/*
 * 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.
 */

package org.apache.myfaces.test.mock;

import java.lang.reflect.Constructor;
import javax.faces.FacesException;
import javax.faces.context.ExternalContext;
import javax.faces.context.FacesContext;
import javax.faces.context.FacesContextFactory;
import javax.faces.lifecycle.Lifecycle;
import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * <p>Mock implementation of <code>FacesContextFactory</code>.</p>
 *
 * $Id$
 */

public class MockFacesContextFactory extends FacesContextFactory {


    // ------------------------------------------------------------ Constructors


    /**
     * <p>Look up the constructor we will use for creating <code>MockFacesContext</code>
     * instances.</p>
     */
    public MockFacesContextFactory() {

        Class clazz = null;

        // Try to load the 1.2 version of our mock FacesContext class
        try {
            clazz = this.getClass().getClassLoader().loadClass("org.apache.myfaces.test.mock.MockFacesContext12");
            constructor = clazz.getConstructor(facesContextSignature);
            jsf12 = true;
        } catch (NoClassDefFoundError e) {
            // We are not running on JSF 1.2, so go to our fallback
            clazz = null;
            constructor = null;
        } catch (ClassNotFoundException e) {
            // Same as above
            clazz = null;
            constructor = null;
        } catch (RuntimeException e) {
            throw e;
        } catch (Exception e) {
            throw new FacesException(e);
        }

        // Fall back to the 1.1 version if we could not load the 1.2 version
        try {
            if (clazz == null) {
                clazz = this.getClass().getClassLoader().loadClass("org.apache.myfaces.test.mock.MockFacesContext");
                constructor = clazz.getConstructor(facesContextSignature);
                jsf12 = false;
            }
        } catch (RuntimeException e) {
            throw e;
        } catch (Exception e) {
            throw new FacesException(e);
        }

    }


    // ----------------------------------------------------- Mock Object Methods


    // ------------------------------------------------------ Instance Variables


    /**
     * <p>The constructor for creating a <code>FacesContext</code> instance,
     * taking an <code>ExternalContext</code> and <code>Lifecycle</code>.</p>
     */
    private Constructor constructor = null;


    /**
     * <p>The parameter signature of the ExternalContext constructor we wish to call.</p>
     */
    private static Class[] externalContextSignature = new Class[] {
        ServletContext.class, HttpServletRequest.class, HttpServletResponse.class
    };


    /**
     * <p>The parameter signature of the FacesContext constructor we wish to call.</p>
     */
    private static Class[] facesContextSignature = new Class[] {
        ExternalContext.class, Lifecycle.class
    };


    /**
     * <p>Flag indicating that we are running in a JSF 1.2 environment.</p>
     */
    private boolean jsf12 = false;


    // --------------------------------------------- FacesContextFactory Methods


    /** {@inheritDoc} */
    public FacesContext getFacesContext(Object context, Object request,
                                        Object response,
                                        Lifecycle lifecycle) throws FacesException {

        // Select the appropriate MockExternalContext implementation class
        Class clazz = MockExternalContext.class;
        if (jsf12) {
            try {
                clazz = this.getClass().getClassLoader().loadClass
                  ("org.apache.myfaces.test.mock.MockExternalContext12");
            } catch (RuntimeException e) {
                throw e;
            } catch (Exception e) {
                throw new FacesException(e);
            }
        }

        // Select the constructor we wish to call
        Constructor mecConstructor = null;
        try {
            mecConstructor = clazz.getConstructor(externalContextSignature);
        } catch (RuntimeException e) {
            throw e;
        } catch (Exception e) {
            throw new FacesException(e);
        }

        // Construct an appropriate MockExternalContext instance
        MockExternalContext externalContext = null;
        try {
            externalContext = (MockExternalContext) mecConstructor.newInstance
              (new Object[] { context, request, response });
        } catch (RuntimeException e) {
            throw e;
        } catch (Exception e) {
            throw new FacesException(e);
        }

        // Construct an appropriate MockFacesContext instance and return it
        try {
            return (MockFacesContext)
              constructor.newInstance(new Object[] { externalContext, lifecycle });
        } catch (RuntimeException e) {
            throw e;
        } catch (Exception e) {
            throw new FacesException(e);
        }

    }


}