/*
 * Created by SharpDevelop.
 * User: Bitl
 * Date: 10/10/2019
 * Time: 6:59 AM
 * 
 * To change this template use Tools | Options | Coding | Edit Standard Headers.
 */
 
using System;
using System.Collections.Generic;
using System.IO;

public static class TextLineRemover
{
	public static void RemoveTextLines(IList<string> linesToRemove, string filename, string tempFilename)
	{
		// Initial values
		int lineNumber = 0;
		int linesRemoved = 0;
		DateTime startTime = DateTime.Now;
	
		// Read file
		using (var sr = new StreamReader(filename)) {
			// Write new file
			using (var sw = new StreamWriter(tempFilename)) {
				// Read lines
				string line;
				while ((line = sr.ReadLine()) != null) {
					lineNumber++;
					// Look for text to remove
					if (!ContainsString(line, linesToRemove)) {
						// Keep lines that does not match
						sw.WriteLine(line);
					} else {
						// Ignore lines that DO match
						linesRemoved++;
						InvokeOnRemovedLine(new RemovedLineArgs {
							RemovedLine = line,
							RemovedLineNumber = lineNumber
						});
					}
				}
			}
		}
		// Delete original file
		File.Delete(filename);
	
		// ... and put the temp file in its place.
		File.Move(tempFilename, filename);
	
		// Final calculations
		DateTime endTime = DateTime.Now;
		InvokeOnFinished(new FinishedArgs {
			LinesRemoved = linesRemoved,
			TotalLines = lineNumber,
			TotalTime = endTime.Subtract(startTime)
		});
	}
	
	private static bool ContainsString(string line, IEnumerable<string> linesToRemove)
	{
		foreach (var lineToRemove in linesToRemove) {
			if (line.Contains(lineToRemove))
				return true;
		}
		return false;
	}
	
	public static event RemovedLine OnRemovedLine;
	public static event Finished OnFinished;
	
	public static void InvokeOnFinished(FinishedArgs args)
	{
		Finished handler = OnFinished;
		if (handler != null)
			handler(null, args);
	}
	
	public static void InvokeOnRemovedLine(RemovedLineArgs args)
	{
		RemovedLine handler = OnRemovedLine;
		if (handler != null)
			handler(null, args);
	}
}
	
public delegate void Finished(object sender, FinishedArgs args);
	
public class FinishedArgs
{
	public int TotalLines { get; set; }
	public int LinesRemoved { get; set; }
	public TimeSpan TotalTime { get; set; }
}
	
public delegate void RemovedLine(object sender, RemovedLineArgs args);
	
public class RemovedLineArgs
{
	public string RemovedLine { get; set; }
	public int RemovedLineNumber { get; set; }
}