/*
 * Greenshot - a free and open source screenshot tool
 * Copyright (C) 2007-2020 Thomas Braun, Jens Klingen, Robin Krom
 *
 * For more information see: http://getgreenshot.org/
 * The Greenshot project is hosted on GitHub https://github.com/greenshot/greenshot
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 1 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

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

namespace Greenshot.IniFile {
	/// <summary>
	/// The IniReader does exactly what it says, it reads the .ini file
	/// </summary>
	public static class IniReader {
		private const char SectionStartToken = '[';
		private const char SectionEndToken = ']';
		private const char CommentToken = ';';
		private static readonly char[] Assignment = { '=' };

		/// <summary>
		/// Read an ini file to a Dictionary, each key is a section and the value is a Dictionary with name and values.
		/// </summary>
		/// <param name="path"></param>
		/// <param name="encoding"></param>
		/// <returns></returns>
		public static IDictionary<string, IDictionary<string, string>> Read(string path, Encoding encoding) {
			var ini = new Dictionary<string, IDictionary<string, string>>();
			using (var fileStream = new FileStream(path, FileMode.Open, FileAccess.Read, FileShare.Read, 1024))
            {
                using var streamReader = new StreamReader(fileStream, encoding);
                IDictionary<string, string> nameValues = new Dictionary<string, string>();
                while (!streamReader.EndOfStream) {
                    string line = streamReader.ReadLine();
                    if (line == null)
                    {
                        continue;
                    }
                    string cleanLine = line.Trim();
                    if (cleanLine.Length == 0 || cleanLine[0] == CommentToken) {
                        continue;
                    }
                    if (cleanLine[0] == SectionStartToken) {
                        var sectionEndIndex = line.IndexOf(SectionEndToken,1);
                        if (sectionEndIndex <0)
                        {
                            continue;
                        }
                        string section = line.Substring(1,sectionEndIndex-1).Trim();
                        if (!ini.TryGetValue(section, out nameValues))
                        {
                            nameValues = new Dictionary<string, string>();
                            ini.Add(section, nameValues);
                        }
                    } else {
                        string[] keyvalueSplitter = line.Split(Assignment, 2);
                        string name = keyvalueSplitter[0];
                        string inivalue = keyvalueSplitter.Length > 1 ? keyvalueSplitter[1] : null;
                        if (nameValues.ContainsKey(name)) {
                            nameValues[name] = inivalue;
                        } else {
                            nameValues.Add(name, inivalue);
                        }
                    }
                }
            }
			return ini;
		}
	}
}