package com.tcm.training.admin.app.popularization.service;

import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.tcm.training.admin.app.popularization.vo.AppHealthPopularizationDetailVO;
import com.tcm.training.admin.app.popularization.vo.AppHealthPopularizationListItemVO;
import com.tcm.training.admin.live.entity.HealthPopularization;
import com.tcm.training.admin.live.mapper.HealthPopularizationMapper;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

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

/**
 * APP 健康科普详情聚合服务。
 */
@Service
public class AppHealthPopularizationService {

    private static final int STATUS_ENABLED = 1;

    private final HealthPopularizationMapper healthPopularizationMapper;

    /**
     * 注入 APP 健康科普详情所需依赖。
     */
    public AppHealthPopularizationService(HealthPopularizationMapper healthPopularizationMapper) {
        this.healthPopularizationMapper = healthPopularizationMapper;
    }

    /**
     * 获取 APP 健康科普列表页数据。
     *
     * @param contentType 内容类型：1 健康知识、2 养生科普；为空则返回全部。
     */
    public List<AppHealthPopularizationListItemVO> list(Integer contentType) {
        List<HealthPopularization> items = healthPopularizationMapper.selectList(new LambdaQueryWrapper<HealthPopularization>()
                .eq(HealthPopularization::getDeleted, 0)
                .eq(HealthPopularization::getStatus, STATUS_ENABLED)
                .eq(contentType != null, HealthPopularization::getContentType, contentType)
                .orderByDesc(HealthPopularization::getSort)
                .orderByDesc(HealthPopularization::getId));
        if (items == null || items.isEmpty()) {
            return Collections.emptyList();
        }
        List<AppHealthPopularizationListItemVO> result =
                new ArrayList<AppHealthPopularizationListItemVO>(items.size());
        for (HealthPopularization item : items) {
            AppHealthPopularizationListItemVO listItemVO = new AppHealthPopularizationListItemVO();
            listItemVO.setId(item.getId());
            listItemVO.setTitle(trimToEmpty(item.getTitle()));
            listItemVO.setCoverImage(trimToEmpty(item.getCoverImg()));
            listItemVO.setContentType(item.getContentType());
            listItemVO.setClickCount(defaultNumber(item.getClickCount()));
            result.add(listItemVO);
        }
        return result;
    }

    /**
     * 获取 APP 健康科普详情页数据，并在每次访问时累加点击量。
     */
    @Transactional
    public AppHealthPopularizationDetailVO detail(Long popularizationId) {
        HealthPopularization item = requireEnabledItem(popularizationId);
        // 参考项目介绍，APP 进入详情后累加点击量并回写。
        item.setClickCount(defaultNumber(item.getClickCount()) + 1);
        healthPopularizationMapper.updateById(item);
        AppHealthPopularizationDetailVO detailVO = new AppHealthPopularizationDetailVO();
        detailVO.setId(item.getId());
        detailVO.setTitle(trimToEmpty(item.getTitle()));
        detailVO.setCoverImage(trimToEmpty(item.getCoverImg()));
        detailVO.setContentType(item.getContentType());
        detailVO.setContentTypeText(resolveContentTypeText(item.getContentType()));
        detailVO.setContent(trimToEmpty(item.getContent()));
        detailVO.setVideoUrl(trimToEmpty(item.getVideoUrl()));
        detailVO.setVideoFileName(trimToEmpty(item.getVideoFileName()));
        detailVO.setVideoDescription(trimToEmpty(item.getVideoDescription()));
        detailVO.setClickCount(defaultNumber(item.getClickCount()));
        return detailVO;
    }

    /**
     * 查询启用中的健康科普详情，避免 APP 访问到后台下线内容。
     */
    private HealthPopularization requireEnabledItem(Long popularizationId) {
        HealthPopularization item = healthPopularizationMapper.selectOne(new LambdaQueryWrapper<HealthPopularization>()
                .eq(HealthPopularization::getId, popularizationId)
                .eq(HealthPopularization::getDeleted, 0)
                .eq(HealthPopularization::getStatus, STATUS_ENABLED)
                .last("LIMIT 1"));
        if (item == null) {
            throw new IllegalArgumentException("健康科普不存在");
        }
        return item;
    }

    /**
     * 解析内容类型文案，便于前端按类型渲染页面。
     */
    private String resolveContentTypeText(Integer contentType) {
        if (contentType != null && contentType.intValue() == HealthPopularization.CONTENT_TYPE_VIDEO) {
            return "视频";
        }
        return "图文";
    }

    /**
     * 将可空数字统一转换为默认值，避免前端列表展示空计数。
     */
    private Integer defaultNumber(Integer value) {
        return value == null ? 0 : value;
    }

    /**
     * 将可空文本统一转换为空字符串。
     */
    private String trimToEmpty(String value) {
        if (value == null) {
            return "";
        }
        String trimmed = value.trim();
        return trimmed.isEmpty() ? "" : trimmed;
    }
}