using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Text;
using System.Text.RegularExpressions;

namespace CPF.ReoGrid.IO
{
	internal static class CSVFormat
	{
		public static void Read(Stream stream, Worksheet sheet, RangePosition targetRange, Encoding encoding = null, int bufferLines = 512, bool autoSpread = true)
		{
			targetRange = sheet.FixRange(targetRange);
			string[] array = new string[bufferLines];
			List<object>[] array2 = new List<object>[bufferLines];
			for (int i = 0; i < array2.Length; i++)
			{
				array2[i] = new List<object>(256);
			}
			Stopwatch stopwatch = Stopwatch.StartNew();
			int num = targetRange.Row;
			int num2 = 0;
			using (StreamReader streamReader = new StreamReader(stream, encoding))
			{
				sheet.SuspendDataChangedEvents();
				int num3 = 0;
				try
				{
					bool flag = false;
					while (!flag)
					{
						int j;
						for (j = 0; j < array.Length; j++)
						{
							string text = streamReader.ReadLine();
							bool flag2 = text == null;
							if (flag2)
							{
								flag = true;
								break;
							}
							array[j] = text;
							num2++;
							bool flag3 = !autoSpread && num2 > targetRange.Rows;
							if (flag3)
							{
								flag = true;
								break;
							}
						}
						bool flag4 = autoSpread && num + j > sheet.RowCount;
						if (flag4)
						{
							int num4 = bufferLines - sheet.RowCount % bufferLines;
							bool flag5 = num4 <= 0;
							if (flag5)
							{
								num4 = bufferLines;
							}
							sheet.AppendRows(num4);
						}
						for (int k = 0; k < j; k++)
						{
							string input = array[k];
							List<object> list = array2[k];
							list.Clear();
							foreach (object obj in CSVFormat.lineRegex.Matches(input))
							{
								Match match = (Match)obj;
								list.Add(match.Groups["item"].Value);
								bool flag6 = list.Count >= targetRange.Cols;
								if (flag6)
								{
									break;
								}
							}
							bool flag7 = num3 < list.Count;
							if (flag7)
							{
								num3 = list.Count;
							}
							bool flag8 = autoSpread && num3 >= sheet.ColumnCount;
							if (flag8)
							{
								sheet.SetCols(num3 + 1);
							}
						}
						sheet.SetRangeData(num, targetRange.Col, j, num3, array2);
						num += j;
					}
				}
				finally
				{
					sheet.ResumeDataChangedEvents();
				}
				sheet.RaiseRangeDataChangedEvent(new RangePosition(targetRange.Row, targetRange.Col, num3, num2));
			}
			stopwatch.Stop();
			Debug.WriteLine("load csv file: " + stopwatch.ElapsedMilliseconds.ToString() + " ms, rows: " + num.ToString());
		}

		public const int DEFAULT_READ_BUFFER_LINES = 512;

		private static Regex lineRegex = new Regex("\\s*(\\\"(?<item>[^\\\"]*)\\\"|(?<item>[^,]*))\\s*,?", RegexOptions.Compiled);
	}
}