SQLAlterTableQuery.java

package org.getlantern.querybuilder.query;

import org.getlantern.querybuilder.NewColumn;
import org.getlantern.querybuilder.SQLQuery;

public class SQLAlterTableQuery implements SQLQuery {

    private String table;
    private String renameTo;
    private NewColumn addColumn;

    @Override
    public String getSQL() {
        if (table == null) throw new NullPointerException("table must not be null!");
        if (renameTo == null && addColumn == null) throw new NullPointerException();
        if (renameTo != null) return String.format("ALTER TABLE %s RENAME TO %s", table, renameTo);
        return String.format("ALTER TABLE %s ADD COLUMN %s", table, addColumn.getSQL());
    }

    void setAddColumn(final NewColumn addColumn) {
        this.addColumn = addColumn;
    }

    void setRenameTo(final String renameTo) {
        this.renameTo = renameTo;
    }

    void setTable(final String table) {
        this.table = table;
    }

    public static final class Builder implements IBuilder<SQLAlterTableQuery> {

        private final SQLAlterTableQuery query = new SQLAlterTableQuery();
        private boolean buildCalled;

        public Builder addColumn(final NewColumn addColumn) {
            checkNotBuilt();
            query.setAddColumn(addColumn);
            return this;
        }

        public Builder alterTable(final String table) {
            checkNotBuilt();
            query.setTable(table);
            return this;
        }

        @Override
        public SQLAlterTableQuery build() {
            return query;
        }

        @Override
        public String buildSQL() {
            return build().getSQL();
        }

        public Builder renameTo(final String renameTo) {
            checkNotBuilt();
            query.setRenameTo(renameTo);
            return this;
        }

        private void checkNotBuilt() {
            if (buildCalled) throw new IllegalStateException();
        }
    }

}