add strategy for controller

src/main/java/ru/soune/no_copy/handler/LoginRequestHandler.java

@@ -0,0 +1,47 @@
+package ru.soune.no_copy.handler;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Component;
+import ru.soune.no_copy.dto.BaseRequest;
+import ru.soune.no_copy.dto.LoginRequest;
+import ru.soune.no_copy.dto.MessageCode;
+import ru.soune.no_copy.exception.NotValidFieldException;
+import ru.soune.no_copy.repository.UserRepository;
+import ru.soune.no_copy.service.AuthService;
+
+import java.util.HashMap;
+import java.util.Map;
+
+@Component
+@RequiredArgsConstructor
+public class LoginRequestHandler implements RequestHandler {
+
+    private final UserRepository userRepository;
+    private final AuthService authService;
+    private final ObjectMapper objectMapper;
+
+    @Override
+    public Map<String, Object> handle(BaseRequest request) {
+        LoginRequest loginRequest = objectMapper.convertValue(request.getMessageBody(), LoginRequest.class);
+
+        if (!userRepository.existsByEmail(loginRequest.getEmail())) {
+            throw new NotValidFieldException("User with email not found: " + loginRequest.getEmail(),
+                    request.getMsgId(), MessageCode.AUTH_EMAIL_NOT_FOUND.getCode(),
+                    MessageCode.AUTH_EMAIL_NOT_FOUND.getDescription());
+        }
+
+        authService.login(loginRequest);
+
+        return fillResponseInfo(request.getMsgId(), MessageCode.SUCCESS.getCode(),
+                MessageCode.SUCCESS.getDescription());
+    }
+
+    private Map<String, Object> fillResponseInfo(Integer msgId, Integer messageCode, String messageDesc) {
+        Map<String, Object> response = new HashMap<>();
+        response.put("msg_id", msgId);
+        response.put("message_code", messageCode);
+        response.put("message_desc", messageDesc);
+        return response;
+    }
+}