package edu.uci.ics.hivesterix.runtime.factory.evaluator;

import org.apache.hadoop.hive.ql.plan.ExprNodeColumnDesc;

import edu.uci.ics.hivesterix.logical.expression.ExpressionTranslator;
import edu.uci.ics.hivesterix.runtime.evaluator.ColumnExpressionEvaluator;
import edu.uci.ics.hivesterix.runtime.jobgen.Schema;
import edu.uci.ics.hyracks.algebricks.common.exceptions.AlgebricksException;
import edu.uci.ics.hyracks.algebricks.core.algebra.base.ILogicalExpression;
import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.IVariableTypeEnvironment;
import edu.uci.ics.hyracks.algebricks.runtime.base.ICopyEvaluator;
import edu.uci.ics.hyracks.algebricks.runtime.base.ICopyEvaluatorFactory;
import edu.uci.ics.hyracks.data.std.api.IDataOutputProvider;

public class ColumnExpressionEvaluatorFactory implements ICopyEvaluatorFactory {

    private static final long serialVersionUID = 1L;

    private ExprNodeColumnDesc expr;

    private Schema inputSchema;

    public ColumnExpressionEvaluatorFactory(ILogicalExpression expression, Schema schema, IVariableTypeEnvironment env)
            throws AlgebricksException {
        try {
            expr = (ExprNodeColumnDesc) ExpressionTranslator.getHiveExpression(expression, env);
        } catch (Exception e) {
            throw new AlgebricksException(e.getMessage());
        }
        inputSchema = schema;
    }

    public ICopyEvaluator createEvaluator(IDataOutputProvider output) throws AlgebricksException {
        return new ColumnExpressionEvaluator(expr, inputSchema.toObjectInspector(), output);
    }

    public String toString() {
        return "column expression evaluator factory: " + expr.toString();
    }

}