[KOBG-13] Lesson 관련 api 제작

build.gradle

@@ -31,6 +31,7 @@ dependencies {
     implementation 'org.springframework.boot:spring-boot-starter-validation'
     implementation 'org.springframework.boot:spring-boot-starter-web'
     implementation 'org.springframework.boot:spring-boot-starter-data-redis'
+    implementation 'org.springframework.boot:spring-boot-starter-webflux'
 
     // google api client
     implementation 'com.google.api-client:google-api-client:2.4.0'

src/main/java/com/edu/kobridge/global/common/filter/JwtAuthorizationFilter.java

@@ -8,7 +8,7 @@
 import com.edu.kobridge.global.error.exception.FilterException;
 import com.edu.kobridge.global.util.JwtUtil;
 import com.edu.kobridge.global.util.ResponseUtil;
-import com.edu.kobridge.user.domain.entity.User;
+import com.edu.kobridge.module.user.domain.entity.User;
 
 import io.jsonwebtoken.ExpiredJwtException;
 import io.jsonwebtoken.JwtException;
@@ -31,6 +31,7 @@ public class JwtAuthorizationFilter implements Filter {
 	// JWT 검사 제외할 경로 설정
 	final String LOGIN_PATH = "/api/user/google-login";
 	final String TOKEN_PATH = "/api/user/token";
+	final String LESSON_PATH = "/api/lesson/chat";
 
 	@Override
 	public void init(FilterConfig filterConfig) throws ServletException {
@@ -54,13 +55,16 @@ public void doFilter(ServletRequest request, ServletResponse response, FilterCha
 			return;
 		}
 
-		// 로그인 및 토큰 재발급 요청은 JWT 인증 필터링 없이 처리
+		// 로그인 및 토큰 재발급 요청, 레슨 시도는 JWT 인증 필터링 없이 처리
 		if (requestURI.equals(LOGIN_PATH) && req.getMethod().equals("GET")) {
 			chain.doFilter(request, response);
 			return;
 		} else if (requestURI.equals(TOKEN_PATH) && req.getMethod().equals("GET")) {
 			chain.doFilter(request, response);
 			return;
+		} else if (requestURI.startsWith(LESSON_PATH)) {
+			chain.doFilter(request, response);
+			return;
 		} else if (requestURI.contains("test/no-auth")) {
 			chain.doFilter(request, response);
 			return;

src/main/java/com/edu/kobridge/global/config/WebClientConfig.java

@@ -0,0 +1,30 @@
+package com.edu.kobridge.global.config;
+
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.MediaType;
+import org.springframework.web.reactive.function.client.WebClient;
+
+@Configuration
+public class WebClientConfig {
+
+	@Bean
+	public WebClient.Builder webClientBuilder() {
+		return WebClient.builder()
+			.defaultHeader(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_JSON_VALUE);
+	}
+
+	@Bean(name = "pronunciationWebClient")
+	public WebClient pronunciationWebClient(WebClient.Builder builder,
+		@Value("${api.e-pre-tx.url}") String baseUrl) {
+		return builder.baseUrl(baseUrl).build();
+	}
+
+	@Bean(name = "chatGptWebClient")
+	public WebClient chatGptWebClient(WebClient.Builder builder,
+		@Value("${api.chat-gpt.url}") String baseUrl) {
+		return builder.baseUrl(baseUrl).build();
+	}
+}

src/main/java/com/edu/kobridge/global/enums/LangType.java

@@ -19,11 +19,11 @@ public enum LangType {
 		this.code = code;
 		this.name = name;
 	}
-
-	public static UserRoleType of(String code) {
-		return Arrays.stream(UserRoleType.values())
+  
+	public static LangType of(String code) {
+		return Arrays.stream(LangType.values())
 			.filter(r -> r.getCode().equals(code))
 			.findAny()
-			.orElse(null);
+			.orElse(ENG);
 	}
 }

src/main/java/com/edu/kobridge/global/util/FileUtil.java

@@ -0,0 +1,29 @@
+package com.edu.kobridge.global.util;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.URL;
+import java.util.Base64;
+
+import org.springframework.stereotype.Component;
+
+import com.edu.kobridge.global.error.GlobalErrorCode;
+import com.edu.kobridge.global.error.exception.AppException;
+
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+
+@Component
+@RequiredArgsConstructor
+@Slf4j
+public class FileUtil {
+	public String convertS3UrlToBase64(String s3Url) {
+		try (InputStream in = new URL(s3Url).openStream()) {
+			byte[] fileBytes = in.readAllBytes();
+			return Base64.getEncoder().encodeToString(fileBytes);
+		} catch (IOException e) {
+			log.error("[FileUtil] file convert error -- " + e.getMessage());
+			throw new AppException(GlobalErrorCode.INTERNAL_SERVER_ERROR);
+		}
+	}
+}

src/main/java/com/edu/kobridge/global/util/GoogleOAuthUtil.java

@@ -8,8 +8,8 @@
 import org.springframework.stereotype.Component;
 
 import com.edu.kobridge.global.error.exception.AppException;
-import com.edu.kobridge.user.domain.entity.User;
-import com.edu.kobridge.user.error.UserErrorCode;
+import com.edu.kobridge.module.user.domain.entity.User;
+import com.edu.kobridge.module.user.error.UserErrorCode;
 import com.google.api.client.googleapis.auth.oauth2.GoogleIdToken;
 import com.google.api.client.googleapis.auth.oauth2.GoogleIdTokenVerifier;
 import com.google.api.client.googleapis.javanet.GoogleNetHttpTransport;

src/main/java/com/edu/kobridge/global/util/JwtUtil.java

@@ -11,8 +11,8 @@
 import com.edu.kobridge.global.enums.JwtVo;
 import com.edu.kobridge.global.error.GlobalErrorCode;
 import com.edu.kobridge.global.error.exception.AppException;
-import com.edu.kobridge.user.domain.entity.User;
-import com.edu.kobridge.user.domain.repository.UserRepository;
+import com.edu.kobridge.module.user.domain.entity.User;
+import com.edu.kobridge.module.user.domain.repository.UserRepository;
 
 import io.jsonwebtoken.Claims;
 import io.jsonwebtoken.Header;

src/main/java/com/edu/kobridge/infra/api/chatgpt/ChatGptService.java

@@ -0,0 +1,91 @@
+package com.edu.kobridge.infra.api.chatgpt;
+
+import java.util.List;
+import java.util.Map;
+
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.http.HttpStatusCode;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+import org.springframework.web.reactive.function.client.WebClient;
+
+import com.edu.kobridge.global.enums.LangType;
+import com.edu.kobridge.global.error.exception.AppException;
+import com.edu.kobridge.infra.api.chatgpt.error.ChatGptErrorCode;
+import com.edu.kobridge.infra.api.chatgpt.res.ChatGptCorrectionResDto;
+import com.edu.kobridge.infra.api.chatgpt.res.ChatGptResDto;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import reactor.core.publisher.Mono;
+
+@Service
+@RequiredArgsConstructor
+@Transactional(readOnly = true)
+@Slf4j
+public class ChatGptService {
+
+	@Value("${api.chat-gpt.key}")
+	private String key;
+
+	@Value("${api.chat-gpt.model}")
+	private String model;
+
+	private final WebClient chatGptWebClient;
+
+	public ChatGptCorrectionResDto postAnswerCorrectionAndResponse(String userSentence, Boolean isNextChatExist,
+		LangType lang) {
+		String userPrompt = String.format(
+			"User sentence: %s | NextChat: %s | Language: %s:",
+			userSentence, isNextChatExist, lang.getName()
+		);
+
+		Map<String, Object> request = Map.of(
+			"model", model,
+			"input", List.of(
+				Map.of("role", "system", "content",
+					"너는 한국어 학습자를 위한 교정 선생님이자 친근한 대화 파트너야. " +
+						"항상 아래 JSON 형식으로만 답해. 출력은 반드시 한국어로 해.\n\n" +
+						"{ \"correction\": \"교정된 한국어 문장\", " +
+						"\"reason\": \"제공하는 교정 이유 (선생님 톤)\", " +
+						"\"translation\": \"Language 로 번역된 correction\", " +
+						"\"response\": \"교정된 문장에 대한 답변 / isNextChatExist 이 false 이면 답변 후 대화 마무리\"}\n\n"
+						+
+						"규칙:\n" +
+						"- correction / reason → 선생님 톤\n" +
+						"- response → 친구처럼 친근한 톤\n" +
+						"- 반드시 유효한 JSON만 출력하고, JSON 외의 다른 텍스트는 출력하지 마."
+				),
+				Map.of("role", "user", "content", userPrompt)
+			),
+			"temperature", 0.7
+		);
+
+		ObjectMapper objectMapper = new ObjectMapper();
+		try {
+			ChatGptResDto chatGptRes = chatGptWebClient.post()
+				.header("Authorization", "Bearer " + key)
+				.bodyValue(request)
+				.retrieve()
+				.onStatus(HttpStatusCode::isError, resp ->
+					resp.bodyToMono(String.class)
+						.flatMap(body -> {
+							log.error("[ChatGPT API] connection error --  Status: {}, Body: {}",
+								resp.statusCode(), body);
+							return Mono.error(new AppException(ChatGptErrorCode.CHAT_GPT_CHAT_API_FAILED));
+						})
+				)
+				.bodyToMono(ChatGptResDto.class)
+				.block();
+
+			String jsonContent = chatGptRes.getOutput().get(0).getContent().get(0).getText();
+
+			return objectMapper.readValue(jsonContent, ChatGptCorrectionResDto.class);
+
+		} catch (Exception e) {
+			log.error("[ChatGPT Chat API] internal error -- " + e.getMessage(), e);
+			throw new AppException(ChatGptErrorCode.CHAT_GPT_CHAT_API_FAILED);
+		}
+	}
+}

src/main/java/com/edu/kobridge/infra/api/chatgpt/error/ChatGptErrorCode.java

@@ -0,0 +1,20 @@
+package com.edu.kobridge.infra.api.chatgpt.error;
+
+import org.springframework.http.HttpStatus;
+
+import com.edu.kobridge.global.error.ErrorCode;
+
+import lombok.Getter;
+
+@Getter
+public enum ChatGptErrorCode implements ErrorCode {
+	CHAT_GPT_CHAT_API_FAILED(HttpStatus.SERVICE_UNAVAILABLE, "chat gpt chat 답변 기능 사용 불가");
+
+	private final HttpStatus httpStatus;
+	private final String message;
+
+	ChatGptErrorCode(HttpStatus httpStatus, String message) {
+		this.httpStatus = httpStatus;
+		this.message = message;
+	}
+}

src/main/java/com/edu/kobridge/infra/api/chatgpt/req/ChatGptReqDto.java

@@ -0,0 +1,35 @@
+package com.edu.kobridge.infra.api.chatgpt.req;
+
+import java.util.List;
+
+import lombok.AccessLevel;
+import lombok.Builder;
+import lombok.Getter;
+
+@Getter
+@Builder(access = AccessLevel.PRIVATE)
+public class ChatGptReqDto {
+	private final String model;
+	private final List<Message> messages;
+
+	@Getter
+	@Builder(access = AccessLevel.PRIVATE)
+	public static class Message {
+		private final String role;
+		private final String content;
+
+		public static Message of(String role, String content) {
+			return Message.builder()
+				.role(role)
+				.content(content)
+				.build();
+		}
+	}
+
+	public static ChatGptReqDto of(String model, List<Message> messages) {
+		return ChatGptReqDto.builder()
+			.model(model)
+			.messages(messages)
+			.build();
+	}
+}

src/main/java/com/edu/kobridge/infra/api/chatgpt/res/ChatGptCorrectionResDto.java

@@ -0,0 +1,15 @@
+package com.edu.kobridge.infra.api.chatgpt.res;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+@Data
+@NoArgsConstructor
+@AllArgsConstructor
+public class ChatGptCorrectionResDto {
+	private String correction;
+	private String reason;
+	private String translation;
+	private String response;
+}

src/main/java/com/edu/kobridge/infra/api/chatgpt/res/ChatGptResDto.java

@@ -0,0 +1,53 @@
+package com.edu.kobridge.infra.api.chatgpt.res;
+
+import java.util.List;
+
+import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+@Data
+@NoArgsConstructor
+@AllArgsConstructor
+@JsonIgnoreProperties(ignoreUnknown = true)
+public class ChatGptResDto {
+	private String id;
+	private String object;
+	private long created_at;
+	private String status;
+	private List<Output> output;
+	private Usage usage;
+
+	@Data
+	@NoArgsConstructor
+	@AllArgsConstructor
+	@JsonIgnoreProperties(ignoreUnknown = true)
+	public static class Output {
+		private String id;
+		private String type;
+		private String status;
+		private List<Content> content;
+		private String role;
+	}
+
+	@Data
+	@NoArgsConstructor
+	@AllArgsConstructor
+	@JsonIgnoreProperties(ignoreUnknown = true)
+	public static class Content {
+		private String type;
+		private String text; // JSON 문자열 그대로 저장
+	}
+
+	@Data
+	@NoArgsConstructor
+	@AllArgsConstructor
+	@JsonIgnoreProperties(ignoreUnknown = true)
+	public static class Usage {
+		private int input_tokens;
+		private int output_tokens;
+		private int total_tokens;
+	}
+}