/*
    *
    * The DbUnit Database Testing Framework
    * Copyright (C)2002-2004, DbUnit.org
    *
    * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   *
   */
  
  package org.dbunit.dataset;
  
  import java.util.Arrays;
  import java.util.Comparator;
  
  import org.dbunit.DatabaseUnitRuntimeException;
  import org.dbunit.dataset.datatype.DataType;
  import org.dbunit.dataset.datatype.TypeCastException;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * This is a ITable decorator that provide a sorted view of the decorated table.
   * This implementation does not keep a separate copy of the decorated table
   * data.
   * 
   * @author Manuel Laflamme
   * @author Last changed by: $Author: jeffjensen $
   * @version $Revision: 1176 $ $Date: 2009-05-01 02:56:07 -0500 (Fri, 01 May 2009)
   *          $
   * @since Feb 19, 2003
   */
  public class SortedTable extends AbstractTable {
  
      /**
       * Logger for this class
       */
      private static final Logger logger =
              LoggerFactory.getLogger(SortedTable.class);
  
      private final ITable _table;
      private final Column[] _columns;
      private Integer[] _indexes;
  
      /**
       * The row comparator which is used for sorting
       */
      private Comparator rowComparator;
  
      /**
       * Sort the decorated table by specified columns order.
       * 
       * @param table
       *            decorated table
       * @param columns
       *            columns to be used for sorting
       * @throws DataSetException
       */
      public SortedTable(ITable table, Column[] columns) throws DataSetException {
          _table = table;
          _columns = validateAndResolveColumns(columns);
          initialize();
      }
  
      /**
       * Sort the decorated table by specified columns order.
       * 
       * @param table
       *            decorated table
       * @param columnNames
       *            names of columns to be used for sorting
       * @throws DataSetException
       */
      public SortedTable(ITable table, String[] columnNames)
              throws DataSetException {
          _table = table;
          _columns = validateAndResolveColumns(columnNames);
          initialize();
      }
  
      /**
       * Sort the decorated table by specified metadata columns order. All
       * metadata columns will be used.
       * 
       * @param table
       *            The decorated table
       * @param metaData
       *            The metadata used to retrieve all columns which in turn are
      *            used for sorting the table
      * @throws DataSetException
      */
     public SortedTable(ITable table, ITableMetaData metaData)
             throws DataSetException {
         this(table, metaData.getColumns());
     }
 
     /**
      * Sort the decorated table by its own columns order which is defined by
      * {@link ITable#getTableMetaData()}. All table columns will be used.
      * 
      * @param table
      *            The decorated table
      * @throws DataSetException
      */
     public SortedTable(ITable table) throws DataSetException {
         this(table, table.getTableMetaData());
     }
 
     /**
      * Verifies that all given columns really exist in the current table and
      * returns the physical {@link Column} objects from the table.
      * 
      * @param columns
      * @return
      * @throws DataSetException
      */
     private Column[] validateAndResolveColumns(Column[] columns)
             throws DataSetException {
         ITableMetaData tableMetaData = _table.getTableMetaData();
         Column[] resultColumns =
                 Columns.findColumnsByName(columns, tableMetaData);
         return resultColumns;
     }
 
     /**
      * Verifies that all given columns really exist in the current table and
      * returns the physical {@link Column} objects from the table.
      * 
      * @param columnNames
      * @return
      * @throws DataSetException
      */
     private Column[] validateAndResolveColumns(String[] columnNames)
             throws DataSetException {
         ITableMetaData tableMetaData = _table.getTableMetaData();
         Column[] resultColumns =
                 Columns.findColumnsByName(columnNames, tableMetaData);
         return resultColumns;
     }
 
     private void initialize() {
         logger.debug("initialize() - start");
 
         // The default comparator is the one that sorts by string - for
         // backwards compatibility
         this.rowComparator =
                 new RowComparatorByString(this._table, this._columns);
     }
 
     /**
      * @return The columns that are used for sorting the table
      */
     public Column[] getSortColumns() {
         return this._columns;
     }
 
     private int getOriginalRowIndex(int row) throws DataSetException {
         if (logger.isDebugEnabled()) {
             logger.debug("getOriginalRowIndex(row={}) - start", Integer
                     .toString(row));
         }
 
         if (_indexes == null) {
             Integer[] indexes = new Integer[getRowCount()];
             for (int i = 0; i < indexes.length; i++) {
                 indexes[i] = new Integer(i);
             }
 
             try {
                 Arrays.sort(indexes, rowComparator);
             } catch (DatabaseUnitRuntimeException e) {
                 throw (DataSetException) e.getCause();
             }
 
             _indexes = indexes;
         }
 
         return _indexes[row].intValue();
     }
 
     /**
      * Whether or not the comparable interface should be used of the compared
      * columns instead of the plain strings Default value is <code>false</code>
      * for backwards compatibility Set whether or not to use the Comparable
      * implementation of the corresponding column DataType for comparing values
      * or not. Default value is <code>false</code> which means that the old
      * string comparison is used. <br>
      * 
      * @param useComparable
      * @since 2.3.0
      */
     public void setUseComparable(boolean useComparable) {
         if (logger.isDebugEnabled()) {
             logger.debug("setUseComparable(useComparable={}) - start", Boolean
                     .valueOf(useComparable));
         }
 
         if (useComparable) {
             setRowComparator(new RowComparator(this._table, this._columns));
         } else {
             setRowComparator(new RowComparatorByString(this._table,
                     this._columns));
         }
     }
 
     /**
      * Sets the comparator to be used for sorting the table rows.
      * 
      * @param comparator
      *            that sorts the table rows
      * @since 2.4.2
      */
     public void setRowComparator(Comparator comparator) {
         if (logger.isDebugEnabled()) {
             logger.debug("setRowComparator(comparator={}) - start", comparator);
         }
 
         if (_indexes != null) {
             // TODO this is an ugly design to avoid increasing the number of
             // constructors from 4 to 8. To be discussed how to implement it the
             // best way.
             throw new IllegalStateException(
                     "Do not use this method after the table has been used (i.e. #getValue() has been called). "
                             + "Please invoke this method immediately after the intialization of this object.");
         }
 
         this.rowComparator = comparator;
     }
 
     // //////////////////////////////////////////////////////////////////////////
     // ITable interface
 
     public ITableMetaData getTableMetaData() {
         logger.debug("getTableMetaData() - start");
 
         return _table.getTableMetaData();
     }
 
     public int getRowCount() {
         logger.debug("getRowCount() - start");
 
         return _table.getRowCount();
     }
 
     public Object getValue(int row, String columnName) throws DataSetException {
         if (logger.isDebugEnabled()) {
             logger.debug("getValue(row={}, columnName={}) - start", Integer
                     .toString(row), columnName);
         }
 
         assertValidRowIndex(row);
 
         return _table.getValue(getOriginalRowIndex(row), columnName);
     }
 
     // //////////////////////////////////////////////////////////////////////////
     // Comparator interface
 
     /**
      * Abstract class for sorting the table rows of a given table in a specific
      * order
      */
     public static abstract class AbstractRowComparator implements Comparator {
         /**
          * Logger for this class
          */
         private final Logger logger =
                 LoggerFactory.getLogger(AbstractRowComparator.class);
         private final ITable _table;
         private final Column[] _sortColumns;
 
         /**
          * @param table
          *            The wrapped table to be sorted
          * @param sortColumns
          *            The columns to be used for sorting in the given order
          */
         public AbstractRowComparator(ITable table, Column[] sortColumns) {
             this._table = table;
             this._sortColumns = sortColumns;
         }
 
         public int compare(Object o1, Object o2) {
             logger.debug("compare(o1={}, o2={}) - start", o1, o2);
 
             Integer i1 = (Integer) o1;
             Integer i2 = (Integer) o2;
 
             try {
                 for (int i = 0; i < _sortColumns.length; i++) {
                     String columnName = _sortColumns[i].getColumnName();
 
                     Object value1 = _table.getValue(i1.intValue(), columnName);
                     Object value2 = _table.getValue(i2.intValue(), columnName);
 
                     if (value1 == null && value2 == null) {
                         continue;
                     }
 
                     if (value1 == null && value2 != null) {
                         return -1;
                     }
 
                     if (value1 != null && value2 == null) {
                         return 1;
                     }
 
                     // Compare the two values with each other for sorting
                     int result = compare(_sortColumns[i], value1, value2);
 
                     if (result != 0) {
                         return result;
                     }
                 }
             } catch (DataSetException e) {
                 throw new DatabaseUnitRuntimeException(e);
             }
 
             return 0;
         }
 
         /**
          * @param column
          *            The column to be compared
          * @param value1
          *            The first value of the given column
          * @param value2
          *            The second value of the given column
          * @return 0 if both values are considered equal.
          * @throws TypeCastException
          */
         protected abstract int compare(Column column, Object value1,
                 Object value2) throws TypeCastException;
 
     }
 
     /**
      * Compares the rows with each other in order to sort them in the correct
      * order using the data type and the Comparable implementation the current
      * column has.
      */
     protected static class RowComparator extends AbstractRowComparator {
         /**
          * Logger for this class
          */
         private final Logger logger =
                 LoggerFactory.getLogger(RowComparator.class);
 
         public RowComparator(ITable table, Column[] sortColumns) {
             super(table, sortColumns);
         }
 
         protected int compare(Column column, Object value1, Object value2)
                 throws TypeCastException {
             if (logger.isDebugEnabled()) {
                 logger.debug(
                         "compare(column={}, value1={}, value2={}) - start",
                         new Object[] {column, value1, value2});
             }
 
             DataType dataType = column.getDataType();
             int result = dataType.compare(value1, value2);
             return result;
         }
 
     }
 
     /**
      * Compares the rows with each other in order to sort them in the correct
      * order using the string value of both values for the comparison.
      */
     protected static class RowComparatorByString extends AbstractRowComparator {
         /**
          * Logger for this class
          */
         private final Logger logger =
                 LoggerFactory.getLogger(RowComparatorByString.class);
 
         public RowComparatorByString(ITable table, Column[] sortColumns) {
             super(table, sortColumns);
         }
 
         protected int compare(Column column, Object value1, Object value2)
                 throws TypeCastException {
             if (logger.isDebugEnabled()) {
                 logger.debug(
                         "compare(column={}, value1={}, value2={}) - start",
                         new Object[] {column, value1, value2});
             }
 
             // Default behavior since ever
             String stringValue1 = DataType.asString(value1);
             String stringValue2 = DataType.asString(value2);
             int result = stringValue1.compareTo(stringValue2);
             return result;
         }
     }
 
     /**
      * {@inheritDoc}
      */
     public String toString() {
         StringBuilder sb = new StringBuilder(2000);
 
         sb.append(getClass().getName()).append("[");
         sb.append("_columns=[").append(Arrays.toString(_columns)).append("], ");
         sb.append("_indexes=[").append(_indexes).append("], ");
         sb.append("_table=[").append(_table).append("]");
         sb.append("]");
 
         return sb.toString();
     }
 }