/*
 * Copyright © Red Gate Software Ltd 2010-2020
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *         http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.flywaydb.core.api.migration;

import org.flywaydb.core.api.FlywayException;
import org.flywaydb.core.api.MigrationVersion;
import org.flywaydb.core.internal.resolver.MigrationInfoHelper;
import org.flywaydb.core.internal.util.Pair;

This is the recommended class to extend for implementing Java-based Migrations.
Subclasses should follow the default Flyway naming convention of having a class name with the following structure:

Versioned Migrations: V2__Add_new_table
Undo Migrations: U2__Add_new_table
Repeatable Migrations: R__Add_new_table

The file name consists of the following parts:

Prefix: V for versioned migrations, U for undo migrations, R for repeatable migrations
Version: Underscores (automatically replaced by dots at runtime) separate as many parts as you like (Not for repeatable migrations)
Separator: __ (two underscores)
Description: Underscores (automatically replaced by spaces at runtime) separate the words

If you need more control over the class name, you can override the default convention by implementing the
JavaMigration interface directly. This will allow you to name your class as you wish. Version, description and
migration category are provided by implementing the respective methods.
/**
 * <p>This is the recommended class to extend for implementing Java-based Migrations.</p>
 * <p>Subclasses should follow the default Flyway naming convention of having a class name with the following structure:</p>
 * <ul>
 * <li><strong>Versioned Migrations:</strong> V2__Add_new_table</li>
 * <li><strong>Undo Migrations:</strong> U2__Add_new_table</li>
 * <li><strong>Repeatable Migrations:</strong> R__Add_new_table</li>
 * </ul>
 *
 * <p>The file name consists of the following parts:</p>
 * <ul>
 * <li><strong>Prefix:</strong> V for versioned migrations, U for undo migrations, R for repeatable migrations</li>
 * <li><strong>Version:</strong> Underscores (automatically replaced by dots at runtime) separate as many parts as you like (Not for repeatable migrations)</li>
 * <li><strong>Separator:</strong> __ (two underscores)</li>
 * <li><strong>Description:</strong> Underscores (automatically replaced by spaces at runtime) separate the words</li>
 * </ul>
 * <p>If you need more control over the class name, you can override the default convention by implementing the
 * JavaMigration interface directly. This will allow you to name your class as you wish. Version, description and
 * migration category are provided by implementing the respective methods.</p>
 */
public abstract class BaseJavaMigration implements JavaMigration {
    private final MigrationVersion version;
    private final String description;




    
Creates a new instance of a Java-based migration following Flyway's default naming convention.
/**
     * Creates a new instance of a Java-based migration following Flyway's default naming convention.
     */
    public BaseJavaMigration() {
        String shortName = getClass().getSimpleName();
        String prefix;



        boolean repeatable = shortName.startsWith("R");
        if (shortName.startsWith("V") || repeatable



        ) {
            prefix = shortName.substring(0, 1);
        } else {
            throw new FlywayException("Invalid Java-based migration class name: " + getClass().getName()
                    + " => ensure it starts with V" +



                    " or R," +
                    " or implement org.flywaydb.core.api.migration.JavaMigration directly for non-default naming");
        }
        Pair<MigrationVersion, String> info =
                MigrationInfoHelper.extractVersionAndDescription(shortName, prefix, "__", new String[]{""}, repeatable);
        version = info.getLeft();
        description = info.getRight();
    }

    @Override
    public MigrationVersion getVersion() {
        return version;
    }

    @Override
    public String getDescription() {
        return description;
    }

    @Override
    public Integer getChecksum() {
        return null;
    }

    @Override
    public boolean isUndo() {




        return false;

    }

    @Override
    public boolean canExecuteInTransaction() {
        return true;
    }
}