package com.tanpu.community.service;

import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.tanpu.common.constant.BizStatus;
import com.tanpu.common.exception.BizException;
import com.tanpu.community.api.beans.req.page.Page;
import com.tanpu.community.api.enums.DeleteTagEnum;
import com.tanpu.community.dao.entity.community.FollowRelEntity;
import com.tanpu.community.dao.mapper.community.FollowRelMapper;
import org.springframework.cache.annotation.EnableCaching;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.Resource;
import java.time.LocalDateTime;
import java.util.List;
import java.util.stream.Collectors;

@EnableCaching
@Service
public class FollowRelService {

    @Resource
    private FollowRelMapper followRelMapper;

    public List<String> queryIdolsByFansId(String followerId) {
        return followRelMapper.selectList(new LambdaQueryWrapper<FollowRelEntity>()
                .eq(FollowRelEntity::getFansId, followerId)
                .eq(FollowRelEntity::getDeleteTag, DeleteTagEnum.NOT_DELETED.getCode()))
                .stream().map(FollowRelEntity::getIdolId)
                .collect(Collectors.toList());
    }

    public Page<String> queryIdolsByFansId(String fansId, Integer pageNum, Integer pageSize) {
        Integer pageStart = (pageNum - 1) * pageSize;

        List<FollowRelEntity> idols = followRelMapper.selectList(new LambdaQueryWrapper<FollowRelEntity>()
                .eq(FollowRelEntity::getFansId, fansId)
                .last("limit " + pageStart + ", " + pageSize)
                .eq(FollowRelEntity::getDeleteTag, DeleteTagEnum.NOT_DELETED.getCode()));

        List<String> list = idols.stream().map(FollowRelEntity::getIdolId)
                .collect(Collectors.toList());

        Integer totalSize = followRelMapper.selectCount(new LambdaQueryWrapper<FollowRelEntity>().eq(FollowRelEntity::getFansId,fansId)
                .eq(FollowRelEntity::getDeleteTag, BizStatus.DeleteTag.tag_init));

        Page<String> tPage = new Page<>(pageNum, pageSize, (long) totalSize, 0, list);
        int totalPage = list.size() / pageSize;
        if (list.size() % pageSize == 0) {
            tPage.setTotalPages(totalPage);
        } else {
            tPage.setTotalPages(totalPage + 1);
        }
        return tPage;
    }

    public Page<String> queryFansByIdolId(String idolId, Integer pageNum, Integer pageSize) {
        Integer pageStart = (pageNum - 1) * pageSize;
        LambdaQueryWrapper<FollowRelEntity> queryWrapper = new LambdaQueryWrapper<FollowRelEntity>()
                .eq(FollowRelEntity::getIdolId, idolId)
                .last("limit " + pageStart + ", " + pageSize)
                .eq(FollowRelEntity::getDeleteTag, DeleteTagEnum.NOT_DELETED.getCode());
        List<String> list = followRelMapper.selectList(queryWrapper)
                .stream().map(FollowRelEntity::getFansId).collect(Collectors.toList());
        // 分页
        Integer totalSize = followRelMapper.selectCount(new LambdaQueryWrapper<FollowRelEntity>().eq(FollowRelEntity::getIdolId, idolId)
                .eq(FollowRelEntity::getDeleteTag, BizStatus.DeleteTag.tag_init));
        Page<String> tPage = new Page<>(pageNum, pageSize, (long) totalSize, 0, list);
        int totalPage = list.size() / pageSize;
        if (list.size() % pageSize == 0) {
            tPage.setTotalPages(totalPage);
        } else {
            tPage.setTotalPages(totalPage + 1);
        }
        return tPage;
    }

    @Transactional
    public boolean addFollowRel(String idolId, String followerId) {
        FollowRelEntity searchResult = queryRecord(idolId, followerId);
        if (searchResult == null) {
            FollowRelEntity entity = FollowRelEntity.builder()
                    .idolId(idolId)
                    .fansId(followerId)
                    .followTime(LocalDateTime.now())
                    .build();

            followRelMapper.insert(entity);
            return true;
        } else {
            searchResult.setFollowTime(LocalDateTime.now());
            searchResult.setDeleteTag(DeleteTagEnum.NOT_DELETED.getCode());
            followRelMapper.updateById(searchResult);
            return false;
        }

    }

    /**
     * 逻辑删除关注关系
     *
     * @param idolId
     * @param followerId
     */
    @Transactional
    public void deleteFollowRel(String idolId, String followerId) {
        FollowRelEntity searchResult = queryRecord(idolId, followerId);
        if (searchResult == null) {
            throw new BizException("未找到关注关系");
        }
        searchResult.setUnfollowTime(LocalDateTime.now());
        searchResult.setDeleteTag(DeleteTagEnum.DELETED.getCode());
        followRelMapper.updateById(searchResult);
    }

    public FollowRelEntity queryRecord(String idolId, String followerId) {
        return followRelMapper.selectOne(new LambdaQueryWrapper<FollowRelEntity>()
                .eq(FollowRelEntity::getIdolId, idolId)
                .eq(FollowRelEntity::getFansId, followerId));
    }

    public boolean checkFollow(String idolId, String followerId) {
        return followRelMapper.selectCount(new LambdaQueryWrapper<FollowRelEntity>()
                .eq(FollowRelEntity::getIdolId, idolId)
                .eq(FollowRelEntity::getFansId, followerId)
                .eq(FollowRelEntity::getDeleteTag, DeleteTagEnum.NOT_DELETED.getCode()))
                > 0;
    }


    public List<FollowRelEntity> queryAll() {
        // todo 会丢失关注后 取消关注的情况，怎么选择？
        return followRelMapper.selectList(new LambdaQueryWrapper<FollowRelEntity>()
                .eq(FollowRelEntity::getDeleteTag,DeleteTagEnum.NOT_DELETED.getCode())
                .orderByAsc(FollowRelEntity::getUpdateTime));
    }
}