/* Copyright (c) 2006 Ricebridge. All Rights Reserved.
 *
 * This file is available under the terms and conditions of the
 * Ricebridge "Open Source API" policy; Ricebridge grants use of this
 * copyrighted work under the terms of a BSD-style license only. See
 * http://www.opensource.org/licenses/bsd-license.php for more
 * information.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 
 *  - Redistributions of source code must retain the above copyright
 *  notice, this list of conditions and the following disclaimer.
 *
 *  - Redistributions in binary form must reproduce the above
 *  copyright notice, this list of conditions and the following
 *  disclaimer in the documentation and/or other materials provided
 *  with the distribution.
 *
 *  - Neither the name of the Ricebridge nor the names of its
 *  contributors may be used to endorse or promote products derived
 *  from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.  
 */

package com.ricebridge.csvman;


import org.jostraca.util.TextUtil;
import org.jostraca.util.Internal;
import org.jostraca.util.Standard;

import java.util.*;


/** Simple implementation of {@link LineProvider} that provides data lines for saving 
 *  from a <code>List</code> of <code>List</code>s of <code>String</code>s.
 *    <p>The easiest way to save your CSV data in this format is to use the
 *  {@link CsvManager#saveAsLists(Object,List) CsvManager.saveAsLists} method.</p>
 *    <p><code>AsListsLineProvider</code> is designed to be subclassed. You can change
 *  the default implementation by calling the 
 *  {@link com.ricebridge.csvman.CsvManagerStore#setAsListsLineProviderClass CsvManagerStore.setAsListsLineProviderClass}
 *  method, and providing a subclass of <code>AsListsLineProvider</code>. {@link CsvManagerStore} can be accessed 
 *  using {@link CsvManager#getCsvManagerStore}.</p>
 *    <p>The <b><a href="AsListsLineProvider.java.html">Source Code</a></b> of this Java class 
 *  is available under a <a href="http://www.opensource.org/licenses/bsd-license.php">BSD-style license</a>.</p>
 *
 *  @see LineProvider
 *  @see CustomLineProvider
 *  @see BasicLineProvider 
 *  @see ResultSetLineProvider 
 *  @see TableModelLineProvider 
 *  @see BeanLineProvider 
 */
public class AsListsLineProvider extends CustomLineProvider {

  // protected

  /** <code>List</code> of <code>Lists</code> of <code>Strings</code>. */
  protected List iData = null;

  /** Index of current line in <code>List</code>. */
  protected long iLineIndex = 0;




  // constructors

  /** Create uninitialised for use with {@link #setData setData}. */
  public AsListsLineProvider() {
    // init with setData
  }


  /** Create with data lines as <code>List</code> of <code>List</code>s of <code>String</code>s.
   *  @param pData list of lines
   */
  public AsListsLineProvider( List pData ) {
    setData( pData );
  }




  // CustomLineProvider methods

  /** Handle start of saving process by reseting line index. */
  public void startProcessImpl() throws Exception {
    iLineIndex = 0;
  }


  /** Return <code>true</code> if line index is less than number of data lines in list. */
  public boolean hasNextLineImpl() throws Exception {
    return iLineIndex < iData.size();
  }


  /** Return next data line from list. */
  public String[] nextLineImpl() throws Exception {
    Object fieldlistobj = null;
    List   fieldlist    = null;

    try {
      fieldlistobj = iData.get( (int) iLineIndex );
      fieldlist    = (List) fieldlistobj;
    }
    catch( ClassCastException cce ) {
      throw new CsvManagerException( CsvManagerException.CODE_cce_list_line, 
                                     new String[] {"index",String.valueOf(iLineIndex), "expected","List", 
                                                   "found", makeLineDescription(fieldlistobj)  }  );
    }

    if( null == fieldlist ) {
      throw new CsvManagerException( CsvManagerException.CODE_null_list_line, 
                                     new String[] {"index",String.valueOf(iLineIndex), "expected","List" }  );
    }
    
    String[] line = new String[fieldlist.size()];
    for( int fI = 0; fI < line.length; fI++ ) {
      line[fI] = String.valueOf( fieldlist.get( fI ) );
    }
    iLineIndex++;

    return line;
  } 




  // public methods
 
  /** Set data lines to save as <code>List</code> of <code>Lists</code> of <code>Strings</code>. */
  public void setData( List pData ) {
    iData = (List) Internal.null_arg( pData );
  }




  // protected methods

  /** Description of data line for error messages. */
  protected String makeLineDescription( Object pLine ) {
    String linedesc = Standard.EMPTY;
    if( pLine instanceof String[] ) {
      linedesc = "String[]{"+TextUtil.array2text((String[])pLine,Standard.COMMA)+"}";
    }
    else {
      linedesc = null==pLine?"null":pLine.getClass().getName()+":"+pLine;
    }
    return linedesc;
  }    

}