package com.yunhai.cms.service.impl;

import com.yunhai.cms.entity.CmsLink;
import com.yunhai.cms.entity.CmsSite;
import com.yunhai.cms.event.SiteContentChangedEvent;
import com.yunhai.cms.model.dto.DeleteRequest;
import com.yunhai.cms.model.dto.LinkSaveRequest;
import com.yunhai.cms.model.vo.LinkVo;
import com.yunhai.cms.repository.CmsLinkRepository;
import com.yunhai.platform.apistd.BizException;
import com.yunhai.platform.utils.exception.ErrorCode;
import com.yunhai.platform.utils.model.BoaUser;
import lombok.RequiredArgsConstructor;
import org.springframework.context.ApplicationEventPublisher;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.util.StringUtils;

import java.util.ArrayList;
import java.util.List;

/**
 * 友情链接管理（方案 §9.1 友情链接管理）。
 */
@Service
@RequiredArgsConstructor
public class LinkService {

    private final CmsLinkRepository linkRepository;
    private final SiteService siteService;
    private final ApplicationEventPublisher eventPublisher;
    private final AttachmentService attachmentService;

    public List<LinkVo> list(BoaUser user, Integer siteId) {
        siteService.requireManageable(user, siteId);
        List<CmsLink> links = linkRepository.findBySiteIdOrderByGroupNameAscSortNoAscIdAsc(siteId);
        List<LinkVo> result = new ArrayList<>();
        for (CmsLink l : links) {
            result.add(LinkVo.of(l));
        }
        return result;
    }

    @Transactional
    public LinkVo save(BoaUser user, LinkSaveRequest req) {
        CmsSite site = siteService.requireManageable(user, req.getSiteId());
        if (!StringUtils.hasText(req.getLinkUrl())
                || !(req.getLinkUrl().startsWith("http://") || req.getLinkUrl().startsWith("https://")
                || req.getLinkUrl().startsWith("/"))) {
            throw new BizException(ErrorCode.PARAM_ERROR, "链接地址必须以 http(s):// 或 / 开头");
        }
        CmsLink link;
        if (req.getId() == null) {
            link = new CmsLink();
            link.setSiteId(site.getId());
        } else {
            link = linkRepository.findById(req.getId())
                    .orElseThrow(() -> new BizException(ErrorCode.PARAM_ERROR, "友链不存在"));
            if (!link.getSiteId().equals(site.getId())) {
                throw new BizException(ErrorCode.FORBIDDEN, "无权修改该友链");
            }
        }
        link.setGroupName(StringUtils.hasText(req.getGroupName()) ? req.getGroupName() : "default");
        link.setName(req.getName());
        link.setLogoUrl(req.getLogoUrl());
        link.setLinkUrl(req.getLinkUrl());
        link.setSortNo(req.getSortNo() == null ? 0 : req.getSortNo());
        link.setStatus(req.getStatus() == null ? 1 : req.getStatus());
        link = linkRepository.save(link);
        // B2 附件引用：先解引用，logoUrl 非空才回写（编辑换图/清空 logo 旧图均回未使用）；幂等
        attachmentService.release("link", link.getId());
        if (StringUtils.hasText(req.getLogoUrl())) {
            attachmentService.markUsed(site.getId(), req.getLogoUrl(), "link", link.getId());
        }
        eventPublisher.publishEvent(new SiteContentChangedEvent(site.getId(), "link"));
        return LinkVo.of(link);
    }

    @Transactional
    public void delete(BoaUser user, DeleteRequest req) {
        CmsSite site = siteService.requireManageable(user, req.getSiteId());
        CmsLink link = linkRepository.findById(req.getId())
                .orElseThrow(() -> new BizException(ErrorCode.PARAM_ERROR, "友链不存在"));
        if (!link.getSiteId().equals(site.getId())) {
            throw new BizException(ErrorCode.FORBIDDEN, "无权删除该友链");
        }
        linkRepository.delete(link);
        attachmentService.release("link", link.getId());
        eventPublisher.publishEvent(new SiteContentChangedEvent(site.getId(), "link"));
    }
}