/*
 * Copyright 2011 Atteo.
 *
 * 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.atteo.moonshine.liquibase;

import java.sql.SQLException;
import java.util.Map;
import java.util.Map.Entry;

import javax.inject.Inject;
import javax.sql.DataSource;

import liquibase.Liquibase;
import liquibase.database.DatabaseConnection;
import liquibase.database.jvm.JdbcConnection;
import liquibase.exception.DatabaseException;
import liquibase.exception.LiquibaseException;
import liquibase.resource.ClassLoaderResourceAccessor;
import liquibase.resource.ResourceAccessor;

/**
 * Liquibase facade for migrations execution.
 * <p>
 * Usage:
 * <pre>
 * &#64;ImportService
 * private DatabaseService database;
 *
 * ...
 *
 * database.registerMigration(new DatabaseMigration() {
 *     &#64;Override
 *     public void execute(DataSource dataSource) {
 *         new LiquibaseFacade(datasource).migrate("/migrations/migration01.xml");
 *     }
 * }
 * </pre>
 * </p>
 */
public class LiquibaseFacade {
    private static final String BEFORE_LAST_UPDATE = "BEFORE_LAST_UPDATE";

    private final DataSource dataSource;

    @Inject
    public LiquibaseFacade(DataSource dataSource) {
        this.dataSource = dataSource;
    }

    /**
     * Migrate using given migration.
     * @param changelog resource with the migration
     */
    public void migrate(String changelog) {
        migrate(changelog, null);
    }

    /**
     * Migrate using given migration.
     * @param changelog resource with the migration
     * @param contexts contexts, see {@link Liquibase#update(String)}.
     */
    public void migrate(String changelog, String contexts) {
        migrate(changelog, contexts, null);
    }

    /**
     * Migrate using given migration.
     * @param changelog resource with the migration
     * @param contexts contexts, see {@link Liquibase#update(String)}.
     * @param changelogParameters changelog parameters, can be null
     */
    public void migrate(String changelog, String contexts, Map<String, Object> changelogParameters) {
        ResourceAccessor resourceAccessor = new ClassLoaderResourceAccessor();

        DatabaseConnection databaseConnection = null;
        changelog = normalizeName(changelog);

        try {
            databaseConnection = new JdbcConnection(dataSource.getConnection());
            Liquibase liquibase = new Liquibase(changelog, resourceAccessor, databaseConnection);
            liquibase.tag(BEFORE_LAST_UPDATE);

            if (changelogParameters != null) {
                for (Entry<String, Object> entry : changelogParameters.entrySet()) {
                    liquibase.setChangeLogParameter(entry.getKey(), entry.getValue());
                }
            }

            liquibase.update(contexts);
        } catch (LiquibaseException | SQLException e) {
            throw new RuntimeException(e);
        } finally {
            try {
                if (databaseConnection != null && !databaseConnection.isClosed())
                    databaseConnection.close();
            } catch (DatabaseException e) {
                throw new RuntimeException(e);
            }
        }
    }

    /**
     * Rollbacks last update.
     * @param changelog resource with the migration
     */
    public void rollbackLastUpdate(String changelog) {
        rollbackLastUpdate(changelog, null);
    }

    /**
     * Rollbacks last update.
     * @param changelog resource with the migration
     * @param contexts contexts, see {@link Liquibase#update(String)}.
     */
    public void rollbackLastUpdate(String changelog, String contexts) {
        rollbackLastUpdate(changelog, contexts, null) ;
    }

    /**
     * Rollbacks given changelog to given tag.
     * @param changelog resource with the migration
     * @param contexts contexts, see {@link Liquibase#update(String)}.
     * @param changelogParameters changelogParameters
     */
    public void rollbackLastUpdate(String changelog, String contexts, Map<String, Object> changelogParameters) {
        rollback(changelog, contexts, changelogParameters, BEFORE_LAST_UPDATE);
    }

    /**
     * Rollbacks given changelog to given tag.
     * @param changelog resource with the migration
     * @param contexts contexts, see {@link Liquibase#update(String)}.
     * @param changelogParameters changelogParameters
     * @param tag tag to rollback to
     */
    private void rollback(String changelog, String contexts, Map<String, Object> changelogParameters, String tag) {
        changelog = normalizeName(changelog);

        ResourceAccessor resourceAccessor = new ClassLoaderResourceAccessor();

        DatabaseConnection databaseConnection = null;

        try {
            databaseConnection = new JdbcConnection(dataSource.getConnection());
            Liquibase liquibase = new Liquibase(changelog, resourceAccessor, databaseConnection);

            if (changelogParameters != null) {
                for (Entry<String, Object> entry : changelogParameters.entrySet()) {
                    liquibase.setChangeLogParameter(entry.getKey(), entry.getValue());
                }
            }

            liquibase.rollback(tag, contexts);
        } catch (LiquibaseException | SQLException e) {
            throw new RuntimeException(e);
        } finally {
            try {
                if (databaseConnection != null && !databaseConnection.isClosed()) {
                    databaseConnection.close();
                }
            } catch (DatabaseException e) {
                throw new RuntimeException(e);
            }
        }
    }

    public void dropAll() {
        ResourceAccessor resourceAccessor = new ClassLoaderResourceAccessor();

        DatabaseConnection databaseConnection = null;

        try {
            databaseConnection = new JdbcConnection(dataSource.getConnection());
            Liquibase liquibase = new Liquibase(null, resourceAccessor, databaseConnection);
            liquibase.dropAll();
        } catch (LiquibaseException | SQLException e) {
            throw new RuntimeException(e);
        } finally {
            try {
                if (databaseConnection != null && !databaseConnection.isClosed())
                    databaseConnection.close();
            } catch (DatabaseException e) {
                throw new RuntimeException(e);
            }
        }
    }

    private String normalizeName(String changelog) {
        if (changelog.startsWith("/") ){
            changelog = changelog.substring(1);
        }
        return changelog;
    }
}