Add daily study missions

2026-08-01 04:02:24 -05:00
parent 2bd2628009
commit ecd5da9162
20 changed files with 619 additions and 6 deletions
@@ -0,0 +1,203 @@
+using MongoDB.Driver;
+using QuestionsApi.Models;
+
+namespace QuestionsApi.Services;
+
+public sealed class DailyMissionStore
+{
+    private readonly IMongoCollection<DailyMissionSet> _sets;
+    private readonly CreditStore _credits;
+    private readonly TimeProvider _clock;
+    private readonly ServiceMetrics _metrics;
+
+    public DailyMissionStore(MongoDatabaseProvider mongo, CreditStore credits, TimeProvider clock, ServiceMetrics metrics)
+    {
+        _sets = mongo.Database.GetCollection<DailyMissionSet>("DailyMissionSets");
+        _credits = credits;
+        _clock = clock;
+        _metrics = metrics;
+        _sets.Indexes.CreateOne(new CreateIndexModel<DailyMissionSet>(
+            Builders<DailyMissionSet>.IndexKeys.Ascending(value => value.UserId).Ascending(value => value.DateUtc),
+            new CreateIndexOptions { Unique = true, Name = "uq_daily_mission_user_date" }));
+    }
+
+    public async Task<DailyMissionEnvelope> GetOrCreateAsync(
+        string userId, DashboardResponse dashboard, IReadOnlyCollection<Question> published)
+    {
+        var now = _clock.GetUtcNow().UtcDateTime;
+        await RecordExpiredAsync(userId, now);
+        var key = DateKey(now);
+        var existing = await _sets.Find(value => value.UserId == userId && value.DateUtc == key).FirstOrDefaultAsync();
+        if (existing is not null) return Envelope(existing);
+        var candidates = BuildCandidates(dashboard, published, now);
+        if (candidates.Count < 3) throw new InvalidOperationException("Not enough eligible question-bank coverage to create daily missions.");
+        var set = new DailyMissionSet
+        {
+            Id = $"{userId}|{key}", UserId = userId, DateUtc = key,
+            Missions = candidates.Take(3).ToList(), ReplacementCandidates = candidates.Skip(3).ToList(),
+            CreatedUtc = now, ExpiresUtc = now.Date.AddDays(1)
+        };
+        try
+        {
+            await _sets.InsertOneAsync(set);
+            foreach (var mission in set.Missions) _metrics.DailyMissionAssigned(mission.Type);
+        }
+        catch (MongoWriteException exception) when (exception.WriteError.Category == ServerErrorCategory.DuplicateKey)
+        {
+            set = await _sets.Find(value => value.UserId == userId && value.DateUtc == key).FirstAsync();
+        }
+        return Envelope(set);
+    }
+
+    public async Task<DailyMissionEnvelope?> ReplaceAsync(string userId, string missionId)
+    {
+        var key = DateKey(_clock.GetUtcNow().UtcDateTime);
+        var set = await _sets.Find(value => value.UserId == userId && value.DateUtc == key).FirstOrDefaultAsync();
+        if (set is null) return null;
+        if (set.ReplacementUsed) throw new InvalidOperationException("Today's mission replacement has already been used.");
+        var index = set.Missions.FindIndex(value => value.Id == missionId);
+        if (index < 0) throw new ArgumentException("Mission not found.");
+        if (set.Missions[index].CompletedUtc.HasValue) throw new InvalidOperationException("Completed missions cannot be replaced.");
+        if (set.ReplacementCandidates.Count == 0) throw new InvalidOperationException("No replacement mission is available.");
+        var replacement = set.ReplacementCandidates[0];
+        replacement.StartsUtc = _clock.GetUtcNow().UtcDateTime;
+        set.Missions[index] = replacement;
+        set.ReplacementCandidates.RemoveAt(0);
+        set.ReplacementUsed = true;
+        var changed = await _sets.ReplaceOneAsync(value => value.Id == set.Id && !value.ReplacementUsed, set);
+        if (changed.ModifiedCount != 1) throw new InvalidOperationException("Today's mission replacement has already been used.");
+        _metrics.DailyMissionReplaced();
+        return Envelope(set);
+    }
+
+    public Task<DailyMissionEnvelope?> RecordQuestionAsync(string userId, QuestionAttempt attempt, Question question) =>
+        !attempt.IsCorrect || attempt.IsSkip ? Task.FromResult<DailyMissionEnvelope?>(null) :
+        RecordAsync(userId, $"question:{attempt.Id}", attempt.CreatedUtc,
+            mission => QualifiesQuestion(mission, attempt, question));
+
+    public Task<DailyMissionEnvelope?> RecordReviewAsync(string userId, QuestionReviewAttempt attempt) =>
+        !attempt.IsCorrect ? Task.FromResult<DailyMissionEnvelope?>(null) :
+        RecordAsync(userId, $"review:{attempt.Id}", attempt.CreatedUtc,
+            mission => QualifiesReview(mission, attempt));
+
+    public static bool QualifiesQuestion(DailyMission mission, QuestionAttempt attempt, Question question)
+    {
+        if (!attempt.IsCorrect || attempt.IsSkip || attempt.CreatedUtc < mission.StartsUtc) return false;
+        var system = Step3SystemCatalog.Normalize(question);
+        return mission.Type == DailyMissionTypes.WeakSystemCorrect && mission.Step3System == system
+            || mission.Type == DailyMissionTypes.DifficultyFourCorrect
+                && mission.Step3System == system && question.Difficulty >= 4;
+    }
+
+    public static bool QualifiesReview(DailyMission mission, QuestionReviewAttempt attempt) =>
+        attempt.IsCorrect && attempt.CreatedUtc >= mission.StartsUtc && mission.Type == DailyMissionTypes.DueReviews;
+
+    private async Task<DailyMissionEnvelope?> RecordAsync(
+        string userId, string eventId, DateTime eventUtc, Func<DailyMission, bool> qualifies)
+    {
+        var key = DateKey(_clock.GetUtcNow().UtcDateTime);
+        var set = await _sets.Find(value => value.UserId == userId && value.DateUtc == key).FirstOrDefaultAsync();
+        if (set is null) return null;
+        foreach (var mission in set.Missions.Where(value => value.CompletedUtc is null
+                     && value.StartsUtc <= eventUtc && qualifies(value)))
+        {
+            var missionFilter = Builders<DailyMission>.Filter.Eq(value => value.Id, mission.Id)
+                & Builders<DailyMission>.Filter.Eq(value => value.CompletedUtc, null)
+                & Builders<DailyMission>.Filter.AnyNin(value => value.AppliedEventIds, [eventId]);
+            var filter = Builders<DailyMissionSet>.Filter.Eq(value => value.Id, set.Id)
+                & Builders<DailyMissionSet>.Filter.ElemMatch(value => value.Missions, missionFilter);
+            await _sets.UpdateOneAsync(filter, Builders<DailyMissionSet>.Update
+                .Inc("Missions.$.Progress", 1).AddToSet("Missions.$.AppliedEventIds", eventId));
+        }
+        set = await _sets.Find(value => value.Id == set.Id).FirstAsync();
+        var awards = new List<CreditAward>();
+        foreach (var mission in set.Missions.Where(value => value.CompletedUtc is null && value.Progress >= value.Target))
+        {
+            var now = _clock.GetUtcNow().UtcDateTime;
+            var filter = Builders<DailyMissionSet>.Filter.Eq(value => value.Id, set.Id)
+                & Builders<DailyMissionSet>.Filter.ElemMatch(value => value.Missions,
+                    item => item.Id == mission.Id && item.CompletedUtc == null && item.Progress >= item.Target);
+            var completed = await _sets.UpdateOneAsync(filter,
+                Builders<DailyMissionSet>.Update.Set("Missions.$.CompletedUtc", now));
+            if (completed.ModifiedCount != 1) continue;
+            var award = await _credits.AwardAsync(userId, new CreditAwardRequest(
+                $"mission:{mission.Id}:complete", 3, CreditReasonCodes.DailyMissionComplete,
+                $"Completed daily mission: {mission.Title}", "daily_mission", mission.Id, true));
+            if (award.Award is not null) awards.Add(award.Award);
+            _metrics.DailyMissionCompleted(mission.Type);
+        }
+        set = await _sets.Find(value => value.Id == set.Id).FirstAsync();
+        return new DailyMissionEnvelope { State = Response(set), CreditAwards = awards };
+    }
+
+    public static List<DailyMission> BuildCandidates(
+        DashboardResponse dashboard, IReadOnlyCollection<Question> published, DateTime now)
+    {
+        var availability = published.GroupBy(Step3SystemCatalog.Normalize)
+            .Where(group => !string.IsNullOrWhiteSpace(group.Key))
+            .ToDictionary(group => group.Key!, group => (All: group.Count(), Hard: group.Count(q => q.Difficulty >= 4)));
+        var systems = dashboard.Systems.Where(value => availability.ContainsKey(value.System))
+            .OrderBy(value => MasteryRank(value.MasteryState)).ThenBy(value => value.MasteryScore)
+            .ThenBy(value => value.DistinctQuestions).ThenBy(value => value.System).ToList();
+        var result = new List<DailyMission>();
+        if (dashboard.MissedQuestionCount > 0)
+            result.Add(New(DailyMissionTypes.DueReviews,
+                $"Complete {Math.Min(10, dashboard.MissedQuestionCount)} scheduled reviews", "", 0,
+                Math.Min(10, dashboard.MissedQuestionCount), now));
+        var weak = systems.Where(value => availability[value.System].All >= 3).Select(system =>
+            New(DailyMissionTypes.WeakSystemCorrect,
+                $"Get 3 first-attempt answers correct in {system.System}", system.System, 0, 3, now));
+        var hard = systems.Where(value => availability[value.System].Hard >= 3)
+                     .OrderBy(value => value.Difficulty4PlusSuccessful).ThenBy(value => value.MasteryScore)
+            .Select(system => New(DailyMissionTypes.DifficultyFourCorrect,
+                $"Get 3 difficulty 4+ answers correct in {system.System}", system.System, 4, 3, now));
+        var weakList = weak.ToList();
+        var hardList = hard.ToList();
+        if (weakList.Count > 0) result.Add(weakList[0]);
+        var firstHard = hardList.FirstOrDefault(value => value.Step3System != weakList.FirstOrDefault()?.Step3System)
+            ?? hardList.FirstOrDefault();
+        if (firstHard is not null) result.Add(firstHard);
+        result.AddRange(weakList.Skip(1));
+        result.AddRange(hardList.Where(value => value.Id != firstHard?.Id));
+        return result.GroupBy(value => $"{value.Type}|{value.Step3System}").Select(group => group.First()).ToList();
+    }
+
+    private static DailyMission New(string type, string title, string system, int difficulty, int target, DateTime now) =>
+        new() { Type = type, Title = title, Step3System = system, DifficultyMin = difficulty,
+            Target = target, StartsUtc = now };
+
+    private static int MasteryRank(string state) => state switch
+    {
+        MasteryStates.Unseen => 0, MasteryStates.Learning => 1, MasteryStates.Practicing => 2,
+        MasteryStates.Strong => 3, _ => 4
+    };
+
+    private static string DateKey(DateTime now) => now.ToString("yyyy-MM-dd", System.Globalization.CultureInfo.InvariantCulture);
+
+    private async Task RecordExpiredAsync(string userId, DateTime now)
+    {
+        var expired = await _sets.Find(value => value.UserId == userId && value.ExpiresUtc <= now
+            && !value.ExpirationRecorded).ToListAsync();
+        foreach (var set in expired)
+        {
+            var changed = await _sets.UpdateOneAsync(value => value.Id == set.Id && !value.ExpirationRecorded,
+                Builders<DailyMissionSet>.Update.Set(value => value.ExpirationRecorded, true));
+            if (changed.ModifiedCount != 1) continue;
+            foreach (var mission in set.Missions.Where(value => value.CompletedUtc is null))
+                _metrics.DailyMissionExpired(mission.Type);
+        }
+    }
+    private static DailyMissionEnvelope Envelope(DailyMissionSet set) => new() { State = Response(set) };
+    private static DailyMissionSetResponse Response(DailyMissionSet set) => new()
+    {
+        DateUtc = set.DateUtc, ExpiresUtc = set.ExpiresUtc,
+        ReplacementAvailable = !set.ReplacementUsed && set.ReplacementCandidates.Count > 0
+            && set.Missions.Any(value => value.CompletedUtc is null),
+        Missions = set.Missions.Select(value => new DailyMissionResponse
+        {
+            Id = value.Id, Type = value.Type, Title = value.Title, Step3System = value.Step3System,
+            DifficultyMin = value.DifficultyMin, Target = value.Target,
+            Progress = Math.Min(value.Progress, value.Target), Completed = value.CompletedUtc.HasValue
+        }).ToList()
+    };
+}
@@ -21,6 +21,10 @@ public sealed class ServiceMetrics
    private readonly System.Collections.Concurrent.ConcurrentDictionary<string, long> _creditCoins = new();
    private readonly System.Collections.Concurrent.ConcurrentDictionary<string, long> _creditDuplicates = new();
    private readonly System.Collections.Concurrent.ConcurrentDictionary<string, long> _creditCapped = new();
+    private readonly System.Collections.Concurrent.ConcurrentDictionary<string, long> _dailyMissionAssigned = new();
+    private readonly System.Collections.Concurrent.ConcurrentDictionary<string, long> _dailyMissionCompleted = new();
+    private readonly System.Collections.Concurrent.ConcurrentDictionary<string, long> _dailyMissionExpired = new();
+    private long _dailyMissionReplaced;

    public void AttemptCreated() => Interlocked.Increment(ref _attemptsCreated);
    public void AttemptDuplicate() => Interlocked.Increment(ref _attemptDuplicates);
@@ -54,6 +58,10 @@ public sealed class ServiceMetrics
    }
    public void CreditDuplicate(string reason) => _creditDuplicates.AddOrUpdate(reason, 1, (_, value) => value + 1);
    public void CreditCapped(string reason) => _creditCapped.AddOrUpdate(reason, 1, (_, value) => value + 1);
+    public void DailyMissionAssigned(string type) => _dailyMissionAssigned.AddOrUpdate(type, 1, (_, value) => value + 1);
+    public void DailyMissionCompleted(string type) => _dailyMissionCompleted.AddOrUpdate(type, 1, (_, value) => value + 1);
+    public void DailyMissionExpired(string type) => _dailyMissionExpired.AddOrUpdate(type, 1, (_, value) => value + 1);
+    public void DailyMissionReplaced() => Interlocked.Increment(ref _dailyMissionReplaced);

    public string RenderPrometheus()
    {
@@ -85,6 +93,16 @@ public sealed class ServiceMetrics
            AppendReasonSample(output, "step3_credit_award_duplicates_total", reason, _creditDuplicates.GetValueOrDefault(reason));
            AppendReasonSample(output, "step3_credit_award_capped_total", reason, _creditCapped.GetValueOrDefault(reason));
        }
+        output.AppendLine("# TYPE step3_daily_missions_assigned_total counter");
+        output.AppendLine("# TYPE step3_daily_missions_completed_total counter");
+        output.AppendLine("# TYPE step3_daily_missions_expired_incomplete_total counter");
+        foreach (var type in _dailyMissionAssigned.Keys.Concat(_dailyMissionCompleted.Keys).Concat(_dailyMissionExpired.Keys).Distinct().Order())
+        {
+            AppendMissionSample(output, "step3_daily_missions_assigned_total", type, _dailyMissionAssigned.GetValueOrDefault(type));
+            AppendMissionSample(output, "step3_daily_missions_completed_total", type, _dailyMissionCompleted.GetValueOrDefault(type));
+            AppendMissionSample(output, "step3_daily_missions_expired_incomplete_total", type, _dailyMissionExpired.GetValueOrDefault(type));
+        }
+        AppendCounter(output, "step3_daily_missions_replaced_total", Interlocked.Read(ref _dailyMissionReplaced));
        output.AppendLine("# TYPE step3_http_request_duration_seconds summary");
        output.Append("step3_http_request_duration_seconds_count ")
            .Append(Interlocked.Read(ref _httpRequests))
@@ -116,4 +134,7 @@ public sealed class ServiceMetrics

    private static void AppendReasonSample(StringBuilder output, string name, string reason, long value) =>
        output.Append(name).Append("{reason=\"").Append(reason.Replace("\"", "")).Append("\"} ").Append(value).AppendLine();
+
+    private static void AppendMissionSample(StringBuilder output, string name, string type, long value) =>
+        output.Append(name).Append("{type=\"").Append(type.Replace("\"", "")).Append("\"} ").Append(value).AppendLine();
 }
@@ -20,7 +20,7 @@ public sealed class UserProfileStore
        "ExternalIdentities", "ExternalAuthTransactions",
        "FlashcardDecks", "FlashcardNotes", "FlashcardSchedules", "FlashcardReviewLogs",
        "FlashcardMediaAssets", "FlashcardSettings", "FlashcardImportPreviews",
-        "UserCreditAccounts", "CreditLedgerEntries", "StudySessions"
+        "UserCreditAccounts", "CreditLedgerEntries", "StudySessions", "DailyMissionSets"
    ];

    public UserProfileStore(MongoDatabaseProvider mongo)