/*

* Copyright (c) 2008 Nokia Corporation and/or its subsidiary(-ies). 

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description:

*

* Trace rule for automatically adding function return value to exit trace

*

*/

package com.nokia.tracecompiler.engine.rules;

import java.util.ArrayList;

import com.nokia.tracecompiler.engine.TraceCompilerEngineErrorMessages;

import com.nokia.tracecompiler.engine.TraceCompilerEngineGlobals;

import com.nokia.tracecompiler.engine.TraceCompilerEngineErrorCodes.TraceCompilerErrorCode;

import com.nokia.tracecompiler.engine.utils.TraceMultiplierRule;

import com.nokia.tracecompiler.model.Trace;

import com.nokia.tracecompiler.model.TraceCompilerException;

import com.nokia.tracecompiler.model.TraceConstantTable;

import com.nokia.tracecompiler.model.TraceObjectRuleCreateObject;

import com.nokia.tracecompiler.model.TraceObjectRuleRemoveOnCreate;

import com.nokia.tracecompiler.model.TraceParameter;

import com.nokia.tracecompiler.source.SourceContext;

import com.nokia.tracecompiler.source.SourceParserException;

import com.nokia.tracecompiler.source.SourceReturn;

import com.nokia.tracecompiler.source.SourceUtils;

import com.nokia.tracecompiler.source.TypeMapping;

/**

 * Trace rule for automatically adding function return value to exit trace

 * 

 */

public final class AutoAddReturnParameterRule extends RuleBase implements

		TraceObjectRuleCreateObject, TraceObjectRuleRemoveOnCreate {

	/**

	 * Parameter name

	 */

	static final String PARAMETER_NAME = "retval"; //$NON-NLS-1$

	/**

	 * The number of handled return statements

	 */

	private static int numberOfHandledReturnStatements = 0;

	/*

	 * (non-Javadoc)

	 * 

	 * @see com.nokia.tracecompiler.model.TraceObjectRuleCreateObject#

	 *      createObject(com.nokia.tracecompiler.model.TraceObject)

	 */

	public void createObject() throws TraceCompilerException {

		// If owner has a multiplier (entry trace), the trace is not added to it

		Trace owner = (Trace) getOwner();

		if (owner.getExtension(TraceMultiplierRule.class) == null) {

			SourceContext context = TraceCompilerEngineGlobals

					.getSourceContextManager().getContext();

			if (!context.isVoid()) {

				TraceConstantTable table = RuleUtils.findConstantTableByType(

						owner.getModel(), context);

				if (table != null) {

					createParameter(owner, table);

				} else {

					createParameter(owner, context);

				}

			}

		}

	}

	/*

	 * (non-Javadoc)

	 * 

	 * @see com.nokia.tracecompiler.model.TraceObjectRuleRemoveOnCreate#canBeRemoved()

	 */

	public boolean canBeRemoved() {

		// If the owner has a multiplier, this needs to be moved to it using the

		// CopyAndRemoveExtensionRule

		return getOwner().getExtension(TraceMultiplierRule.class) == null;

	}

	/**

	 * Creates a return parameter that was not associated with a constant table

	 * 

	 * @param owner

	 *            the owner for the parameter

	 * @param context

	 *            the context specifying the parameter type 

	 */

	private void createParameter(Trace owner, SourceContext context) {

		TypeMapping type = SourceUtils.mapSymbianTypeToParameterType(context);

		String return_value_name = PARAMETER_NAME;

		ArrayList<SourceReturn> returnList = new ArrayList<SourceReturn>();

		// Find out return value name

		try {

			context.parseReturnValues(returnList);

			if (numberOfHandledReturnStatements <= (returnList.size() - 1)) {

				return_value_name = returnList.get(

						numberOfHandledReturnStatements).getReturnStatement();

			}

			numberOfHandledReturnStatements++;

		} catch (SourceParserException e) {

			String msg = Messages

					.getString("RuleUtils.FailedToParseReturnValues"); //$NON-NLS-1$

			String cname = context.getClassName();

			String source;

			if (cname != null) {

				source = cname + "::" + context.getFunctionName(); //$NON-NLS-1$;

			} else {

				source = context.getFunctionName();

			}

			TraceCompilerEngineGlobals.getEvents().postErrorMessage(msg, source, true);

		}

		try {

			if (!type.needsCasting) {

				// If an extension header is generated, the parameter needs to

				// be cast, since the return statement may contain anything.

				type.needsCasting = type.type != TraceParameter.HEX32

						&& type.type != TraceParameter.SDEC32

						&& type.type != TraceParameter.UDEC32;

			}

			RuleUtils.createParameterFromType(owner, return_value_name, type);

		} catch (TraceCompilerException e) {

			if (e.getErrorCode() == TraceCompilerErrorCode.INVALID_PARAMETER_NAME) {

				String msg = TraceCompilerEngineErrorMessages

						.getErrorMessage(

								TraceCompilerErrorCode.INVALID_PARAMETER_NAME_IN_RETURN_VALUE,

								null);

				TraceCompilerEngineGlobals.getEvents().postWarningMessage(msg, owner);

			} else {

				TraceCompilerException exception = new TraceCompilerException(e.getErrorCode(), e

						.getErrorParameters(), null);

				TraceCompilerEngineGlobals.getEvents().postError(

						exception);

			}

		}

	}

	/**

	 * Creates a return parameter that was associated with a constant table

	 * 

	 * @param owner

	 *            the owner for the parameter

	 * @param table

	 *            the constant table the parameter was associated to

	 */

	private void createParameter(Trace owner, TraceConstantTable table) {

		try {

			RuleUtils.createParameterFromConstantTable(owner, PARAMETER_NAME,

					table);

		} catch (TraceCompilerException e) {

			TraceCompilerException exception = new TraceCompilerException(e.getErrorCode(), e

					.getErrorParameters(), null);

			TraceCompilerEngineGlobals.getEvents().postError(

					exception);

		}

	}

	/**

	 * Reset static variables

	 */

	static void resetNumberOfHandledReturnStatements() {

		numberOfHandledReturnStatements = 0;

	}

	/**

	 * Increase number of handled return statements

	 */

	static void increaseNumberOfHandledReturnStatements() {

		numberOfHandledReturnStatements++;

	}

}