package liquibase.sqlgenerator.core;

 import liquibase.database.Database;

 import liquibase.database.core.DB2Database;

 import liquibase.database.core.FirebirdDatabase;

 import liquibase.database.core.H2Database;

 import liquibase.database.core.HsqlDatabase;

 import liquibase.database.core.MaxDBDatabase;

 import liquibase.exception.ValidationErrors;

 import liquibase.sql.Sql;

 import liquibase.sql.UnparsedSql;

 import liquibase.sqlgenerator.SqlGeneratorChain;

 import liquibase.statement.core.CreateSequenceStatement;

 public class CreateSequenceGenerator extends AbstractSqlGenerator<CreateSequenceStatement> {

     @Override

     public boolean supports(CreateSequenceStatement statement, Database database) {

         return database.supportsSequences();

     }

     @Override

     public ValidationErrors validate(CreateSequenceStatement statement, Database database,

             SqlGeneratorChain sqlGeneratorChain) {

         ValidationErrors validationErrors = new ValidationErrors();

         validationErrors.checkRequiredField("sequenceName", statement.getSequenceName());

         validationErrors

                 .checkDisallowedField("startValue", statement.getStartValue(), database, FirebirdDatabase.class);

         validationErrors.checkDisallowedField("incrementBy", statement.getIncrementBy(), database,

                 FirebirdDatabase.class);

         validationErrors.checkDisallowedField("minValue", statement.getMinValue(), database, FirebirdDatabase.class,

                 H2Database.class, HsqlDatabase.class);

         validationErrors.checkDisallowedField("maxValue", statement.getMaxValue(), database, FirebirdDatabase.class,

                 H2Database.class, HsqlDatabase.class);

         validationErrors.checkDisallowedField("ordered", statement.getOrdered(), database, DB2Database.class,

                 MaxDBDatabase.class);

         return validationErrors;

     }

     @Override

     public Sql[] generateSql(CreateSequenceStatement statement, Database database, SqlGeneratorChain sqlGeneratorChain) {

         StringBuffer buffer = new StringBuffer();

         buffer.append("CREATE SEQUENCE ");

         buffer.append(database.escapeSequenceName(statement.getSchemaName(), statement.getSequenceName()));

         if (statement.getStartValue() != null) {

             buffer.append(" START WITH ").append(statement.getStartValue());

         }

         if (statement.getIncrementBy() != null) {

             buffer.append(" INCREMENT BY ").append(statement.getIncrementBy());

         }

         if (statement.getMinValue() != null) {

             buffer.append(" MINVALUE ").append(statement.getMinValue());

         }

         if (statement.getMaxValue() != null) {

             buffer.append(" MAXVALUE ").append(statement.getMaxValue());

         }

         if (statement.getOrdered() != null) {

             if (statement.getOrdered()) {

                 buffer.append(" ORDER");

             }

         }

         if (statement.getCycle() != null) {

             if (statement.getCycle()) {

                 buffer.append(" CYCLE");

             }

         }

         return new Sql[] { new UnparsedSql(buffer.toString()) };

     }

 }