Add flashcards feature with spaced repetition scheduling

Adds a full flashcards system: FSRS-based scheduling, cloze/basic card types, CSV import/export, media storage, and study UI, wired into navigation and the dashboard alongside existing question flows.
2026-07-21 15:08:52 -05:00
parent 29b89dc404
commit 48a8c8361d
41 changed files with 4458 additions and 8 deletions
@@ -0,0 +1,36 @@
+using MongoDB.Driver;
+using QuestionsApi.Models;
+
+namespace QuestionsApi.Services.Flashcards;
+
+public sealed class FlashcardSettingsStore
+{
+    private readonly IMongoCollection<FlashcardSettings> _settings;
+
+    public FlashcardSettingsStore(MongoDatabaseProvider mongo)
+    {
+        _settings = mongo.Database.GetCollection<FlashcardSettings>("FlashcardSettings");
+        _settings.Indexes.CreateOne(new CreateIndexModel<FlashcardSettings>(
+            Builders<FlashcardSettings>.IndexKeys.Ascending(v => v.UserId),
+            new CreateIndexOptions { Unique = true, Name = "flashcard_settings_unique_user" }));
+    }
+
+    public async Task<FlashcardSettings> GetAsync(string userId) =>
+        await _settings.Find(v => v.UserId == userId).FirstOrDefaultAsync()
+        ?? new FlashcardSettings { UserId = userId };
+
+    public async Task<FlashcardSettings> UpdateAsync(string userId, UpdateFlashcardSettingsRequest request)
+    {
+        var now = DateTime.UtcNow;
+        return await _settings.FindOneAndUpdateAsync(
+            v => v.UserId == userId,
+            Builders<FlashcardSettings>.Update
+                .Set(v => v.NewCardsPerDay, Math.Clamp(request.NewCardsPerDay, 0, 2000))
+                .Set(v => v.ReviewsPerDay, Math.Clamp(request.ReviewsPerDay, 0, 5000))
+                .Set(v => v.DesiredRetention, FsrsFlashcardScheduler.DesiredRetention)
+                .Set(v => v.UpdatedUtc, now)
+                .Inc(v => v.Revision, 1)
+                .SetOnInsert(v => v.UserId, userId),
+            new FindOneAndUpdateOptions<FlashcardSettings> { IsUpsert = true, ReturnDocument = ReturnDocument.After });
+    }
+}