using System;
using System.Data;
using System.Linq.Expressions;

namespace Mtxfw.Utility.DataAccess
{
    public partial class Sql :DbHelperSqlSugar
    {
        #region 分类迭代
        /// <summary>
        /// 迭代查询
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="predicate">查询条件 linq语句</param>
        /// <param name="parent_id">上级ID</param>
        /// <param name="channel_id">频道ID</param>
        /// <param name="isLevel">是否添加等级字段 (class_layer)</param>
        /// <param name="orderBy">排序</param>
        /// <param name="parent_field">上级字段名称 (如:parent_id)</param>
        /// <param name="strWhere">其他条件</param>
        /// <returns></returns>
        public DataTable Iteration<T>(Expression<Func<T, bool>> predicate, int parent_id = 0, int channel_id = 0, bool isLevel = false, string orderBy = "id desc", string parent_field = "parent_id", string strWhere = "") where T : class, new()
        {
            DataTable dt = Db.Queryable<T>().Where(predicate)
                .WhereIF(channel_id > 0, "channel_id=" + channel_id)
                .Where(strWhere)
                .OrderBy(orderBy).ToDataTable();
            //复制结构
            DataTable newData = dt.Clone();
            if (isLevel)
            {
                newData.Columns.Add("class_list", typeof(string));
                newData.Columns.Add("class_layer", typeof(int));
                GetChildsLayer(dt, newData, parent_field, parent_id, "", 0);
            }
            else
            {
                GetChilds(dt, newData, parent_field, parent_id, channel_id);
            }
            //调用迭代组合成DAGATABLE

            return newData;
        }

        /// <summary>
        /// 从内存中取得所有下级类别列表（自身迭代）
        /// </summary>
        public void GetChilds(DataTable oldData, DataTable newData, string parent_field, int parent_id, int channel_id)
        {
            DataRow[] dr = oldData.Select(parent_field + "=" + parent_id);
            for (int i = 0; i < dr.Length; i++)
            {
                DataRow row = newData.NewRow();//创建新行
                //循环查找列数量赋值
                for (int j = 0; j < dr[i].Table.Columns.Count; j++)
                {
                    row[dr[i].Table.Columns[j].ColumnName] = dr[i][dr[i].Table.Columns[j].ColumnName];
                }
                newData.Rows.Add(row);
                //调用自身迭代
                this.GetChilds(oldData, newData, parent_field, int.Parse(dr[i]["id"].ToString()), channel_id);
            }
        }

        /// <summary>
        /// 从内存中取得所有下级类别列表（自身迭代）
        /// </summary>
        private void GetChildsLayer(DataTable oldData, DataTable newData, string parent_field, int parent_id, string str_ids, int class_layer)
        {
            class_layer++;
            DataRow[] dr = oldData.Select(parent_field + "=" + parent_id);
            for (int i = 0; i < dr.Length; i++)
            {
                DataRow row = newData.NewRow();//创建新行
                //循环查找列数量赋值
                string strId = ""; string strClassList = "";
                for (int j = 0; j < dr[i].Table.Columns.Count; j++)
                {
                    row[dr[i].Table.Columns[j].ColumnName] = dr[i][dr[i].Table.Columns[j].ColumnName];
                    if ("id".Equals(dr[i].Table.Columns[j].ColumnName))
                    {
                        strId = dr[i][dr[i].Table.Columns[j].ColumnName].ToString();
                    }
                    if ("class_list".Equals(dr[i].Table.Columns[j].ColumnName))
                    {
                        strClassList = dr[i][dr[i].Table.Columns[j].ColumnName].ToString();
                    }
                }

                row["class_list"] = strClassList + "," + strId;
                row["class_layer"] = class_layer;//赋值深度字段
                newData.Rows.Add(row);//添加新行
                //调用自身迭代
                this.GetChildsLayer(oldData, newData, parent_field, int.Parse(dr[i]["id"].ToString()), str_ids, class_layer);
            }
        }
        #endregion
    }
}