/*
 * Copyright 2009-2010 by The Regents of the University of California
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * you may obtain a copy of the License from
 * 
 *     http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package edu.uci.ics.hyracks.algebricks.core.algebra.functions;

import java.util.HashMap;
import java.util.Map;

public class AlgebricksBuiltinFunctions {
    public enum ComparisonKind {
        EQ,
        LE,
        GE,
        LT,
        GT,
        NEQ
    }

    public static final String ALGEBRICKS_NS = "algebricks";

    // comparisons
    public final static FunctionIdentifier EQ = new FunctionIdentifier(ALGEBRICKS_NS, "eq", 2);
    public final static FunctionIdentifier LE = new FunctionIdentifier(ALGEBRICKS_NS, "le", 2);
    public final static FunctionIdentifier GE = new FunctionIdentifier(ALGEBRICKS_NS, "ge", 2);
    public final static FunctionIdentifier LT = new FunctionIdentifier(ALGEBRICKS_NS, "lt", 2);
    public final static FunctionIdentifier GT = new FunctionIdentifier(ALGEBRICKS_NS, "gt", 2);
    public final static FunctionIdentifier NEQ = new FunctionIdentifier(ALGEBRICKS_NS, "neq", 2);

    // booleans
    public final static FunctionIdentifier NOT = new FunctionIdentifier(ALGEBRICKS_NS, "not", 1);
    public final static FunctionIdentifier AND = new FunctionIdentifier(ALGEBRICKS_NS, "and",
            FunctionIdentifier.VARARGS);
    public final static FunctionIdentifier OR = new FunctionIdentifier(ALGEBRICKS_NS, "or", FunctionIdentifier.VARARGS);

    // numerics
    public final static FunctionIdentifier NUMERIC_ADD = new FunctionIdentifier(ALGEBRICKS_NS, "numeric-add", 2);

    // nulls
    public final static FunctionIdentifier IS_NULL = new FunctionIdentifier(ALGEBRICKS_NS, "is-null", 1);

    private static final Map<FunctionIdentifier, ComparisonKind> comparisonFunctions = new HashMap<FunctionIdentifier, ComparisonKind>();
    static {
        comparisonFunctions.put(AlgebricksBuiltinFunctions.EQ, ComparisonKind.EQ);
        comparisonFunctions.put(AlgebricksBuiltinFunctions.LE, ComparisonKind.LE);
        comparisonFunctions.put(AlgebricksBuiltinFunctions.GE, ComparisonKind.GE);
        comparisonFunctions.put(AlgebricksBuiltinFunctions.LT, ComparisonKind.LT);
        comparisonFunctions.put(AlgebricksBuiltinFunctions.GT, ComparisonKind.GT);
        comparisonFunctions.put(AlgebricksBuiltinFunctions.NEQ, ComparisonKind.NEQ);
    }

    public static ComparisonKind getComparisonType(FunctionIdentifier fi) {
        return comparisonFunctions.get(fi);
    }

    public static boolean isComparisonFunction(FunctionIdentifier fi) {
        return comparisonFunctions.get(fi) != null;
    }
}