first commit

app/Services/SocialAuthService.php

@@ -0,0 +1,45 @@
+<?php
+
+namespace App\Services;
+
+use App\Models\SocialAccount;
+use Illuminate\Support\Facades\Http;
+use Illuminate\Support\Facades\Log;
+
+class SocialAuthService
+{
+    /**
+     * Revoke the OAuth token for a given social account.
+     * Mandatory for security compliance.
+     */
+    public function revokeToken(SocialAccount $account): bool
+    {
+        if (!$account->token) {
+            return false;
+        }
+
+        try {
+            if ($account->provider === 'google') {
+                $response = Http::asForm()->post('https://oauth2.googleapis.com/revoke', [
+                    'token' => $account->token,
+                ]);
+
+                if ($response->successful()) {
+                    Log::info("Successfully revoked Google token for User ID: {$account->user_id}");
+                    $account->update([
+                        'token' => null,
+                        'refresh_token' => null,
+                        'expires_at' => null,
+                    ]);
+                    return true;
+                }
+                
+                Log::error("Failed to revoke Google token for User ID: {$account->user_id}. Status: " . $response->status());
+            }
+        } catch (\Exception $e) {
+            Log::error("Error during token revocation: " . $e->getMessage());
+        }
+
+        return false;
+    }
+}

app/Services/SrsService.php

@@ -0,0 +1,129 @@
+<?php
+
+namespace App\Services;
+
+use App\Models\SrsReview;
+use App\Models\User;
+use App\Models\Vocabulary;
+use Carbon\Carbon;
+
+class SrsService
+{
+    /**
+     * Process a review using SuperMemo-2 Algorithm.
+     * 
+     * @param User $user
+     * @param Vocabulary $vocab
+     * @param int $grade (1=Again, 2=Hard, 3=Good, 4=Easy)
+     *        Mapped to SM-2 Quality (q):
+     *        1 (Again) -> q=1
+     *        2 (Hard)  -> q=3
+     *        3 (Good)  -> q=4
+     *        4 (Easy)  -> q=5
+     */
+    public function processReview(User $user, Vocabulary $vocab, int $grade)
+    {
+        // Map UI Grade to SM-2 Quality
+        // Mapping: 1->1, 2->3, 3->4, 4->5
+        $qualityMap = [1 => 1, 2 => 3, 3 => 4, 4 => 5];
+        $q = $qualityMap[$grade] ?? 3;
+
+        // Find existing review or create new
+        $review = SrsReview::firstOrNew([
+            'user_id' => $user->id,
+            'vocabulary_id' => $vocab->id
+        ]);
+
+        if (!$review->exists) {
+            // Defaults
+            $review->ease_factor = 2.5;
+            $review->interval = 0;
+            $review->repetitions = 0;
+            $review->status = 'new';
+        }
+
+        // SM-2 Algorithm Implementation
+        if ($q >= 3) {
+            // Correct response
+            if ($review->repetitions == 0) {
+                $review->interval = 1;
+            } elseif ($review->repetitions == 1) {
+                $review->interval = 6;
+            } else {
+                $review->interval = round($review->interval * $review->ease_factor);
+            }
+            $review->repetitions++;
+            $review->status = $review->interval > 21 ? 'graduated' : 'review';
+        } else {
+            // Incorrect response
+            $review->repetitions = 0;
+            $review->interval = 1;
+            $review->status = 'learning';
+        }
+
+        // Update Ease Factor
+        // EF' = EF + (0.1 - (5 - q) * (0.08 + (5 - q) * 0.02))
+        $review->ease_factor = $review->ease_factor + (0.1 - (5 - $q) * (0.08 + (5 - $q) * 0.02));
+        if ($review->ease_factor < 1.3) {
+            $review->ease_factor = 1.3;
+        }
+
+        $review->last_review_at = Carbon::now();
+        $review->next_review_at = Carbon::now()->addDays($review->interval);
+        
+        $review->save();
+
+        // Track Activity (XP and Streak)
+        $this->trackActivity($user, $grade);
+
+        return $review;
+    }
+
+    public function trackActivity(User $user, int $grade)
+    {
+        $today = Carbon::today();
+        $lastActivity = $user->last_activity_at ? Carbon::parse($user->last_activity_at)->startOfDay() : null;
+
+        // Award XP (Easy gives slightly more?)
+        // Let's just do 5 XP per card for now.
+        $user->xp_points += 5;
+
+        if (!$lastActivity) {
+            // First activity ever
+            $user->current_streak = 1;
+        } elseif ($today->isSameDay($lastActivity)) {
+            // Already active today, do nothing to streak
+        } elseif ($today->diffInDays($lastActivity) === 1) {
+            // Consecutive day
+            $user->current_streak += 1;
+        } else {
+            // Streak broken
+            $user->current_streak = 1;
+        }
+
+        $user->last_activity_at = Carbon::now();
+        $user->save();
+    }
+
+    public function getDueReviews(User $user, int $limit = 20)
+    {
+        return SrsReview::where('user_id', $user->id)
+            ->where('next_review_at', '<=', Carbon::now())
+            ->with(['vocabulary'])
+            ->orderBy('next_review_at', 'asc')
+            ->limit($limit)
+            ->get();
+    }
+    
+    public function getNewCards(User $user, int $limit = 5)
+    {
+        // Get vocabularies NOT in srs_reviews
+        $reviewedIds = SrsReview::where('user_id', $user->id)->pluck('vocabulary_id');
+        
+        return Vocabulary::whereNotIn('id', $reviewedIds)
+            // Ideally filter by User's Level (e.g. N5)
+            // ->where('level', $user->level ?? 'N5') 
+            ->limit($limit)
+            ->get();
+    }
+}