// Copyright (C) Michael Still (mikal@stillhq.com) 2005
// Released under the terms of the GNU LGPL. See COPYING for more details...

using System;
using System.IO;
using System.Text;

namespace OpenPdf
{
	public class Object
	{
		private int m_number;
		private int m_generation;
		private long m_parseStartedAt = -1;
		
		private Dictionary m_dictionary = new Dictionary();
		private ByteBuilder m_stream = new ByteBuilder();
		private string m_directValue;
		
		// It has already been verified that the next thing in the stream is an object
		public Object(PdfStream st, string number, string generation, string extra)
		{
			Console.WriteLine("Object header extra is: " + extra);
			st.Position -= extra.Length;
			m_parseStartedAt = st.Position;
			m_number = Int32.Parse(number);
			m_generation = Int32.Parse(generation);
			Parse(st);
		}
		
		public void Parse(PdfStream st)
		{
			Console.WriteLine("Read object parse pass for object " + Number + " " + Generation);
		
			try
			{
				m_dictionary.ReadDictionary(st);
				ReadStream(st);
				ReadDirectValue(st);
				if(st.PeekLine(true, true) != "endobj")
				{
					throw new ParseException("Object " + Number + " " + Generation + " ended early: \"" + 
						st.PeekLine(true, true) + "\"");
				}
				st.ReadLine();
			}
			catch(ParseException ex)
			{
				Utility.CrashDump(m_parseStartedAt, st.Position, st);
				throw new RuntimeException("Error processing object " + Number + " " + Generation + ": " +
					ex.Message);
			}
		}
		
		public Object(int number, int generation)
		{
			m_number = number;
			m_generation = generation;
		}
		
		public Object()
		{
			m_number = -1;
			m_generation = -1;
		}
		
#region Parsing methods
		private void ReadStream(PdfStream st)
		{
			if(st.PeekLine() == "stream")
			{
				Console.WriteLine("Read stream: ");
				st.ReadLine();
				while(!st.PeekLine(true, true).EndsWith("endstream") && !st.Eof)
				{
					Console.Write("-");
					m_stream.Append(st.ReadLineAsBytes());
				}
				Console.WriteLine(" Done");
				st.ReadLine();
			}
		}
		
		private void ReadDirectValue(PdfStream st)
		{
			if(m_dictionary.Count == 0)
			{
				while(st.PeekLine() != "endobj")
				{
					m_directValue += st.ReadLine();
				}
			}
			else
			{
				Console.WriteLine("Not eligible for direct value");
			}
		}
#endregion
		
#region Utility methods
		public bool Valid
		{
			get
			{
				if((m_number != -1) && (m_generation != -1))
					return true;
				else
					return false;
			}
		}
		
		public string Type
		{
			get
			{
				DictionaryItem di = m_dictionary.Get("Type");
				if(di.Valid)
				{
					return di.ValueAsString();
				}
				
				return "";
			}
		}
		
		public int Number
		{
			get
			{
				if(Valid)
					return m_number;
				else
					throw new RuntimeException("No number as object is invalid");
			}
		}
		
		public int Generation
		{
			get
			{
				if(Valid)
					return m_generation;
				else
					throw new RuntimeException("No generation, as object is invalid");
			}
		}
		
		public Dictionary Dictionary
		{
			get
			{
				return m_dictionary;
			}
		}
#endregion
	}
}