package liquibase.sqlgenerator.core;

 import liquibase.database.Database;

 import liquibase.database.typeconversion.TypeConverterFactory;

 import liquibase.exception.UnexpectedLiquibaseException;

 import liquibase.exception.ValidationErrors;

 import liquibase.sql.Sql;

 import liquibase.sqlgenerator.SqlGenerator;

 import liquibase.sqlgenerator.SqlGeneratorChain;

 import liquibase.sqlgenerator.SqlGeneratorFactory;

 import liquibase.statement.core.LockDatabaseChangeLogStatement;

 import liquibase.statement.core.UpdateStatement;

 import liquibase.util.NetUtil;

 import java.net.InetAddress;

 import java.sql.Timestamp;

 public class LockDatabaseChangeLogGenerator extends AbstractSqlGenerator<LockDatabaseChangeLogStatement> {

     public ValidationErrors validate(LockDatabaseChangeLogStatement statement, Database database,

             SqlGeneratorChain sqlGeneratorChain) {

         return new ValidationErrors();

     }

     public Sql[] generateSql(LockDatabaseChangeLogStatement statement, Database database,

             SqlGeneratorChain sqlGeneratorChain) {

         String liquibaseSchema = null;

         liquibaseSchema = database.getLiquibaseSchemaName();

         InetAddress localHost;

         try {

             localHost = NetUtil.getLocalHost();

         } catch (Exception e) {

             throw new UnexpectedLiquibaseException(e);

         }

         UpdateStatement updateStatement = new UpdateStatement(liquibaseSchema,

                 database.getDatabaseChangeLogLockTableName());

         updateStatement.addNewColumnValue("LOCKED", true);

         updateStatement.addNewColumnValue("LOCKGRANTED", new Timestamp(new java.util.Date().getTime()));

         updateStatement

                 .addNewColumnValue("LOCKEDBY", localHost.getHostName() + " (" + localHost.getHostAddress() + ")");

         updateStatement.setWhereClause(database.escapeColumnName(liquibaseSchema,

                 database.getDatabaseChangeLogTableName(), "ID")

                 + " = 1 AND "

                 + database.escapeColumnName(liquibaseSchema, database.getDatabaseChangeLogTableName(), "LOCKED")

                 + " = "

                 + TypeConverterFactory.getInstance().findTypeConverter(database).getBooleanType()

                         .getFalseBooleanValue());

         return SqlGeneratorFactory.getInstance().generateSql(updateStatement, database);

     }

 }