package kr.re.etri.autoflow.specification;

import jakarta.annotation.PostConstruct;
import jakarta.persistence.EntityManager;
import jakarta.persistence.criteria.Predicate;
import jakarta.persistence.metamodel.Attribute;
import jakarta.persistence.metamodel.EntityType;
import jakarta.persistence.metamodel.Metamodel;
import kr.re.etri.autoflow.entity.MinioAttachmentEntity;
import lombok.extern.slf4j.Slf4j;
import org.springframework.data.jpa.domain.Specification;
import org.springframework.stereotype.Component;

import java.time.LocalDate;
import java.util.Set;
import java.util.stream.Collectors;

@Slf4j
@Component
public class MinioAttachmentSpecification {

    private final EntityManager entityManager;

    private Set<String> stringFields;

    public MinioAttachmentSpecification(EntityManager entityManager) {
        this.entityManager = entityManager;
    }

    @PostConstruct
    public void init() {
        Metamodel metamodel = entityManager.getMetamodel();
        EntityType<MinioAttachmentEntity> entityType = metamodel.entity(MinioAttachmentEntity.class);

        // 문자열 타입 필드명만 추출
        stringFields = entityType.getAttributes().stream()
                .filter(attr -> attr.getJavaType().equals(String.class))
                .map(Attribute::getName)
                .collect(Collectors.toSet());

        log.info("MinioAttachmentEntity string fields: {}", stringFields);
    }

    public Specification<MinioAttachmentEntity> searchByConditions(
            String refType,
            Integer refId,
            String searchType,
            String keyword,
            LocalDate startDate,
            LocalDate endDate
    ) {
        return (root, query, cb) -> {
            Predicate predicate = cb.conjunction();

            // refType 조건 추가
            if (refType != null && !refType.isBlank()) {
                predicate = cb.and(predicate, cb.equal(root.get("refType"), refType));
            }

            // refId 조건 추가
            if (refId != null ) {
                predicate = cb.and(predicate, cb.equal(root.get("refId"), refId));
            }

            // keyword 검색
            if (keyword != null && !keyword.isEmpty()) {
                if (searchType == null || searchType.isEmpty()
                        || "전체".equalsIgnoreCase(searchType)
                        || "all".equalsIgnoreCase(searchType)) {
                    Predicate orPredicate = cb.disjunction();
                    for (String field : stringFields) {
                        orPredicate = cb.or(orPredicate,
                                cb.like(cb.lower(root.get(field)), "%" + keyword.toLowerCase() + "%"));
                    }
                    predicate = cb.and(predicate, orPredicate);
                } else if (stringFields.contains(searchType)) {
                    predicate = cb.and(predicate,
                            cb.like(cb.lower(root.get(searchType)), "%" + keyword.toLowerCase() + "%"));
                }
            }

            // 날짜 검색
            if (startDate != null) {
                predicate = cb.and(predicate,
                        cb.greaterThanOrEqualTo(root.get("regDt"), startDate.atStartOfDay()));
            }

            if (endDate != null) {
                predicate = cb.and(predicate,
                        cb.lessThanOrEqualTo(root.get("regDt"), endDate.atTime(23, 59, 59)));
            }

            return predicate;
        };
    }
}