package nl.tudelft.simulation.dsol.interpreter.operations;

import java.io.DataInput;
import java.io.IOException;
import java.lang.reflect.Field;

import org.djutils.reflection.ClassUtil;

import nl.tudelft.simulation.dsol.interpreter.InterpreterException;
import nl.tudelft.simulation.dsol.interpreter.LocalVariable;
import nl.tudelft.simulation.dsol.interpreter.OperandStack;
import nl.tudelft.simulation.dsol.interpreter.classfile.Constant;
import nl.tudelft.simulation.dsol.interpreter.classfile.ConstantFieldref;

/**
 * The PUTSTATIC operation as defined in <a href="https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-6.html#jvms-6.5">
 * https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-6.html#jvms-6.5 </a>.
 * <p>
 * Copyright (c) 2002-2021 Delft University of Technology, Jaffalaan 5, 2628 BX Delft, the Netherlands. All rights reserved. See
 * for project information <a href="https://simulation.tudelft.nl/" target="_blank"> https://simulation.tudelft.nl</a>. The DSOL
 * project is distributed under a three-clause BSD-style license, which can be found at
 * <a href="https://simulation.tudelft.nl/dsol/3.0/license.html" target="_blank">
 * https://simulation.tudelft.nl/dsol/3.0/license.html</a>.
 * </p>
 * @author <a href="https://www.linkedin.com/in/peterhmjacobs">Peter Jacobs</a>
 * @author <a href="https://www.tudelft.nl/averbraeck">Alexander Verbraeck</a>
 */
public class PUTSTATIC extends VoidOperation
{
    /** OP refers to the operand code. */
    public static final int OP = 179;

    /** the index to load. */
    private final int index;

    /**
     * constructs a new PUTSTATIC.
     * @param dataInput DataInput; the dataInput
     * @throws IOException on IOfailure
     */
    public PUTSTATIC(final DataInput dataInput) throws IOException
    {
        super();
        this.index = dataInput.readUnsignedShort();
    }

    /** {@inheritDoc} */
    @Override
    public final void execute(final OperandStack stack, final Constant[] constantPool, final LocalVariable[] localVariables)
    {
        try
        {
            Field field = null;
            ConstantFieldref constantFieldref = (ConstantFieldref) constantPool[this.index];
            Class<?> referenceClass = constantFieldref.getConstantClass().getValue().getClassValue();
            field = ClassUtil.resolveField(referenceClass, constantFieldref.getConstantNameAndType().getName());
            field.setAccessible(true);
            Object value = stack.pop();
            Object target = null;

            if (!field.getType().isPrimitive())
            {
                field.set(target, value);
                return;
            }

            if (field.getType().equals(boolean.class))
            {
                field.setBoolean(target, ((int) value) == 1);
                return;
            }

            if (field.getType().equals(byte.class))
            {
                field.setByte(target, ((Integer) value).byteValue());
                return;
            }

            if (field.getType().equals(char.class))
            {
                field.setChar(target, (char) (((Integer) value).byteValue()));
                return;
            }

            if (field.getType().equals(short.class))
            {
                field.setShort(target, ((Short) value).shortValue());
                return;
            }

            if (field.getType().equals(int.class))
            {
                field.setInt(target, ((Integer) value).intValue());
                return;
            }

            if (field.getType().equals(float.class))
            {
                field.setFloat(target, ((Float) value).floatValue());
                return;
            }

            if (field.getType().equals(long.class))
            {
                field.setLong(target, ((Long) value).longValue());
                return;
            }

            if (field.getType().equals(double.class))
            {
                field.setDouble(target, ((Double) value).doubleValue());
                return;
            }
        }
        catch (Exception exception)
        {
            throw new InterpreterException(exception);
        }
    }

    /** {@inheritDoc} */
    @Override
    public final int getByteLength()
    {
        return OPCODE_BYTE_LENGTH + 2;
    }

    /** {@inheritDoc} */
    @Override
    public final int getOpcode()
    {
        return PUTSTATIC.OP;
    }
}