package org.simantics.scl.compiler.elaboration.java;

import org.cojen.classfile.TypeDesc;
import org.simantics.scl.compiler.constants.FunctionValue;
import org.simantics.scl.compiler.internal.codegen.references.Val;
import org.simantics.scl.compiler.internal.codegen.utils.Constants;
import org.simantics.scl.compiler.internal.codegen.utils.MethodBuilder;
import org.simantics.scl.compiler.types.TVar;
import org.simantics.scl.compiler.types.Type;
import org.simantics.scl.compiler.types.Types;
import org.simantics.scl.compiler.types.kinds.Kinds;

public class HashCodeFunction extends FunctionValue {
    private static final TVar A = Types.var(Kinds.STAR);
    public static final HashCodeFunction INSTANCE = new HashCodeFunction();
    
    private HashCodeFunction() {
        super(new TVar[] {A}, Types.NO_EFFECTS, Types.INTEGER, A);
    }

    @Override
    public Type applyExact(MethodBuilder mb, Val[] parameters) {
        TypeDesc parameterType = mb.getJavaTypeTranslator().getTypeDesc(parameters[0]);
        parameters[0].push(mb);
        switch(parameterType.getTypeCode()) {
        case TypeDesc.VOID_CODE:
            mb.loadStaticField(Constants.TUPLE0, "INSTANCE", Constants.TUPLE0);
            mb.invokeVirtual("java/lang/Object", "hashCode", TypeDesc.INT, Constants.OBJECTS[1]);
            break;
        case TypeDesc.OBJECT_CODE:
            mb.invokeStatic("java/util/Objects", "hashCode", TypeDesc.INT, Constants.OBJECTS[1]);
            break;
        case TypeDesc.INT_CODE:
            mb.invokeStatic("java/lang/Integer", "hashCode", TypeDesc.INT, new TypeDesc[] {TypeDesc.INT});
            break;
        case TypeDesc.LONG_CODE:
            mb.invokeStatic("java/lang/Long", "hashCode", TypeDesc.LONG, new TypeDesc[] {TypeDesc.LONG});
            break;
        case TypeDesc.DOUBLE_CODE:
            mb.invokeStatic("java/lang/Double", "hashCode", TypeDesc.DOUBLE, new TypeDesc[] {TypeDesc.DOUBLE});
            break;
        case TypeDesc.FLOAT_CODE:
            mb.invokeStatic("java/lang/Float", "hashCode", TypeDesc.FLOAT, new TypeDesc[] {TypeDesc.FLOAT});
            break;
        case TypeDesc.SHORT_CODE:
            mb.invokeStatic("java/lang/Short", "hashCode", TypeDesc.SHORT, new TypeDesc[] {TypeDesc.SHORT});
            break;
        }
        return Types.INTEGER;
    }
}