implement ConfirmUserEmail use case

backend/app/User/UseCases/ConfirmUserEmail/ConfirmUserEmail.php

@@ -0,0 +1,65 @@
+<?php
+
+namespace App\User\UseCases\ConfirmUserEmail;
+
+use App\Auth\Clock;
+use App\Auth\PasswordHasher;
+use App\Email\EmailConfirmationToken\EmailConfirmationTokenRepository;
+use App\Exceptions\BadRequestException;
+use App\User\User;
+use App\User\UserRepository;
+use DomainException;
+
+class ConfirmUserEmail
+{
+    private const MIN_PASSWORD_LENGTH = 8;
+
+    public function __construct(
+        private UserRepository $userRepo,
+        private EmailConfirmationTokenRepository $tokenRepo,
+        private PasswordHasher $hasher,
+        private Clock $clock,
+    ) {}
+
+    /**
+     * @throws BadRequestException
+     * @throws DomainException
+     */
+    public function execute(ConfirmUserEmailRequest $request): void
+    {
+        if ($request->token === null || $request->token === '') {
+            throw new BadRequestException('token is required');
+        }
+        if ($request->password === null || $request->password === '') {
+            throw new BadRequestException('password is required');
+        }
+        if (strlen($request->password) < self::MIN_PASSWORD_LENGTH) {
+            throw new BadRequestException(
+                'password must be at least '
+                .self::MIN_PASSWORD_LENGTH.' characters'
+            );
+        }
+
+        $token = $this->tokenRepo->findByToken($request->token);
+        if ($token === null) {
+            throw new DomainException('token not found');
+        }
+
+        $now = $this->clock->now();
+        if ($token->getAvailableTo() < $now) {
+            throw new DomainException('token expired');
+        }
+
+        $user = $token->getUser();
+        $confirmedUser = new User(
+            id: $user->getId(),
+            email: $user->getEmail(),
+            displayName: $user->getDisplayName(),
+            passwordHash: $this->hasher->hash($request->password),
+            isAdmin: $user->isAdmin(),
+            emailConfirmedAt: $now,
+        );
+        $this->userRepo->update($confirmedUser);
+        $this->tokenRepo->delete($token->getId());
+    }
+}

backend/app/User/UseCases/ConfirmUserEmail/ConfirmUserEmailRequest.php

@@ -0,0 +1,11 @@
+<?php
+
+namespace App\User\UseCases\ConfirmUserEmail;
+
+class ConfirmUserEmailRequest
+{
+    public function __construct(
+        public ?string $token,
+        public ?string $password,
+    ) {}
+}