/*
 * Copyright (c) 2002-2008 Gargoyle Software Inc.
 *
 * Licensed 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 com.gargoylesoftware.htmlunit.util;

import java.io.IOException;
import java.net.URL;

import com.gargoylesoftware.htmlunit.WebClient;
import com.gargoylesoftware.htmlunit.WebConnection;
import com.gargoylesoftware.htmlunit.WebRequestSettings;
import com.gargoylesoftware.htmlunit.WebResponse;
import com.gargoylesoftware.htmlunit.WebResponseData;
import com.gargoylesoftware.htmlunit.WebResponseImpl;

/**
 * Extension of {@link WebConnectionWrapper} providing facility methods to deliver something else than
 * what the wrapped connection would deliver.
 *
 * @version $Revision$
 * @author Marc Guillemot
 */
public abstract class FalsifyingWebConnection extends WebConnectionWrapper {

    /**
     * Constructs a WebConnection object wrapping provided WebConnection.
     * @param webConnection the webConnection that does the real work
     * @throws IllegalArgumentException if the connection is <code>null</code>
     */
    public FalsifyingWebConnection(final WebConnection webConnection) throws IllegalArgumentException {
        super(webConnection);
    }

    /**
     * Constructs an instance and places itself as connection of the WebClient.
     * @param webClient the WebClient which WebConnection should be wrapped
     * @throws IllegalArgumentException if the WebClient is <code>null</code>
     */
    public FalsifyingWebConnection(final WebClient webClient) throws IllegalArgumentException {
        super(webClient);
    }

    /**
     * Delivers the content for an alternate URL as if it comes from the requested URL.
     * @param webRequestSettings the original web request settings
     * @param url the URL from which the content should be retrieved
     * @return the response
     * @throws IOException if a problem occurred
     */
    protected WebResponse deliverFromAlternateUrl(final WebRequestSettings webRequestSettings, final URL url)
        throws IOException {
        final URL originalUrl = webRequestSettings.getUrl();
        webRequestSettings.setUrl(url);
        final WebResponse resp = super.getResponse(webRequestSettings);
        return new WebResponseWrapper(resp) {
            @Override
            public URL getUrl() {
                return originalUrl;
            }
        };
    }

    /**
     * Builds a WebResponse with new content, preserving all other information.
     * @param webResponse the web response to adapt
     * @param newContent the new content to place in the response
     * @return a web response with the new content
     * @throws IOException if an encoding problem occurred
     */
    protected WebResponse replaceContent(final WebResponse webResponse, final String newContent) throws IOException {
        final byte[] body = newContent.getBytes(webResponse.getContentCharSet());
        final WebResponseData wrd = new WebResponseData(body, webResponse.getStatusCode(),
                webResponse.getStatusMessage(), webResponse.getResponseHeaders());
        return new WebResponseImpl(wrd, webResponse.getUrl(), webResponse.getRequestMethod(),
                webResponse.getLoadTimeInMilliSeconds());
    }
}