#106 Feat: 로드맵 채팅 시 작성하는 자격증을 사용자 맞춤으로 추천해주는 API를 추가한다 (#107)

* #106 Feat: 로드맵 채팅 시 자격증 추천 API를 추가한다

* #106 Feat: 사용자 맞춤형 AI 자격증 request를 추가한다

* #106 Feat: 사용자 맞춤형 AI 자격증 API의 Http 메소드를 POST로 변경한다

Author: 51taek

src/main/java/next/career/domain/openai/service/OpenAiService.java

@@ -557,4 +557,77 @@ private Map<String, Object> setStrengthReportPrompt(String system) {
         );
     }
 
+    public List<String> getCertificationList(String occupation) {
+
+        List<Prompt> certification = promptRepository.findAllByTag("certification");
+
+        String system = certification.stream()
+                .map(Prompt::getContent)
+                .filter(Objects::nonNull)
+                .map(String::trim)
+                .filter(s -> !s.isEmpty())
+                .collect(Collectors.joining("\n"));
+
+        String finalSystemPrompt = system + "\n\n[사용자 희망 직무]\n" + occupation;
+
+        Map<String, Object> body = setCertificationPrompt(finalSystemPrompt);
+
+        try {
+            Map res = requestOpenAI(body);
+            log.info("res = {}", res);
+
+            List<Map<String, Object>> choices = (List<Map<String, Object>>) res.get("choices");
+
+            String content = getContent(choices);
+
+            RoadmapDto.CertificationResponse dto =
+                    MAPPER.readValue(content, RoadmapDto.CertificationResponse.class);
+
+            return Optional.ofNullable(dto.getCertificationList()).orElseGet(List::of)
+                    .stream()
+                    .filter(Objects::nonNull)
+                    .map(String::trim)
+                    .filter(s -> !s.isEmpty())
+                    .distinct()
+                    .limit(10)
+                    .toList();
+
+        } catch (Exception e) {
+            throw new CoreException(GlobalErrorType.GET_CERTIFICATION_ERROR);
+        }
+    }
+
+    private Map<String, Object> setCertificationPrompt(String system) {
+
+        List<Map<String, Object>> messages = new ArrayList<>();
+
+        if (!system.isBlank()) {
+            messages.add(Map.of("role", "system", "content", system));
+        }
+
+        Map<String, Object> responseFormat = Map.of(
+                "type", "json_schema",
+                "json_schema", Map.of(
+                        "name", "certification_response",
+                        "schema", Map.of(
+                                "type", "object",
+                                "properties", Map.of(
+                                        "certificationList", Map.of(
+                                                "type", "array",
+                                                "items", Map.of("type", "string")
+                                        )
+                                ),
+                                "required", List.of("certificationList")
+                        )
+                )
+        );
+
+        return Map.of(
+                "model", "gpt-4o",
+                "messages", messages,
+                "temperature", 0.5,
+                "max_tokens", 800,
+                "response_format", responseFormat
+        );
+    }
 }

src/main/java/next/career/domain/roadmap/controller/RoadmapController.java

@@ -177,6 +177,30 @@ public ApiResponse<RoadmapDto.RoadmapActionRecommendResponse> recommendRoadmapAc
         return ApiResponse.success(response);
     }
 
+    @PostMapping("/certification")
+    @Operation(
+            summary = "사용자 맞춤형 AI 자격증 추천",
+            description = """
+                사용자의 직무 정보를 입력받아, 
+                해당 직무에 적합한 자격증 목록을 AI 모델을 통해 추천합니다.
+
+                예시 요청:
+                {
+                  "occupation": "백엔드 개발자"
+                }
+                """
+    )
+    public ApiResponse<RoadmapDto.CertificationResponse> getCertifications(
+            @io.swagger.v3.oas.annotations.parameters.RequestBody(
+                    description = "자격증 추천 요청 DTO (occupation 필드 필수)",
+                    required = true
+            )
+            @RequestBody RoadmapDto.CertificationRequest request
+    ) {
+        List<String> certifications = roadmapService.getCertifications(request.getOccupation());
+        RoadmapDto.CertificationResponse response = RoadmapDto.CertificationResponse.of(certifications);
+        return ApiResponse.success(response);
+    }
 
 
 }

src/main/java/next/career/domain/roadmap/controller/dto/RoadmapDto.java

@@ -47,4 +47,26 @@ public static class RoadMapUpdateRequest {
         private String period;
         private String experience;
     }
+
+    @Getter
+    @NoArgsConstructor
+    @AllArgsConstructor
+    @Builder
+    public static class CertificationResponse {
+        private List<String> certificationList;
+
+        public static CertificationResponse of(List<String> certificationList) {
+            return CertificationResponse.builder()
+                    .certificationList(certificationList)
+                    .build();
+        }
+    }
+
+    @Getter
+    @NoArgsConstructor
+    @AllArgsConstructor
+    public static class CertificationRequest{
+        private String occupation;
+    }
+
 }

src/main/java/next/career/domain/roadmap/service/RoadmapService.java

@@ -141,4 +141,8 @@ public void updateRoadmapInput(RoadmapDto.RoadMapUpdateRequest request, Member m
 
         roadmapInput.update(request.getCareer(), request.getPeriod(), request.getExperience());
     }
+
+    public List<String> getCertifications(String occupation) {
+        return openAiService.getCertificationList(occupation);
+    }
 }

src/main/java/next/career/global/apiPayload/exception/GlobalErrorType.java

@@ -41,6 +41,7 @@ public enum GlobalErrorType implements ErrorType {
     ROAD_MAP_ACTION_NOT_FOUND(HttpStatus.INTERNAL_SERVER_ERROR, "로드맵 할 일이 존재하지 않습니다"),
     ROAD_MAP_NOT_FOUND(HttpStatus.INTERNAL_SERVER_ERROR, "로드맵이 존재하지 않습니다"),
     GET_RECOMMEND_ROADMAP_ACTION_ERROR(HttpStatus.INTERNAL_SERVER_ERROR, "로드맵 액션 추천에 실패했습니다"),
+    GET_CERTIFICATION_ERROR(HttpStatus.INTERNAL_SERVER_ERROR, "자격증 추천에 실패했습니다"),
 
     MEMBER_OCCUPATION_NOT_FOUND(HttpStatus.INTERNAL_SERVER_ERROR, "추천 직업이 존재하지 않습니다"),