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

namespace MapViewer
{
	class IniFile
	{
		Dictionary<string, IniSection> sections = new Dictionary<string, IniSection>();
		IniSection currentSection;

		public IniFile(Stream s)
		{
			
			StreamReader reader = new StreamReader(s);
			while (!reader.EndOfStream)
			{
				string line = reader.ReadLine();
				if (!ProcessEntry(line))
					ProcessSection(line);
			}
		}

		Regex sectionPattern = new Regex(@"\[([^]]*)\]");
		Regex entryPattern = new Regex(@"([^=]+)=([^;]*)");

		bool ProcessSection(string line)
		{
			Match m = sectionPattern.Match(line);
			if (m == null || !m.Success)
				return false;

			string sectionName = m.Groups[1].Value;
			currentSection = new IniSection(sectionName);
			sections.Add(sectionName, currentSection);

			return true;
		}

		bool ProcessEntry(string line)
		{
			Match m = entryPattern.Match(line);
			if (m == null || !m.Success)
				return false;

			if (currentSection == null)
				throw new InvalidOperationException("No current INI section");

			string keyName = m.Groups[1].Value;
			string keyValue = m.Groups[2].Value;

			currentSection.Add(keyName, keyValue);

			return true;
		}

		public IniSection GetSection(string s)
		{
			IniSection section;
			sections.TryGetValue(s, out section);
			return section;
		}
	}

	class IniSection
	{
		string name;
		Dictionary<string, string> values = new Dictionary<string, string>();

		public IniSection(string name)
		{
			this.name = name;
		}

		public void Add(string key, string value)
		{
			values.Add(key, value);
		}

		public string GetValue(string key, string defaultValue)
		{
			string s;
			return values.TryGetValue( key, out s ) ? s : defaultValue;
		}
	}
}