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

namespace Intelix.Helper.Sql;

public class BerkeleyDB
{
	public List<KeyValuePair<string, string>> Keys { get; }

	public BerkeleyDB(byte[] file)
	{
		List<byte> list = new List<byte>();
		Keys = new List<KeyValuePair<string, string>>();
		using (MemoryStream input = new MemoryStream(file))
		{
			using BinaryReader binaryReader = new BinaryReader(input);
			int i = 0;
			for (int num = (int)binaryReader.BaseStream.Length; i < num; i++)
			{
				list.Add(binaryReader.ReadByte());
			}
		}
		string text = BitConverter.ToString(Extract(list.ToArray(), 0, 4, littleEndian: false)).Replace("-", "");
		int num2 = BitConverter.ToInt32(Extract(list.ToArray(), 12, 4, littleEndian: true), 0);
		if (!text.Equals("00061561"))
		{
			return;
		}
		int num3 = int.Parse(BitConverter.ToString(Extract(list.ToArray(), 56, 4, littleEndian: false)).Replace("-", ""));
		int num4 = 1;
		while (Keys.Count < num3)
		{
			string[] array = new string[(num3 - Keys.Count) * 2];
			for (int j = 0; j < (num3 - Keys.Count) * 2; j++)
			{
				array[j] = BitConverter.ToString(Extract(list.ToArray(), num2 * num4 + 2 + j * 2, 2, littleEndian: true)).Replace("-", "");
			}
			Array.Sort(array);
			for (int k = 0; k < array.Length; k += 2)
			{
				int num5 = Convert.ToInt32(array[k], 16) + num2 * num4;
				int num6 = Convert.ToInt32(array[k + 1], 16) + num2 * num4;
				int num7 = ((k + 2 >= array.Length) ? (num2 + num2 * num4) : (Convert.ToInt32(array[k + 2], 16) + num2 * num4));
				string text2 = Encoding.ASCII.GetString(Extract(list.ToArray(), num6, num7 - num6, littleEndian: false));
				string value = BitConverter.ToString(Extract(list.ToArray(), num5, num6 - num5, littleEndian: false));
				if (!string.IsNullOrWhiteSpace(text2))
				{
					Keys.Add(new KeyValuePair<string, string>(text2, value));
				}
			}
			num4++;
		}
	}

	private static byte[] Extract(byte[] source, int start, int length, bool littleEndian)
	{
		byte[] array = new byte[length];
		int num = 0;
		for (int i = start; i < start + length; i++)
		{
			array[num] = source[i];
			num++;
		}
		if (littleEndian)
		{
			Array.Reverse(array);
		}
		return array;
	}
}