/***************************************************************************
                            Invocation.java -  description
                             -------------------
    begin                : Tue Oct 31 06:12:14 2000
    copyright            : (C) 2000 Lost Highway Ltd. All rights reserved.
    email                : Lost_Highway@tipitina.demon.co.uk
    written by           : Richard Dale.
 ***************************************************************************/

/***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 *   Lost Highway Ltd reserves the right to issue additional license types *
 *   compatible with the Trolltech AS Qt commercial license.               *
 ***************************************************************************/

package org.kde.qt;

import java.util.*;
import java.lang.reflect.*;

/** A utility class for creating a closure to invoke later - when a Java
	slot or event handler needs to be activated
	
	@author Richard Dale <Richard_Dale@tipitina.demon.co.uk>
 */
public class Invocation {
	/** The target object */
	private Object		onThis;
	/** Arguments from an emitted signal to pass to the slot method */
	private Object[]	arguments;
	/** The Java method that implements the slot, (or emit() for a signal target) */
	private Method		method;
	/** An optional instance variable, used when the target is a signal,
		rather than a slot. */
	private String		signalName;
	
	/** Converts a type signature from a Qt signal or slot to an array of
		Class objects corresponding to the Java types of the parameters */
	private static Class[] fromQtTypeSignature(String qtTypeSignature) {
		ArrayList parameterTypes = new ArrayList();
		StringTokenizer tokenizer = new StringTokenizer(qtTypeSignature, ",");
		
		while (tokenizer.hasMoreTokens()) {
			String token = tokenizer.nextToken();
			
			if (token.equals("")) {
				parameterTypes.add(null);
			} else if (token.equals("boolean")) {
				parameterTypes.add(boolean.class);
			} else if (token.equals("char")) {
				parameterTypes.add(char.class);
			} else if (token.equals("long")) {
				parameterTypes.add(long.class);
			} else if (token.equals("int")) {
				parameterTypes.add(int.class);
			} else if (token.equals("short")) {
				parameterTypes.add(short.class);
			} else if (token.equals("float")) {
				parameterTypes.add(float.class);
			} else if (token.equals("double")) {
				parameterTypes.add(double.class);
			} else if (token.equals("int[]")) {
				parameterTypes.add(int[].class);
			} else if (token.equals("byte[]")) {
				parameterTypes.add(byte[].class);
			} else {
				try {
					parameterTypes.add(Class.forName(token));
				} catch (ClassNotFoundException e) {
					Qt.qWarning("QObject.connect: No such argument type: " + token);
					return null;
				}
			}
		}
		
		return (Class[]) parameterTypes.toArray(new Class[0]);
	}
	
	/** Contained in a C++ JavaSlot instance, allows the JavaSlot to act as a proxy for the Java method to be invoked.
		The method name in the slot string is converted to a Java Method instance, and the arguments to a suitable
		Class[] structure, as the corresponding argument type list. */
	Invocation(Object target, String receiverString) {
		Method		targetMethod = null;
		Class		targetClass = null;
		String		methodName;
		Class[]		parameterTypes;
		
		if (receiverString.startsWith("2")) {
			// Target is a signal
			methodName = "emit";
			parameterTypes = new Class[] {java.lang.String.class, Object[].class};
			signalName = receiverString;
		} else {
			// Target is a slot
			methodName = receiverString.substring(1, receiverString.indexOf('('));
			parameterTypes = fromQtTypeSignature(receiverString.substring(	receiverString.indexOf('(') + 1,
																			receiverString.indexOf(')') ) );
			if (parameterTypes == null) {
				return;
			}
			signalName = null;
		}

		// A slot can either be public or protected. However, it isn't possible
		// to obtain inherited protected members using getMethod() or
		// getDeclaredMethod(). Hence, the apparently over complicated loop here.
		targetClass = target.getClass();
		
		do {
			try {
				targetMethod = targetClass.getDeclaredMethod(methodName, parameterTypes);
			} catch (NoSuchMethodException e1) {
				try {
					targetMethod = targetClass.getMethod(methodName, parameterTypes);
				} catch (NoSuchMethodException e2) {
					;
				}
			}
			
			if (targetMethod != null) {
				onThis = target;
				arguments = null;
				method = targetMethod;
				method.setAccessible(true);
				return;
			}
			
			targetClass = targetClass.getSuperclass();
		} while (targetClass != null);
		
		System.out.print("QObject.connect: No such slot " + methodName + "(");
		for (int index = 0; index < parameterTypes.length; index++) {
			System.out.print(parameterTypes[index].toString());
						
			if (index + 1 < parameterTypes.length) {
				System.out.print(",");
			}
		}
		System.out.println(")");
		return;
	}
		
	Invocation(Object target, Object[] args, Method aMethod) {
		onThis = target;
		arguments = args;
		method = aMethod;
		method.setAccessible(true);
	}
	
	public void setArguments(Object[] args) {
		arguments = args;
	}
	
	/** Not used at present, here for completeness */
	public Object invoke() throws IllegalAccessException, InvocationTargetException {
		try {
			Object result = method.invoke(onThis, arguments);
		} catch (InvocationTargetException e) {
			return null;
		} catch (IllegalAccessException e) {
			return null;
		} finally {
			return null;
		}
	}
	
	/** Used for Java slot/signal targets, handles callbacks */
	public Object invoke(Object[] args) throws IllegalAccessException, InvocationTargetException {
		if (signalName != null) {
			// If the target is a signal, then there are two parameters needed for QObject.emit().
			// A signal name, followed by an array of arguments to be emitted.
			Object[] emitArgs = new Object[2];
			emitArgs[0] = signalName;
			emitArgs[1] = args;
			setArguments(emitArgs);
		} else {
			// If the target is a slot, then just pass on the arguments to the target slot
			setArguments(args);
		}
		
		try {
			Object result = method.invoke(onThis, arguments);
		} catch (InvocationTargetException e) {
			Qt.qWarning("Slot invocation failed");
			e.printStackTrace();
			return null;
		} catch (IllegalAccessException e) {
			Qt.qWarning("Slot invocation failed");
			e.printStackTrace();
			return null;
		} finally {
			return null;
		}
	}
	
	/** Used for boolean slot handling callbacks */
	public Object invoke(boolean arg) throws IllegalAccessException, InvocationTargetException {
		arguments = new Object[1];
		arguments[0] = new Boolean(arg);
		return invoke(arguments);
	}
	
	/** Used for C++ sender to byte (ie unsigned char in C++) Java slot handling callbacks */
	public Object invoke(byte arg) throws IllegalAccessException, InvocationTargetException {
		arguments = new Object[1];
		arguments[0] = new Byte(arg);
		return invoke(arguments);
	}
	
	/** Used for C++ sender to char Java slot handling callbacks */
	public Object invoke(char arg) throws IllegalAccessException, InvocationTargetException {
		arguments = new Object[1];
		arguments[0] = new Character(arg);
		return invoke(arguments);
	}
	
	/** Used for C++ sender to short Java slot handling callbacks */
	public Object invoke(short arg) throws IllegalAccessException, InvocationTargetException {
		arguments = new Object[1];
		arguments[0] = new Short(arg);
		return invoke(arguments);
	}
	
	/** Used for C++ sender to int Java slot handling callbacks */
	public Object invoke(int arg)  throws IllegalAccessException, InvocationTargetException{
		arguments = new Object[1];
		arguments[0] = new Integer(arg);
		return invoke(arguments);
	}
	
	/** Used for C++ sender to long Java slot handling callbacks */
	public Object invoke(long arg) throws IllegalAccessException, InvocationTargetException{
		arguments = new Object[1];
		arguments[0] = new Long(arg);
		return invoke(arguments);
	}
	
	/** Used for C++ sender float Java slot handling callbacks */
	public Object invoke(float arg) throws IllegalAccessException, InvocationTargetException{
		arguments = new Object[1];
		arguments[0] = new Float(arg);
		return invoke(arguments);
	}
	
	/** Used for C++ sender to double Java slot handling callbacks */
	public Object invoke(double arg) throws IllegalAccessException, InvocationTargetException {
		arguments = new Object[1];
		arguments[0] = new Double(arg);
		return invoke(arguments);
	}
	
	public Object invoke(Object arg) throws IllegalAccessException, InvocationTargetException {
		arguments = new Object[1];
		arguments[0] = arg;
		return invoke(arguments);
	}
	
	public Object invoke(Object arg1, byte[] arg2) throws IllegalAccessException, InvocationTargetException {
		arguments = new Object[2];
		arguments[0] = arg1;
		arguments[1] = arg2;
		return invoke(arguments);
	}

	public Object invoke(Object arg1, Object arg2) throws IllegalAccessException, InvocationTargetException {
		arguments = new Object[2];
		arguments[0] = arg1;
		arguments[1] = arg2;
		return invoke(arguments);
	}
	
	public Object invoke(Object arg1, Object arg2, Object arg3) throws IllegalAccessException, InvocationTargetException {
		arguments = new Object[3];
		arguments[0] = arg1;
		arguments[1] = arg2;
		arguments[2] = arg3;
		return invoke(arguments);
	}
	
	public Object invoke(Object arg1, Object arg2, Object arg3, Object arg4) throws IllegalAccessException, InvocationTargetException {
		arguments = new Object[4];
		arguments[0] = arg1;
		arguments[1] = arg2;
		arguments[2] = arg3;
		arguments[3] = arg4;
		return invoke(arguments);
	}
	
	public Object invoke(Object arg1, boolean arg2) throws IllegalAccessException, InvocationTargetException {
		arguments = new Object[2];
		arguments[0] = arg1;
		arguments[1] = new Boolean(arg2);
		return invoke(arguments);
	}
	
	public Object invoke(Object arg1, Object arg2, int arg3) throws IllegalAccessException, InvocationTargetException {
		arguments = new Object[3];
		arguments[0] = arg1;
		arguments[1] = arg2;
		arguments[2] = new Integer(arg3);
		return invoke(arguments);
	}
	
	public Object invoke(int arg1, Object arg2) throws IllegalAccessException, InvocationTargetException {
		arguments = new Object[2];
		arguments[0] = new Integer(arg1);
		arguments[1] = arg2;
		return invoke(arguments);
	}
	
	public Object invoke(int arg1, Object arg2, Object arg3) throws IllegalAccessException, InvocationTargetException {
		arguments = new Object[3];
		arguments[0] = new Integer(arg1);
		arguments[1] = arg2;
		arguments[2] = arg3;
		return invoke(arguments);
	}
	
	public Object invoke(int arg1, Object arg2, Object arg3, int arg4) throws IllegalAccessException, InvocationTargetException {
		arguments = new Object[3];
		arguments[0] = new Integer(arg1);
		arguments[1] = arg2;
		arguments[2] = arg3;
		arguments[3] = new Integer(arg4);
		return invoke(arguments);
	}
	
	public Object invoke(int arg1, boolean arg2) throws IllegalAccessException, InvocationTargetException {
		arguments = new Object[2];
		arguments[0] = new Integer(arg1);
		arguments[1] = new Boolean(arg2);
		return invoke(arguments);
	}
	
	public Object invoke(int arg1, int arg2) throws IllegalAccessException, InvocationTargetException {
		arguments = new Object[2];
		arguments[0] = new Integer(arg1);
		arguments[1] = new Integer(arg2);
		return invoke(arguments);
	}
	
	public Object invoke(int arg1, int arg2, int arg3) throws IllegalAccessException, InvocationTargetException {
		arguments = new Object[3];
		arguments[0] = new Integer(arg1);
		arguments[1] = new Integer(arg2);
		arguments[2] = new Integer(arg3);
		return invoke(arguments);
	}
	
	public Object invoke(int arg1, int arg2, int arg3, Object arg4) throws IllegalAccessException, InvocationTargetException {
		arguments = new Object[4];
		arguments[0] = new Integer(arg1);
		arguments[1] = new Integer(arg2);
		arguments[2] = new Integer(arg3);
		arguments[2] = arg4;
		return invoke(arguments);
	}

	/** Invoke the named method on the target object with no arguments. Returns false
		iff the target method was successfully invoked AND returned false. Unlike the other
		variants of boolean invoke(), this method returns true if no target java method exists.
		Used for boolean callbacks such as KMainWindow::queryClose() */
	public static boolean invoke(long target, String methodName) throws NoSuchMethodException, ClassNotFoundException  {
		Method	method;
		Object onThis = qtjava.objectForQtKey(target, "QObject", false);

		try {
			method = onThis.getClass().getMethod(methodName, null);
		} catch (NoSuchMethodException e1) {
			try {
				method = onThis.getClass().getDeclaredMethod(methodName, null);
			} catch (NoSuchMethodException e2) {
				return true;
			}
		}

		try {
			method.setAccessible(true);
			Object result = method.invoke(onThis, null);
			return ((Boolean) result).booleanValue();
		} catch (InvocationTargetException e) {
			Qt.qWarning("Invocation failed : " + onThis.getClass().getName() + "." + methodName + "()");
			e.printStackTrace();
			return true;
		} catch (IllegalAccessException e) {
			Qt.qWarning("Invocation failed : " + onThis.getClass().getName() + "." + methodName + "()");
			e.printStackTrace();
			return true;
		}
	}

	/** Invoke the named method on the target object with a single argument. Returns true
		if the method was successfully invoked, otherwise false.
		Used for event handling callbacks */
	public static boolean invoke(long target, long arg, String argClass, String methodName) throws NoSuchMethodException, ClassNotFoundException  {
		Method	method;
		Class[] parameterType = new Class[1];
		parameterType[0] = Class.forName(qtjava.toFullyQualifiedClassName(argClass));
		Object onThis = qtjava.objectForQtKey(target, "org.kde.qt.QObject", false);
		
		try {
			// Assume that an event handler is a protected method, so use getDeclaredMethod()
			method = onThis.getClass().getDeclaredMethod(methodName, parameterType);
			method.setAccessible(true);
		} catch (NoSuchMethodException e) {
			return false;
		}

		// Ignore any native code event handling methods
		if ((method.getModifiers() & Modifier.NATIVE) != 0) {
			return false;
		}

		Object[] arguments = new Object[1];
		arguments[0] = qtjava.objectForQtKey(arg, argClass, false);

		try {
			// Invoke the event handler
			Object result = method.invoke(onThis, arguments);
			
			// The event will no longer be referenced, so force remove its java mapping entry.
			qtjava.removeObjectForQtKey(arg);
		} catch (InvocationTargetException e) {
			Qt.qWarning("Event handler failed : " + onThis.getClass().getName() + "." + methodName + "(" + qtjava.toFullyQualifiedClassName(argClass) + " event)");
			e.printStackTrace();
			return false;
		} catch (IllegalAccessException e) {
			Qt.qWarning("Event handler failed : " + onThis.getClass().getName() + "." + methodName + "(" + qtjava.toFullyQualifiedClassName(argClass) + " event)");
			e.printStackTrace();
			return false;
		} finally {
			return true;
		}
	}

	/** Invoke the named method on the target object with two arguments. Returns true
		if the method was successfully invoked, otherwise false.
		Used for event filter callbacks */
	public static boolean invoke(long target, long arg1, String arg1class, long arg2, String arg2class, String methodName) throws NoSuchMethodException, ClassNotFoundException  {
		Method	method;
		Boolean	result = null;
		Object[] arguments = new Object[2];
		arguments[0] = qtjava.objectForQtKey(arg1, arg1class, false);
		arguments[1] = qtjava.objectForQtKey(arg2, arg2class, false);

		Class[] parameterTypes = new Class[] { QObject.class, QEvent.class };
		Object onThis = qtjava.objectForQtKey(target, "QObject", false);
		
		try {
			method = onThis.getClass().getMethod(methodName, parameterTypes);
			method.setAccessible(true);
		} catch (NoSuchMethodException e) {
			return false;
		}

		try {
			result = (Boolean) method.invoke(onThis, arguments);
		} catch (InvocationTargetException e) {
			Qt.qWarning("Event filter failed : " + onThis.getClass().getName() + "." + methodName + "()");
			e.printStackTrace();
			return false;
		} catch (IllegalAccessException e) {
			Qt.qWarning("Event filter failed : " + onThis.getClass().getName() + "." + methodName + "()");
			e.printStackTrace();
			return false;
		} finally {
			return result.booleanValue();
		}
	}

}
