/*
 * 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.axis2.jaxws.runtime.description.marshal.impl;

import org.apache.axis2.java.security.AccessController;
import org.apache.axis2.jaxws.ExceptionFactory;
import org.apache.axis2.jaxws.description.EndpointDescription;
import org.apache.axis2.jaxws.description.FaultDescription;
import org.apache.axis2.jaxws.description.OperationDescription;
import org.apache.axis2.jaxws.description.ServiceDescription;
import org.apache.axis2.jaxws.runtime.description.marshal.AnnotationDesc;
import org.apache.axis2.jaxws.runtime.description.marshal.FaultBeanDesc;
import org.apache.axis2.jaxws.utility.ClassUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import java.security.PrivilegedActionException;
import java.security.PrivilegedExceptionAction;
import java.util.HashMap;
import java.util.Map;

/**
 * Examines a ServiceDesc and locates and/or builds the JAX-WS artifacts. The JAX-WS artifacts are:
 * - request wrapper classes - response wrapper classes - fault beans for non-JAX-WS compliant
 * exceptions
 */
class ArtifactProcessor {

    private static final Log log = LogFactory.getLog(ArtifactProcessor.class);

    private ServiceDescription serviceDesc;
    private Map<OperationDescription, String> requestWrapperMap =
            new HashMap<OperationDescription, String>();
    private Map<OperationDescription, String> responseWrapperMap =
            new HashMap<OperationDescription, String>();
    private Map<FaultDescription, FaultBeanDesc> faultBeanDescMap =
            new HashMap<FaultDescription, FaultBeanDesc>();

    /**
     * Artifact Processor
     *
     * @param serviceDesc
     */
    ArtifactProcessor(ServiceDescription serviceDesc) {
        this.serviceDesc = serviceDesc;
    }

    Map<OperationDescription, String> getRequestWrapperMap() {
        return requestWrapperMap;
    }

    Map<OperationDescription, String> getResponseWrapperMap() {
        return responseWrapperMap;
    }

    Map<FaultDescription, FaultBeanDesc> getFaultBeanDescMap() {
        return faultBeanDescMap;
    }

    void build() {
        for (EndpointDescription ed : serviceDesc.getEndpointDescriptions()) {
            if (ed.getEndpointInterfaceDescription() != null) {
                for (OperationDescription opDesc : ed.getEndpointInterfaceDescription()
                        .getOperations()) {

                    String declaringClassName = opDesc.getJavaDeclaringClassName();
                    String packageName = getPackageName(declaringClassName);
                    String simpleName = getSimpleClassName(declaringClassName);
                    String methodName = opDesc.getJavaMethodName();

                    // There is no default for @RequestWrapper/@ResponseWrapper classname  None is listed in Sec. 7.3 on p. 80 of
                    // the JAX-WS spec, BUT Conformance(Using javax.xml.ws.RequestWrapper) in Sec 2.3.1.2 on p. 13
                    // says the entire annotation "...MAY be omitted if all its properties would have default vaules."
                    // We will assume that this statement gives us the liberty to find a wrapper class/build a wrapper class or 
                    // implement an engine w/o the wrapper class.

                    // @RequestWrapper className processing
                    String requestWrapperName = opDesc.getRequestWrapperClassName();
                    if (requestWrapperName == null) {
                        if (packageName.length() > 0) {
                            requestWrapperName =
                                    packageName + "." + javaMethodToClassName(methodName);
                        } else {
                            requestWrapperName = javaMethodToClassName(methodName);
                        }
                    }
                    String foundRequestWrapperName = findArtifact(requestWrapperName);
                    if (foundRequestWrapperName == null) {
                        foundRequestWrapperName = findArtifact(requestWrapperName, ed.getAxisService().getClassLoader());
                    }
                    if (foundRequestWrapperName == null) {
                        foundRequestWrapperName = missingArtifact(requestWrapperName);
                    }
                    if (foundRequestWrapperName != null) {
                        requestWrapperMap.put(opDesc, foundRequestWrapperName);
                    }

                    // @ResponseWrapper className processing
                    String responseWrapperName = opDesc.getResponseWrapperClassName();
                    if (responseWrapperName == null) {
                        if (packageName.length() > 0) {
                            responseWrapperName = packageName + "." +
                                    javaMethodToClassName(methodName) + "Response";
                        } else {
                            responseWrapperName = javaMethodToClassName(methodName) + "Response";
                        }
                    }
                    String foundResponseWrapperName = findArtifact(responseWrapperName);
                    if (foundResponseWrapperName == null) {
                        foundResponseWrapperName = findArtifact(responseWrapperName, ed.getAxisService().getClassLoader());
                    }
                    if (foundResponseWrapperName == null) {
                        foundResponseWrapperName = missingArtifact(responseWrapperName);
                    }
                    if (foundResponseWrapperName != null) {
                        responseWrapperMap.put(opDesc, foundResponseWrapperName);
                    }

                    for (FaultDescription faultDesc : opDesc.getFaultDescriptions()) {
                        FaultBeanDesc faultBeanDesc = create(ed, faultDesc, opDesc);
                        faultBeanDescMap.put(faultDesc, faultBeanDesc);
                    }
                }
            }
        }
    }

    private FaultBeanDesc create(EndpointDescription ed, FaultDescription faultDesc, OperationDescription opDesc) {
        /* FaultBeanClass algorithm
         *   1) The class defined on @WebFault of the exception
         *   2) If not present or invalid, the class defined by getFaultInfo.
         *   3) If not present, the class is found by looking for the
         *      a class named <exceptionName>Bean in the interface's package.
         *   4) If not present, the class is found by looking for the
         *      a class named <exceptionName>Bean in the interface + jaxws package
         */
        String faultBeanClassName = faultDesc.getFaultBean();
        if (faultBeanClassName == null || faultBeanClassName.length() == 0) {
            faultBeanClassName = faultDesc.getFaultInfo();
        }
        if (faultBeanClassName == null || faultBeanClassName.length() == 0) {
            String declaringClassName = opDesc.getJavaDeclaringClassName();
            String packageName = getPackageName(declaringClassName);
            String simpleName = getSimpleClassName(faultDesc.getExceptionClassName());
            if (packageName.length() > 0) {
                faultBeanClassName = packageName + "." + simpleName + "Bean";
            } else {
                faultBeanClassName = simpleName + "Bean";
            }
        }
        String foundClassName = findArtifact(faultBeanClassName);
        if (foundClassName == null) {
            faultBeanClassName = findArtifact(faultBeanClassName, ed.getAxisService().getClassLoader());
        }
        if (foundClassName == null) {
            faultBeanClassName = missingArtifact(faultBeanClassName);
        }
        if (foundClassName != null) {
            faultBeanClassName = foundClassName;
        }

        /* Local NameAlgorithm:
        *   1) The name defined on the @WebFault of the exception.
        *   2) If not present, the name defined via the @XmlRootElement of the fault bean class.
        *   3) If not present, the <exceptionName>Bean
        */
        String faultBeanLocalName = faultDesc.getName();
        if (faultBeanLocalName == null || faultBeanLocalName.length() == 0) {
            if (faultBeanClassName != null && faultBeanClassName.length() > 0) {
                try {
                    Class faultBean;
                    try {
                        faultBean = loadClass(faultBeanClassName, getContextClassLoader());
                    } catch (ClassNotFoundException e){
                        faultBean = loadClass(faultBeanClassName, ed.getAxisService().getClassLoader());
                    }
                    AnnotationDesc aDesc = AnnotationDescImpl.create(faultBean);
                    if (aDesc.hasXmlRootElement()) {
                        faultBeanLocalName = aDesc.getXmlRootElementName();
                    }
                } catch (Throwable t) {
                    throw ExceptionFactory.makeWebServiceException(t);
                }
            }
        }
        if (faultBeanLocalName == null || faultBeanLocalName.length() == 0) {
            faultBeanLocalName = getSimpleClassName(faultDesc.getExceptionClassName()) + "Bean";
        }

        /* Algorithm for fault bean namespace
        *   1) The namespace defined on the @WebFault of the exception.
        *   2) If not present, the namespace defined via the @XmlRootElement of the class name.
        *   3) If not present, the namespace of the method's declared class + "/jaxws"
        */
        String faultBeanNamespace = faultDesc.getTargetNamespace();
        if (faultBeanNamespace == null || faultBeanNamespace.length() == 0) {
            if (faultBeanClassName != null && faultBeanClassName.length() > 0) {
                try {
                    Class faultBean;
                    try {
                        faultBean = loadClass(faultBeanClassName, getContextClassLoader());
                    } catch (ClassNotFoundException e){
                        faultBean = loadClass(faultBeanClassName, ed.getAxisService().getClassLoader());
                    }
                    AnnotationDesc aDesc = AnnotationDescImpl.create(faultBean);
                    if (aDesc.hasXmlRootElement()) {
                        faultBeanNamespace = aDesc.getXmlRootElementNamespace();
                    }
                } catch (Throwable t) {
                   throw ExceptionFactory.makeWebServiceException(t);
                }
            }
        }
        if (faultBeanNamespace == null || faultBeanNamespace.length() == 0) {
            faultBeanNamespace = opDesc.getEndpointInterfaceDescription().getTargetNamespace();
        }

        return new FaultBeanDescImpl(
                faultBeanClassName,
                faultBeanLocalName,
                faultBeanNamespace);
    }

    /**
     * @param className
     * @return package name
     */
    private static String getPackageName(String className) {
        int index = className.lastIndexOf(".");
        if (index <= 0) {
            return "";
        } else {
            return className.substring(0, index);
        }
    }

    /**
     * @param className
     * @return simple class name
     */
    private static String getSimpleClassName(String className) {
        int index = className.lastIndexOf(".");
        if (index <= 0) {
            return className;
        } else {
            return className.substring(index + 1);
        }
    }

    /**
     * @param methodName
     * @return method name converted into a class name
     */
    private static String javaMethodToClassName(String methodName) {
        String className = null;
        if (methodName != null) {
            StringBuffer buildClassName = new StringBuffer(methodName);
            buildClassName.replace(0, 1, methodName.substring(0, 1).toUpperCase());
            className = buildClassName.toString();
        }
        return className;
    }

    /**
     * This method is invoked if the artifact is missing
     *
     * @param artifactName
     * @return newly constructed name or null
     */
    private String missingArtifact(String artifactName) {

        if (log.isDebugEnabled()) {
            log.debug("The following class was not found: " + artifactName + " Processing continues without this class.");
        }
        return null;
    }

    /**
     * Determine the actual packager name for the generated artifacts by trying to load the class
     * from one of two packages.  This is necessary because the RI implementations of WSGen and
     * WSImport generate the artifacts in different packages: - WSImport generates the artifacts in
     * the same package as the SEI - WSGen generates the artifacts in a "jaxws" sub package under
     * the SEI package. Note that from reading the JAX-WS spec, it seems that WSGen is doing that
     * correctly; See the conformance requirement in JAX-WS 2.0 Spec Section 3.6.2.1 Document
     * Wrapped on page 36: Conformance (Default wrapper bean package): In the absence of
     * customizations, the wrapper beans package MUST be a generated jaxws subpackage of the SEI
     * package. ^^^^^^^^^^^^^^^^
     *
     * @param artifactClassName
     * @return
     */
    static final String JAXWS_SUBPACKAGE = "jaxws";

    private static String findArtifact(String artifactClassName) {
        return findArtifact(artifactClassName, getContextClassLoader());
    }

    private static String findArtifact(String artifactClassName, ClassLoader classLoader) {
        String returnArtifactClassName = null;
        if (artifactClassName == null) {
            return returnArtifactClassName;
        }

        // Try to load the class that was passed in
        try {
            forName(artifactClassName, true, classLoader);
            returnArtifactClassName = artifactClassName;
        }
        catch (ClassNotFoundException e) {
            // Couldn't load the class; we'll try another one below.
        }

        // If the original class couldn't be loaded, try adding ".jaxws." to the package
        if (returnArtifactClassName == null) {
            String originalPackage = getPackageName(artifactClassName);
            if (originalPackage.length() > 0) {
                String alternatePackage = originalPackage + "." + JAXWS_SUBPACKAGE;
                String className = getSimpleClassName(artifactClassName);
                String alternateWrapperClass = alternatePackage + "." + className;
                try {
                    loadClass(alternateWrapperClass, getContextClassLoader());
                    returnArtifactClassName = alternateWrapperClass;
                }
                catch (ClassNotFoundException e) {
                    // Couldn't load the class
                }
            }
        }

        return returnArtifactClassName;
    }

    private static Class loadClass(String className, ClassLoader classLoader) throws ClassNotFoundException {
        // Don't make this public, its a security exposure
        return forName(className, true, classLoader);
    }

    /**
     * Return the class for this name
     *
     * @return Class
     */
    private static Class forName(final String className, final boolean initialize,
                                 final ClassLoader classloader) throws ClassNotFoundException {
        // NOTE: This method must remain protected because it uses AccessController
        Class cl = null;
        try {
            cl = (Class)AccessController.doPrivileged(
                    new PrivilegedExceptionAction() {
                        public Object run() throws ClassNotFoundException {
                            // Class.forName does not support primitives
                        	Class cls = ClassUtils.getPrimitiveClass(className);
                        	try{
                        		if (cls == null) {
                        			cls = Class.forName(className, initialize, classloader);
                        		}
                        		return cls;
                        		//Lets catch NoClassDefFoundError as its part of Throwable
                        		//Any Exception that extends Exception will be handled by doPriv method.    
                        	} catch (NoClassDefFoundError e) {
                        	    /**
                        	     * In different jaxws scenarios, some classes may be missing.  So it is normal behavior
                        	     * to get to this point.  The exception is swallowed and a null is returned.  
                        	     * The exception is not logged...as this would give servicability folks the idea that a problem occurred.
                        	     */
                        	} 
                        	return cls;
                        }
                    }
            );
        } catch (PrivilegedActionException e) {
            /**
             * In different jaxws scenarios, some classes may be missing.  So it is normal behavior
             * to get to this point. 
             * The exception is not logged...as this would give servicability folks the idea that a problem occurred.
             */
            throw (ClassNotFoundException)e.getException();
        }

        return cl;
    }

    /** @return ClassLoader */
    private static ClassLoader getContextClassLoader() {
        // NOTE: This method must remain private because it uses AccessController
        ClassLoader cl = null;
        try {
            cl = (ClassLoader)AccessController.doPrivileged(
                    new PrivilegedExceptionAction() {
                        public Object run() throws ClassNotFoundException {
                            return Thread.currentThread().getContextClassLoader();
                        }
                    }
            );
        } catch (PrivilegedActionException e) {
            if (log.isDebugEnabled()) {
                log.debug("Exception thrown from AccessController: " + e);
            }
            throw (RuntimeException)e.getException();
        }

        return cl;
    }
}