/**

  * SQL-DK

  * Copyright © 2013 František Kučera (frantovo.cz)

  *

  * 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, version 3 of the License.

  *

  * 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 info.globalcode.sql.dk.formatting;

 import java.util.ArrayList;

 import java.util.List;

 /**

  * <p>

  * Prefetches whole result set and computes column widths. Whole table is flushed at once in

  * {@linkplain #writeEndResultSet()}.

  * </p>

  *

  * <p>

  * Long values will not overflow the cells, but whole result set must be loaded into the memory.

  * </p>

  *

  * @author Ing. František Kučera (frantovo.cz)

  */

 public class TabularPrefetchingFormatter extends TabularFormatter {

 	public static final String NAME = "tabular-prefetching"; // bash-completion:formatter

 	private ColumnsHeader currentHeader;

 	private List<Object[]> currentResultSet;

 	private Object[] currentRow;

 	private int currentColumnsCount;

 	private boolean prefetchDone = false;

 	public TabularPrefetchingFormatter(FormatterContext formatterContext) {

 		super(formatterContext);

 	}

 	@Override

 	protected int getCurrentColumnsCount() {

 		if (prefetchDone) {

 			return super.getCurrentColumnsCount();

 		} else {

 			return currentColumnsCount;

 		}

 	}

 	@Override

 	public void writeStartResultSet(ColumnsHeader header) {

 		currentResultSet = new ArrayList<>();

 		currentHeader = header;

 		initColumnWidths(header.getColumnCount());

 	}

 	@Override

 	public void writeStartRow() {

 		currentRow = new Object[currentHeader.getColumnCount()];

 		currentResultSet.add(currentRow);

 		currentColumnsCount = 0;

 	}

 	@Override

 	public void writeColumnValue(Object value) {

 		currentRow[currentColumnsCount] = value;

 		currentColumnsCount++;

 		String textRepresentation = toString(value);

 		/** TODO: count only printable characters (currently not an issue) */

 		updateColumnWidth(currentColumnsCount, textRepresentation.length());

 	}

 	@Override

 	public void writeEndRow() {

 		// do nothing

 	}

 	@Override

 	public void writeEndResultSet() {

 		prefetchDone = true;

 		postprocessPrefetchedResultSet(currentHeader, currentResultSet);

 		super.writeStartResultSet(currentHeader);

 		for (Object[] row : currentResultSet) {

 			super.writeStartRow();

 			for (Object cell : row) {

 				super.writeColumnValue(cell);

 			}

 			super.writeEndRow();

 		}

 		currentColumnsCount = 0;

 		currentHeader = null;

 		currentRow = null;

 		currentResultSet = null;

 		super.writeEndResultSet();

 		prefetchDone = false;

 	}

 	/**

 	 * Optional post-processing – override in sub-classes if needed.

 	 * Don't forget to {@linkplain #updateColumnWidth(int, int)}

 	 *

 	 * @param currentHeader

 	 * @param currentResultSet

 	 */

 	protected void postprocessPrefetchedResultSet(ColumnsHeader currentHeader, List<Object[]> currentResultSet) {

 	}

 }