package com.sb.web.account.service;

import com.sb.web.account.domain.BudgetOnetime;
import com.sb.web.account.dto.BudgetOnetimeRequest;
import com.sb.web.account.dto.BudgetOnetimeResponse;
import com.sb.web.account.mapper.BudgetOnetimeMapper;
import com.sb.web.common.exception.ApiException;
import lombok.RequiredArgsConstructor;
import org.springframework.http.HttpStatus;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.util.List;

@Service
@RequiredArgsConstructor
public class BudgetOnetimeService {

    private final BudgetOnetimeMapper mapper;

    public List<BudgetOnetimeResponse> list(Long memberId) {
        return mapper.findByMember(memberId).stream()
                .map(b -> {
                    long spent = mapper.sumExpenseInRange(
                            memberId, b.getStartDate(), b.getEndDate(), b.getCategory());
                    return BudgetOnetimeResponse.from(b, spent);
                })
                .toList();
    }

    @Transactional
    public BudgetOnetimeResponse create(BudgetOnetimeRequest req, Long memberId) {
        validate(req);
        BudgetOnetime b = BudgetOnetime.builder()
                .memberId(memberId)
                .title(req.getTitle().trim())
                .category(blankToNull(req.getCategory()))
                .amount(req.getAmount())
                .startDate(req.getStartDate())
                .endDate(req.getEndDate())
                .build();
        mapper.insert(b);
        long spent = mapper.sumExpenseInRange(memberId, b.getStartDate(), b.getEndDate(), b.getCategory());
        return BudgetOnetimeResponse.from(b, spent);
    }

    @Transactional
    public BudgetOnetimeResponse update(Long id, BudgetOnetimeRequest req, Long memberId) {
        validate(req);
        BudgetOnetime b = mustFind(id, memberId);
        b.setTitle(req.getTitle().trim());
        b.setCategory(blankToNull(req.getCategory()));
        b.setAmount(req.getAmount());
        b.setStartDate(req.getStartDate());
        b.setEndDate(req.getEndDate());
        mapper.update(b);
        long spent = mapper.sumExpenseInRange(memberId, b.getStartDate(), b.getEndDate(), b.getCategory());
        return BudgetOnetimeResponse.from(b, spent);
    }

    @Transactional
    public void delete(Long id, Long memberId) {
        mustFind(id, memberId);
        mapper.delete(id, memberId);
    }

    private void validate(BudgetOnetimeRequest req) {
        if (req.getEndDate().isBefore(req.getStartDate())) {
            throw new ApiException(HttpStatus.BAD_REQUEST, "종료일이 시작일보다 빠를 수 없습니다.");
        }
    }

    private BudgetOnetime mustFind(Long id, Long memberId) {
        BudgetOnetime b = mapper.findByIdAndMember(id, memberId);
        if (b == null) throw new ApiException(HttpStatus.NOT_FOUND, "1회성 예산을 찾을 수 없습니다.");
        return b;
    }

    private String blankToNull(String s) {
        return (s == null || s.isBlank()) ? null : s.trim();
    }
}