Add support for disallowing usage of difficulty reduction mods to complete beatmap pack

app/Libraries/ModsHelper.php

···
 
         [29, 'V2'],
     ];
+    const DIFFICULTY_REDUCTION_MODS = ['NF', 'EZ', 'HT', 'SO'];
     const PREFERENCE_MODS_BITSET = 0b01000000000000000100001000100000; // SD, NC, PF, MR
 
     public static function toArray($bitset)

app/Models/BeatmapPack.php

···
 
 namespace App\Models;
 
+use App\Libraries\ModsHelper;
 use Exception;
 
 /**
···
     protected $table = 'osu_beatmappacks';
     protected $primaryKey = 'pack_id';
 
-    protected $casts = ['hidden' => 'boolean'];
+    protected $casts = [
+        'hidden' => 'boolean',
+        'no_diff_reduction' => 'boolean',
+    ];
 
     protected $dates = ['date'];
     public $timestamps = false;
···
                                 ->where('playmode', '=', $scoreRelation['playmode'])
                                 ->whereHas($scoreRelation['relation'], function ($scoreQuery) use ($userId) {
                                     $scoreQuery->where('user_id', '=', $userId);
+
+                                    if ($this->no_diff_reduction) {
+                                        $scoreQuery->withoutMods(ModsHelper::DIFFICULTY_REDUCTION_MODS);
+                                    }
                                 });
                         });
                     }
···
 
                 $query->whereHas($scoreRelation, function ($query) use ($userId) {
                     $query->where('user_id', '=', $userId);
+
+                    if ($this->no_diff_reduction) {
+                        $query->withoutMods(ModsHelper::DIFFICULTY_REDUCTION_MODS);
+                    }
                 });
             }
 

app/Models/Score/Model.php

···
 namespace App\Models\Score;
 
 use App\Exceptions\ClassNotFoundException;
+use App\Libraries\ModsHelper;
 use App\Models\Beatmap;
 use App\Models\Model as BaseModel;
 use App\Models\User;
 use App\Traits\Scoreable;
-use App\Libraries\ModsHelper;
 
 /**
  * @property Beatmap $beatmap
···
                 $q->orWhereRaw('enabled_mods & ? = ?', [$preferenceMask | $bitset, $bitset]);
             }
         });
+    }
+
+    public function scopeWithoutMods($query, $modsArray)
+    {
+        $bitset = ModsHelper::toBitset($modsArray);
+
+        return $query->whereRaw('enabled_mods & ? = 0', $bitset);
     }
 
     public function beatmap()

database/migrations/2020_11_13_025024_add_no_diff_reduction_to_beatmap_packs.php

···
+<?php
+
+// Copyright (c) ppy Pty Ltd <[e-mail]>. Licensed under the GNU Affero General Public License v3.0.
+// See the LICENCE file in the repository root for full licence text.
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+class AddNoDiffReductionToBeatmapPacks extends Migration
+{
+    /**
+     * Run the migrations.
+     *
+     * @return void
+     */
+    public function up()
+    {
+        Schema::table('osu_beatmappacks', function (Blueprint $table) {
+            $table->boolean('no_diff_reduction')->default(false);
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     *
+     * @return void
+     */
+    public function down()
+    {
+        Schema::table('osu_beatmappacks', function (Blueprint $table) {
+            $table->dropColumn('no_diff_reduction');
+        });
+    }
+}