package kr.re.etri.autoflow.service;

import kr.re.etri.autoflow.entity.DatasetAttachmentEntity;
import kr.re.etri.autoflow.entity.DatasetEntity;
import kr.re.etri.autoflow.payload.request.BaseSearchRequest;
import kr.re.etri.autoflow.repository.DatasetAttachmentRepository;
import kr.re.etri.autoflow.repository.DatasetRepository;
import kr.re.etri.autoflow.specification.DatasetSpecification;
import lombok.RequiredArgsConstructor;
import org.springframework.beans.BeanUtils;
import org.springframework.data.domain.*;
import org.springframework.data.jpa.domain.Specification;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.web.multipart.MultipartFile;

import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
import java.time.format.DateTimeParseException;
import java.util.ArrayList;
import java.util.List;
import java.util.Optional;
import java.util.UUID;

@Service
@RequiredArgsConstructor
@Transactional(readOnly = true)
public class DatasetService {

    private final DatasetRepository datasetRepository;
    private final DatasetAttachmentRepository datasetAttachmentRepository;

    private final DatasetSpecification datasetSpecification;

    private final DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd");

    public List<DatasetEntity> findAll() {
        return datasetRepository.findAll();
    }

    public Optional<DatasetEntity> findById(Long id) {
        return datasetRepository.findById(id);
    }

    public Page<DatasetEntity> search(BaseSearchRequest request) {
        int pageIndex = request.getPage() > 0 ? request.getPage() - 1 : 0;

        Pageable pageable = PageRequest.of(
                pageIndex,
                request.getSize(),
                Sort.by(Sort.Direction.fromString(request.getSortDirection()), request.getSortField())
        );

        LocalDate startDate = parseDate(request.getStartDate());
        LocalDate endDate = parseDate(request.getEndDate());

        Specification<DatasetEntity> spec = datasetSpecification.searchByConditions(
                request.getSearchType(),
                request.getKeyword(),
                startDate,
                endDate
        );

        return datasetRepository.findAll(spec, pageable);
    }

    private LocalDate parseDate(String dateStr) {
        if (dateStr == null || dateStr.isBlank()) return null;
        try {
            return LocalDate.parse(dateStr, formatter);
        } catch (DateTimeParseException e) {
            throw new IllegalArgumentException("날짜 형식이 잘못되었습니다. yyyy-MM-dd 형식이어야 합니다: " + dateStr);
        }
    }

    @Transactional
    public DatasetEntity create(DatasetEntity dataset) {
        return datasetRepository.save(dataset);
    }

    @Transactional
    public Optional<DatasetEntity> update(Long id) {
        return datasetRepository.findById(id);
    }

    @Transactional
    public boolean delete(Long id) {
        if (!datasetRepository.existsById(id)) {
            return false;
        }
        datasetRepository.deleteById(id);
        return true;
    }

    @Transactional
    public DatasetEntity createWithFiles(DatasetEntity dataset, List<MultipartFile> files) {
        DatasetEntity saved = datasetRepository.save(dataset);

        if (files != null && !files.isEmpty()) {
            List<DatasetAttachmentEntity> attachments = new ArrayList<>();
            for (MultipartFile file : files) {
                DatasetAttachmentEntity attachment = DatasetAttachmentEntity.builder()
                        .originalName(file.getOriginalFilename())
                        .storedName(storeFile(file)) // 실제 파일 저장 로직 필요
                        .contentType(file.getContentType())
                        .size(file.getSize())
                        .regUserId(dataset.getRegUserId())
                        .regDt(LocalDateTime.now())
                        .title(file.getOriginalFilename())
                        .version(1)
                        .description("")
                        .build();
                attachments.add(attachment);
            }
            // attachment 저장
            datasetAttachmentRepository.saveAll(attachments);

            // 엔티티에 첨부파일 리스트 설정
            //saved.setFiles(attachments);
        }

        return saved;
    }

    // 파일 저장 예시
    private String storeFile(MultipartFile file) {
        // TODO: MinIO 또는 로컬 스토리지에 실제 저장 후 경로 반환
        String storedName = UUID.randomUUID() + "-" + file.getOriginalFilename();
        // file.transferTo(new File(uploadPath + storedName));
        return storedName;
    }

}