/android/import-contacts

/*

 * VCFImporter.java

 *

 * Copyright (C) 2009 Tim Marston <edam@waxworlds.org>

 *

 * This file is part of the Import Contacts program (hereafter referred

 * to as "this program"). For more information, see

 * http://www.waxworlds.org/edam/software/android/import-contacts

 *

 * This program is free software: you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation, either version 3 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 General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program.  If not, see <http://www.gnu.org/licenses/>.

 */

package org.waxworlds.edam.importcontacts;

import java.io.BufferedReader;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileNotFoundException;

import java.io.FileReader;

import java.io.FilenameFilter;

import java.io.IOException;

import java.io.UnsupportedEncodingException;

import java.nio.ByteBuffer;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.HashSet;

import java.util.Iterator;

import java.util.List;

import java.util.NoSuchElementException;

import java.util.Set;

import java.util.Vector;

import java.util.regex.Matcher;

import java.util.regex.Pattern;

import android.content.SharedPreferences;

import android.provider.Contacts;

import android.provider.Contacts.PhonesColumns;

public class VCFImporter extends Importer

{

	private int _vCardCount = 0;

	private int _progress = 0;

	public VCFImporter( Doit doit )

	{

		super( doit );

	}

	@Override

	protected void onImport() throws AbortImportException

	{

		SharedPreferences prefs = getSharedPreferences();

		// update UI

		setProgressMessage( R.string.doit_scanning );

		// get a list of vcf files

		File[] files = null;

		try

		{

			// open directory

			String path = "/sdcard" + prefs.getString( "location", "/" );

			File file = new File( path );

			if( !file.exists() )

				showError( R.string.error_locationnotfound );

			// directory, or file?

			if( file.isDirectory() )

			{

				// get files

				class VCardFilter implements FilenameFilter {

					public boolean accept( File dir, String name ) {

						return name.toLowerCase().endsWith( ".vcf" );

					}

				}

				files = file.listFiles( new VCardFilter() );

			}

			else

			{

				// use just this file

				files = new File[ 1 ];

				files[ 0 ] = file;

			}

		}

		catch( SecurityException e ) {

			showError( R.string.error_locationpermissions );

		}

		// check num files and set progress max

		if( files != null && files.length > 0 )

			setProgressMax( files.length );

		else

			showError( R.string.error_locationnofiles );

		// scan through the files

		setTmpProgress( 0 );

		for( int i = 0; i < files.length; i++ ) {

			countVCardFile( files[ i ] );

			setTmpProgress( i );

		}

		setProgressMax( _vCardCount );	// will also update tmp progress

		// import them

		setProgress( 0 );

		for( int i = 0; i < files.length; i++ )

			importVCardFile( files[ i ] );

	}

	private void countVCardFile( File file ) throws AbortImportException

	{

		try

		{

			// open file

			BufferedReader reader = new BufferedReader(

				new FileReader( file ) );

			// read

			String line;

			boolean inVCard = false;

			while( ( line = reader.readLine() ) != null )

			{

				if( !inVCard ) {

					// look for vcard beginning

					if( line.matches( "^BEGIN:VCARD" ) ) {

						inVCard = true;

						_vCardCount++;

					}

				}

				else if( line.matches( "^END:VCARD" ) )

					inVCard = false;

			}

		}

		catch( FileNotFoundException e ) {

			showError( getText( R.string.error_filenotfound ) +

				file.getName() );

		}

		catch( IOException e ) {

			showError( getText( R.string.error_ioerror ) + file.getName() );

		}

	}

	private void importVCardFile( File file ) throws AbortImportException

	{

		// check file is good

		if( !file.exists() )

			showError( getText( R.string.error_filenotfound ) +

				file.getName() );

		if( file.length() == 0 )

			showError( getText( R.string.error_fileisempty ) +

				file.getName() );

		try

		{

			// open/read file

			FileInputStream istream = new FileInputStream( file );

			byte[] content = new byte[ (int)file.length() ];

			istream.read( content );

			// import

			importVCardFileContent( content, file.getName() );

		}

		catch( FileNotFoundException e ) {

			showError( getText( R.string.error_filenotfound ) +

				file.getName() );

		}

		catch( IOException e ) {

			showError( getText( R.string.error_ioerror ) + file.getName() );

		}

	}

	private void importVCardFileContent( byte[] content, String fileName )

		throws AbortImportException

	{

		// go through lines

		VCard vCard = null;

		ContentLineIterator cli = new ContentLineIterator( content );

		while( cli.hasNext() )

		{

			ByteBuffer buffer = cli.next();

			// get a US-ASCII version of the line for processing

			String line;

			try {

				line = new String( buffer.array(), buffer.position(),

					buffer.limit() - buffer.position(), "US-ASCII" );

			}

			catch( UnsupportedEncodingException e ) {

				// we know US-ASCII is supported, so appease the compiler...

				line = "";

			}

			if( vCard == null ) {

				// look for vcard beginning

				if( line.matches( "^BEGIN:VCARD" ) ) {

					setProgress( ++_progress );

					vCard = new VCard();

				}

			}

			else {

				// look for vcard content or ending

				if( line.matches( "^END:VCARD" ) )

				{

					// store vcard and do away with it

					try {

						vCard.finaliseParsing();

						importContact( vCard );

					}

					catch( VCard.ParseException e ) {

						skipContact();

						if( !showContinue(

							getText( R.string.error_vcf_parse ).toString()

							+ fileName + "\n" + e.getMessage() ) )

						{

							finish( ACTION_ABORT );

						}

					}

					catch( VCard.SkipContactException e ) {

						skipContact();

						// do nothing

					}

					vCard = null;

				}

				else

				{

					// try giving the line to the vcard

					try {

						vCard.parseLine( buffer, line,

							cli.doesNextLineLookFolded() );

					}

					catch( VCard.ParseException e ) {

						skipContact();

						if( !showContinue(

							getText( R.string.error_vcf_parse ).toString()

							+ fileName + "\n" + e.getMessage() ) )

						{

							finish( ACTION_ABORT );

						}

						// although we're continuing, we still need to abort

						// this vCard. Further lines will be ignored until we

						// get to another BEGIN:VCARD line.

						vCard = null;

					}

					catch( VCard.SkipContactException e ) {

						skipContact();

						// abort this vCard. Further lines will be ignored until

						// we get to another BEGIN:VCARD line.

						vCard = null;

					}

				}

			}

		}

	}

	class ContentLineIterator implements Iterator< ByteBuffer >

	{

		protected byte[] _content = null;

		protected int _pos = 0;

		public ContentLineIterator( byte[] content )

		{

			_content = content;

		}

		@Override

		public boolean hasNext()

		{

			return _pos < _content.length;

		}

		@Override

		public ByteBuffer next()

		{

			int initial_pos = _pos;

			// find newline

			for( ; _pos < _content.length; _pos++ )

				if( _content[ _pos ] == '\n' )

				{

					// adjust for a \r preceding the \n

					int to = ( _pos > 0 && _content[ _pos - 1 ] == '\r' &&

						_pos > initial_pos )? _pos - 1 : _pos;

					_pos++;

					return ByteBuffer.wrap( _content, initial_pos,

						to - initial_pos );

				}

			// we didn't find one, but were there bytes left?

			if( _pos != initial_pos ) {

				int to = _pos;

				_pos++;

				return ByteBuffer.wrap( _content, initial_pos,

					to - initial_pos );

			}

			// no bytes left

			throw new NoSuchElementException();

		}

		@Override

		public void remove()

		{

			throw new UnsupportedOperationException();

		}

		/**

		 * Does the next line, if there is one, look like it should be folded

		 * onto the end of this one?

		 * @return

		 */

		public boolean doesNextLineLookFolded()

		{

			return _pos > 0 && _pos < _content.length &&

				_content[ _pos - 1 ] == '\n' && _content[ _pos ] == ' ';

		}

	}

	private class VCard extends ContactData

	{

		private final static int NAMELEVEL_NONE = 0;

		private final static int NAMELEVEL_ORG = 1;

		private final static int NAMELEVEL_FN = 2;

		private final static int NAMELEVEL_N = 3;

		private final static int MULTILINE_NONE = 0;

		private final static int MULTILINE_ENCODED = 1;	// v2.1 quoted-printable

		private final static int MULTILINE_ESCAPED = 2;	// v2.1 \\CRLF

		private final static int MULTILINE_FOLDED = 3;	// v3.0 folding

		private String _version = null;

		private Vector< ByteBuffer > _buffers = null;

		private int _name_level = NAMELEVEL_NONE;

		private int _parser_multiline_state = MULTILINE_NONE;

		private String _parser_current_name_and_params = null;

		private String _parser_buffered_value_so_far = "";

		protected class UnencodeResult

		{

			private boolean _another_line_required;

			private ByteBuffer _buffer;

			public UnencodeResult( boolean another_line_required,

				ByteBuffer buffer )

			{

				_another_line_required = another_line_required;

				_buffer = buffer;

			}

			public boolean isAnotherLineRequired()

			{

				return _another_line_required;

			}

			public ByteBuffer getBuffer()

			{

				return _buffer;

			}

		}

		@SuppressWarnings("serial")

		protected class ParseException extends Exception

		{

			@SuppressWarnings("unused")

			public ParseException( String error )

			{

				super( error );

			}

			public ParseException( int res )

			{

				super( VCFImporter.this.getText( res ).toString() );

			}

		}

		@SuppressWarnings("serial")

		protected class SkipContactException extends Exception { }

		private String extractCollonPartFromLine( ByteBuffer buffer,

			String line, boolean former )

		{

			String ret = null;

			// get a US-ASCII version of the line for processing, unless we were

			// supplied with one

			if( line == null ) {

				try {

					line = new String( buffer.array(), buffer.position(),

						buffer.limit() - buffer.position(), "US-ASCII" );

				}

				catch( UnsupportedEncodingException e ) {

					// we know US-ASCII is supported, so appease the compiler...

					line = "";

				}

			}

			// split line into name and value parts and check to make sure we

			// only got 2 parts and that the first part is not zero in length

			String[] parts = line.split( ":", 2 );

			if( parts.length == 2 && parts[ 0 ].length() > 0 )

				ret = parts[ former? 0 : 1 ];

			return ret;

		}

		private String extractNameAndParamsFromLine( ByteBuffer buffer,

			String line )

		{

			return extractCollonPartFromLine( buffer, line, true );

		}

		private String extractValueFromLine( ByteBuffer buffer, String line )

		{

			return extractCollonPartFromLine( buffer, line, false );

		}

		public void parseLine( ByteBuffer buffer, String line,

			boolean next_line_looks_folded )

			throws ParseException, SkipContactException,

			AbortImportException

		{

			// do we have a version yet?

			if( _version == null )

			{

				// tentatively get name and params from line

				String name_and_params =

					extractNameAndParamsFromLine( buffer, line );

				// is it a version line?

				if( name_and_params != null &&

					name_and_params.equals( "VERSION" ) )

				{

					// yes, get it!

					String value = extractValueFromLine( buffer, line );

					if( !value.equals( "2.1" ) && !value.equals( "3.0" ) )

						throw new ParseException( R.string.error_vcf_version );

					_version = value;

					// parse any buffers we've been accumulating while we waited

					// for a version

					if( _buffers != null )

						for( int i = 0; i < _buffers.size(); i++ )

							parseLine( _buffers.get( i ), null,

								i + 1 < _buffers.size() &&

								_buffers.get( i + 1 ).hasRemaining() &&

								_buffers.get( i + 1 ).get(

									_buffers.get( i + 1 ).position() ) == ' ' );

					_buffers = null;

				}

				else

				{

					// no, so stash this line till we get a version

					if( _buffers == null )

						_buffers = new Vector< ByteBuffer >();

					_buffers.add( buffer );

				}

			}

			else

			{

				// name and params and the position in the buffer where the

				// "value" part of the line start

				String name_and_params;

				int pos;

				if( _parser_multiline_state != MULTILINE_NONE )

				{

					// if we're currently in a multi-line value, use the stored

					// property name and parameters

					name_and_params = _parser_current_name_and_params;

					// skip some initial line characters, depending on the type

					// of multi-line we're handling

					pos = buffer.position();

					switch( _parser_multiline_state )

					{

					case MULTILINE_FOLDED:

						pos++;

						break;

					case MULTILINE_ENCODED:

						while( pos < buffer.limit() && (

							buffer.get( pos ) == ' ' ||

							buffer.get( pos ) == '\t' ) )

						{

							pos++;

						}

						break;

					default:

						// do nothing

					}

					// take us out of multi-line so that we can re-detect that

					// this line is a multi-line or not

					_parser_multiline_state = MULTILINE_NONE;

				}

				else

				{

					// get name and params from line, and since we're not

					// parsing a subsequent line in a multi-line, this should

					// not fail, or it's an error

					name_and_params =

						extractNameAndParamsFromLine( buffer, line );

					if( name_and_params == null )

						throw new ParseException(

							R.string.error_vcf_malformed );

					// calculate how many chars to skip from beginning of line

					// so we skip the property "name:" part

					pos = buffer.position() + name_and_params.length() + 1;

					// reset the saved multi-line state

					_parser_current_name_and_params = name_and_params;

					_parser_buffered_value_so_far = "";

				}

				// get value from buffer, as raw bytes

				ByteBuffer value;

				value = ByteBuffer.wrap( buffer.array(), pos,

					buffer.limit() - pos );

				// get parameter parts

				String[] name_param_parts = name_and_params.split( ";", -1 );

				for( int i = 0; i < name_param_parts.length; i++ )

					name_param_parts[ i ] = name_param_parts[ i ].trim();

				// parse encoding parameter

				String encoding = checkParam( name_param_parts, "ENCODING" );

				if( encoding != null ) encoding = encoding.toUpperCase();

				if( encoding != null && !encoding.equals( "8BIT" ) &&

					!encoding.equals( "QUOTED-PRINTABLE" ) )

					//&& !encoding.equals( "BASE64" ) )

				{

					throw new ParseException( R.string.error_vcf_encoding );

				}

				// parse charset parameter

				String charset = checkParam( name_param_parts, "CHARSET" );

				if( charset != null ) charset = charset.toUpperCase();

				if( charset != null && !charset.equals( "US-ASCII" ) &&

					!charset.equals( "ASCII" ) &&

					!charset.equals( "UTF-8" ) )

				{

					throw new ParseException( R.string.error_vcf_charset );

				}

				// do unencoding (or default to a fake unencoding result with

				// the raw string)

				UnencodeResult unencoding_result = null;

				if( encoding != null && encoding.equals( "QUOTED-PRINTABLE" ) )

					unencoding_result = unencodeQuotedPrintable( value );

//				else if( encoding != null && encoding.equals( "BASE64" ) )

//					unencoding_result = unencodeBase64( props[ 1 ], charset );

				if( unencoding_result != null ) {

					value = unencoding_result.getBuffer();

					if( unencoding_result.isAnotherLineRequired() )

						_parser_multiline_state = MULTILINE_ENCODED;

				}

				// convert 8-bit ASCII charset to US-ASCII

				if( charset == null || charset.equals( "ASCII" ) ) {

					value = transcodeAsciiToUtf8( value );

					charset = "UTF-8";

				}

				// process charset

				String string_value;

				try {

					string_value = new String( value.array(), value.position(),

						value.limit() - value.position(), charset );

				} catch( UnsupportedEncodingException e ) {

					throw new ParseException( R.string.error_vcf_charset );

				}

				// for some entries that have semicolon-separated value parts,

				// check to see if the value ends in an escape character, which

				// indicates that we have a multi-line value

				if( ( name_param_parts[ 0 ].equals( "N" ) ||

					name_param_parts[ 0 ].equals( "ORG" ) ||

					name_param_parts[ 0 ].equals( "ADR" ) ) &&

					doesStringEndInAnEscapeChar( string_value ) )

				{

					_parser_multiline_state = MULTILINE_ESCAPED;

					string_value = string_value.substring( 0,

						string_value.length() - 1 );

				}

				// now we know whether we're in an encoding multi-line,

				// determine if we're in a v3 folded multi-line or not

				if( _parser_multiline_state == MULTILINE_NONE &&

					_version.equals( "3.0" ) && next_line_looks_folded )

				{

					_parser_multiline_state = MULTILINE_FOLDED;

				}

				// handle multi-lines by buffering them and parsing them when we

				// are processing the last line in a multi-line sequence

				if( _parser_multiline_state != MULTILINE_NONE ) {

					_parser_buffered_value_so_far += string_value;

					return;

				}

				String complete_value =

					( _parser_buffered_value_so_far + string_value ).trim();

				// ignore empty values

				if( complete_value.length() < 1 ) return;

				// parse some properties

				if( name_param_parts[ 0 ].equals( "N" ) )

					parseN( name_param_parts, complete_value );

				else if( name_param_parts[ 0 ].equals( "FN" ) )

					parseFN( name_param_parts, complete_value );

				else if( name_param_parts[ 0 ].equals( "ORG" ) )

					parseORG( name_param_parts, complete_value );

				else if( name_param_parts[ 0 ].equals( "TEL" ) )

					parseTEL( name_param_parts, complete_value );

				else if( name_param_parts[ 0 ].equals( "EMAIL" ) )

					parseEMAIL( name_param_parts, complete_value );

				else if( name_param_parts[ 0 ].equals( "ADR" ) )

					parseADR( name_param_parts, complete_value );

			}

		}

		private boolean doesStringEndInAnEscapeChar( String string )

		{

			// count the number of backslashes at the end of the string

			int count = 0;

			for( int a = string.length() - 1; a >= 0; a-- )

				if( string.charAt( a ) == '\\' )

					count++;

				else

					break;

			// if there are an even number of backslashes then the final one

			// doesn't count

			return ( count & 1 ) == 1;

		}

		private String[] splitValueBySemicolon( String value )

		{

			// split string in to parts by semicolon

			ArrayList< String > parts = new ArrayList< String >(

				Arrays.asList( value.split(  ";" ) ) );

			// go through parts

			for( int a = 0; a < parts.size(); a++ )

			{

				String str = parts.get( a );

				// look for parts that end in an escape character, but ignore

				// the final part. We've already detected escape chars at the

				// end of the final part in parseLine() and handled multi-lines

				// accordingly.

				if( a < parts.size() - 1 &&

					doesStringEndInAnEscapeChar( str ) )

				{

					// join the next part to this part and remove the next part

					parts.set( a, str.substring( 0, str.length() - 1 ) +

						';' + parts.get( a + 1 ) );

					parts.remove( a + 1 );

					// re-visit this part

					a--;

					continue;

				}

				// trim and replace string

				str = str.trim();

				parts.set( a, str );

			}

			String[] ret = new String[ parts.size() ];

			return parts.toArray( ret );

		}

		private void parseN( String[] params, String value )

			throws ParseException, SkipContactException,

			AbortImportException

		{

			// already got a better name?

			if( _name_level >= NAMELEVEL_N ) return;

			// get name parts

			String[] name_parts = splitValueBySemicolon( value );

			// build name

			value = "";

			if( name_parts.length > 1 && name_parts[ 1 ].length() > 0 )

				value += name_parts[ 1 ];

			if( name_parts.length > 0 && name_parts[ 0 ].length() > 0 )

				value += ( value.length() == 0? "" : " " ) + name_parts[ 0 ];

			// set name

			setName( value );

			_name_level = NAMELEVEL_N;

			// check now to see if we need to import this contact (to avoid

			// parsing the rest of the vCard unnecessarily)

			if( !isImportRequired( getName() ) )

				throw new SkipContactException();

		}

		private void parseFN( String[] params, String value )

			throws ParseException, SkipContactException

		{

			// already got a better name?

			if( _name_level >= NAMELEVEL_FN ) return;

			// set name

			setName( value );

			_name_level = NAMELEVEL_FN;

		}

		private void parseORG( String[] params, String value )

			throws ParseException, SkipContactException

		{

			// already got a better name?

			if( _name_level >= NAMELEVEL_ORG ) return;

			// get org parts

			String[] org_parts = splitValueBySemicolon( value );

			// build name

			if( org_parts.length > 1 && org_parts[ 0 ].length() == 0 )

				value = org_parts[ 1 ];

			else if( org_parts.length > 1 && org_parts[ 1 ].length() > 0 )

				value = org_parts[ 0 ] + ", " + org_parts[ 1 ];

			else

				value = org_parts[ 0 ];

			// set name

			setName( value );

			_name_level = NAMELEVEL_ORG;

		}

		private void parseTEL( String[] params, String value )

			throws ParseException

		{

			if( value.length() == 0 ) return;

			Set< String > types = extractTypes( params, Arrays.asList(

				"PREF", "HOME", "WORK", "VOICE", "FAX", "MSG", "CELL",

				"PAGER", "BBS", "MODEM", "CAR", "ISDN", "VIDEO" ) );

			// here's the logic...

			boolean preferred = types.contains( "PREF" );

			int type = PhonesColumns.TYPE_MOBILE;

			if( types.contains( "VOICE" ) )

				if( types.contains( "WORK" ) )

					type = PhonesColumns.TYPE_WORK;

				else

					type = PhonesColumns.TYPE_HOME;

			else if( types.contains( "CELL" ) || types.contains( "VIDEO" ) )

				type = PhonesColumns.TYPE_MOBILE;

			if( types.contains( "FAX" ) )

				if( types.contains( "HOME" ) )

					type = PhonesColumns.TYPE_FAX_HOME;

				else

					type = PhonesColumns.TYPE_FAX_WORK;

			if( types.contains( "PAGER" ) )

				type = PhonesColumns.TYPE_PAGER;

			// add phone number

			addPhone( value, type, preferred );

		}

		public void parseEMAIL( String[] params, String value )

			throws ParseException

		{

			if( value.length() == 0 ) return;

			Set< String > types = extractTypes( params, Arrays.asList(

				"PREF", "WORK", "HOME", "INTERNET" ) );

			// add email address

			boolean preferred = types.contains( "PREF" );

			if( types.contains( "WORK" ) )

				addEmail( value, Contacts.ContactMethods.TYPE_WORK, preferred );

			else

				addEmail( value, Contacts.ContactMethods.TYPE_HOME, preferred );

		}

		private void parseADR( String[] params, String value )

			throws ParseException, SkipContactException

		{

			// get address parts

			String[] adr_parts = splitValueBySemicolon( value );

			// build address

			value = "";

			for( int a = 0; a < adr_parts.length; a++ ) {

				if( value.length() > 0 ) value += "\n";

				value += adr_parts[ a ].trim();

			}

			Set< String > types = extractTypes( params, Arrays.asList(

				"PREF", "WORK", "HOME", "INTERNET" ) );

			// add address

			if( types.contains( "WORK" ) )

				addAddress( value, Contacts.ContactMethods.TYPE_WORK );

			else

				addAddress( value, Contacts.ContactMethods.TYPE_HOME);

		}

		public void finaliseParsing()

			throws ParseException, SkipContactException,

			AbortImportException

		{

			// missing version (and data is present)

			if( _version == null && _buffers != null )

				throw new ParseException( R.string.error_vcf_malformed );

			//  missing name properties?

			if( _name_level == NAMELEVEL_NONE )

				throw new ParseException( R.string.error_vcf_noname );

			// check if we should import this one? If we've already got an 'N'-

			// type name, this will already have been done by parseN() so we

			// mustn't do this here (or it could prompt twice!)

			if( _name_level < NAMELEVEL_N && !isImportRequired( getName() ) )

				throw new SkipContactException();

		}

		private String checkParam( String[] params, String name )

		{

			Pattern p = Pattern.compile(

				"^" + name + "[ \\t]*=[ \\t]*(\"?)(.*)\\1$" );

			for( int i = 0; i < params.length; i++ ) {

				Matcher m = p.matcher( params[ i ] );

				if( m.matches() )

					return m.group( 2 );

			}

			return null;

		}

		private Set< String > extractTypes( String[] params,

			List< String > valid_types )

		{

			HashSet< String > types = new HashSet< String >();

			// get 3.0-style TYPE= param

			String type_param;

			if( ( type_param = checkParam( params, "TYPE" ) ) != null ) {

				String[] parts = type_param.split( "," );

				for( int i = 0; i < parts.length; i++ )

					if( valid_types.contains( parts[ i ] ) )

						types.add( parts[ i ] );

			}

			// get 2.1-style type param

			if( _version.equals( "2.1" ) ) {

				for( int i = 1; i < params.length; i++ )

					if( valid_types.contains( params[ i ] ) )

						types.add( params[ i ] );

			}

			return types;

		}

		private UnencodeResult unencodeQuotedPrintable( ByteBuffer in )

		{

			boolean another = false;

			// unencode quoted-printable encoding, as per RFC1521 section 5.1

			byte[] out = new byte[ in.limit() - in.position() ];

			int j = 0;

			for( int i = in.position(); i < in.limit(); i++ )

			{

				// get next char and process...

				byte ch = in.array()[ i ];

				if( ch == '=' && i < in.limit() - 2 )

				{

					// we found a =XX format byte, add it

					out[ j ] = (byte)(

							Character.digit( in.array()[ i + 1 ], 16 ) * 16 +

							Character.digit( in.array()[ i + 2 ], 16 ) );

					i += 2;

				}

				else if( ch == '=' && i == in.limit() - 1 )

				{

					// we found a '=' at the end of a line signifying a multi-

					// line string, so we don't add it.

					another = true;

					continue;

				}

				else

					// just a normal char...

					out[ j ] = (byte)ch;

				j++;

			}

			return new UnencodeResult( another, ByteBuffer.wrap( out, 0, j ) );

		}

		private ByteBuffer transcodeAsciiToUtf8( ByteBuffer in )

		{

			// transcode

			byte[] out = new byte[ ( in.limit() - in.position() ) * 2 ];

			int j = 0;

			for( int a = in.position(); a < in.limit(); a++ )

			{

				// if char is < 127, keep it as-is

				if( in.array()[ a ] >= 0 )

					out[ j++ ] = in.array()[ a ];

				// else, convert it to UTF-8

				else {

					int b = 0xff & (int)in.array()[ a ];

					out[ j++ ] = (byte)( 0xc0 | ( b >> 6 ) );

					out[ j++ ] = (byte)( 0x80 | ( b & 0x3f ) );

				}

			}

			return ByteBuffer.wrap( out, 0, j );

		}

	}

}