Add video engagement tracking and heatmap

app/Http/Controllers/Api/StreamApiController.php

@@ -4,11 +4,14 @@ namespace App\Http\Controllers\Api;
 
 use App\Http\Controllers\Controller;
 use App\Models\Episode;
+use App\Models\VideoEngagement;
 use App\Models\Watched;
 use Illuminate\Http\JsonResponse;
 use Illuminate\Http\Request;
 use Illuminate\Support\Carbon;
 use Illuminate\Support\Facades\Auth;
+use Illuminate\Support\Facades\DB;
+use Illuminate\Support\Facades\RateLimiter;
 
 class StreamApiController extends Controller
 {
@@ -70,4 +73,71 @@ class StreamApiController extends Controller
 
         return response()->json(['watched' => true], 200);
     }
+
+    /**
+     * Track engagement segments that the authenticated user has watched.
+     * Called periodically client-side while the video is playing.
+     * Segments are 10-second chunks; segment 0 (0-10s) is excluded.
+     */
+    public function trackEngagement(Request $request): JsonResponse
+    {
+        $validated = $request->validate([
+            'episode_id' => 'required|integer|exists:episodes,id',
+            'segments' => 'required|array',
+            'segments.*' => 'integer|min:1',
+        ]);
+
+        $user = Auth::user();
+        if (! $user) {
+            return response()->json(['tracked' => 0], 401);
+        }
+
+        $rateLimitKey = 'engagement:'.$user->id;
+        if (RateLimiter::tooManyAttempts($rateLimitKey, 10)) {
+            $seconds = RateLimiter::availableIn($rateLimitKey);
+
+            return response()->json([
+                'tracked' => 0,
+                'message' => 'Rate limit exceeded. Try again in '.$seconds.' seconds.',
+            ], 429);
+        }
+        RateLimiter::hit($rateLimitKey, 60);
+
+        $episodeId = $request->input('episode_id');
+        $segments = $request->input('segments');
+        $tracked = 0;
+
+        foreach ($segments as $segment) {
+            // upsert: insert if not exists, otherwise ignore (unique constraint prevents dupes)
+            VideoEngagement::firstOrCreate([
+                'episode_id' => $episodeId,
+                'user_id' => $user->id,
+                'segment' => $segment,
+            ]);
+            $tracked++;
+        }
+
+        return response()->json(['tracked' => $tracked], 200);
+    }
+
+    /**
+     * Get engagement heatmap data for an episode.
+     * Returns watch counts per segment, aggregated across all users.
+     */
+    public function getEngagement(int $episodeId): JsonResponse
+    {
+        $episode = Episode::findOrFail($episodeId);
+
+        $data = cache()->remember(
+            "engagement:{$episodeId}",
+            600, // 10-minute cache
+            fn () => VideoEngagement::where('episode_id', $episodeId)
+                ->select('segment', DB::raw('count(*) as watch_count'))
+                ->groupBy('segment')
+                ->pluck('watch_count', 'segment')
+                ->toArray()
+        );
+
+        return response()->json($data, 200);
+    }
 }