/*
 * 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 javax.servlet;

import java.io.BufferedReader;
import java.io.IOException;
import java.util.Enumeration;
import java.util.Locale;
import java.util.Map;

/**
 * Provides a convenient implementation of the ServletRequest interface that can
 * be subclassed by developers wishing to adapt the request to a Servlet. This
 * class implements the Wrapper or Decorator pattern. Methods default to calling
 * through to the wrapped request object.
 * 
 * @since v 2.3
 * @see javax.servlet.ServletRequest
 */
public class ServletRequestWrapper implements ServletRequest {
    private ServletRequest request;

    /**
     * Creates a ServletRequest adaptor wrapping the given request object.
     * 
     * @throws IllegalArgumentException if the request is null
     */
    public ServletRequestWrapper(ServletRequest request) {
        if (request == null) {
            throw new IllegalArgumentException("Request cannot be null");
        }
        this.request = request;
    }

    /**
     * Get the wrapped request.
     * @return the wrapped request object
     */
    public ServletRequest getRequest() {
        return this.request;
    }

    /**
     * Sets the request object being wrapped.
     * @param request The new wrapped request.
     *
     * @throws IllegalArgumentException if the request is null.
     */
    public void setRequest(ServletRequest request) {
        if (request == null) {
            throw new IllegalArgumentException("Request cannot be null");
        }
        this.request = request;
    }

    /**
     * The default behavior of this method is to call getAttribute(String name)
     * on the wrapped request object.
     */
    @Override
    public Object getAttribute(String name) {
        return this.request.getAttribute(name);
    }

    /**
     * The default behavior of this method is to return getAttributeNames() on
     * the wrapped request object.
     */
    @Override
    public Enumeration<String> getAttributeNames() {
        return this.request.getAttributeNames();
    }

    /**
     * The default behavior of this method is to return getCharacterEncoding()
     * on the wrapped request object.
     */
    @Override
    public String getCharacterEncoding() {
        return this.request.getCharacterEncoding();
    }

    /**
     * The default behavior of this method is to set the character encoding on
     * the wrapped request object.
     */
    @Override
    public void setCharacterEncoding(String enc)
            throws java.io.UnsupportedEncodingException {
        this.request.setCharacterEncoding(enc);
    }

    /**
     * The default behavior of this method is to return getContentLength() on
     * the wrapped request object.
     */
    @Override
    public int getContentLength() {
        return this.request.getContentLength();
    }

    /**
     * The default behavior of this method is to return getContentType() on the
     * wrapped request object.
     */
    @Override
    public String getContentType() {
        return this.request.getContentType();
    }

    /**
     * The default behavior of this method is to return getInputStream() on the
     * wrapped request object.
     */
    @Override
    public ServletInputStream getInputStream() throws IOException {
        return this.request.getInputStream();
    }

    /**
     * The default behavior of this method is to return getParameter(String
     * name) on the wrapped request object.
     */
    @Override
    public String getParameter(String name) {
        return this.request.getParameter(name);
    }

    /**
     * The default behavior of this method is to return getParameterMap() on the
     * wrapped request object.
     */
    @Override
    public Map<String, String[]> getParameterMap() {
        return this.request.getParameterMap();
    }

    /**
     * The default behavior of this method is to return getParameterNames() on
     * the wrapped request object.
     */
    @Override
    public Enumeration<String> getParameterNames() {
        return this.request.getParameterNames();
    }

    /**
     * The default behavior of this method is to return
     * getParameterValues(String name) on the wrapped request object.
     */
    @Override
    public String[] getParameterValues(String name) {
        return this.request.getParameterValues(name);
    }

    /**
     * The default behavior of this method is to return getProtocol() on the
     * wrapped request object.
     */
    @Override
    public String getProtocol() {
        return this.request.getProtocol();
    }

    /**
     * The default behavior of this method is to return getScheme() on the
     * wrapped request object.
     */
    @Override
    public String getScheme() {
        return this.request.getScheme();
    }

    /**
     * The default behavior of this method is to return getServerName() on the
     * wrapped request object.
     */
    @Override
    public String getServerName() {
        return this.request.getServerName();
    }

    /**
     * The default behavior of this method is to return getServerPort() on the
     * wrapped request object.
     */
    @Override
    public int getServerPort() {
        return this.request.getServerPort();
    }

    /**
     * The default behavior of this method is to return getReader() on the
     * wrapped request object.
     */
    @Override
    public BufferedReader getReader() throws IOException {
        return this.request.getReader();
    }

    /**
     * The default behavior of this method is to return getRemoteAddr() on the
     * wrapped request object.
     */
    @Override
    public String getRemoteAddr() {
        return this.request.getRemoteAddr();
    }

    /**
     * The default behavior of this method is to return getRemoteHost() on the
     * wrapped request object.
     */
    @Override
    public String getRemoteHost() {
        return this.request.getRemoteHost();
    }

    /**
     * The default behavior of this method is to return setAttribute(String
     * name, Object o) on the wrapped request object.
     */
    @Override
    public void setAttribute(String name, Object o) {
        this.request.setAttribute(name, o);
    }

    /**
     * The default behavior of this method is to call removeAttribute(String
     * name) on the wrapped request object.
     */
    @Override
    public void removeAttribute(String name) {
        this.request.removeAttribute(name);
    }

    /**
     * The default behavior of this method is to return getLocale() on the
     * wrapped request object.
     */
    @Override
    public Locale getLocale() {
        return this.request.getLocale();
    }

    /**
     * The default behavior of this method is to return getLocales() on the
     * wrapped request object.
     */
    @Override
    public Enumeration<Locale> getLocales() {
        return this.request.getLocales();
    }

    /**
     * The default behavior of this method is to return isSecure() on the
     * wrapped request object.
     */
    @Override
    public boolean isSecure() {
        return this.request.isSecure();
    }

    /**
     * The default behavior of this method is to return
     * getRequestDispatcher(String path) on the wrapped request object.
     */
    @Override
    public RequestDispatcher getRequestDispatcher(String path) {
        return this.request.getRequestDispatcher(path);
    }

    /**
     * The default behavior of this method is to return getRealPath(String path)
     * on the wrapped request object.
     * 
     * @deprecated As of Version 3.0 of the Java Servlet API
     */
    @Override
    @SuppressWarnings("dep-ann")
    // Spec API does not use @Deprecated
    public String getRealPath(String path) {
        return this.request.getRealPath(path);
    }

    /**
     * The default behavior of this method is to return getRemotePort() on the
     * wrapped request object.
     * 
     * @since 2.4
     */
    @Override
    public int getRemotePort() {
        return this.request.getRemotePort();
    }

    /**
     * The default behavior of this method is to return getLocalName() on the
     * wrapped request object.
     * 
     * @since 2.4
     */
    @Override
    public String getLocalName() {
        return this.request.getLocalName();
    }

    /**
     * The default behavior of this method is to return getLocalAddr() on the
     * wrapped request object.
     * 
     * @since 2.4
     */
    @Override
    public String getLocalAddr() {
        return this.request.getLocalAddr();
    }

    /**
     * The default behavior of this method is to return getLocalPort() on the
     * wrapped request object.
     * 
     * @since 2.4
     */
    @Override
    public int getLocalPort() {
        return this.request.getLocalPort();
    }

    /**
     * The default behavior of this method is to return getServletContext() on
     * the wrapped request object.
     * 
     * @since Servlet 3.0
     */
    @Override
    public ServletContext getServletContext() {
        return request.getServletContext();
    }

    /**
     * The default behavior of this method is to return startAsync() on the
     * wrapped request object.
     * 
     * @throws IllegalStateException If asynchronous processing is not supported
     *         for this request or if the request is already in asynchronous
     *         mode
     * @since Servlet 3.0
     */
    @Override
    public AsyncContext startAsync() {
        return request.startAsync();
    }

    /**
     * The default behavior of this method is to return startAsync(Runnable) on
     * the wrapped request object.
     * 
     * @param servletRequest    The ServletRequest with which to initialise the
     *                          asynchronous context
     * @param servletResponse   The ServletResponse with which to initialise the
     *                          asynchronous context
     * @throws IllegalStateException If asynchronous processing is not supported
     *         for this request or if the request is already in asynchronous
     *         mode
     * @since Servlet 3.0
     */
    @Override
    public AsyncContext startAsync(ServletRequest servletRequest,
            ServletResponse servletResponse) throws IllegalStateException {
        return request.startAsync(servletRequest, servletResponse);
    }

    /**
     * The default behavior of this method is to return isAsyncStarted() on the
     * wrapped request object.
     * 
     * @since Servlet 3.0
     */
    @Override
    public boolean isAsyncStarted() {
        return request.isAsyncStarted();
    }

    /**
     * The default behavior of this method is to return isAsyncSupported() on
     * the wrapped request object.
     * 
     * @since Servlet 3.0
     */
    @Override
    public boolean isAsyncSupported() {
        return request.isAsyncSupported();
    }

    /**
     * The default behavior of this method is to return getAsyncContext() on the
     * wrapped request object.
     * 
     * @since Servlet 3.0
     */
    @Override
    public AsyncContext getAsyncContext() {
        return request.getAsyncContext();
    }

    /**
     * TODO SERVLET3 - Add comments
     * @param wrapped The request to compare to the wrapped request
     * @return <code>true</code> if the request wrapped by this wrapper (or
     *         series of wrappers) is the same as the supplied request,
     *         otherwise <code>false</code>
     * @since Servlet 3.0
     */
    public boolean isWrapperFor(ServletRequest wrapped) {
        if (request == wrapped) {
            return true;
        }
        if (request instanceof ServletRequestWrapper) {
            return ((ServletRequestWrapper) request).isWrapperFor(wrapped);
        }
        return false;
    }

    /**
     * TODO SERVLET3 - Add comments
     * @param wrappedType The class to compare to the class of the wrapped
     *                    request
     * @return <code>true</code> if the request wrapped by this wrapper (or
     *         series of wrappers) is the same type as the supplied type,
     *         otherwise <code>false</code>
     * @since Servlet 3.0
     */
    @SuppressWarnings("unchecked")
    // Spec API does not use generics
    public boolean isWrapperFor(@SuppressWarnings("rawtypes") Class wrappedType) {
        if (wrappedType.isAssignableFrom(request.getClass())) {
            return true;
        }
        if (request instanceof ServletRequestWrapper) {
            return ((ServletRequestWrapper) request).isWrapperFor(wrappedType);
        }
        return false;
    }

    /**
     * The default behavior of this method is to call getDispatcherType() on the
     * wrapped request object.
     * 
     * @since Servlet 3.0
     */
    @Override
    public DispatcherType getDispatcherType() {
        return this.request.getDispatcherType();
    }
}