package edu.brown.markov.features;

import org.voltdb.catalog.ProcParameter;
import org.voltdb.catalog.Procedure;
import org.voltdb.utils.Pair;

import edu.brown.hstore.HStoreConstants;
import edu.brown.markov.FeatureSet;
import edu.brown.utils.PartitionEstimator;
import edu.brown.workload.TransactionTrace;

/**
 * The hash value of a particular parameter equals the same thing as the base partition
 * @author pavlo
 *
 */
public class ParamHashEqualsBasePartitionFeature extends AbstractFeature {

    public ParamHashEqualsBasePartitionFeature(PartitionEstimator p_estimator, Procedure catalog_proc) {
        super(p_estimator, catalog_proc, ParamHashEqualsBasePartitionFeature.class);
    }
    
    @Override
    public void extract(FeatureSet fset, TransactionTrace txn_trace) throws Exception {
        int base_partition = this.p_estimator.getBasePartition(this.catalog_proc, txn_trace.getParams());
        for (ProcParameter catalog_param : this.catalog_proc.getParameters()) {
            Object param = txn_trace.getParam(catalog_param.getIndex());
            if (catalog_param.getIsarray()) {
                Object inner[]  = (Object[])param;
                for (int i = 0; i < inner.length; i++) {
                    int param_hash = this.p_estimator.getHasher().hash(inner[i]);
                    fset.addFeature(txn_trace, this.getFeatureKey(catalog_param, i), (param_hash == base_partition));
                } // FOR
                
            } else {
                int param_hash = this.p_estimator.getHasher().hash(param);
                fset.addFeature(txn_trace, this.getFeatureKey(catalog_param), (param_hash == base_partition));
            }
        } // FOR
    }
    
    @Override
    public Object calculate(String key, Object params[]) throws Exception {
        Pair<ProcParameter, Integer> p = this.getProcParameterWithIndex(key);
        int base_partition = this.p_estimator.getBasePartition(this.catalog_proc, params);
        assert(base_partition != HStoreConstants.NULL_PARTITION_ID);
        
        Object param = params[p.getFirst().getIndex()];
        Integer param_hash = null; 
        if (p.getSecond() != null) {
            assert(p.getFirst().getIsarray()) : "Invalid: " + key;
            param_hash = this.p_estimator.getHasher().hash(((Object[])param)[p.getSecond()]);
        } else {
            param_hash = this.p_estimator.getHasher().hash(param);
        }
        return (base_partition == param_hash);
    }

}