/* csvorbis
 * Copyright (C) 2000 ymnk, JCraft,Inc.
 *  
 * Written by: 2000 ymnk<ymnk@jcraft.com>
 * Ported to C# from JOrbis by: Mark Crichton <crichton@gimp.org> 
 *   
 * Thanks go to the JOrbis team, for licencing the code under the
 * LGPL, making my job a lot easier.
 * 
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public License
 * as published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
   
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Library General Public License for more details.
 * 
 * You should have received a copy of the GNU Library General Public
 * License along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */


using System;
using System.Text;
using csogg;

namespace csvorbis 
{
	// the comments are not part of vorbis_info so that vorbis_info can be
	// static storage
	public class Comment
	{
		private static String _vorbis="vorbis";

		//private static int OV_EFAULT=-129;
		private static int OV_EIMPL=-130;

		// unlimited user comment fields.  libvorbis writes 'libvorbis'
		// whatever vendor is set to in encode
		public byte[][] user_comments;
		public int[] comment_lengths; 
		public int comments;
		public byte[] vendor;

		public void init()
		{
			user_comments=null;
			comments=0;
			vendor=null;
		}

		public void add(String comment)
		{
			Encoding AE = Encoding.UTF8;
			byte[] comment_byt = AE.GetBytes(comment);
			add(comment_byt);
		}

		private void add(byte[] comment)
		{
			byte[][] foo=new byte[comments+2][];
			if(user_comments!=null)
			{
				Array.Copy(user_comments, 0, foo, 0, comments);
			}
			user_comments=foo;

			int[] goo=new int[comments+2];
			if(comment_lengths!=null)
			{
				Array.Copy(comment_lengths, 0, goo, 0, comments);
			}
			comment_lengths=goo;

			byte[] bar=new byte[comment.Length+1];
			Array.Copy(comment, 0, bar, 0, comment.Length);
			user_comments[comments]=bar;
			comment_lengths[comments]=comment.Length;
			comments++;
			user_comments[comments]=null;
		}

		public void add_tag(String tag, String contents)
		{
			if(contents==null) contents="";
			add(tag+"="+contents);
		}

		/*
		  private void add_tag(byte[] tag, byte[] contents){
			byte[] foo=new byte[tag.length+contents.length+1];
			int j=0; 
			for(int i=0; i<tag.length; i++){foo[j++]=tag[i];}
			foo[j++]=(byte)'='; j++;
			for(int i=0; i<contents.length; i++){foo[j++]=tag[i];}
			add(foo);
		  }
		*/
 
		// This is more or less the same as strncasecmp - but that doesn't exist
		// * everywhere, and this is a fairly trivial function, so we include it
		static bool tagcompare(byte[] s1, byte[] s2, int n)
		{
			int c=0;
			byte u1, u2;
			while(c < n)
			{
				u1=s1[c]; u2=s2[c];
				if(u1>='A')u1=(byte)(u1-'A'+'a');
				if(u2>='A')u2=(byte)(u2-'A'+'a');
				if(u1!=u2){ return false; }
				c++;
			}
			return true;
		}

		public String query(String tag)
		{
			return query(tag, 0);
		}

		public String query(String tag, int count)
		{
			Encoding AE = Encoding.UTF8;
			byte[] tag_byt = AE.GetBytes(tag);
			
			int foo=query(tag_byt, count);
			if(foo==-1)return null;
			byte[] comment=user_comments[foo];
			for(int i=0; i<comment_lengths[foo]; i++)
			{
				if(comment[i]=='=')
				{
					char[] comment_uni = AE.GetChars(comment);
					return new String(comment_uni, i+1, comment_lengths[foo]-(i+1));
				}
			}
			return null;
		}

		private int query(byte[] tag, int count)
		{
			int i=0;
			int found = 0;
			int taglen = tag.Length;
			byte[] fulltag = new byte[taglen+2];
			Array.Copy(tag, 0, fulltag, 0, tag.Length);
			fulltag[tag.Length]=(byte)'=';

			for(i=0;i<comments;i++)
			{
				if(tagcompare(user_comments[i], fulltag, taglen))
				{
					if(count==found)
					{
						// We return a pointer to the data, not a copy
						//return user_comments[i] + taglen + 1;
						return i;
					}
					else{ found++; }
				}
			}
			return -1;
		}

		internal int unpack(csBuffer opb)
		{
			int vendorlen=opb.read(32);
			if(vendorlen<0)
			{
				//goto err_out;
				clear();
				return(-1);
			}
			vendor=new byte[vendorlen+1];
			opb.read(vendor,vendorlen);
			comments=opb.read(32);
			if(comments<0)
			{
				//goto err_out;
				clear();
				return(-1);
			}
			user_comments=new byte[comments+1][];
			comment_lengths=new int[comments+1];
	    
			for(int i=0;i<comments;i++)
			{
				int len=opb.read(32);
				if(len<0)
				{
					//goto err_out;
					clear();
					return(-1);
				}
				comment_lengths[i]=len;
				user_comments[i]=new byte[len+1];
				opb.read(user_comments[i], len);
			}	  
			if(opb.read(1)!=1)
			{
				//goto err_out; // EOP check
				clear();
				return(-1);

			}
			return(0);
			//  err_out:
			//    comment_clear(vc);
			//    return(-1);
		}

		int pack(csBuffer opb)
		{
			String temp="Xiphophorus libVorbis I 20000508";

			Encoding AE = Encoding.UTF8;
			byte[] temp_byt = AE.GetBytes(temp);
			byte[] _vorbis_byt = AE.GetBytes(_vorbis);
			
			// preamble
			opb.write(0x03,8);
			opb.write(_vorbis_byt);

			// vendor
			opb.write(temp.Length,32);
			opb.write(temp_byt);

			// comments

			opb.write(comments,32);
			if(comments!=0)
			{
				for(int i=0;i<comments;i++)
				{
					if(user_comments[i]!=null)
					{
						opb.write(comment_lengths[i],32);
						opb.write(user_comments[i]);
					}
					else
					{
						opb.write(0,32);
					}
				}
			}
			opb.write(1,1);
			return(0);
		}

		public int header_out(Packet op)
		{
			csBuffer opb=new csBuffer();
			opb.writeinit();

			if(pack(opb)!=0) return OV_EIMPL;

			op.packet_base = new byte[opb.bytes()];
			op.packet=0;
			op.bytes=opb.bytes();
			Array.Copy(opb.buf(), 0, op.packet_base, 0, op.bytes);
			op.b_o_s=0;
			op.e_o_s=0;
			op.granulepos=0;
			return 0;
		}
 
		internal void clear()
		{
			for(int i=0;i<comments;i++)
				user_comments[i]=null;
			user_comments=null;
			vendor=null;
		}

		public String getVendor()
		{
			Encoding AE = Encoding.UTF8;
			char[] vendor_uni = AE.GetChars(vendor);
			return new String(vendor_uni);
		}

		public String getComment(int i)
		{
			Encoding AE = Encoding.UTF8;
			if(comments<=i)return null;
			
			char[] user_comments_uni = AE.GetChars(user_comments[i]);
			return new String(user_comments_uni);
		}

		public String toString()
		{
			Encoding AE = Encoding.UTF8;
			String long_string = "Vendor: " + new String(AE.GetChars(vendor));

			for(int i=0; i < comments; i++)
				long_string = long_string + "\nComment: " + new String(AE.GetChars(user_comments[i]));
			
			long_string = long_string + "\n";

			return long_string;
		}
	}
}