package liquibase.sqlgenerator.core;

 import java.util.ArrayList;

 import java.util.Arrays;

 import java.util.List;

 import liquibase.change.ColumnConfig;

 import liquibase.database.Database;

 import liquibase.database.core.SQLiteDatabase;

 import liquibase.database.structure.Index;

 import liquibase.exception.DatabaseException;

 import liquibase.exception.UnexpectedLiquibaseException;

 import liquibase.exception.UnsupportedChangeException;

 import liquibase.sql.Sql;

 import liquibase.sqlgenerator.SqlGeneratorChain;

 import liquibase.sqlgenerator.SqlGeneratorFactory;

 import liquibase.statement.SqlStatement;

 import liquibase.statement.core.AddAutoIncrementStatement;

 /**

  * SQLite does not support this ALTER TABLE operation until now. For more information see:

  * http://www.sqlite.org/omitted.html. This is a small work around...

  */

 public class AddAutoIncrementGeneratorSQLite extends AddAutoIncrementGenerator {

     @Override

     public int getPriority() {

         return PRIORITY_DATABASE;

     }

     @Override

     public boolean supports(AddAutoIncrementStatement statement, Database database) {

         return database instanceof SQLiteDatabase;

     }

     @Override

     public Sql[] generateSql(final AddAutoIncrementStatement statement, Database database,

             SqlGeneratorChain sqlGeneratorChain) {

         List<Sql> statements = new ArrayList<Sql>();

         // define alter table logic

         SQLiteDatabase.AlterTableVisitor rename_alter_visitor = new SQLiteDatabase.AlterTableVisitor() {

             @Override

             public ColumnConfig[] getColumnsToAdd() {

                 return new ColumnConfig[0];

             }

             @Override

             public boolean copyThisColumn(ColumnConfig column) {

                 return true;

             }

             @Override

             public boolean createThisColumn(ColumnConfig column) {

                 if (column.getName().equals(statement.getColumnName())) {

                     column.setAutoIncrement(true);

                     column.setType("INTEGER");

                 }

                 return true;

             }

             @Override

             public boolean createThisIndex(Index index) {

                 return true;

             }

         };

         try {

             // alter table

             for (SqlStatement generatedStatement : SQLiteDatabase.getAlterTableStatements(rename_alter_visitor,

                     database, statement.getSchemaName(), statement.getTableName())) {

                 statements.addAll(Arrays.asList(SqlGeneratorFactory.getInstance().generateSql(generatedStatement,

                         database)));

             }

         } catch (DatabaseException e) {

             e.printStackTrace();

         } catch (UnsupportedChangeException e) {

             throw new UnexpectedLiquibaseException(e);

         }

         return statements.toArray(new Sql[statements.size()]);

     }

 }