list following recommendation base on country and addiction type

app/Http/Controllers/UserFollowingController.php

@@ -3,7 +3,9 @@
 namespace App\Http\Controllers;
 
 use App\Http\Resources\TinyUserResource;
+use App\Http\Resources\UserRecommendationResource;
 use App\Models\User;
+use App\Services\FollowingRecommendation;
 
 class UserFollowingController extends Controller
 {
@@ -23,4 +25,14 @@ public function index(User $user)
             TinyUserResource::collection($following)
         );
     }
+
+    public function recommendations(User $user)
+    {
+        $recommendations = (new FollowingRecommendation($user))
+            ->recommend();
+
+        return $this->ok(
+            UserRecommendationResource::collection($recommendations)
+        );
+    }
 }

app/Http/Resources/UserRecommendationResource.php

@@ -0,0 +1,24 @@
+<?php
+
+namespace App\Http\Resources;
+
+use Illuminate\Http\Request;
+use Illuminate\Http\Resources\Json\JsonResource;
+
+class UserRecommendationResource extends JsonResource
+{
+    /**
+     * Transform the resource into an array.
+     *
+     * @return array<string, mixed>
+     */
+    public function toArray(Request $request): array
+    {
+        return [
+            'id' => $this->id,
+            'nick_name' => $this->nick_name,
+            'avatar_url' => $this->avatar_url,
+            'bio' => $this->bio,
+        ];
+    }
+}

app/Services/FollowingRecommendation.php

@@ -0,0 +1,32 @@
+<?php
+
+namespace App\Services;
+
+use App\Models\User;
+use Illuminate\Support\Facades\DB;
+
+class FollowingRecommendation
+{
+    public function __construct(
+        private User $user,
+    ) {
+    }
+
+    public function recommend($count = 5)
+    {
+        $followingIds = DB::table('followers')
+            ->select('following_id')
+            ->where('follower_id', $this->user->id)
+            ->pluck('following_id');
+
+        return User::query()
+            ->select('id', 'nick_name', 'avatar_url', 'bio')
+            ->whereNotIn('id', $followingIds)
+            ->whereNot('id', $this->user->id)
+            ->where('country_id', '=', $this->user->country_id)
+            ->where('addiction_type', '=', $this->user->addiction_type)
+            ->inRandomOrder()
+            ->limit($count)
+            ->get();
+    }
+}

database/migrations/2014_10_12_000000_create_users_table.php

@@ -18,8 +18,8 @@ public function up(): void
             $table->string('nick_name');
             $table->string('bio')->nullable();
             $table->string('avatar_url')->nullable();
-            $table->foreignId('country_id')->constrained();
-            $table->unsignedTinyInteger('addiction_type');
+            $table->foreignId('country_id')->index('country_id_index')->constrained();
+            $table->unsignedTinyInteger('addiction_type')->index('addiction_type_index');
             $table->boolean('is_recovered')->default(false);
             $table->unsignedInteger('score')->default(0);
             $table->date('birth_date')->nullable();

routes/api.php

@@ -44,8 +44,13 @@
 Route::post('comments/{comment}/likes', [CommentLikesController::class, 'store']);
 Route::delete('comments/{comment}/likes', [CommentLikesController::class, 'destroy']);
 
+Route::prefix('users/{user}/following')
+    ->group(function () {
+        Route::get('/', [UserFollowingController::class, 'index']);
+        Route::get('/recommendations', [UserFollowingController::class, 'recommendations']);
+    });
+
 Route::apiResource('users', UsersController::class)->only('index', 'show');
-Route::get('users/{user}/following', [UserFollowingController::class, 'index']);
 Route::get('users/{user}/followers', [UserFollowersController::class, 'index']);
 Route::post('users/{user}/followers', [UserFollowersController::class, 'store']);
 Route::delete('users/{user}/followers', [UserFollowersController::class, 'destroy']);

tests/Feature/UserFollowingRecommendationTest.php

@@ -0,0 +1,48 @@
+<?php
+
+namespace Tests\Feature;
+
+use App\Models\Country;
+use App\Models\User;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Tests\TestCase;
+
+class UserFollowingRecommendationTest extends TestCase
+{
+    use RefreshDatabase;
+
+    private $user;
+
+    public function setUp(): void
+    {
+        parent::setUp();
+
+        Country::create([
+            'code' => 'GB',
+            'name' => 'United Kingdom',
+        ]);
+
+        $this->user = $this->signIn();
+    }
+
+    public function test_user_can_gets_recommendation_list_contain_users_from_same_addiction_and_country()
+    {
+        $followers = User::factory()->count(5)->create();
+        $this->user->following()->attach($followers->pluck('id'));
+        User::factory()->create();
+        $recommendations = User::factory()->count(5)->create([
+            'country_id' => $this->user->country_id,
+            'addiction_type' => $this->user->addiction_type,
+        ]);
+
+        $response = $this
+            ->getJson("api/users/{$this->user->id}/following/recommendations");
+
+        $response->assertOk();
+        $this->assertCount(5, $response['data']);
+        $this->assertEquals(
+            $recommendations->pluck(['id', 'nike_name', 'avatar_url', 'bio']),
+            collect($response['data'])->pluck(['id', 'nike_name', 'avatar_url', 'bio']),
+        );
+    }
+}