/// <summary>
/// 取消关注
/// </summary>
/// <param name="followerId">关注者ID</param>
/// <param name="unFollowPerId">取消关注者ID</param>
/// <returns></returns>
public async Task<bool> UnFollowAsync(long followerId, long unFollowPerId)
{
PersonXPersonHandler pxpHandler = new PersonXPersonHandler(_dbContext);
//1. 检查关注人的关注名单是否已经关注了。
PersonXPerson pxp = await pxpHandler.Fetch(x => x.FollowerID == followerId && x.FollowingID == unFollowPerId).SingleOrDefaultAsync();
//2. 如果存在记录，则删除记录，取消关注。
if(pxp != null)
{
pxpHandler.MarkAsDeleted(pxp);
return await pxpHandler.SaveChangesAsync() > 0;
}
return true;
}
/// <summary>
/// 关注
/// </summary>
/// <param name="followerId">关注者ID</param>
/// <param name="followingId">被关注者ID</param>
/// <returns></returns>
public async Task<bool> FollowAsync(long followerId, long followingId)
{
GroupHandler groupHandler = new GroupHandler(_dbContext);
PersonXPersonHandler pxpHandler = new PersonXPersonHandler(_dbContext);
//1. 检查被关注人黑名单是否存在关注人，若已拉黑，则无法关注。
Group blackGroup = await groupHandler.Include(x => x.GroupMembers).SingleOrDefaultAsync(x => x.PersonID == followingId && x.Type == GroupType.BlackList);
if(blackGroup != null && blackGroup.GroupMembers.Count > 0)
{
bool isInGroupMember = blackGroup.GroupMembers.Select(x => x.PersonID).Contains(followerId);
if(isInGroupMember)
{
throw new DisplayableException("由于用户设置，你无法关注。");
}
}
//2. 检查关注人的关注名单是否已经关注了。
bool isFollow = await pxpHandler.Fetch(x => x.FollowerID == followerId && x.FollowingID == followingId).SingleOrDefaultAsync() != null;
//3. 如果未关注则添加纪录。
if(!isFollow)
{
PersonXPerson pxp = new PersonXPerson()
{
FollowerID = followerId,
FollowingID = followingId
};
pxpHandler.Add(pxp);
return await SaveChangesAsync() > 0;
}
return true;
}