package liquibase.sqlgenerator;

 import liquibase.database.Database;

 import liquibase.exception.ValidationErrors;

 import liquibase.exception.Warnings;

 import liquibase.sql.Sql;

 import liquibase.statement.SqlStatement;

 import java.util.Iterator;

 import java.util.SortedSet;

 public class SqlGeneratorChain {

     private Iterator<SqlGenerator> sqlGenerators;

     public SqlGeneratorChain(SortedSet<SqlGenerator> sqlGenerators) {

         if (sqlGenerators != null) {

             this.sqlGenerators = sqlGenerators.iterator();

         }

     }

     public Sql[] generateSql(SqlStatement statement, Database database) {

         if (sqlGenerators == null) {

             return null;

         }

         if (!sqlGenerators.hasNext()) {

             return new Sql[0];

         }

         return sqlGenerators.next().generateSql(statement, database, this);

     }

     public Warnings warn(SqlStatement statement, Database database) {

         if (sqlGenerators == null || !sqlGenerators.hasNext()) {

             return new Warnings();

         }

         return sqlGenerators.next().warn(statement, database, this);

     }

     public ValidationErrors validate(SqlStatement statement, Database database) {

         if (sqlGenerators == null || !sqlGenerators.hasNext()) {

             return new ValidationErrors();

         }

         return sqlGenerators.next().validate(statement, database, this);

     }

 }