Introduce pluggable email and image upload

src/main/java/com/openisle/controller/AuthController.java

@@ -1,7 +1,7 @@
 package com.openisle.controller;
 
 import com.openisle.model.User;
-import com.openisle.service.EmailService;
+import com.openisle.service.EmailSender;
 import com.openisle.service.JwtService;
 import com.openisle.service.UserService;
 import lombok.Data;
@@ -42,7 +42,7 @@ curl -X POST http://localhost:8080/api/auth/login \
 public class AuthController {
     private final UserService userService;
     private final JwtService jwtService;
-    private final EmailService emailService;
+    private final EmailSender emailService;
 
     @PostMapping("/register")
     public ResponseEntity<?> register(@RequestBody RegisterRequest req) {

src/main/java/com/openisle/controller/UserController.java

@@ -0,0 +1,53 @@
+package com.openisle.controller;
+
+import com.openisle.model.User;
+import com.openisle.service.ImageUploader;
+import com.openisle.service.UserService;
+import lombok.Data;
+import lombok.RequiredArgsConstructor;
+import org.springframework.http.ResponseEntity;
+import org.springframework.security.core.Authentication;
+import org.springframework.web.bind.annotation.*;
+import org.springframework.web.multipart.MultipartFile;
+
+import java.io.IOException;
+import java.util.Map;
+
+@RestController
+@RequestMapping("/api/users")
+@RequiredArgsConstructor
+public class UserController {
+    private final UserService userService;
+    private final ImageUploader imageUploader;
+
+    @GetMapping("/me")
+    public ResponseEntity<UserDto> me(Authentication auth) {
+        User user = userService.findByUsername(auth.getName()).orElseThrow();
+        return ResponseEntity.ok(toDto(user));
+    }
+
+    @PostMapping("/me/avatar")
+    public ResponseEntity<?> uploadAvatar(@RequestParam("file") MultipartFile file,
+                                          Authentication auth) throws IOException {
+        String url = imageUploader.upload(file.getBytes(), file.getOriginalFilename());
+        userService.updateAvatar(auth.getName(), url);
+        return ResponseEntity.ok(Map.of("url", url));
+    }
+
+    private UserDto toDto(User user) {
+        UserDto dto = new UserDto();
+        dto.setId(user.getId());
+        dto.setUsername(user.getUsername());
+        dto.setEmail(user.getEmail());
+        dto.setAvatar(user.getAvatar());
+        return dto;
+    }
+
+    @Data
+    private static class UserDto {
+        private Long id;
+        private String username;
+        private String email;
+        private String avatar;
+    }
+}