#region ================== Namespaces

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

#endregion

namespace CodeImp.DoomBuilder.ZDoom
{
	internal sealed class SndSeqParser : ZDTextParser
	{
		#region ================== Variables

		private readonly List<string> sequences;
		private readonly List<string> sequencegroups;
		private readonly HashSet<string> seqencenames;

		#endregion

		#region ================== Constructor

		public SndSeqParser()
		{
			specialtokens = "";
			sequences = new List<string>();
			sequencegroups = new List<string>();
			seqencenames = new HashSet<string>();
		}

		#endregion

		#region ================== Parsing

		public override bool Parse(Stream stream, string sourcefilename)
		{
			base.Parse(stream, sourcefilename);
			
			char[] dots = new[] { ':' };
			char[] brace = new[] { '[' };

			// Continue until at the end of the stream
			while(SkipWhitespace(true))
			{
				string token = ReadToken();

				if(!string.IsNullOrEmpty(token))
				{
					// Sound sequence definition
					if(token.StartsWith(":"))
					{
						string val = token.TrimStart(dots);
						if(!string.IsNullOrEmpty(val) && !seqencenames.Contains(val.ToUpper()))
						{
							sequences.Add(val);
							seqencenames.Add(val.ToUpper());
						}
					}
					// Group definition
					else if(token.StartsWith("["))
					{
						string val = token.TrimStart(brace);
						if(!string.IsNullOrEmpty(val) && !seqencenames.Contains(val.ToUpper()))
						{
							sequencegroups.Add(val);
							seqencenames.Add(val.ToUpper());
						}
					} 
				}
			}

			return true;
		}

		internal List<string> GetSoundSequences() 
		{
			List<string> result = new List<string>(sequencegroups.Count + sequences.Count);
			
			// Add to the collection
			sequencegroups.Sort();
			result.AddRange(sequencegroups);

			sequences.Sort();
			result.AddRange(sequences);

			// Return the collection
			return result;
		}

		#endregion
	}
}