/*******************************************************************************
 * Copyright (c) 2000, 2003 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials 
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.jdi.internal;


import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import org.eclipse.jdi.internal.jdwp.JdwpID;
import org.eclipse.jdi.internal.jdwp.JdwpObjectID;

import com.sun.jdi.InternalException;
import com.sun.jdi.InvalidTypeException;
import com.sun.jdi.PrimitiveType;
import com.sun.jdi.Type;
import com.sun.jdi.Value;

/**
 * this class implements the corresponding interfaces
 * declared by the JDI specification. See the com.sun.jdi package
 * for more information.
 *
 */
public abstract class ValueImpl extends MirrorImpl implements Value {
	/**
	 * Creates new ValueImpl.
	 */
	protected ValueImpl(String description, VirtualMachineImpl vmImpl) {
		super(description, vmImpl);
	}

	/**
	 * @returns type of value.
	 */
	public abstract Type type();

	/**
	 * @returns type of value.
	 */
	public abstract byte getTag();
	
	/**
	 * @return Reads JDWP representation and returns new instance.
	 */
	public static ValueImpl readWithTag(MirrorImpl target, DataInputStream in) throws IOException {
		byte tag = target.readByte("object tag", JdwpID.tagMap(), in); //$NON-NLS-1$
	   	return readWithoutTag(target, tag, in);
	}
	
	/**
	 * @return Reads JDWP representation and returns new instance.
	 */
	public static ValueImpl readWithoutTag(MirrorImpl target, int type, DataInputStream in) throws IOException {	
		VirtualMachineImpl vmImpl = target.virtualMachineImpl();
		// See also ArrayReference Impl.
		switch(type) {
			case ArrayReferenceImpl.tag:
				return ArrayReferenceImpl.read(target, in);
			case ClassLoaderReferenceImpl.tag:
				return ClassLoaderReferenceImpl.read(target, in);
			case ClassObjectReferenceImpl.tag:
				return ClassObjectReferenceImpl.read(target, in);
			case StringReferenceImpl.tag:
				return StringReferenceImpl.read(target, in);
			case ObjectReferenceImpl.tag:
				return ObjectReferenceImpl.readObjectRefWithoutTag(target, in);
			case ThreadGroupReferenceImpl.tag:
				return ThreadGroupReferenceImpl.read(target, in);
			case ThreadReferenceImpl.tag:
				return ThreadReferenceImpl.read(target, in);
			case BooleanValueImpl.tag:
				return BooleanValueImpl.read(target, in);
			case ByteValueImpl.tag:
				return ByteValueImpl.read(target, in);
			case CharValueImpl.tag:
				return CharValueImpl.read(target, in);
			case DoubleValueImpl.tag:
				return DoubleValueImpl.read(target, in);
			case FloatValueImpl.tag:
				return FloatValueImpl.read(target, in);
			case IntegerValueImpl.tag:
				return IntegerValueImpl.read(target, in);
			case LongValueImpl.tag:
				return LongValueImpl.read(target, in);
			case ShortValueImpl.tag:
				return ShortValueImpl.read(target, in);
			case VoidValueImpl.tag:
				return new VoidValueImpl(vmImpl);
			case 0:
				return null;
			default:
				throw new InternalException(JDIMessages.getString("ValueImpl.Invalid_Value_tag_encountered___1") + type); //$NON-NLS-1$
		}
	}

	/**
	 * Writes value with value tag.
	 */
	public void writeWithTag(MirrorImpl target, DataOutputStream out) throws IOException {
		target.writeByte(getTag(), "tag", JdwpID.tagMap(), out); //$NON-NLS-1$
		write(target, out);
	}

	/**
	 * Writes value without value tag.
	 */
	public abstract void write(MirrorImpl target, DataOutputStream out) throws IOException;
	
	/**
	 * Writes null value without value tag.
	 */
	public static void writeNull(MirrorImpl target, DataOutputStream out) throws IOException {
		JdwpObjectID nullID = new JdwpObjectID(target.virtualMachineImpl());
		nullID.write(out);
		if (target.fVerboseWriter != null)
			target.fVerboseWriter.println("objectReference", nullID.value()); //$NON-NLS-1$
	}
	
	/**
	 * Writes null value with value tag.
	 */
	public static void writeNullWithTag(MirrorImpl target, DataOutputStream out) throws IOException {
		target.writeByte(ObjectReferenceImpl.tag, "tag", JdwpID.tagMap(), out); //$NON-NLS-1$
		writeNull(target, out);
	}

	/**
	 * Check the type and the vm of each values, according to the associated type.
	 * For primitive values, convert the value for match the given type if needed.
	 * The two list must have the same size.
	 * @return the (converted) values.
	 * @see checkValue(Value, Type, VirtualMachineImpl)
	 */
	protected static List checkValues(List values, List types, VirtualMachineImpl vm) throws InvalidTypeException {
		List result= new ArrayList(values.size());
		Iterator iterValues= values.iterator();
		Iterator iterTypes= types.iterator();
		while (iterValues.hasNext()) {
			Value value= (Value)iterValues.next();
			Type type= (Type)iterTypes.next();
			result.add(checkValue(value, type, vm));
		}
		return result;
	}

	/**
	 * Check the type and the vm of the given value.
	 * In case of primitive value, the value is converted if needed.
	 * @return the (converted) value.
	 * @throws InvalidTypeException if the value and the type are not both
	 * primitive or not primitive or, in case of primitive, if the given
	 * value is no assignment compatible with the given type.
	 * @see checkPrimitiveValue(PrimitiveValueImpl, PrimitiveTypeImpl, PrimitiveTypeImpl)
	 */
	protected static ValueImpl checkValue(Value value, Type type, VirtualMachineImpl vm) throws InvalidTypeException {
		if (value == null) {
			if (type instanceof PrimitiveType) {
				throw new InvalidTypeException(JDIMessages.getString("ValueImpl.Type_of_the_value_not_compatible_with_the_expected_type._1")); //$NON-NLS-1$
			}
			return null;
		} else {
			vm.checkVM(value);
			TypeImpl valueType= (TypeImpl)value.type();
			if ((type instanceof PrimitiveType) ^ (valueType instanceof PrimitiveType)) {
				throw new InvalidTypeException(JDIMessages.getString("ValueImpl.Type_of_the_value_not_compatible_with_the_expected_type._1")); //$NON-NLS-1$
			}
			if (type instanceof PrimitiveType) {
				return checkPrimitiveValue((PrimitiveValueImpl) value, (PrimitiveTypeImpl) valueType, (PrimitiveTypeImpl) type);
			} else {
				return (ValueImpl)value;
			}
		}
	}

	/**
	 * Check the type of the given value, and convert the value to the given
	 * type if needed (see Java Language Spec, section 5.2).
	 * @return the (converted) value.
	 * @throws InvalidTypeException if the given value is no assignment
	 * compatible with the given type.
	 */
	protected static ValueImpl checkPrimitiveValue(PrimitiveValueImpl value, PrimitiveTypeImpl valueType, PrimitiveTypeImpl type) throws InvalidTypeException {
		char valueTypeSignature= valueType.signature().charAt(0);
		char typeSignature= type.signature().charAt(0);
		if (valueTypeSignature == typeSignature) {
			return value;
		}
		VirtualMachineImpl vm= value.virtualMachineImpl();
		switch (typeSignature) {
			case 'D':
				if (valueTypeSignature != 'Z') {
					return new DoubleValueImpl(vm, new Double(value.doubleValue()));
				}
				break;
			case 'F':
				if (valueTypeSignature != 'Z' && valueTypeSignature != 'D') {
					return new FloatValueImpl(vm, new Float(value.floatValue()));
				}
				break;
			case 'J':
				if (valueTypeSignature != 'Z' && valueTypeSignature != 'D' && valueTypeSignature != 'F') {
					return new LongValueImpl(vm, new Long(value.longValue()));
				}
				break;
			case 'I':
				if (valueTypeSignature == 'B' || valueTypeSignature == 'C' || valueTypeSignature == 'S') {
					return new IntegerValueImpl(vm, new Integer(value.intValue()));
				}
				break;
			case 'S':
				if (valueTypeSignature == 'B') {
					return new ShortValueImpl(vm, new Short(value.shortValue()));
				}
				break;
		}
		throw new InvalidTypeException(JDIMessages.getString("ValueImpl.Type_of_the_value_not_compatible_with_the_expected_type._1")); //$NON-NLS-1$
	}
}