BJS2-77358 Создание и настройка скиллов (#2967)

* Created custom exception DataValidationException. Created new packages with DTO and controller with service. Also created a new mapper interface SkillMapper with methods for mapping.

* Added new method in SkillController. New method acquireSkillFromOffers in SkillService.

* Fixed few issues with wrappers.

* Added exceptions in acquireSkillFromOffers. Mapping to UserSkillGuarantee now is in default method in SkillMapper.

* Moved validateSkill in SkillService for cleaner Controller. Added annotations for all methods from controller for rest requests.

Author: danbg12

src/main/java/school/faang/user_service/controller/SkillController.java

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+package school.faang.user_service.controller;
+
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+import school.faang.user_service.dto.skill.SkillCandidateDto;
+import school.faang.user_service.dto.skill.SkillDto;
+import school.faang.user_service.service.SkillService;
+
+import java.util.List;
+
+@Slf4j
+@RestController
+@RequestMapping("/skills")
+@RequiredArgsConstructor
+public class SkillController {
+    private final SkillService skillService;
+
+    @PostMapping
+    public SkillDto create(@RequestBody SkillDto skill) {
+        return skillService.create(skill);
+    }
+
+    @GetMapping(params = "userId")
+    public List<SkillDto> getUserSkills(@RequestParam Long userId) {
+        return skillService.getUserSkills(userId);
+    }
+
+    @GetMapping(value = "/offered", params = "userId")
+    public List<SkillCandidateDto> getOfferedSkills(@RequestParam long userId) {
+        return skillService.getOfferedSkills(userId);
+    }
+
+    @GetMapping(value = "/acquire", params = {"skillId", "userId"})
+    public SkillDto acquireSkillFromOffers(@RequestParam long skillId, @RequestParam long userId) {
+        return skillService.acquireSkillFromOffers(skillId, userId);
+    }
+}

src/main/java/school/faang/user_service/dto/skill/SkillCandidateDto.java

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+package school.faang.user_service.dto.skill;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+
+@Data
+@AllArgsConstructor
+public class SkillCandidateDto {
+    private SkillDto skill;
+    private Long offersAmount;
+}

src/main/java/school/faang/user_service/dto/skill/SkillDto.java

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+package school.faang.user_service.dto.skill;
+
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+@Data
+@NoArgsConstructor
+public class SkillDto {
+    private Long id;
+    private String title;
+}

src/main/java/school/faang/user_service/exception/DataValidationException.java

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+package school.faang.user_service.exception;
+
+public class DataValidationException extends RuntimeException {
+    public DataValidationException(String message) {
+        super(message);
+    }
+}

src/main/java/school/faang/user_service/mapper/SkillMapper.java

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+package school.faang.user_service.mapper;
+
+import org.mapstruct.Mapper;
+import school.faang.user_service.dto.skill.SkillCandidateDto;
+import school.faang.user_service.dto.skill.SkillDto;
+import school.faang.user_service.entity.Skill;
+import school.faang.user_service.entity.UserSkillGuarantee;
+import school.faang.user_service.entity.recommendation.SkillOffer;
+import school.faang.user_service.repository.UserRepository;
+
+@Mapper(componentModel = "spring")
+public interface SkillMapper {
+    Skill toEntity(SkillDto skillDto);
+
+    SkillDto toDto(Skill skill);
+
+    default SkillCandidateDto toSkillCandidateDto(SkillDto skillDto, long count) {
+        return new SkillCandidateDto(skillDto, count);
+    }
+
+    default UserSkillGuarantee toUserSkillGuarantee(UserRepository userRepository,
+                                                    SkillOffer offer,
+                                                    long userId) {
+        return UserSkillGuarantee.builder()
+                .user(userRepository.getReferenceById(userId))
+                .skill(offer.getSkill())
+                .guarantor(offer.getRecommendation().getAuthor())
+                .build();
+    }
+}

src/main/java/school/faang/user_service/service/SkillService.java

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+package school.faang.user_service.service;
+
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+import school.faang.user_service.dto.skill.SkillCandidateDto;
+import school.faang.user_service.dto.skill.SkillDto;
+import school.faang.user_service.entity.Skill;
+import school.faang.user_service.entity.UserSkillGuarantee;
+import school.faang.user_service.entity.recommendation.SkillOffer;
+import school.faang.user_service.exception.DataValidationException;
+import school.faang.user_service.mapper.SkillMapper;
+import school.faang.user_service.repository.SkillRepository;
+import school.faang.user_service.repository.UserRepository;
+import school.faang.user_service.repository.UserSkillGuaranteeRepository;
+import school.faang.user_service.repository.recommendation.SkillOfferRepository;
+
+import java.util.List;
+import java.util.Objects;
+import java.util.function.Function;
+import java.util.stream.Collectors;
+
+@Slf4j
+@Service
+@RequiredArgsConstructor
+public class SkillService {
+    private final SkillRepository skillRepository;
+    private final SkillMapper skillMapper;
+    private final SkillOfferRepository offerRepository;
+    private final UserSkillGuaranteeRepository guaranteeRepository;
+    private final UserRepository userRepository;
+    private static final int MIN_SKILL_OFFERS = 3;
+
+    public SkillDto create(SkillDto skill) {
+        validateSkill(skill);
+        if (!skillRepository.existsByTitle(skill.getTitle())) {
+            Skill newSkill = skillRepository.save(skillMapper.toEntity(skill));
+            return skillMapper.toDto(newSkill);
+        }
+        throw new DataValidationException("Skill " + skill.getTitle() + " already exists!");
+    }
+
+    public List<SkillCandidateDto> getOfferedSkills(long userId) {
+        return skillRepository.findSkillsOfferedToUser(userId).stream()
+                .map(skillMapper::toDto)
+                .collect(Collectors.groupingBy(Function.identity(), Collectors.counting()))
+                .entrySet().stream()
+                .map(entry -> skillMapper.toSkillCandidateDto(entry.getKey(), entry.getValue()))
+                .collect(Collectors.toList());
+    }
+
+    @Transactional
+    public SkillDto acquireSkillFromOffers(long skillId, long userId) {
+        if (skillRepository.findUserSkill(skillId, userId).isPresent()) {
+            throw new DataValidationException("User already have this skill!");
+        }
+        if (offerRepository.findAllOffersOfSkill(skillId, userId).size() < MIN_SKILL_OFFERS) {
+            throw new DataValidationException("Not enough skill offers!");
+        }
+        skillRepository.assignSkillToUser(skillId, userId);
+        for (SkillOffer offer : offerRepository.findAllOffersOfSkill(skillId, userId)) {
+            UserSkillGuarantee skillGuarantor =
+                    skillMapper.toUserSkillGuarantee(userRepository, offer, userId);
+            guaranteeRepository.save(skillGuarantor);
+        }
+        return skillMapper.toDto(skillRepository.getReferenceById(skillId));
+    }
+
+    public List<SkillDto> getUserSkills(long userId) {
+        return skillRepository.findAllByUserId(userId)
+                .stream()
+                .map(skillMapper::toDto)
+                .toList();
+    }
+
+    private void validateSkill(SkillDto skill) {
+        if (Objects.isNull(skill)) {
+            log.error("The SkillDto submitted in method validateSkill is null!");
+            throw new DataValidationException("SkillDto from argument is null!");
+        }
+        if (skill.getTitle() == null || skill.getTitle().isBlank()) {
+            log.error("The SkillDto submitted to method validateSkill doesn't have a name!");
+            throw new DataValidationException("SkillDto has no name!");
+        }
+    }
+}