/*

 * Copyright (c) 2004, 2013, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 * questions.

 */

package com.sun.rowset.internal;

import java.sql.*;

import javax.sql.*;

import java.util.*;

import java.math.BigDecimal;

import javax.sql.rowset.*;

import javax.sql.rowset.spi.*;

import com.sun.rowset.*;

import java.io.IOException;

import java.io.ObjectInputStream;

/**

 * There will be two sets of data which will be maintained by the rowset at the

 * time of synchronization. The {@code SyncProvider} will utilize the

 * {@code SyncResolver} to synchronize the changes back to database.

 */

public class SyncResolverImpl extends CachedRowSetImpl implements SyncResolver {

    /**

     * This CachedRowSet object will encapsulate a rowset

     * which will be sync'ed with the datasource but will

     * contain values in rows where there is conflict.

     * For rows other than conflict, it will *not* contain

     * any data. For rows containing conflict it will

     * return either of the three values set by SyncResolver.*_CONFLICT

     * from getStatus()

     */

    private CachedRowSetImpl crsRes;

    /**

     * This is the actual CachedRowSet object

     * which is being synchronized back to

     * datasource.

     */

    private CachedRowSetImpl crsSync;

    /**

     *  This ArrayList will contain the status of a row

     *  from the SyncResolver.* values else it will be null.

     */

    private ArrayList<?> stats;

    /**

     * The RowSetWriter associated with the original

     * CachedRowSet object which is being synchronized.

     */

    private CachedRowSetWriter crw;

    /**

     * Row number identifier

     */

    private int rowStatus;

    /**

     * This will contain the size of the {@code CachedRowSet} object

     */

    private int sz;

    /**

     * The {@code Connection} handle used to synchronize the changes

     * back to datasource. This is the same connection handle as was passed

     * to the CachedRowSet while fetching the data.

     */

    private transient Connection con;

    /**

     * The {@code CachedRowSet} object which will encapsulate

     * a row at any time. This will be built from CachedRowSet and

     * SyncResolver values. Synchronization takes place on a row by

     * row basis encapsulated as a CahedRowSet.

     */

    private CachedRowSet row;

    private JdbcRowSetResourceBundle resBundle;

    /**

     * Public constructor

     */

    public SyncResolverImpl() throws SQLException {

        try {

            crsSync = new CachedRowSetImpl();

            crsRes = new CachedRowSetImpl();

            crw = new CachedRowSetWriter();

            row = new CachedRowSetImpl();

            rowStatus = 1;

            try {

                resBundle = JdbcRowSetResourceBundle.getJdbcRowSetResourceBundle();

            } catch(IOException ioe) {

                throw new RuntimeException(ioe);

            }

        } catch(SQLException sqle) {

        }

     }

    /**

     * Retrieves the conflict status of the current row of this

     * {@code SyncResolver}, which indicates the operationthe {@code RowSet}

     * object was attempting when the conflict occurred.

     *

     * @return one of the following constants:

     *         {@code SyncResolver.UPDATE_ROW_CONFLICT},

     *         {@code SyncResolver.DELETE_ROW_CONFLICT}, or

     *         {@code SyncResolver.INSERT_ROW_CONFLICT}

     */

    public int getStatus() {

        return ((Integer)stats.get(rowStatus-1)).intValue();

    }

    /**

     * Retrieves the value in the designated column in the current row of this

     * {@code SyncResolver} object, which is the value that caused a conflict.

     *

     * @param index {@code int} designating the column in this row of this

     *        {@code SyncResolver} object from which to retrieve the value

     *        causing a conflict

     */

    public Object getConflictValue(int index) throws SQLException {

        try {

             return crsRes.getObject(index);

        } catch(SQLException sqle) {

            throw new SQLException(sqle.getMessage());

        }

    }

    /**

     * Retrieves the value in the designated column in the current row of this

     * {@code SyncResolver} object, which is the value that caused a conflict.

     *

     * @param columnName a {@code String} object designating the column in this row of this

     *        {@code SyncResolver} object from which to retrieve the value

     *        causing a conflict

     */

    public Object getConflictValue(String columnName) throws SQLException {

        try {

             return crsRes.getObject(columnName);

        } catch(SQLException sqle) {

             throw new SQLException(sqle.getMessage());

        }

    }

    /**

     * Sets <i>obj</i> as the value in column <i>index</i> in the current row of the

     * {@code RowSet} object. This value is the resolved value that is to be

     * persisted in the data source.

     *

     * @param index an {@code int} giving the number of the column into which to

     *        set the value to be persisted

     * @param obj an {@code Object} that is the value to be set in the data source

     */

    public void setResolvedValue(int index, Object obj) throws SQLException {

        // modify method to throw SQLException in spec

        /**

         * When a value is resolved properly make it to null

         * inside crsRes for that column.

         *

         * For more than one conflicts in the row,

         * check for the last resolved value of the current row

         * (Note: it can be resolved randomly for same row)

         * then sync back immediately.

         **/

        try {

            // check whether the index is in range

            if(index<=0 || index > crsSync.getMetaData().getColumnCount() ) {

                throw new SQLException(resBundle.handleGetObject("syncrsimpl.indexval").toString()+ index);

            }

             // check whether index col is in conflict

            if(crsRes.getObject(index) == null) {

                throw new SQLException(resBundle.handleGetObject("syncrsimpl.noconflict").toString());

            }

        } catch (SQLException sqle) {

            // modify method to throw for SQLException

            throw new SQLException(sqle.getMessage());

        }

        try {

             boolean bool = true;

             /** Check resolved value to be either of conflict

               * or in rowset else throw sql exception.

               * If we allow a value other than that in CachedRowSet or

               * datasource we will end up in looping the loop of exceptions.

              **/

             if( ((crsSync.getObject(index)).toString()).equals(obj.toString()) ||

                     ((crsRes.getObject(index)).toString()).equals(obj.toString()) ) {

                /**

                 * Check whether this is the only conflict in the row.

                 * If yes, synchronize this row back

                 * which has been resolved, else wait

                 * for all conflicts of current row to be resolved

                 *

                 * Step 1: Update crsRes and make the index col as null

                 * i.e. resolved

                 * crsRes.updateObject(index, obj);

                 **/

                  crsRes.updateNull(index);

                  crsRes.updateRow();

                 /**

                  * Step 2: Change the value in the CachedRowSetImpl object

                  * crsSync.updateObject(index, obj);

                  * crsSync.updateRow();

                  **/

                 if(row.size() != 1) {

                    row = buildCachedRow();

                 }

                 row.updateObject(index, obj);

                 row.updateRow();

                 for(int j=1; j < crsRes.getMetaData().getColumnCount(); j++) {

                     if(crsRes.getObject(j) != null) {

                        bool = false;

                        break;

                         // break out of loop and wait for other cols

                         // in same row to get resolved

                     } //end if

                  } //end for

                  if(bool) {

                     /**

                      * sync data back using CachedRowSetWriter

                      * construct the present row and pass it to the writer

                      * to write back to db.

                      **/

                     try {

                           /**

                            * Note : The use of CachedRowSetWriter to get *same* Connection handle.

                            * The CachedRowSetWriter uses the connection handle

                            * from the reader, Hence will use the same connection handle

                            * as of original CachedRowSetImpl

                            **/

                          writeData(row);

                          //crw.writeData( (RowSetInternal)crsRow);

                          //System.out.printlnt.println("12");

                     } catch(SyncProviderException spe) {

                         /**

                          * This will occur if db is not allowing

                          * even after resolving the conflicts

                          * due to some reasons.

                          * Also will prevent from going into a loop of SPE's

                          **/

                         throw new SQLException(resBundle.handleGetObject("syncrsimpl.syncnotpos").toString());

                     }

                  } //end if(bool)

             } else {

                 throw new SQLException(resBundle.handleGetObject("syncrsimpl.valtores").toString());

             } //end if (crs.getObject ...) block

        } catch(SQLException sqle) {

           throw new SQLException(sqle.getMessage());

        }

    }

    /**

     * This passes a CachedRowSet as a row to the CachedRowSetWriter

     * after the values have been resolved, back to the datasource.

     *

     * @param row a {@code CachedRowSet} object which will hold the

     *        values of a particular row after they have been resolved by

     *        the user to synchronize back to datasource.

     * @throws SQLException if synchronization does not happen properly

     *         maybe beacuse {@code Connection} has timed out.

     **/

     private void writeData(CachedRowSet row) throws SQLException {

        crw.updateResolvedConflictToDB(row, crw.getReader().connect((RowSetInternal)crsSync));

     }

    /**

     * This function builds a row  as a {@code CachedRowSet} object

     * which has been resolved and is ready to be synchrinized to the datasource

     *

     * @throws SQLException if there is problem in building

     *         the metadata of the row.

     **/

     private CachedRowSet buildCachedRow() throws SQLException {

       int iColCount;

       CachedRowSetImpl crsRow = new CachedRowSetImpl();

       RowSetMetaDataImpl rsmd = new RowSetMetaDataImpl();

       RowSetMetaDataImpl rsmdWrite = (RowSetMetaDataImpl)crsSync.getMetaData();

       RowSetMetaDataImpl rsmdRow = new RowSetMetaDataImpl();

       iColCount = rsmdWrite.getColumnCount();

       rsmdRow.setColumnCount(iColCount);

       for(int i =1;i<=iColCount;i++) {

          rsmdRow.setColumnType(i,rsmdWrite.getColumnType(i));

          rsmdRow.setColumnName(i,rsmdWrite.getColumnName(i));

          rsmdRow.setNullable(i,ResultSetMetaData.columnNullableUnknown);

          try {

             rsmdRow.setCatalogName(i, rsmdWrite.getCatalogName(i));

             rsmdRow.setSchemaName(i, rsmdWrite.getSchemaName(i));

          } catch(SQLException e) {

               e.printStackTrace();

          }

        } //end for

       crsRow.setMetaData(rsmdRow);

       crsRow.moveToInsertRow();

       for(int col=1;col<=crsSync.getMetaData().getColumnCount();col++) {

           crsRow.updateObject(col, crsSync.getObject(col));

       }

       crsRow.insertRow();

       crsRow.moveToCurrentRow();

       crsRow.absolute(1);

       crsRow.setOriginalRow();

      try {

          crsRow.setUrl(crsSync.getUrl());

      } catch(SQLException sqle) {

      }

      try {

          crsRow.setDataSourceName(crsSync.getCommand());

       } catch(SQLException sqle) {

       }

       try {

           if(crsSync.getTableName()!= null){

              crsRow.setTableName(crsSync.getTableName());

           }

        } catch(SQLException sqle) {

        }

       try {

            if(crsSync.getCommand() != null)

                crsRow.setCommand(crsSync.getCommand());

       } catch(SQLException sqle) {

       }

       try {

            crsRow.setKeyColumns(crsSync.getKeyColumns());

       } catch(SQLException sqle) {

       }

       return crsRow;

    }

    /**

     * Sets <i>obj</i> as the value in column <i>columnName</i> in the current row of the

     * {@code RowSet} object. This value is the resolved value that is to be

     * persisted in the data source.

     *

     * @param columnName a {@code String} object giving the name of the column

     *        into which to set the value to be persisted

     * @param obj an {@code Object} that is the value to be set in the data source

     */

    public void setResolvedValue(String columnName, Object obj) throws SQLException {

       // modify method to throw SQLException in spec

       // %%% Missing implementation!

    }

    /**

     * This function is package private,

     * i.e. cannot be accesses outside this package.

     * This is used to set the actual CachedRowSet

     * which is being synchronized to the database

     **/

   void setCachedRowSet(CachedRowSet crs) {

           crsSync = (CachedRowSetImpl)crs;

    }

    /**

     * This function is package private,

     * i.e. cannot be accesses outside this package.

     * This is used to set the CachedRowSet formed

     * with conflict values.

     **/

    void setCachedRowSetResolver(CachedRowSet crs){

         try {

              crsRes = (CachedRowSetImpl)crs;

              crsRes.afterLast();

              sz = crsRes.size();

         } catch (SQLException sqle) {

            // do nothing

         }

    }

    /**

     * This function is package private,

     * i.e. cannot be accesses outside this package.

     * This is used to set the status of each row

     * to either of the values SyncResolver.*_CONFLICT

     **/

    @SuppressWarnings("rawtypes")

    void setStatus(ArrayList status){

             stats = status;

    }

    /**

     * This function is package private,

     * i.e. cannot be accesses outside this package.

     * This is used to set the handle to the writer object

     * which will write the resolved values back to datasource

     **/

    void setCachedRowSetWriter(CachedRowSetWriter CRWriter) {

         crw = CRWriter;

    }

    /**

     * Moves the cursor down one row from its current position. A {@code SyncResolver}

     * cursor is initially positioned before the first conflict row; the first call to the

     * method {@code nextConflict()} makes the first conflict row the current row;

     * the second call makes the second conflict row the current row, and so on.

     * <p>

     * If an input stream is open for the current row, a call to the method next will

     * implicitly close it. A {@code SyncResolver} object's warning chain is cleared

     * when a new row

     *

     * @return true if the new current row is valid; false if there are no more rows

     * @throws SQLException if a database access occurs

     *

     */

    public boolean nextConflict() throws SQLException {

        /**

          * The next() method will hop from

          * one conflict to another

          *

          * Internally do a crs.next() until

          * next conflict.

          **/

      boolean bool = false;

      crsSync.setShowDeleted(true);

      while(crsSync.next()) {

           crsRes.previous();

           rowStatus++;  //sz--;

          if((rowStatus-1) >= stats.size()) {

             bool = false;

             break;

          }

          if(((Integer)stats.get(rowStatus-1)).intValue() == SyncResolver.NO_ROW_CONFLICT) {

              // do nothing

              // bool remains as false

             ;

           } else {

             bool = true;

             break;

           } //end if

      } //end while

        crsSync.setShowDeleted(false);

        return bool;

   } // end next() method

    /**

     * Moves the cursor to the previous conflict row in this {@code SyncResolver} object.

     *

     * @return {@code true} if the cursor is on a valid row; {@code false}

     *     if it is off the result set

     * @throws SQLException if a database access error occurs or the result set type

     *     is TYPE_FORWARD_ONLY

     */

   public boolean previousConflict() throws SQLException {

       throw new UnsupportedOperationException();

   }

    //-----------------------------------------------------------------------

    // Properties

    //-----------------------------------------------------------------------

    /**

     * Sets this {@code CachedRowSetImpl} object's command property

     * to the given {@code String} object and clears the parameters,

     * if any, that were set for the previous command.

     * <P>

     * The command property may not be needed

     * if the rowset is produced by a data source, such as a spreadsheet,

     * that does not support commands. Thus, this property is optional

     * and may be {@code null}.