using System;
using System.Data;
using System.Xml;

namespace WX.CRM.Common
{
    public class DataTableHelper
    {
        private DataTable dataTable;

        public DataTable GetDataTable
        {
            get { return dataTable; }
            set { dataTable = value; }
        }

        public DataTableHelper()
        {
            dataTable = new DataTable();
        }
        /// <summary>
        /// 给DataTable添加列
        /// </summary>
        /// <param name="name"></param>
        /// <param name="type"></param>
        public void AddColumn(string name, Type type)
        {
            DataColumn column = new DataColumn();
            column.ColumnName = name;
            column.DataType = type;
            dataTable.Columns.Add(column);
        }
        /// <summary>
        /// 给DataTable添加列(默认string类型)
        /// </summary>
        /// <param name="name"></param>
        public void AddColumn(string name)
        {
            DataColumn column = new DataColumn();
            column.ColumnName = name;
            column.DataType = typeof(System.String);
            dataTable.Columns.Add(column);
        }
        public void LoadData(XmlDocument doc)
        {
            XmlElement root = doc.DocumentElement;
            foreach (XmlNode row in root.ChildNodes)
            {
                DataRow dataRow = dataTable.NewRow();
                foreach (XmlNode item in row.ChildNodes)
                {
                    if (dataTable.Columns.Contains(item.Name))
                    {
                        dataRow[item.Name] = item.InnerText.Trim();
                    }
                }
                dataTable.Rows.Add(dataRow);
            }
        }
        /// <summary>
        /// 两个DataTable合并（表结构不一样）
        /// </summary>
        /// <param name="tab1">表1</param>
        /// <param name="tab2">表2</param>
        /// <returns></returns>
        public static DataTable TwoDataTableMerge(DataTable tab1, DataTable tab2)
        {
            //克隆DataTable1的结构
            DataTable newDataTable = tab1.Copy();
            //-------把没有tab2的字段加上去
            foreach (DataColumn column in tab2.Columns)
            {
                if (!newDataTable.Columns.Contains(column.ColumnName))
                {
                    //column.Caption = model.EXCEL_COLNAME;
                    DataColumn col = new DataColumn(column.ColumnName, column.DataType);
                    //if (column.DataType == typeof(System.Decimal))
                    //    col.DefaultValue = 0;
                    col.Caption = column.Caption;
                    newDataTable.Columns.Add(col);
                }
            }
            foreach (DataRow row in tab2.Rows)
            {
                DataRow newRow = newDataTable.NewRow();
                foreach (DataColumn column in tab2.Columns)
                {
                    newRow[column.ColumnName] = row[column.ColumnName];
                }
                newDataTable.Rows.Add(newRow);
            }
            return newDataTable;
        }
        /// <summary>
        /// 两个DataTable合并（优化版,数据量多的作为基表）
        /// </summary>
        /// <param name="tab1">表1</param>
        /// <param name="tab2">表2</param>
        /// <returns></returns>
        public static DataTable TwoDataTableMergeEfficiency(DataTable tab1, DataTable tab2)
        {
            if (tab2.Rows.Count > tab1.Rows.Count)
                return TwoDataTableMerge(tab2, tab1);
            else
                return TwoDataTableMerge(tab1, tab2);
        }
    }
}