CREATE TABLE `tb_follow` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT COMMENT '主鍵',
  `user_id` bigint(20) unsigned NOT NULL COMMENT '用戶id',
  `follow_user_id` bigint(20) unsigned NOT NULL COMMENT '關(guān)聯(lián)的用戶id',
  `create_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '創(chuàng)建時(shí)間',
  PRIMARY KEY (`id`) USING BTREE
) ENGINE=InnoDB AUTO_INCREMENT=9 DEFAULT CHARSET=utf8mb4 ROW_FORMAT=COMPACT;

//關(guān)注
@PutMapping("/{id}/{isFollow}")
public Result follow(@PathVariable("id") Long followUserId, @PathVariable("isFollow") Boolean isFollow) {
    return followService.follow(followUserId, isFollow);
}
//取消關(guān)注
@GetMapping("/or/not/{id}")
public Result isFollow(@PathVariable("id") Long followUserId) {
    return followService.isFollow(followUserId);
}

@Override
public Result follow(Long followUserId, Boolean isFollow) {
    // 1.獲取登錄用戶
    Long userId = UserHolder.getUser().getId();
    String key = "follows:" + userId;
    // 1.判斷到底是關(guān)注還是取關(guān)
    if (isFollow) {
        // 2.關(guān)注，新增數(shù)據(jù)
        Follow follow = new Follow();
        follow.setUserId(userId);
        follow.setFollowUserId(followUserId);
        boolean isSuccess = save(follow);
        if (isSuccess) {
            stringRedisTemplate.opsForSet().add(key, followUserId.toString());
        }
    } else {
        // 3.取關(guān)，刪除 delete from tb_follow where user_id = ? and follow_user_id = ?
        boolean isSuccess = remove(new QueryWrapper<Follow>()
                                   .eq("user_id", userId).eq("follow_user_id", followUserId));
        if (isSuccess) {
            // 把關(guān)注用戶的id從Redis集合中移除
            stringRedisTemplate.opsForSet().remove(key, followUserId.toString());
        }
    }
    return Result.ok();
}

@Override
public Result isFollow(Long followUserId) {
    // 1.獲取登錄用戶
    Long userId = UserHolder.getUser().getId();
    // 2.查詢是否關(guān)注 select count(*) from tb_follow where user_id = ? and follow_user_id = ?
    Integer count = query().eq("user_id", userId).eq("follow_user_id", followUserId).count();
    // 3.判斷
    return Result.ok(count > 0);
}

// UserController 根據(jù)id查詢用戶
@GetMapping("/{id}")
public Result queryUserById(@PathVariable("id") Long userId){
    // 查詢?cè)斍?
    User user = userService.getById(userId);
    if (user == null) {
        return Result.ok();
    }
    UserDTO userDTO = BeanUtil.copyProperties(user, UserDTO.class);
    // 返回
    return Result.ok(userDTO);
}

@GetMapping("/of/user")
public Result queryBlogByUserId(
    @RequestParam(value = "current", defaultValue = "1") Integer current,
    @RequestParam("id") Long id) {
    // 根據(jù)用戶查詢
    Page<Blog> page = blogService.query()
        .eq("user_id", id).page(new Page<>(current, SystemConstants.MAX_PAGE_SIZE));
    // 獲取當(dāng)前頁(yè)數(shù)據(jù)
    List<Blog> records = page.getRecords();
    return Result.ok(records);
}

@Override
public Result follow(Long followUserId, Boolean isFollow) {
    // 1.獲取登錄用戶
    Long userId = UserHolder.getUser().getId();
    String key = "follows:" + userId;
    // 1.判斷到底是關(guān)注還是取關(guān)
    if (isFollow) {
        // 2.關(guān)注，新增數(shù)據(jù)
        Follow follow = new Follow();
        follow.setUserId(userId);
        follow.setFollowUserId(followUserId);
        boolean isSuccess = save(follow);
        if (isSuccess) {
            stringRedisTemplate.opsForSet().add(key, followUserId.toString());
        }
    } else {
        // 3.取關(guān)，刪除 delete from tb_follow where user_id = ? and follow_user_id = ?
        boolean isSuccess = remove(new QueryWrapper<Follow>()
                                   .eq("user_id", userId).eq("follow_user_id", followUserId));
        if (isSuccess) {
            // 把關(guān)注用戶的id從Redis集合中移除
            stringRedisTemplate.opsForSet().remove(key, followUserId.toString());
        }
    }
    return Result.ok();
}

// 具體獲取好友共同關(guān)注代碼

@Override
public Result followCommons(Long id) {
    // 1.獲取當(dāng)前用戶
    Long userId = UserHolder.getUser().getId();
    String key = "follows:" + userId;
    // 2.求交集
    String key2 = "follows:" + id;
    Set<String> intersect = stringRedisTemplate.opsForSet().intersect(key, key2);
    if (intersect == null || intersect.isEmpty()) {
        // 無(wú)交集
        return Result.ok(Collections.emptyList());
    }
    // 3.解析id集合
    List<Long> ids = intersect.stream().map(Long::valueOf).collect(Collectors.toList());
    // 4.查詢用戶
    List<UserDTO> users = userService.listByIds(ids)
        .stream()
        .map(user -> BeanUtil.copyProperties(user, UserDTO.class))
        .collect(Collectors.toList());
    return Result.ok(users);
}