*  Licensed to the Apache Software Foundation (ASF) under one

*  or more contributor license agreements.  See the NOTICE file

*  distributed with this work for additional information

*  regarding copyright ownership.  The ASF licenses this file

*  to you under the Apache License, Version 2.0 (the

*  "License"); you may not use this file except in compliance

*  with the License.  You may obtain a copy of the License at

*

*   http://www.apache.org/licenses/LICENSE-2.0

*

*  Unless required by applicable law or agreed to in writing,

*  software distributed under the License is distributed on an

*   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY

*  KIND, either express or implied.  See the License for the

*  specific language governing permissions and limitations

*  under the License.

*/

* A Synapse mediator that calls a function in any scripting language supported by BSF. The ScriptMediator using a registry property to define the

* registry property which contains the script source.

* <p>

*

* <pre>

*    &lt;script key=&quot;property-key&quot; function=&quot;script-function-name&quot; &lt;script/&gt;

* </pre>

*

* <p>

* The function is an optional attribute defining the name of the script function to call, if not specified it defaults to a function named 'mediate'.

* The function takes a single parameter which is the Synapse MessageContext. The function may return a boolean, if it does not then true is assumed.

*/

    protected String scriptKey;

    protected String functionName;

    protected BSFEngine bsfEngine;

    protected OMElementConvertor convertor;

    protected BSFManager bsfManager;

    public ScriptMediator(String scriptKey, String functionName) {

        this.scriptKey = scriptKey;

        this.functionName = functionName;

        bsfManager = new BSFManager();

    }

    public boolean mediate(MessageContext synCtx) {

        try {

            BSFEngine engine = getBSFEngine(synCtx.getConfiguration());

            Object[] args = new Object[] { new ScriptMessageContext(synCtx, convertor) };

            Object response = engine.call(null, functionName, args);

            if (response instanceof Boolean) {

                return ((Boolean) response).booleanValue();

            }

            return true; // default to returning true

        } catch (BSFException e) {

            throw new SynapseException(e);

        }

    }

    public synchronized BSFEngine getBSFEngine(SynapseConfiguration synapseConfig) {

        Property dp = synapseConfig.getPropertyObject(scriptKey);

        // boolean requiresRefresh = (dp != null) && (!dp.isCached() || dp.isExpired());

        // if (bsfEngine == null || requiresRefresh) { TODO: sort out caching

        if (bsfEngine == null) {

            OMElement el = (OMElement) synapseConfig.getProperty(scriptKey);

            String scriptSrc = el.getText();

            String scriptName = dp.getSrc().toString();

            this.bsfEngine = createBSFEngine(scriptName, scriptSrc);

            this.convertor = createOMElementConvertor(scriptName);

            convertor.setEngine(bsfEngine);

        }

        return bsfEngine;

    }

    protected BSFEngine createBSFEngine(String scriptName, String scriptSrc) {

        try {

            String scriptLanguage = BSFManager.getLangFromFilename(scriptName);

            BSFEngine bsfEngine = bsfManager.loadScriptingEngine(scriptLanguage);

            bsfEngine.exec(scriptName, 0, 0, scriptSrc);

            return bsfEngine;

        } catch (BSFException e) {

            throw new SynapseException(e.getTargetException());

        }

    }

    protected OMElementConvertor createOMElementConvertor(String scriptName) {

        OMElementConvertor oc = null;

        int lastDot = scriptName.lastIndexOf('.');

        if (lastDot > -1) {

            String suffix = scriptName.substring(lastDot + 1).toUpperCase();

            String className = OMElementConvertor.class.getName();

            int i = className.lastIndexOf('.');

            String packageName = className.substring(0, i + 1);

            String convertorClassName = packageName + suffix + className.substring(i + 1);

            try {

                oc = (OMElementConvertor) Class.forName(convertorClassName, true, getClass().getClassLoader()).newInstance();

            } catch (Exception e) {

                // ignore

            }

        }

        if (oc == null) {

            oc = new DefaultOMElementConvertor();

        }

        return oc;

    }

}