using System.Text;

internal static class Formatter
{
	public static string Indent = "    ";

	public static void AppendIndent(StringBuilder sb, int count)
	{
		while (count > 0)
		{
			sb.Append(Indent);
			count--;
		}
	}

	public static bool IsEscaped(StringBuilder sb, int index)
	{
		bool escaped = false;
		while (index > 0 && sb[--index] == '\\')
		{
			escaped = !escaped;
		}
		return escaped;
	}

	public static string PrettyPrint(string input)
	{
		StringBuilder output = new StringBuilder(input.Length * 2);
		char? quote = null;
		int depth = 0;
		for (int i = 0; i < input.Length; i++)
		{
			char ch = input[i];
			switch (ch)
			{
			case '[':
			case '{':
				output.Append(ch);
				if (!quote.HasValue)
				{
					output.AppendLine();
					AppendIndent(output, ++depth);
				}
				break;
			case ']':
			case '}':
				if (quote.HasValue)
				{
					output.Append(ch);
					break;
				}
				output.AppendLine();
				AppendIndent(output, --depth);
				output.Append(ch);
				break;
			case '"':
			case '\'':
				output.Append(ch);
				if (quote.HasValue)
				{
					if (!IsEscaped(output, i))
					{
						quote = null;
					}
				}
				else
				{
					quote = ch;
				}
				break;
			case ',':
				output.Append(ch);
				if (!quote.HasValue)
				{
					output.AppendLine();
					AppendIndent(output, depth);
				}
				break;
			case ':':
				if (quote.HasValue)
				{
					output.Append(ch);
				}
				else
				{
					output.Append(" : ");
				}
				break;
			default:
				if (quote.HasValue || !char.IsWhiteSpace(ch))
				{
					output.Append(ch);
				}
				break;
			}
		}
		return output.ToString();
	}
}