using Infrastructure.Attribute;
using Infrastructure.Extensions;
using ZR.LiveForum.Model.Liveforum.Dto;
using ZR.LiveForum.Model.Liveforum;
using ZR.Repository;
using ZR.Service.Liveforum.ILiveforumService;

namespace ZR.Service.Liveforum
{
    /// <summary>
    /// 帖子评论记录Service业务层处理
    /// </summary>
    [AppService(ServiceType = typeof(IT_CommentsService), ServiceLifetime = LifeTime.Transient)]
    public class T_CommentsService : BaseService<T_Comments>, IT_CommentsService
    {
        /// <summary>
        /// 查询帖子评论记录列表
        /// </summary>
        /// <param name="parm"></param>
        /// <returns></returns>
        public PagedInfo<T_CommentsDto> GetList(T_CommentsQueryDto parm)
        {
            var predicate = QueryExp(parm);

            var query = Queryable()
                .Where(predicate.ToExpression())
                .LeftJoin<T_Users>((c, u) => c.UserId == u.Id)
                .LeftJoin<T_Users>((c, u, ru) => c.ReplyToUserId == ru.Id)
                .LeftJoin<T_Posts>((c, u, ru, p) => c.PostId == p.Id)
                .LeftJoin<T_Comments>((c, u, ru, p, pc) => c.ParentCommentId == pc.Id);

            // 排序：顶级评论在前，回复评论在后，同层级按创建时间倒序
            // 使用多个OrderBy组合排序
            query = query.OrderBy((c, u, ru, p, pc) => c.ParentCommentId == null ? 0 : 1, OrderByType.Asc)
                .OrderBy((c, u, ru, p, pc) => c.CreatedAt, OrderByType.Desc);

            var response = query.Select((c, u, ru, p, pc) => new T_CommentsDto()
            {
                Id = c.Id,
                PostId = c.PostId,
                UserId = c.UserId,
                ParentCommentId = c.ParentCommentId,
                ReplyToUserId = c.ReplyToUserId,
                Content = c.Content,
                LikeCount = c.LikeCount,
                ReplyCount = c.ReplyCount,
                Status = c.Status,
                IpAddress = c.IpAddress,
                CreatedAt = c.CreatedAt,
                UpdatedAt = c.UpdatedAt,
                IsDeleted = c.IsDeleted,
                DeletedAt = c.DeletedAt,
                UserName = u.NickName,
                ReplyToUserName = ru.NickName,
                PostTitle = p.Title,
                ParentCommentContent = pc.Content,
            }, true);
            
            var resp = ToPage(response, parm);
            return resp;
        }

        /// <summary>
        /// 分页查询（排序已在Select之前完成）
        /// </summary>
        private PagedInfo<T> ToPage<T>(ISugarQueryable<T> source, PagerInfo parm)
        {
            var page = new PagedInfo<T>();
            var total = 0;
            page.PageSize = parm.PageSize;
            page.PageIndex = parm.PageNum;
            // 注意：排序已经在 Select 之前完成了，这里不再需要排序
            page.Result = source
                .ToPageList(parm.PageNum, parm.PageSize, ref total);
            page.TotalNum = total;
            return page;
        }


        /// <summary>
        /// 获取详情
        /// </summary>
        /// <param name="Id"></param>
        /// <returns></returns>
        public T_Comments GetInfo(long Id)
        {
            var response = Queryable()
                .Where(x => x.Id == Id)
                .First();

            return response;
        }

        /// <summary>
        /// 添加帖子评论记录
        /// </summary>
        /// <param name="model"></param>
        /// <returns></returns>
        public T_Comments AddT_Comments(T_Comments model)
        {
            return Insertable(model).ExecuteReturnEntity();
        }

        /// <summary>
        /// 修改帖子评论记录
        /// </summary>
        /// <param name="model"></param>
        /// <returns></returns>
        public int UpdateT_Comments(T_Comments model)
        {
            return Update(model, true);
        }

        /// <summary>
        /// 查询导出表达式
        /// </summary>
        /// <param name="parm"></param>
        /// <returns></returns>
        private static Expressionable<T_Comments> QueryExp(T_CommentsQueryDto parm)
        {
            var predicate = Expressionable.Create<T_Comments>();

            predicate = predicate.AndIF(parm.PostId != null, it => it.PostId == parm.PostId);
            predicate = predicate.AndIF(parm.UserId != null, it => it.UserId == parm.UserId);
            return predicate;
        }
    }
}