate { get; set; }
+
+        [JsonProperty("great_hit_window")]
         public double GreatHitWindow { get; set; }
     }
 }

osu.Game/Rulesets/Difficulty/DifficultyAttributes.cs

@@ -1,6 +1,7 @@
 // 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 Newtonsoft.Json;
 using osu.Game.Rulesets.Difficulty.Skills;
 using osu.Game.Rulesets.Mods;
 
@@ -8,10 +9,16 @@ namespace osu.Game.Rulesets.Difficulty
 {
     public class DifficultyAttributes
     {
+        [JsonIgnore]
         public Mod[] Mods { get; set; }
+
+        [JsonIgnore]
         public Skill[] Skills { get; set; }
 
+        [JsonProperty("star_rating")]
         public double StarRating { get; set; }
+
+        [JsonProperty("max_combo")]
         public int MaxCombo { get; set; }
 
         public DifficultyAttributes()