Merge branch 'feature/set-ordering'

ai/backend-context.md

@@ -40,11 +40,14 @@ intentionally omitted here - update this section as entities land.
 
 ## Migrations
 
-- This project is not in production. By default, schema changes should update
+- This project is in production. Never edit, delete, rename, or reorder an
-  the relevant create-table migration so migrations describe the current desired
+  existing migration file. Every schema change must use a new forward
-  schema from scratch.
+  migration.
-- Do not add alter-table or data-backfill migrations unless the user explicitly
+- Production migrations must preserve existing data, include any required
-  asks for production-style migration safety.
+  backfill, and define a safe rollback.
+- Plan schema changes for the deployment order and for compatibility between
+  the old and new application versions. Use expand/backfill/contract sequencing
+  when a single compatible migration is not safe.
 - Put seed data in seeders, not migrations.
 
 ## PHP rules

backend/app/Controllers/SetController.php

@@ -11,6 +11,8 @@ use App\Set\UseCases\CreateSetWithRoot\CreateSetWithRoot;
 use App\Set\UseCases\CreateSetWithRoot\CreateSetWithRootRequest;
 use App\Set\UseCases\DeleteSet\DeleteSet;
 use App\Set\UseCases\DeleteSet\DeleteSetRequest;
+use App\Set\UseCases\ReorderSets\ReorderSets;
+use App\Set\UseCases\ReorderSets\ReorderSetsRequest;
 use App\Set\UseCases\UpdateSet\UpdateSet;
 use App\Set\UseCases\UpdateSet\UpdateSetRequest;
 use App\Shared\Files\Filesystem;
@@ -26,19 +28,34 @@ class SetController
         private CreateSetWithRoot $createSetWithRoot,
         private UpdateSet $updateSet,
         private DeleteSet $deleteSet,
+        private ReorderSets $reorderSets,
         private Filesystem $filesystem,
     ) {
     }
 
     public function index(): JsonResponse
     {
-        $sets = [];
+        return new JsonResponse([
-        foreach ($this->setRepository->getAll() as $set) {
+            'sets' => $this->buildSetPayloads(
-            $sets[] = $this->buildSetPayload($set);
+                $this->setRepository->getAll(),
+            ),
+        ], 200);
+    }
+
+    public function reorder(Request $request): JsonResponse
+    {
+        try {
+            $sets = $this->reorderSets->execute(new ReorderSetsRequest(
+                setIds: $this->intArrayInput($request, 'setIds'),
+            ));
+        } catch (BadRequestException $exception) {
+            return new JsonResponse([
+                'error' => $exception->getMessage(),
+            ], 400);
         }
 
         return new JsonResponse([
-            'sets' => $sets,
+            'sets' => $this->buildSetPayloads($sets),
         ], 200);
     }
 
@@ -141,6 +158,58 @@ class SetController
         ];
     }
 
+    /**
+     * @param DomainSet[] $sets
+     * @return array<int, array{
+     *     id: int,
+     *     name: string,
+     *     description: string,
+     *     iconImageUrl: string,
+     *     rootElementId: int|null
+     * }>
+     */
+    private function buildSetPayloads(array $sets): array
+    {
+        $setPayloads = [];
+        foreach ($sets as $set) {
+            $setPayloads[] = $this->buildSetPayload($set);
+        }
+
+        return $setPayloads;
+    }
+
+    /**
+     * @return int[]|null
+     */
+    private function intArrayInput(Request $request, string $key): ?array
+    {
+        if (! $request->exists($key)) {
+            return null;
+        }
+
+        $value = $request->input($key);
+        if (! is_array($value)) {
+            return null;
+        }
+
+        $integerValues = [];
+        foreach ($value as $item) {
+            if (is_int($item)) {
+                $integerValues[] = $item;
+                continue;
+            }
+
+            if (is_string($item) && ctype_digit($item)) {
+                $integerValues[] = (int) $item;
+                continue;
+            }
+
+            return null;
+        }
+
+        return $integerValues;
+    }
+
     private function stringInput(Request $request, string $key): ?string
     {
         if (! $request->exists($key)) {

backend/app/Set/EloquentSetRepository.php

@@ -3,6 +3,7 @@
 namespace App\Set;
 
 use DomainException;
+use Illuminate\Support\Facades\DB;
 
 class EloquentSetRepository implements SetRepository
 {
@@ -12,6 +13,7 @@ class EloquentSetRepository implements SetRepository
             'name' => $dto->name,
             'description' => $dto->description,
             'icon_image_url' => $dto->iconImageUrl,
+            'sort_order' => $this->nextSortOrder(),
         ]);
 
         return $this->toDomain($model);
@@ -55,7 +57,7 @@ class EloquentSetRepository implements SetRepository
 
     public function getAll(): array
     {
-        $models = SetModel::orderBy('id')->get();
+        $models = SetModel::orderBy('sort_order')->orderBy('id')->get();
         $sets = [];
         foreach ($models as $model) {
             $sets[] = $this->toDomain($model);
@@ -64,6 +66,30 @@ class EloquentSetRepository implements SetRepository
         return $sets;
     }
 
+    public function reorder(array $setIds): array
+    {
+        DB::transaction(function () use ($setIds): void {
+            $sortOrder = 1;
+            foreach ($setIds as $setId) {
+                SetModel::where('id', $setId)
+                    ->update(['sort_order' => $sortOrder]);
+                $sortOrder++;
+            }
+        });
+
+        return $this->getAll();
+    }
+
+    private function nextSortOrder(): int
+    {
+        $currentMaxSortOrder = SetModel::max('sort_order');
+        if ($currentMaxSortOrder === null) {
+            return 1;
+        }
+
+        return (int) $currentMaxSortOrder + 1;
+    }
+
     private function toDomain(SetModel $model): Set
     {
         return new Set(

backend/app/Set/SetModel.php

@@ -10,12 +10,14 @@ use Illuminate\Database\Eloquent\Model;
  * @property string $name
  * @property string $description
  * @property string $icon_image_url
+ * @property int $sort_order
  *
  * @method static Builder<static>|SetModel newModelQuery()
  * @method static Builder<static>|SetModel newQuery()
  * @method static Builder<static>|SetModel query()
  * @method static Builder<static>|SetModel whereId($value)
  * @method static Builder<static>|SetModel whereName($value)
+ * @method static Builder<static>|SetModel whereSortOrder($value)
  *
  * @mixin \Eloquent
  */
@@ -25,5 +27,14 @@ class SetModel extends Model
 
     public $timestamps = false;
 
-    protected $fillable = ['name', 'description', 'icon_image_url'];
+    protected $fillable = [
+        'name',
+        'description',
+        'icon_image_url',
+        'sort_order',
+    ];
+
+    protected $casts = [
+        'sort_order' => 'integer',
+    ];
 }

backend/app/Set/SetRepository.php

@@ -16,4 +16,10 @@ interface SetRepository
      * @return Set[]
      */
     public function getAll(): array;
+
+    /**
+     * @param int[] $setIds
+     * @return Set[]
+     */
+    public function reorder(array $setIds): array;
 }

backend/app/Set/UseCases/ReorderSets/ReorderSets.php

@@ -0,0 +1,128 @@
+<?php
+
+namespace App\Set\UseCases\ReorderSets;
+
+use App\Exceptions\BadRequestException;
+use App\Set\Set;
+use App\Set\SetRepository;
+
+class ReorderSets
+{
+    public function __construct(private SetRepository $setRepository)
+    {
+    }
+
+    /**
+     * @return Set[]
+     * @throws BadRequestException
+     */
+    public function execute(ReorderSetsRequest $request): array
+    {
+        if ($request->setIds === null) {
+            throw new BadRequestException('setIds is required');
+        }
+
+        $setIds = $this->validatedSetIds($request->setIds);
+        $existingSetIds = $this->setIds($this->setRepository->getAll());
+
+        $this->validateNoDuplicateIds($setIds);
+        $this->validateAllIdsAreSets($setIds, $existingSetIds);
+        $this->validateEverySetWasSubmitted($setIds, $existingSetIds);
+
+        return $this->setRepository->reorder($setIds);
+    }
+
+    /**
+     * @param mixed[] $setIds
+     * @return int[]
+     * @throws BadRequestException
+     */
+    private function validatedSetIds(array $setIds): array
+    {
+        $validatedSetIds = [];
+        foreach ($setIds as $setId) {
+            if (! is_int($setId)) {
+                throw new BadRequestException(
+                    'setIds must contain integers',
+                );
+            }
+
+            $validatedSetIds[] = $setId;
+        }
+
+        return $validatedSetIds;
+    }
+
+    /**
+     * @param int[] $setIds
+     * @throws BadRequestException
+     */
+    private function validateNoDuplicateIds(array $setIds): void
+    {
+        $seenSetIds = [];
+        foreach ($setIds as $setId) {
+            if (isset($seenSetIds[$setId])) {
+                throw new BadRequestException(
+                    'Set order contains duplicate ids',
+                );
+            }
+
+            $seenSetIds[$setId] = true;
+        }
+    }
+
+    /**
+     * @param int[] $setIds
+     * @param int[] $existingSetIds
+     * @throws BadRequestException
+     */
+    private function validateAllIdsAreSets(
+        array $setIds,
+        array $existingSetIds,
+    ): void {
+        $existingSetIdsById = [];
+        foreach ($existingSetIds as $existingSetId) {
+            $existingSetIdsById[$existingSetId] = true;
+        }
+
+        foreach ($setIds as $setId) {
+            if (! isset($existingSetIdsById[$setId])) {
+                throw new BadRequestException(
+                    'Set order contains invalid set',
+                );
+            }
+        }
+    }
+
+    /**
+     * @param int[] $setIds
+     * @param int[] $existingSetIds
+     * @throws BadRequestException
+     */
+    private function validateEverySetWasSubmitted(
+        array $setIds,
+        array $existingSetIds,
+    ): void {
+        if (count($setIds) === count($existingSetIds)) {
+            return;
+        }
+
+        throw new BadRequestException(
+            'Set order must include every set',
+        );
+    }
+
+    /**
+     * @param Set[] $sets
+     * @return int[]
+     */
+    private function setIds(array $sets): array
+    {
+        $setIds = [];
+        foreach ($sets as $set) {
+            $setIds[] = $set->getId();
+        }
+
+        return $setIds;
+    }
+}

backend/app/Set/UseCases/ReorderSets/ReorderSetsRequest.php

@@ -0,0 +1,13 @@
+<?php
+
+namespace App\Set\UseCases\ReorderSets;
+
+class ReorderSetsRequest
+{
+    /**
+     * @param mixed[]|null $setIds
+     */
+    public function __construct(public ?array $setIds)
+    {
+    }
+}

backend/database/migrations/2026_07_31_000000_add_sort_order_to_sets_table.php

@@ -0,0 +1,38 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\DB;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    public function up(): void
+    {
+        Schema::table('sets', function (Blueprint $table): void {
+            $table->unsignedInteger('sort_order')->nullable();
+        });
+
+        $setIds = DB::table('sets')->orderBy('id')->pluck('id');
+        $sortOrder = 1;
+        foreach ($setIds as $setId) {
+            DB::table('sets')
+                ->where('id', $setId)
+                ->update(['sort_order' => $sortOrder]);
+            $sortOrder++;
+        }
+
+        Schema::table('sets', function (Blueprint $table): void {
+            $table->unsignedInteger('sort_order')
+                ->nullable(false)
+                ->change();
+        });
+    }
+
+    public function down(): void
+    {
+        Schema::table('sets', function (Blueprint $table): void {
+            $table->dropColumn('sort_order');
+        });
+    }
+};

backend/routes/api.php

@@ -11,6 +11,8 @@ Route::post('/logout', [AuthController::class, 'logout']);
 Route::get('/me', [AuthController::class, 'me'])
     ->middleware(AuthMiddleware::class);
 Route::get('/sets', [SetController::class, 'index']);
+Route::put('/sets/order', [SetController::class, 'reorder'])
+    ->middleware(AuthMiddleware::class);
 Route::post('/sets', [SetController::class, 'create'])
     ->middleware(AuthMiddleware::class);
 Route::post('/sets/{id}/update', [SetController::class, 'update'])

backend/tests/Fakes/FakeSetRepository.php

@@ -13,6 +13,11 @@ class FakeSetRepository implements SetRepository
      */
     private array $setsById = [];
 
+    /**
+     * @var array<int, int>
+     */
+    private array $sortOrdersById = [];
+
     public function create(CreateSetDto $dto): DomainSet
     {
         $id = count($this->setsById) + 1;
@@ -23,6 +28,7 @@ class FakeSetRepository implements SetRepository
             iconImageUrl: $dto->iconImageUrl,
         );
         $this->setsById[$id] = $set;
+        $this->sortOrdersById[$id] = $this->nextSortOrder();
 
         return $set;
     }
@@ -38,6 +44,7 @@ class FakeSetRepository implements SetRepository
     public function delete(DomainSet $set): void
     {
         unset($this->setsById[$set->getId()]);
+        unset($this->sortOrdersById[$set->getId()]);
     }
 
     public function find(int $id): ?DomainSet
@@ -58,10 +65,35 @@ class FakeSetRepository implements SetRepository
         foreach ($this->setsById as $set) {
             $sets[] = $this->cloneSet($set);
         }
+        usort($sets, function (
+            DomainSet $firstSet,
+            DomainSet $secondSet,
+        ): int {
+            $firstSortOrder = $this->sortOrdersById[$firstSet->getId()]
+                ?? $firstSet->getId();
+            $secondSortOrder = $this->sortOrdersById[$secondSet->getId()]
+                ?? $secondSet->getId();
+            if ($firstSortOrder === $secondSortOrder) {
+                return $firstSet->getId() <=> $secondSet->getId();
+            }
+
+            return $firstSortOrder <=> $secondSortOrder;
+        });
 
         return $sets;
     }
 
+    public function reorder(array $setIds): array
+    {
+        $sortOrder = 1;
+        foreach ($setIds as $setId) {
+            $this->sortOrdersById[$setId] = $sortOrder;
+            $sortOrder++;
+        }
+
+        return $this->getAll();
+    }
+
     private function cloneSet(DomainSet $set): DomainSet
     {
         return new DomainSet(
@@ -71,4 +103,13 @@ class FakeSetRepository implements SetRepository
             iconImageUrl: $set->getIconImageUrl(),
         );
     }
+
+    private function nextSortOrder(): int
+    {
+        if ($this->sortOrdersById === []) {
+            return 1;
+        }
+
+        return max($this->sortOrdersById) + 1;
+    }
 }

backend/tests/Feature/SetOrderingMigrationTest.php

@@ -0,0 +1,86 @@
+<?php
+
+namespace Tests\Feature;
+
+use Illuminate\Database\QueryException;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Illuminate\Support\Facades\DB;
+use Illuminate\Support\Facades\Schema;
+use Tests\TestCase;
+
+class SetOrderingMigrationTest extends TestCase
+{
+    use RefreshDatabase;
+
+    private const MIGRATION_PATH =
+        'migrations/2026_07_31_000000_add_sort_order_to_sets_table.php';
+
+    public function testBackfillsExistingSetsInCurrentDisplayOrder(): void
+    {
+        $migration = $this->runMigrationAgainstLegacySets();
+
+        $this->assertSame(
+            [2, 7],
+            DB::table('sets')->orderBy('sort_order')->pluck('id')->all(),
+        );
+        $this->assertSame(
+            [1, 2],
+            DB::table('sets')
+                ->orderBy('sort_order')
+                ->pluck('sort_order')
+                ->all(),
+        );
+
+        $this->expectException(QueryException::class);
+        DB::table('sets')->insert([
+            'id' => 9,
+            'name' => 'Unordered Set',
+            'description' => 'A set without an explicit position',
+            'icon_image_url' => '/assets/unordered.png',
+        ]);
+    }
+
+    public function testRollbackRemovesOrderWithoutDeletingSets(): void
+    {
+        $migration = $this->runMigrationAgainstLegacySets();
+
+        $migration->down();
+
+        $this->assertFalse(Schema::hasColumn('sets', 'sort_order'));
+        $this->assertSame(
+            [2, 7],
+            DB::table('sets')->orderBy('id')->pluck('id')->all(),
+        );
+    }
+
+    private function runMigrationAgainstLegacySets(): object
+    {
+        if (Schema::hasColumn('sets', 'sort_order')) {
+            Schema::table('sets', function (Blueprint $table): void {
+                $table->dropColumn('sort_order');
+            });
+        }
+
+        DB::table('sets')->delete();
+        DB::table('sets')->insert([
+            [
+                'id' => 7,
+                'name' => 'Later Set',
+                'description' => 'Created later',
+                'icon_image_url' => '/assets/later.png',
+            ],
+            [
+                'id' => 2,
+                'name' => 'Earlier Set',
+                'description' => 'Created earlier',
+                'icon_image_url' => '/assets/earlier.png',
+            ],
+        ]);
+
+        $migration = require database_path(self::MIGRATION_PATH);
+        $migration->up();
+
+        return $migration;
+    }
+}

backend/tests/Feature/SetsEndpointTest.php

@@ -73,6 +73,98 @@ class SetsEndpointTest extends TestCase
         ]);
     }
 
+    public function testReorderSetsRequiresAuthentication(): void
+    {
+        $response = $this->putJson('/api/sets/order', [
+            'setIds' => [1, 2],
+        ]);
+
+        $response->assertUnauthorized();
+        $response->assertExactJson([
+            'error' => 'unauthenticated',
+        ]);
+    }
+
+    public function testAuthenticatedReorderSetsPersistsPublicOrder(): void
+    {
+        $setRepository = app(SetRepository::class);
+        $firstSet = $setRepository->create(new CreateSetDto(
+            name: 'First Set',
+            description: 'First set description',
+            iconImageUrl: '/assets/first.png',
+        ));
+        $secondSet = $setRepository->create(new CreateSetDto(
+            name: 'Second Set',
+            description: 'Second set description',
+            iconImageUrl: '/assets/second.png',
+        ));
+        $thirdSet = $setRepository->create(new CreateSetDto(
+            name: 'Third Set',
+            description: 'Third set description',
+            iconImageUrl: '/assets/third.png',
+        ));
+        $this->createSession('valid-token');
+
+        $response = $this->withCredentials()
+            ->withUnencryptedCookie('auth_token', 'valid-token')
+            ->putJson('/api/sets/order', [
+                'setIds' => [
+                    $thirdSet->getId(),
+                    $firstSet->getId(),
+                    $secondSet->getId(),
+                ],
+            ]);
+
+        $response->assertOk();
+        $response->assertJsonCount(3, 'sets');
+        $response->assertJsonPath('sets.0.id', $thirdSet->getId());
+        $response->assertJsonPath('sets.1.id', $firstSet->getId());
+        $response->assertJsonPath('sets.2.id', $secondSet->getId());
+
+        $publicResponse = $this->getJson('/api/sets');
+        $publicResponse->assertOk();
+        $publicResponse->assertJsonPath('sets.0.id', $thirdSet->getId());
+        $publicResponse->assertJsonPath('sets.1.id', $firstSet->getId());
+        $publicResponse->assertJsonPath('sets.2.id', $secondSet->getId());
+    }
+
+    public function testCreatedSetAppendsToSavedOrder(): void
+    {
+        $setRepository = app(SetRepository::class);
+        $firstSet = $setRepository->create(new CreateSetDto(
+            name: 'First Set',
+            description: 'First set description',
+            iconImageUrl: '/assets/first.png',
+        ));
+        $secondSet = $setRepository->create(new CreateSetDto(
+            name: 'Second Set',
+            description: 'Second set description',
+            iconImageUrl: '/assets/second.png',
+        ));
+        $this->createSession('valid-token');
+        $this->withCredentials()
+            ->withUnencryptedCookie('auth_token', 'valid-token')
+            ->putJson('/api/sets/order', [
+                'setIds' => [
+                    $secondSet->getId(),
+                    $firstSet->getId(),
+                ],
+            ])
+            ->assertOk();
+
+        $thirdSet = $setRepository->create(new CreateSetDto(
+            name: 'Third Set',
+            description: 'Third set description',
+            iconImageUrl: '/assets/third.png',
+        ));
+
+        $publicResponse = $this->getJson('/api/sets');
+        $publicResponse->assertOk();
+        $publicResponse->assertJsonPath('sets.0.id', $secondSet->getId());
+        $publicResponse->assertJsonPath('sets.1.id', $firstSet->getId());
+        $publicResponse->assertJsonPath('sets.2.id', $thirdSet->getId());
+    }
+
     public function testCreateSetRequiresAuthentication(): void
     {
         $response = $this->postJson('/api/sets', [

backend/tests/Unit/Set/UseCases/ReorderSetsTest.php

@@ -0,0 +1,135 @@
+<?php
+
+namespace Tests\Unit\Set\UseCases;
+
+use App\Exceptions\BadRequestException;
+use App\Set\CreateSetDto;
+use App\Set\Set as DomainSet;
+use App\Set\UseCases\ReorderSets\ReorderSets;
+use App\Set\UseCases\ReorderSets\ReorderSetsRequest;
+use Tests\Fakes\FakeSetRepository;
+use Tests\TestCase;
+
+class ReorderSetsTest extends TestCase
+{
+    private FakeSetRepository $setRepository;
+
+    private ReorderSets $reorderSets;
+
+    protected function setUp(): void
+    {
+        $this->setRepository = new FakeSetRepository();
+        $this->reorderSets = new ReorderSets($this->setRepository);
+    }
+
+    public function testReordersEverySet(): void
+    {
+        $firstSet = $this->createSet('First Set');
+        $secondSet = $this->createSet('Second Set');
+        $thirdSet = $this->createSet('Third Set');
+
+        $sets = $this->reorderSets->execute(new ReorderSetsRequest(
+            setIds: [
+                $thirdSet->getId(),
+                $firstSet->getId(),
+                $secondSet->getId(),
+            ],
+        ));
+
+        $expectedSetIds = [
+            $thirdSet->getId(),
+            $firstSet->getId(),
+            $secondSet->getId(),
+        ];
+        $this->assertSame($expectedSetIds, $this->setIds($sets));
+        $this->assertSame(
+            $expectedSetIds,
+            $this->setIds($this->setRepository->getAll()),
+        );
+    }
+
+    public function testThrowsWhenSetIdsAreMissing(): void
+    {
+        $this->expectException(BadRequestException::class);
+        $this->expectExceptionMessage('setIds is required');
+
+        $this->reorderSets->execute(new ReorderSetsRequest(setIds: null));
+    }
+
+    public function testThrowsWhenSetIdsAreNotIntegers(): void
+    {
+        $firstSet = $this->createSet('First Set');
+
+        $this->expectException(BadRequestException::class);
+        $this->expectExceptionMessage('setIds must contain integers');
+
+        $this->reorderSets->execute(new ReorderSetsRequest(
+            setIds: [$firstSet->getId(), 'invalid'],
+        ));
+    }
+
+    public function testThrowsWhenSetIdsContainDuplicates(): void
+    {
+        $firstSet = $this->createSet('First Set');
+        $secondSet = $this->createSet('Second Set');
+
+        $this->expectException(BadRequestException::class);
+        $this->expectExceptionMessage('Set order contains duplicate ids');
+
+        $this->reorderSets->execute(new ReorderSetsRequest(
+            setIds: [
+                $firstSet->getId(),
+                $firstSet->getId(),
+                $secondSet->getId(),
+            ],
+        ));
+    }
+
+    public function testThrowsWhenSetOrderContainsUnknownSet(): void
+    {
+        $firstSet = $this->createSet('First Set');
+
+        $this->expectException(BadRequestException::class);
+        $this->expectExceptionMessage('Set order contains invalid set');
+
+        $this->reorderSets->execute(new ReorderSetsRequest(
+            setIds: [$firstSet->getId(), 999],
+        ));
+    }
+
+    public function testThrowsWhenSetOrderOmitsSet(): void
+    {
+        $firstSet = $this->createSet('First Set');
+        $this->createSet('Second Set');
+
+        $this->expectException(BadRequestException::class);
+        $this->expectExceptionMessage('Set order must include every set');
+
+        $this->reorderSets->execute(new ReorderSetsRequest(
+            setIds: [$firstSet->getId()],
+        ));
+    }
+
+    private function createSet(string $name): DomainSet
+    {
+        return $this->setRepository->create(new CreateSetDto(
+            name: $name,
+            description: "$name description",
+            iconImageUrl: "/assets/$name.png",
+        ));
+    }
+
+    /**
+     * @param DomainSet[] $sets
+     * @return int[]
+     */
+    private function setIds(array $sets): array
+    {
+        $setIds = [];
+        foreach ($sets as $set) {
+            $setIds[] = $set->getId();
+        }
+
+        return $setIds;
+    }
+}

frontend/rabbi_gerzi/cypress/e2e/media.cy.ts

@@ -188,6 +188,85 @@ describe('media page sets', () => {
     cy.get('[data-cy="media-set-delete"]').should('not.exist')
   })
 
+  it('reorders sets and persists the public order', () => {
+    cy.resetDb()
+    loginAsAdmin()
+    cy.visit('/media')
+    cy.intercept('PUT', /\/api\/sets\/order$/).as('reorderSets')
+
+    cy.contains('[data-cy="media-set-card"]', 'Daily Learning')
+      .within(() => {
+        cy.get('[data-cy="media-set-move-up"]').click()
+      })
+    cy.wait('@reorderSets')
+
+    cy.get('[data-cy="media-set-order-status"]')
+      .should('be.visible')
+      .and('contain.text', 'Set order saved')
+    cy.get('[data-cy="media-set-card"]')
+      .eq(0)
+      .should('contain.text', 'Daily Learning')
+      .within(() => {
+        cy.get('[data-cy="media-set-move-up"]').should('be.disabled')
+      })
+    cy.get('[data-cy="media-set-card"]')
+      .eq(1)
+      .should('contain.text', 'Baderech HaAvodah')
+      .within(() => {
+        cy.get('[data-cy="media-set-move-down"]').should('be.disabled')
+      })
+
+    cy.reload()
+    cy.get('[data-cy="media-set-card"]')
+      .eq(0)
+      .should('contain.text', 'Daily Learning')
+    cy.get('[data-cy="media-set-card"]')
+      .eq(1)
+      .should('contain.text', 'Baderech HaAvodah')
+
+    cy.clearCookie('auth_token')
+    cy.reload()
+    cy.get('[data-cy="media-set-card"]')
+      .eq(0)
+      .should('contain.text', 'Daily Learning')
+    cy.get('[data-cy="media-set-card"]')
+      .eq(1)
+      .should('contain.text', 'Baderech HaAvodah')
+    cy.get('[data-cy="media-set-move-up"]').should('not.exist')
+    cy.get('[data-cy="media-set-move-down"]').should('not.exist')
+
+    cy.resetDb()
+  })
+
+  it('preserves set order when saving fails', () => {
+    cy.resetDb()
+    loginAsAdmin()
+    cy.visit('/media')
+    cy.intercept('PUT', /\/api\/sets\/order$/, {
+      statusCode: 500,
+      body: { error: 'Unexpected failure' },
+    }).as('reorderSets')
+
+    cy.contains('[data-cy="media-set-card"]', 'Daily Learning')
+      .within(() => {
+        cy.get('[data-cy="media-set-move-up"]').click()
+      })
+    cy.wait('@reorderSets')
+
+    cy.get('[data-cy="media-set-order-error"]')
+      .should('be.visible')
+      .and('contain.text', 'Could not save set order')
+    cy.get('[data-cy="media-set-order-status"]').should('not.exist')
+    cy.get('[data-cy="media-set-card"]')
+      .eq(0)
+      .should('contain.text', 'Baderech HaAvodah')
+    cy.get('[data-cy="media-set-card"]')
+      .eq(1)
+      .should('contain.text', 'Daily Learning')
+
+    cy.resetDb()
+  })
+
   it('creates a set from the logged-in media page modal', () => {
     loginAsAdmin()
     cy.visit('/media')

frontend/rabbi_gerzi/src/stores/mediaSets.ts

@@ -43,9 +43,11 @@ export const useMediaSetsStore = defineStore('mediaSets', () => {
   const isCreating = ref(false)
   const isUpdating = ref(false)
   const isDeleting = ref(false)
+  const isReordering = ref(false)
   const createError = ref<string | null>(null)
   const updateError = ref<string | null>(null)
   const deleteError = ref<string | null>(null)
+  const reorderError = ref<string | null>(null)
 
   async function fetchSets(): Promise<void> {
     error.value = null
@@ -187,6 +189,43 @@ export const useMediaSetsStore = defineStore('mediaSets', () => {
     }
   }
 
+  async function reorderSets(setIds: number[]): Promise<boolean> {
+    reorderError.value = null
+    isReordering.value = true
+
+    try {
+      const response = await fetch(`${API_BASE_URL}/api/sets/order`, {
+        method: 'PUT',
+        headers: { 'Content-Type': 'application/json' },
+        credentials: 'include',
+        body: JSON.stringify({ setIds }),
+      })
+
+      if (!response.ok) {
+        if (response.status === 401) {
+          reorderError.value = 'Please log in again'
+        } else if (response.status === 400) {
+          reorderError.value = await errorMessage(
+            response,
+            'Could not save set order',
+          )
+        } else {
+          reorderError.value = 'Could not save set order'
+        }
+        return false
+      }
+
+      const data: SetsResponse = await response.json()
+      sets.value = data.sets
+      return true
+    } catch {
+      reorderError.value = 'Network error - could not save set order'
+      return false
+    } finally {
+      isReordering.value = false
+    }
+  }
+
   async function errorMessage(
     response: Response,
     fallbackMessage: string,
@@ -206,12 +245,15 @@ export const useMediaSetsStore = defineStore('mediaSets', () => {
     isCreating,
     isUpdating,
     isDeleting,
+    isReordering,
     createError,
     updateError,
     deleteError,
+    reorderError,
     fetchSets,
     createSet,
     updateSet,
     deleteSet,
+    reorderSets,
   }
 })

frontend/rabbi_gerzi/src/views/MediaPage.vue

@@ -3,6 +3,8 @@ import { storeToRefs } from 'pinia'
 import { computed, onMounted, reactive, ref } from 'vue'
 import {
   AlertTriangle as AlertTriangleIcon,
+  ChevronDown as ChevronDownIcon,
+  ChevronUp as ChevronUpIcon,
   Pencil as PencilIcon,
   Plus as PlusIcon,
   Trash2 as TrashIcon,
@@ -18,6 +20,8 @@ interface CreateSetForm {
   description: string
 }
 
+type SetMoveDirection = 'up' | 'down'
+
 const router = useRouter()
 const authStore = useAuthStore()
 const mediaSetsStore = useMediaSetsStore()
@@ -28,9 +32,11 @@ const {
   isCreating,
   isUpdating,
   isDeleting,
+  isReordering,
   createError,
   updateError,
   deleteError,
+  reorderError,
 } = storeToRefs(mediaSetsStore)
 const isCreateModalOpen = ref(false)
 const isEditModalOpen = ref(false)
@@ -42,6 +48,7 @@ const localCreateError = ref<string | null>(null)
 const localEditError = ref<string | null>(null)
 const editingSet = ref<MediaSet | null>(null)
 const deletingSet = ref<MediaSet | null>(null)
+const setOrderStatus = ref<string | null>(null)
 
 const createSetForm = reactive<CreateSetForm>({
   name: '',
@@ -231,6 +238,42 @@ async function handleDeleteSet(): Promise<void> {
   deletingSet.value = null
 }
 
+async function handleMoveSet(
+  setId: number,
+  direction: SetMoveDirection,
+): Promise<void> {
+  const currentIndex = sets.value.findIndex((mediaSet) => {
+    return mediaSet.id === setId
+  })
+  if (currentIndex === -1) {
+    return
+  }
+
+  const targetIndex = direction === 'up' ? currentIndex - 1 : currentIndex + 1
+  if (targetIndex < 0 || targetIndex >= sets.value.length) {
+    return
+  }
+
+  const reorderedSets = [...sets.value]
+  const movingSet = reorderedSets[currentIndex]
+  const targetSet = reorderedSets[targetIndex]
+  if (movingSet === undefined || targetSet === undefined) {
+    return
+  }
+
+  reorderedSets[currentIndex] = targetSet
+  reorderedSets[targetIndex] = movingSet
+  const setIds = reorderedSets.map((mediaSet) => {
+    return mediaSet.id
+  })
+
+  setOrderStatus.value = null
+  const saved = await mediaSetsStore.reorderSets(setIds)
+  if (saved) {
+    setOrderStatus.value = 'Set order saved'
+  }
+}
+
 function openSet(mediaSet: MediaSet): void {
   if (mediaSet.rootElementId === null) {
     return
@@ -287,6 +330,30 @@ function resetEditSetForm(): void {
       </header>
 
       <section class="media-page__sets" aria-label="Featured sets">
+        <p
+          v-if="setOrderStatus !== null"
+          :class="[
+            'media-page__status',
+            'media-page__status--success',
+            'media-page__order-message',
+          ]"
+          data-cy="media-set-order-status"
+          aria-live="polite"
+        >
+          {{ setOrderStatus }}
+        </p>
+        <p
+          v-if="reorderError !== null"
+          :class="[
+            'media-page__status',
+            'media-page__status--error',
+            'media-page__order-message',
+          ]"
+          data-cy="media-set-order-error"
+          role="alert"
+        >
+          {{ reorderError }}
+        </p>
         <p v-if="isLoading" class="media-page__status">Loading media sets...</p>
         <p
           v-else-if="error"
@@ -302,7 +369,7 @@ function resetEditSetForm(): void {
           No media sets are available yet.
         </p>
         <div v-else class="media-page__grid" data-cy="media-set-grid">
-          <template v-for="mediaSet in sets" :key="mediaSet.id">
+          <template v-for="(mediaSet, setIndex) in sets" :key="mediaSet.id">
             <article
               v-if="authStore.isAuthenticated"
               class="media-page__card media-page__card--managed"
@@ -350,6 +417,34 @@ function resetEditSetForm(): void {
                   <TrashIcon :size="18" aria-hidden="true" />
                 </button>
               </div>
+              <div
+                class="media-page__card-order-actions"
+                aria-label="Set order actions"
+                @click.stop
+              >
+                <button
+                  type="button"
+                  class="media-page__card-action"
+                  data-cy="media-set-move-up"
+                  :disabled="isReordering || setIndex === 0"
+                  :aria-label="`Move ${mediaSet.name} up`"
+                  :title="`Move ${mediaSet.name} up`"
+                  @click="handleMoveSet(mediaSet.id, 'up')"
+                >
+                  <ChevronUpIcon :size="18" aria-hidden="true" />
+                </button>
+                <button
+                  type="button"
+                  class="media-page__card-action"
+                  data-cy="media-set-move-down"
+                  :disabled="isReordering || setIndex === sets.length - 1"
+                  :aria-label="`Move ${mediaSet.name} down`"
+                  :title="`Move ${mediaSet.name} down`"
+                  @click="handleMoveSet(mediaSet.id, 'down')"
+                >
+                  <ChevronDownIcon :size="18" aria-hidden="true" />
+                </button>
+              </div>
             </article>
             <RouterLink
               v-else-if="mediaSet.rootElementId !== null"
@@ -697,6 +792,15 @@ function resetEditSetForm(): void {
   border-color: #e5b8b8;
 }
 
+.media-page__status--success {
+  color: var(--color-olive);
+  border-color: #c8d0ba;
+}
+
+.media-page__order-message {
+  margin-bottom: 1.25rem;
+}
+
 .media-page__grid {
   display: grid;
   max-width: 1745px;
@@ -762,6 +866,14 @@ a.media-page__card:focus-visible {
   gap: 0.5rem;
 }
 
+.media-page__card-order-actions {
+  position: absolute;
+  top: 1rem;
+  left: 1rem;
+  display: flex;
+  gap: 0.5rem;
+}
+
 .media-page__card-action {
   display: inline-flex;
   align-items: center;
@@ -776,21 +888,26 @@ a.media-page__card:focus-visible {
   box-shadow: 0 8px 18px rgb(44 44 44 / 8%);
 }
 
-.media-page__card-action:hover,
+.media-page__card-action:not(:disabled):hover,
-.media-page__card-action:focus-visible {
+.media-page__card-action:not(:disabled):focus-visible {
   color: var(--color-olive);
   border-color: #d4ad5f;
   outline: 3px solid rgb(212 173 95 / 24%);
   outline-offset: 2px;
 }
 
-.media-page__card-action--danger:hover,
+.media-page__card-action--danger:not(:disabled):hover,
-.media-page__card-action--danger:focus-visible {
+.media-page__card-action--danger:not(:disabled):focus-visible {
   color: #9f2d2d;
   border-color: #d9a3a3;
   outline-color: rgb(159 45 45 / 18%);
 }
 
+.media-page__card-action:disabled {
+  cursor: not-allowed;
+  opacity: 0.45;
+}
+
 .media-page__card-icon {
   display: block;
   width: 140px;