/* ====================================================================
   Licensed to the Apache Software Foundation (ASF) under one or more
   contributor license agreements.  See the NOTICE file distributed with
   this work for additional information regarding copyright ownership.
   The ASF licenses this file to You under the Apache License, Version 2.0
   (the "License"); you may not use this file except in compliance with
   the License.  You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
==================================================================== */

package org.apache.poi.hssf.record;

import org.apache.poi.util.LittleEndianOutput;
import org.apache.poi.util.StringUtil;

/**
 * Common header/footer base class
 *
 * @author Josh Micich
 */
public abstract class HeaderFooterBase extends StandardRecord {
	private boolean field_2_hasMultibyte;
	private String field_3_text;

	protected HeaderFooterBase(String text) {
		setText(text);
	}

	protected HeaderFooterBase(RecordInputStream in) {
		if (in.remaining() > 0) {
			int field_1_footer_len = in.readShort();
			//61287 -- if the footer_len == 0, there may not be a multibyte flag
			if (field_1_footer_len == 0) {
				field_3_text = "";
				if (in.remaining() == 0) {
					return;
				}
			}
			field_2_hasMultibyte = in.readByte() != 0x00;

			if (field_2_hasMultibyte) {
				field_3_text = in.readUnicodeLEString(field_1_footer_len);
			} else {
				field_3_text = in.readCompressedUnicode(field_1_footer_len);
			}
		} else {
			// Note - this is unusual for BIFF records in general, but normal for header / footer records:
			// when the text is empty string, the whole record is empty (just the 4 byte BIFF header)
			field_3_text = "";
		}
	}

	/**
	 * set the footer string
	 *
	 * @param text string to display
	 */
	public final void setText(String text) {
		if (text == null) {
			throw new IllegalArgumentException("text must not be null");
		}
		field_2_hasMultibyte = StringUtil.hasMultibyte(text);
		field_3_text = text;

		// Check it'll fit into the space in the record
		if (getDataSize() > RecordInputStream.MAX_RECORD_DATA_SIZE) {
			throw new IllegalArgumentException("Header/Footer string too long (limit is "
					+ RecordInputStream.MAX_RECORD_DATA_SIZE + " bytes)");
		}
	}

	/**
	 * get the length of the footer string
	 *
	 * @return length of the footer string
	 */
	private int getTextLength() {
		return field_3_text.length();
	}

	public final String getText() {
		return field_3_text;
	}

	public final void serialize(LittleEndianOutput out) {
		if (getTextLength() > 0) {
			out.writeShort(getTextLength());
			out.writeByte(field_2_hasMultibyte ? 0x01 : 0x00);
			if (field_2_hasMultibyte) {
				StringUtil.putUnicodeLE(field_3_text, out);
			} else {
				StringUtil.putCompressedUnicode(field_3_text, out);
			}
		}
	}

	protected final int getDataSize() {
		if (getTextLength() < 1) {
			return 0;
		}
		return 3 + getTextLength() * (field_2_hasMultibyte ? 2 : 1);
	}
}
