package com.tcm.training.admin.system.service;

import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.tcm.training.admin.common.PageResponse;
import com.tcm.training.admin.system.dto.ActivityNoticeCreateRequest;
import com.tcm.training.admin.system.entity.ActivityNotice;
import com.tcm.training.admin.system.mapper.ActivityNoticeMapper;
import com.tcm.training.admin.system.vo.ActivityNoticeListItemVO;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

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

@Service
public class ActivityNoticeAppService {

    private final ActivityNoticeMapper activityNoticeMapper;

    public ActivityNoticeAppService(ActivityNoticeMapper activityNoticeMapper) {
        this.activityNoticeMapper = activityNoticeMapper;
    }

    public PageResponse<ActivityNoticeListItemVO> page(int page, int pageSize, String title) {
        LambdaQueryWrapper<ActivityNotice> qw = new LambdaQueryWrapper<ActivityNotice>()
                .eq(ActivityNotice::getDeleted, 0)
                .like(title != null && !title.trim().isEmpty(), ActivityNotice::getTitle, title == null ? null : title.trim())
                .orderByDesc(ActivityNotice::getCreatedAt)
                .orderByDesc(ActivityNotice::getId);
        IPage<ActivityNotice> result = activityNoticeMapper.selectPage(new Page<ActivityNotice>(page, pageSize), qw);
        List<ActivityNoticeListItemVO> list = new ArrayList<ActivityNoticeListItemVO>();
        for (ActivityNotice item : result.getRecords()) {
            list.add(toListItem(item));
        }
        return PageResponse.of(list, result.getTotal(), result.getCurrent(), result.getSize());
    }

    @Transactional
    public ActivityNoticeListItemVO create(ActivityNoticeCreateRequest request) {
        ActivityNotice item = new ActivityNotice();
        item.setTitle(normalizeTitle(request.getTitle()));
        item.setContentHtml(normalizeContent(request.getContentHtml()));
        item.setDeleted(0);
        activityNoticeMapper.insert(item);
        return toListItem(requireItem(item.getId()));
    }

    @Transactional
    public void delete(Long id) {
        requireItem(id);
        activityNoticeMapper.deleteById(id);
    }

    private ActivityNotice requireItem(Long id) {
        ActivityNotice item = activityNoticeMapper.selectOne(new LambdaQueryWrapper<ActivityNotice>()
                .eq(ActivityNotice::getId, id)
                .eq(ActivityNotice::getDeleted, 0)
                .last("limit 1"));
        if (item == null) {
            throw new IllegalArgumentException("活动通知不存在");
        }
        return item;
    }

    private ActivityNoticeListItemVO toListItem(ActivityNotice item) {
        ActivityNoticeListItemVO vo = new ActivityNoticeListItemVO();
        vo.setId(item.getId());
        vo.setTitle(item.getTitle());
        vo.setCreatedAt(item.getCreatedAt());
        return vo;
    }

    private String normalizeTitle(String title) {
        String trimmed = trimToNull(title);
        if (trimmed == null) {
            throw new IllegalArgumentException("请输入通知标题");
        }
        return trimmed;
    }

    private String normalizeContent(String contentHtml) {
        String trimmed = trimToNull(contentHtml);
        if (trimmed == null || isBlankRichText(trimmed)) {
            throw new IllegalArgumentException("请输入通知内容");
        }
        return trimmed;
    }

    private boolean isBlankRichText(String html) {
        String normalized = html
                .replaceAll("(?i)<br\\s*/?>", "")
                .replaceAll("(?i)</p>", "")
                .replace("&nbsp;", "")
                .replace("&#160;", "")
                .replaceAll("<[^>]+>", "")
                .trim();
        if (!normalized.isEmpty()) {
            return false;
        }
        String lowerCaseHtml = html.toLowerCase();
        return !lowerCaseHtml.contains("<img")
                && !lowerCaseHtml.contains("<video")
                && !lowerCaseHtml.contains("<audio")
                && !lowerCaseHtml.contains("<iframe");
    }

    private String trimToNull(String value) {
        if (value == null) {
            return null;
        }
        String trimmed = value.trim();
        return trimmed.isEmpty() ? null : trimmed;
    }
}