EDIT

/**

* Copyright (C) 2020 EDIT

* European Distributed Institute of Taxonomy

* http://www.e-taxonomy.eu

*

* The contents of this file are subject to the Mozilla Public License Version 1.1

* See LICENSE.TXT at the top of this package for the full license terms.

*/

package eu.etaxonomy.cdm.database.update;

import java.math.BigDecimal;

import java.sql.ResultSet;

import java.sql.SQLException;

import java.util.ArrayList;

import java.util.List;

import eu.etaxonomy.cdm.common.monitor.IProgressMonitor;

import eu.etaxonomy.cdm.database.ICdmDataSource;

import eu.etaxonomy.cdm.hibernate.BigDecimalUserType;

/**

 * Changes a float column into a BigDecimal (2 columns) for usage in {@link BigDecimalUserType}.

 * First renames the old column and creates the 2 new columns via {@link #getInnerSteps() inner steps}

 * and then fills the new columns by using the mapping algorithm defined in

 *  {@link #invokeOnTable(String, ICdmDataSource, IProgressMonitor, CaseType, SchemaUpdateResult)}.

 *

 * Does not yet delete the old column. This should be done in a follow up model update.

 *

 * @author a.mueller

 * @since 27.04.2020

 */

public class Float2BigDecimalTypeChanger extends AuditedSchemaUpdaterStepBase {

    private static final String OLD_POSTFIX = "_old";

    private final String valueColumn;

    private final String scaleColumn;

    private final Integer newScale;

    private final Integer newPrecision;

    private final boolean isNotNull = false;

    private boolean isRounder = false;

    public static Float2BigDecimalTypeChanger NewInstance (List<? extends ISchemaUpdaterStep> stepList,

            String stepName, String tableName, String valueColumn, String scaleColumn, Integer newPrecision, Integer newScale,

            boolean includedAudTable){

        return new Float2BigDecimalTypeChanger(stepList, stepName, tableName, valueColumn,

                scaleColumn, newPrecision, newScale, includedAudTable);

    }

    protected Float2BigDecimalTypeChanger(List<? extends ISchemaUpdaterStep> stepList,

            String stepName, String tableName, String valueColumn, String scaleColumn,

            Integer newPrecision, Integer newScale, boolean includedAudTable) {

        super(stepList, stepName, tableName, includedAudTable);

        this.valueColumn = valueColumn;

        this.scaleColumn = scaleColumn;

        this.newPrecision = newPrecision;

        this.newScale = newScale;

    }

    @Override

    protected void invokeOnTable(String tableName, ICdmDataSource datasource, IProgressMonitor monitor,

            CaseType caseType, SchemaUpdateResult result) {

        if(!isRounder){

            return;

        }

        String sql = "SELECT id, %s as value_float FROM %s as t ";

        sql = String.format(sql, valueColumn+OLD_POSTFIX, tableName);

        try {

            ResultSet rs = datasource.executeQuery(sql);

            while(rs.next()){

                Float floatValue = rs.getFloat("value_float");

                BigDecimal bd = new BigDecimal(floatValue.toString());

                int id = rs.getInt("id");

                sql = "UPDATE %s SET %s = %s, %s = %s WHERE id = %s ";

                sql = String.format(sql, tableName, valueColumn, bd.toString(), scaleColumn, bd.scale(), String.valueOf(id));

                datasource.executeUpdate(sql);

            }

        } catch (SQLException e) {

            e.printStackTrace();

        }

    }

    @Override

    public List<ISchemaUpdaterStep> getInnerSteps() {

        if(!isRounder){

            List<ISchemaUpdaterStep> result = new ArrayList<>();

            ColumnNameChanger.NewFloatInstance(result, stepName +  " - rename old column", tableName, valueColumn, valueColumn + OLD_POSTFIX, includeAudTable);

            ColumnAdder.NewDecimalInstance(result, stepName + " - add value column", tableName, valueColumn, newPrecision, newScale, includeAudTable, 0, isNotNull);

            ColumnAdder.NewIntegerInstance(result, stepName + " - add scale column", tableName, scaleColumn, includeAudTable, newScale, isNotNull);

            Float2BigDecimalTypeChanger rounder = Float2BigDecimalTypeChanger.NewInstance(result, stepName + " - round", tableName, valueColumn, scaleColumn, newPrecision, newScale, this.includeAudTable);

            rounder.isRounder = true;

            return result;

        }else{

            return super.getInnerSteps();

        }

    }

}