HostsEditor.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;

namespace Hosts;

public class HostsEditor : List<HostsItem>
{
	public string FileName { get; set; }
	public Encoding Encoding { get; protected set; }

	public HostsEditor(string filename = null) : base()
	{
		FileName = filename;
		Encoding = new UTF8Encoding(false);
	}

	public HostsEditor(HostsEditor source) : base(source.Select(item => item.Clone()).ToArray())
	{
		this.FileName = source.FileName;
		this.Encoding = source.Encoding;
	}

	public HostsEditor Clone()
	{
		return new HostsEditor(this);
	}

	private bool IsUTF8(byte[] data)
	{
		try
		{
			new UTF8Encoding(false, true).GetCharCount(data);
			return true;
		}
		catch
		{
			return false;
		}
	}

	public void Load()
	{
		Load(FileName);
	}

	public void Load(string filename)
	{
		Clear();

		FileName = filename;
		Encoding = new UTF8Encoding(false);

		if (!File.Exists(filename))
		{
			return;
		}

		byte[] HostsData = File.ReadAllBytes(filename);
		Encoding = (IsUTF8(HostsData)) ? new UTF8Encoding(false) : Encoding.Default;
		var HostsReader = new StreamReader(new MemoryStream(HostsData), Encoding);
		string line;
		while ((line = HostsReader.ReadLine()) != null)
		{
			HostsItem item = new HostsItem(line);
			this.Add(item);
		}
	}

	public void Save()
	{
		Save(FileName);
	}

	public void Save(string filename)
	{
		var HostsStream = new FileStream(filename, FileMode.Create, FileAccess.Write);
		var HostsWriter = new StreamWriter(HostsStream, Encoding);
		foreach (HostsItem item in this)
		{
			if (!item.Deleted)
			{
				HostsWriter.WriteLine(item.RawString);
			}
		}
		HostsWriter.Close();
	}

	public void Add(NetAddress ip, HostAliases hosts, string comment = "")
	{
		base.Add(new HostsItem(ip, hosts, comment));
	}

	public void ResetFormat(bool resetFormat = true)
	{
		this.ForEach(item => item.ResetFormat = resetFormat);
	}

	public void RemoveInvalid()
	{
		this.RemoveAll(item => !item.Valid || item.Deleted);
	}

	public void RemoveDeleted()
	{
		this.RemoveAll(item => item.Deleted);
	}

	public int RemoveLinesWithHost(HostName host)
	{
		return this.RemoveAll(item => item.Valid && item.Aliases.Contains(host));
	}

	public int RemoveLinesWithHost(HostName host, NetAddressType type)
	{
		return this.RemoveAll(item => item.Valid && (type == NetAddressType.None || item.IP.Type == type) && item.Aliases.Contains(host));
	}

	public int RemoveLinesWithIp(NetAddress ip)
	{
		return this.RemoveAll(item => item.Valid && item.IP == ip);
	}

	public List<HostsItem> GetValid()
	{
		return this.FindAll(item => item.Valid && !item.Deleted);
	}

	public List<HostsItem> GetMatched(string pattern, Func<HostsItem, bool> check = null)
	{
		var wp = new WildcardPattern(pattern);
		return this.GetValid().FindAll(item => item.Aliases.IsMatch(wp) && (check == null ? true : check(item)));
	}
}