Add daily study missions

api/QuestionsApi/Models/CreditModels.cs

@@ -110,6 +110,7 @@ public static class CreditReasonCodes
     public const string MasteryMastered = "mastery_mastered";
     public const string ExamSimulationComplete = "exam_simulation_complete";
     public const string SessionGoalComplete = "session_goal_complete";
+    public const string DailyMissionComplete = "daily_mission_complete";
     public const string Purchase = "purchase";
 }
 

api/QuestionsApi/Models/DailyMissionModels.cs

@@ -0,0 +1,64 @@
+using MongoDB.Bson.Serialization.Attributes;
+
+namespace QuestionsApi.Models;
+
+public static class DailyMissionTypes
+{
+    public const string DueReviews = "due_reviews";
+    public const string WeakSystemCorrect = "weak_system_correct";
+    public const string DifficultyFourCorrect = "difficulty_four_correct";
+}
+
+public sealed class DailyMission
+{
+    public string Id { get; set; } = Guid.NewGuid().ToString("N");
+    public string Type { get; set; } = "";
+    public string Title { get; set; } = "";
+    public string Step3System { get; set; } = "";
+    public int DifficultyMin { get; set; }
+    public int Target { get; set; }
+    public int Progress { get; set; }
+    public DateTime StartsUtc { get; set; }
+    public DateTime? CompletedUtc { get; set; }
+    public List<string> AppliedEventIds { get; set; } = [];
+}
+
+public sealed class DailyMissionSet
+{
+    [BsonId]
+    public string Id { get; set; } = "";
+    public string UserId { get; set; } = "";
+    public string DateUtc { get; set; } = "";
+    public List<DailyMission> Missions { get; set; } = [];
+    public List<DailyMission> ReplacementCandidates { get; set; } = [];
+    public bool ReplacementUsed { get; set; }
+    public bool ExpirationRecorded { get; set; }
+    public DateTime CreatedUtc { get; set; }
+    public DateTime ExpiresUtc { get; set; }
+}
+
+public sealed class DailyMissionResponse
+{
+    public string Id { get; set; } = "";
+    public string Type { get; set; } = "";
+    public string Title { get; set; } = "";
+    public string Step3System { get; set; } = "";
+    public int DifficultyMin { get; set; }
+    public int Target { get; set; }
+    public int Progress { get; set; }
+    public bool Completed { get; set; }
+}
+
+public sealed class DailyMissionSetResponse
+{
+    public string DateUtc { get; set; } = "";
+    public DateTime ExpiresUtc { get; set; }
+    public bool ReplacementAvailable { get; set; }
+    public List<DailyMissionResponse> Missions { get; set; } = [];
+}
+
+public sealed class DailyMissionEnvelope
+{
+    public DailyMissionSetResponse State { get; set; } = new();
+    public List<CreditAward> CreditAwards { get; set; } = [];
+}

api/QuestionsApi/Models/QuestionResponse.cs

@@ -149,6 +149,7 @@ public class FirstQuestionAttemptResponse
     public List<CreditAward> CreditAwards { get; set; } = [];
     public StudySessionProgress? StudySessionProgress { get; set; }
     public StudySessionSummary? SessionSummary { get; set; }
+    public DailyMissionSetResponse? DailyMissions { get; set; }
 }
 
 public class SkipQuestionResponse

api/QuestionsApi/Models/ReviewQueueModels.cs

@@ -86,6 +86,7 @@ public sealed class ReviewQueueAttemptResponse
     public List<CreditAward> CreditAwards { get; set; } = [];
     public StudySessionProgress? StudySessionProgress { get; set; }
     public StudySessionSummary? SessionSummary { get; set; }
+    public DailyMissionSetResponse? DailyMissions { get; set; }
 }
 
 public sealed class ReviewQueueRecordResult