/**
 * Copyright (C) 2009-2013 FoundationDB, LLC
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package com.foundationdb.server.types.mcompat.mfuncs;

import com.foundationdb.server.types.LazyList;
import com.foundationdb.server.types.TExecutionContext;
import com.foundationdb.server.types.TScalar;
import com.foundationdb.server.types.TOverloadResult;
import com.foundationdb.server.types.mcompat.mtypes.MNumeric;
import com.foundationdb.server.types.mcompat.mtypes.MString;
import com.foundationdb.server.types.value.ValueSource;
import com.foundationdb.server.types.value.ValueTarget;
import com.foundationdb.server.types.texpressions.TInputSetBuilder;
import com.foundationdb.server.types.texpressions.TScalarBase;

public class MStrcmp extends TScalarBase {
    public static final TScalar INSTANCE = new MStrcmp();
    
    private MStrcmp(){}
            
    @Override
    protected void buildInputSets(TInputSetBuilder builder) {
        builder.covers(MString.VARCHAR, 0, 1);
    }

    @Override
    protected void doEvaluate(TExecutionContext context, LazyList<? extends ValueSource> inputs, ValueTarget output) {
        String st1 = inputs.get(0).getString();
        String st2 = inputs.get(1).getString();

        int cmp = st1.compareTo(st2);
        if (cmp < 0)
            cmp = -1;
        else if (cmp > 0)
            cmp = 1;
        output.putInt32(cmp);
    }

    @Override
    public String displayName() {
        return "STRCMP";
    }

    @Override
    public TOverloadResult resultType() {
        return TOverloadResult.fixed(MNumeric.INT);
    }

}