package liquibase.sqlgenerator.core;

 import liquibase.database.Database;

 import liquibase.database.core.DB2Database;

 import liquibase.database.core.MSSQLDatabase;

 import liquibase.database.core.MySQLDatabase;

 import liquibase.database.core.SQLiteDatabase;

 import liquibase.database.core.SybaseASADatabase;

 import liquibase.exception.ValidationErrors;

 import liquibase.sql.Sql;

 import liquibase.sql.UnparsedSql;

 import liquibase.sqlgenerator.SqlGeneratorChain;

 import liquibase.statement.core.AddPrimaryKeyStatement;

 import liquibase.util.StringUtils;

 public class AddPrimaryKeyGenerator extends AbstractSqlGenerator<AddPrimaryKeyStatement> {

     @Override

     public boolean supports(AddPrimaryKeyStatement statement, Database database) {

         return (!(database instanceof SQLiteDatabase));

     }

     @Override

     public ValidationErrors validate(AddPrimaryKeyStatement addPrimaryKeyStatement, Database database,

             SqlGeneratorChain sqlGeneratorChain) {

         ValidationErrors validationErrors = new ValidationErrors();

         validationErrors.checkRequiredField("columnNames", addPrimaryKeyStatement.getColumnNames());

         validationErrors.checkRequiredField("tableName", addPrimaryKeyStatement.getTableName());

         return validationErrors;

     }

     @Override

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

         String sql;

         if (statement.getConstraintName() == null || database instanceof MySQLDatabase

                 || database instanceof SybaseASADatabase) {

             sql = "ALTER TABLE " + database.escapeTableName(statement.getSchemaName(), statement.getTableName())

                     + " ADD PRIMARY KEY (" + database.escapeColumnNameList(statement.getColumnNames()) + ")";

         } else {

             sql = "ALTER TABLE " + database.escapeTableName(statement.getSchemaName(), statement.getTableName())

                     + " ADD CONSTRAINT " + database.escapeConstraintName(statement.getConstraintName())

                     + " PRIMARY KEY (" + database.escapeColumnNameList(statement.getColumnNames()) + ")";

         }

         if (StringUtils.trimToNull(statement.getTablespace()) != null && database.supportsTablespaces()) {

             if (database instanceof MSSQLDatabase) {

                 sql += " ON " + statement.getTablespace();

             } else if (database instanceof DB2Database || database instanceof SybaseASADatabase) {

                 ; // not supported

             } else {

                 sql += " USING INDEX TABLESPACE " + statement.getTablespace();

             }

         }

         return new Sql[] { new UnparsedSql(sql) };

     }

 }