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

import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.tcm.training.admin.app.search.vo.AppSearchHealthCourseVO;
import com.tcm.training.admin.app.search.vo.AppSearchHealthPopularizationVO;
import com.tcm.training.admin.app.search.vo.AppSearchResultVO;
import com.tcm.training.admin.live.entity.HealthPopularization;
import com.tcm.training.admin.live.mapper.HealthCourseMapper;
import com.tcm.training.admin.live.mapper.HealthPopularizationMapper;
import com.tcm.training.admin.live.vo.HealthCourseListRow;
import org.springframework.stereotype.Service;

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

/**
 * APP 首页搜索聚合服务。
 */
@Service
public class AppSearchService {

    private static final int STATUS_ENABLED = 1;

    private final HealthCourseMapper healthCourseMapper;
    private final HealthPopularizationMapper healthPopularizationMapper;

    /**
     * 注入 APP 搜索所需依赖。
     */
    public AppSearchService(HealthCourseMapper healthCourseMapper,
                            HealthPopularizationMapper healthPopularizationMapper) {
        this.healthCourseMapper = healthCourseMapper;
        this.healthPopularizationMapper = healthPopularizationMapper;
    }

    /**
     * 按关键词聚合搜索养生课程与健康科普。
     */
    public AppSearchResultVO search(String keyword) {
        String normalizedKeyword = trimToNull(keyword);
        AppSearchResultVO resultVO = new AppSearchResultVO();
        if (normalizedKeyword == null) {
            resultVO.setCourses(Collections.<AppSearchHealthCourseVO>emptyList());
            resultVO.setPopularizations(Collections.<AppSearchHealthPopularizationVO>emptyList());
            return resultVO;
        }
        resultVO.setCourses(toCourseList(healthCourseMapper.selectAppSearchCourses(normalizedKeyword)));
        resultVO.setPopularizations(toPopularizationList(listPopularizations(normalizedKeyword)));
        return resultVO;
    }

    /**
     * 查询命中的健康科普内容。
     */
    private List<HealthPopularization> listPopularizations(String keyword) {
        List<HealthPopularization> list = healthPopularizationMapper.selectList(new LambdaQueryWrapper<HealthPopularization>()
                .eq(HealthPopularization::getDeleted, 0)
                .eq(HealthPopularization::getStatus, STATUS_ENABLED)
                .and(wrapper -> wrapper
                        .like(HealthPopularization::getTitle, keyword)
                        .or()
                        .like(HealthPopularization::getContent, keyword)
                        .or()
                        .like(HealthPopularization::getCreatedBy, keyword))
                .orderByAsc(HealthPopularization::getSort)
                .orderByDesc(HealthPopularization::getId));
        return list == null ? Collections.<HealthPopularization>emptyList() : list;
    }

    /**
     * 将课程搜索结果转换为 APP 搜索页卡片响应。
     */
    private List<AppSearchHealthCourseVO> toCourseList(List<HealthCourseListRow> rows) {
        if (rows == null || rows.isEmpty()) {
            return Collections.emptyList();
        }
        List<AppSearchHealthCourseVO> result = new ArrayList<AppSearchHealthCourseVO>(rows.size());
        for (HealthCourseListRow row : rows) {
            AppSearchHealthCourseVO courseVO = new AppSearchHealthCourseVO();
            courseVO.setId(row.getId());
            courseVO.setTitle(trimToEmpty(row.getTitle()));
            courseVO.setCoverImage(trimToEmpty(row.getCoverImg()));
            courseVO.setLevelName(trimToEmpty(row.getLevelName()));
            courseVO.setDifficultyName(trimToEmpty(row.getDifficultyName()));
            courseVO.setSalePrice(defaultPrice(row.getSalePrice()));
            courseVO.setLearnUserCount(defaultNumber(row.getLearnUserCount()));
            courseVO.setStudyingCount(defaultNumber(row.getStudyingCount()));
            result.add(courseVO);
        }
        return result;
    }

    /**
     * 将健康科普搜索结果转换为 APP 搜索页卡片响应。
     */
    private List<AppSearchHealthPopularizationVO> toPopularizationList(List<HealthPopularization> items) {
        if (items == null || items.isEmpty()) {
            return Collections.emptyList();
        }
        List<AppSearchHealthPopularizationVO> result =
                new ArrayList<AppSearchHealthPopularizationVO>(items.size());
        for (HealthPopularization item : items) {
            AppSearchHealthPopularizationVO popularizationVO = new AppSearchHealthPopularizationVO();
            popularizationVO.setId(item.getId());
            popularizationVO.setTitle(trimToEmpty(item.getTitle()));
            popularizationVO.setCoverImage(trimToEmpty(item.getCoverImg()));
            popularizationVO.setContentType(item.getContentType());
            result.add(popularizationVO);
        }
        return result;
    }

    /**
     * 兜底空价格字段。
     */
    private BigDecimal defaultPrice(BigDecimal value) {
        return value == null ? BigDecimal.ZERO : value;
    }

    /**
     * 兜底空数字字段。
     */
    private Integer defaultNumber(Integer value) {
        return value == null ? 0 : value;
    }

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

    /**
     * 将可空关键字转换为可搜索文本。
     */
    private String trimToNull(String value) {
        if (value == null) {
            return null;
        }
        String trimmed = value.trim();
        return trimmed.isEmpty() ? null : trimmed;
    }
}