Add server-side ELO ratings

api/QuestionsApi/Models/Question.cs

@@ -19,6 +19,7 @@ public class Question
     public Dictionary<string, int> ChoiceSelectionPercentages { get; set; } = [];
     public string Discipline { get; set; } = "";
     public string System { get; set; } = "";
+    public string PerformanceCategory { get; set; } = "";
     public int Difficulty { get; set; } = 1;
     public List<QuestionLab> Labs { get; set; } = [];
     public List<string> Media { get; set; } = [];

api/QuestionsApi/Models/QuestionAttempt.cs

@@ -13,5 +13,6 @@ public class QuestionAttempt
     public string UserId { get; set; } = "";
     public string ChoiceId { get; set; } = "";
     public bool IsCorrect { get; set; }
+    public bool IsSkip { get; set; }
     public DateTime CreatedUtc { get; set; } = DateTime.UtcNow;
 }

api/QuestionsApi/Models/QuestionRequests.cs

@@ -22,6 +22,7 @@ public class UpsertQuestionRequest
     public Dictionary<string, int> ChoiceSelectionPercentages { get; set; } = [];
     public string Discipline { get; set; } = "";
     public string System { get; set; } = "";
+    public string PerformanceCategory { get; set; } = "";
     public int Difficulty { get; set; } = 1;
     public List<QuestionLab> Labs { get; set; } = [];
     public List<string> Media { get; set; } = [];

api/QuestionsApi/Models/QuestionResponse.cs

@@ -13,12 +13,17 @@ public class QuestionResponse
     public Dictionary<string, int> ChoiceSelectionPercentages { get; set; } = [];
     public string Discipline { get; set; } = "";
     public string System { get; set; } = "";
+    public string PerformanceCategory { get; set; } = "";
     public int Difficulty { get; set; }
+    public int QuestionElo { get; set; } = 1000;
     public List<QuestionLab> Labs { get; set; } = [];
     public List<string> Media { get; set; } = [];
     public List<string> Tags { get; set; } = [];
 
-    public static QuestionResponse FromModel(Question question, Dictionary<string, int>? liveChoiceSelectionPercentages = null) => new()
+    public static QuestionResponse FromModel(
+        Question question,
+        Dictionary<string, int>? liveChoiceSelectionPercentages = null,
+        int questionElo = 1000) => new()
     {
         Id = question.Id ?? "",
         ExternalId = question.ExternalId,
@@ -31,7 +36,9 @@ public class QuestionResponse
         ChoiceSelectionPercentages = BuildChoiceSelectionPercentages(question, liveChoiceSelectionPercentages),
         Discipline = question.Discipline,
         System = question.System,
+        PerformanceCategory = RatingCategory.Normalize(question.PerformanceCategory, question.System, question.Discipline),
         Difficulty = question.Difficulty,
+        QuestionElo = questionElo,
         Labs = question.Labs,
         Media = question.Media,
         Tags = question.Tags
@@ -52,4 +59,59 @@ public class FirstQuestionAttemptResponse
 {
     public string QuestionExternalId { get; set; } = "";
     public Dictionary<string, int> ChoiceSelectionPercentages { get; set; } = [];
+    public int QuestionElo { get; set; } = 1000;
+    public RatingChangeResponse? Rating { get; set; }
+}
+
+public class SkipQuestionResponse
+{
+    public string QuestionExternalId { get; set; } = "";
+    public string CorrectChoiceId { get; set; } = "";
+    public Dictionary<string, int> ChoiceSelectionPercentages { get; set; } = [];
+    public int QuestionElo { get; set; } = 1000;
+    public RatingChangeResponse? Rating { get; set; }
+}
+
+public static class RatingCategory
+{
+    public const string Uncategorized = "Uncategorized";
+
+    public static readonly string[] Categories =
+    [
+        "Renal/Urinary & Male/Female Systems & Pregnancy",
+        "Behavioral Health & Social Sciences: Communication, Ethics, Patient Safety",
+        "Immune/Blood & Lymphoreticular/Endocrine/Multisystem",
+        "Biostatistics & Epidemiology/Population Health",
+        "Musculoskeletal/Skin & Subcutaneous Tissue",
+        "Cardiovascular System",
+        "Nervous System & Special Senses",
+        "Respiratory System",
+        "Gastrointestinal System",
+        Uncategorized
+    ];
+
+    public static string Normalize(string? explicitCategory, string? system, string? discipline)
+    {
+        foreach (var value in new[] { explicitCategory, system, discipline })
+        {
+            if (string.IsNullOrWhiteSpace(value))
+                continue;
+            var normalized = Categories.FirstOrDefault(c => string.Equals(c, value.Trim(), StringComparison.OrdinalIgnoreCase));
+            if (normalized is not null)
+                return normalized;
+
+            var lower = value.ToLowerInvariant();
+            if (lower.Contains("cardio")) return "Cardiovascular System";
+            if (lower.Contains("resp")) return "Respiratory System";
+            if (lower.Contains("gastro") || lower.Contains("hepato")) return "Gastrointestinal System";
+            if (lower.Contains("neuro") || lower.Contains("special sense")) return "Nervous System & Special Senses";
+            if (lower.Contains("renal") || lower.Contains("urinary") || lower.Contains("pregnan") || lower.Contains("reproductive")) return "Renal/Urinary & Male/Female Systems & Pregnancy";
+            if (lower.Contains("behavior") || lower.Contains("ethic") || lower.Contains("communication") || lower.Contains("safety")) return "Behavioral Health & Social Sciences: Communication, Ethics, Patient Safety";
+            if (lower.Contains("immune") || lower.Contains("blood") || lower.Contains("endocrine") || lower.Contains("multisystem")) return "Immune/Blood & Lymphoreticular/Endocrine/Multisystem";
+            if (lower.Contains("biostat") || lower.Contains("epidemi") || lower.Contains("population")) return "Biostatistics & Epidemiology/Population Health";
+            if (lower.Contains("musculo") || lower.Contains("skin") || lower.Contains("derm")) return "Musculoskeletal/Skin & Subcutaneous Tissue";
+        }
+
+        return Uncategorized;
+    }
 }

api/QuestionsApi/Models/RatingModels.cs

@@ -0,0 +1,48 @@
+using MongoDB.Bson;
+using MongoDB.Bson.Serialization.Attributes;
+
+namespace QuestionsApi.Models;
+
+public class UserRating
+{
+    [BsonId]
+    [BsonRepresentation(BsonType.ObjectId)]
+    public string? Id { get; set; }
+
+    public string UserId { get; set; } = "";
+    public int OverallElo { get; set; } = 1000;
+    public Dictionary<string, int> CategoryElos { get; set; } = [];
+    public int RatedQuestionCount { get; set; }
+    public DateTime UpdatedUtc { get; set; } = DateTime.UtcNow;
+}
+
+public class QuestionRating
+{
+    [BsonId]
+    [BsonRepresentation(BsonType.ObjectId)]
+    public string? Id { get; set; }
+
+    public string QuestionExternalId { get; set; } = "";
+    public int Elo { get; set; } = 1000;
+    public int AttemptCount { get; set; }
+    public DateTime UpdatedUtc { get; set; } = DateTime.UtcNow;
+}
+
+public class RatingChangeResponse
+{
+    public bool Rated { get; set; }
+    public string Category { get; set; } = "";
+    public int UserOverallElo { get; set; }
+    public int UserOverallDelta { get; set; }
+    public int UserCategoryElo { get; set; }
+    public int UserCategoryDelta { get; set; }
+    public int QuestionElo { get; set; }
+    public int QuestionEloDelta { get; set; }
+}
+
+public class RatingProfileResponse
+{
+    public int OverallElo { get; set; }
+    public int RatedQuestionCount { get; set; }
+    public Dictionary<string, int> CategoryElos { get; set; } = [];
+}