using System;
using System.Data;
using System.IO;

public class DataTableHelper
{

	/// 
	/// Can stream DataTable to Browser, directly, you need to set 
	/// 
	/// Response.Clear();
	/// Response.Buffer= true;
	/// Response.ContentType = "application/vnd.ms-excel";
	/// Response.AddHeader("Content-Disposition", "inline;filename=Clientes.xls"); Response.Charset = "";
	/// this.EnableViewState = false
	/// // ACTUAL CODE 
	/// ProduceCSV(dt, Response.Output, true);
	/// 
	public static void ProduceCSV(DataTable dt, System.IO.TextWriter httpStream, bool WriteHeader)
	{
		if(WriteHeader)
		{
			string[] arr = new String[dt.Columns.Count];
			for(int i = 0; i<dt.Columns.Count; i++)
			{
				arr[i] = dt.Columns[i].ColumnName;
				arr[i] = GetWriteableValue(arr[i]);
			}

			httpStream.WriteLine(string.Join(",", arr));
		}

		for(int j = 0; j<dt.Rows.Count; j++)
		{
			string[] dataArr = new String[dt.Columns.Count];
			for(int i = 0; i<dt.Columns.Count; i++)
			{
				object o = dt.Rows[j][i];
				dataArr[i] = GetWriteableValue(o);
			}
			httpStream.WriteLine(string.Join(",", dataArr));
		}
	}

	#region CSV Producer
	public static void ProduceCSV(DataTable dt, System.IO.StreamWriter file, bool WriteHeader)
	{
		if(WriteHeader)
		{
			string[] arr = new String[dt.Columns.Count];
			for(int i = 0; i<dt.Columns.Count; i++)
			{
				arr[i] = dt.Columns[i].ColumnName;
				arr[i] = GetWriteableValue(arr[i]);
			}

			file.WriteLine(string.Join(",", arr));
		}

		for(int j = 0; j<dt.Rows.Count; j++)
		{
			string[] dataArr = new String[dt.Columns.Count];
			for(int i = 0; i<dt.Columns.Count; i++)
			{
				object o = dt.Rows[j][i];
				dataArr[i] = GetWriteableValue(o);
			}
			file.WriteLine(string.Join(",", dataArr));
		}
	}

	public static string GetWriteableValue(object o)
	{
		if(o==null || o == Convert.DBNull)
			return "";
		else if(o.ToString().IndexOf(",")==-1)
			return o.ToString();
		else
			return "\"" + o.ToString() + "\"";

	}
	#endregion
}