/*
j8583 A Java implementation of the ISO8583 protocol
Copyright (C) 2011 Enrique Zamudio Lopez

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

This library 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
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
*/
package com.solab.iso8583.parse;

import java.io.UnsupportedEncodingException;
import java.text.ParseException;

import com.solab.iso8583.CustomField;
import com.solab.iso8583.IsoType;
import com.solab.iso8583.IsoValue;

/** This is the class used to parse ALPHA fields.
 * 
 * @author Enrique Zamudio
 */
public class AlphaParseInfo extends AlphaNumericFieldParseInfo {

	public AlphaParseInfo(int len) {
		super(IsoType.ALPHA, len);
	}

    @Override
	public <T> IsoValue<?> parseBinary(final int field, final byte[] buf, final int pos,
                                   final CustomField<T> custom)
            throws ParseException, UnsupportedEncodingException {
		if (pos < 0) {
			throw new ParseException(String.format("Invalid bin ALPHA field %d position %d",
                    field, pos), pos);
		} else if (pos+length > buf.length) {
			throw new ParseException(String.format(
                    "Insufficient data for bin %s field %d of length %d, pos %d",
				type, field, length, pos), pos);
		}
        try {
            if (custom == null) {
                return new IsoValue<>(type, new String(buf, pos, length, getCharacterEncoding()), length, null);
            } else {
                T decoded = custom.decodeField(new String(buf, pos, length, getCharacterEncoding()));
                return decoded == null ?
                    new IsoValue<>(type, new String(buf, pos, length, getCharacterEncoding()), length, null) :
                    new IsoValue<>(type, decoded, length, custom);
            }
        } catch (IndexOutOfBoundsException ex) {
            throw new ParseException(String.format(
                    "Insufficient data for bin %s field %d of length %d, pos %d",
         				type, field, length, pos), pos);
        }
	}

}