add json user repository

app/User/JsonUserRepository.php

@@ -0,0 +1,84 @@
+<?php
+
+namespace App\User;
+
+use App\User\UseCases\CreateUserDto;
+use App\ValueObjects\EmailAddress;
+
+class JsonUserRepository implements UserRepository
+{
+    private string $filePath;
+
+    public function __construct()
+    {
+        $this->filePath = __DIR__ . '/../../data/users.json';
+    }
+
+    public function create(CreateUserDto $dto): User
+    {
+        $users = $this->readUsers();
+        $id = $this->getNextId($users);
+
+        $users[] = [
+            'id' => $id,
+            'email' => (string) $dto->email,
+        ];
+        $this->writeUsers($users);
+
+        return new User(
+            id: $id,
+            email: $dto->email,
+        );
+    }
+
+    public function find(int $id): ?User
+    {
+        $users = $this->readUsers();
+
+        foreach ($users as $data) {
+            if ($data['id'] === $id) {
+                return new User(
+                    id: $data['id'],
+                    email: new EmailAddress($data['email']),
+                );
+            }
+        }
+
+        return null;
+    }
+
+    private function readUsers(): array
+    {
+        if (!file_exists($this->filePath)) {
+            return [];
+        }
+
+        $content = file_get_contents($this->filePath);
+
+        return json_decode($content, true) ?? [];
+    }
+
+    private function writeUsers(array $users): void
+    {
+        file_put_contents(
+            $this->filePath,
+            json_encode($users, JSON_PRETTY_PRINT)
+        );
+    }
+
+    private function getNextId(array $users): int
+    {
+        if (empty($users)) {
+            return 0;
+        }
+
+        $maxId = -1;
+        foreach ($users as $user) {
+            if ($user['id'] > $maxId) {
+                $maxId = $user['id'];
+            }
+        }
+
+        return $maxId + 1;
+    }
+}