/**
 * Copyright © Microsoft Open Technologies, Inc.
 *
 * All Rights Reserved
 *
 * 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
 *
 * THIS CODE IS PROVIDED *AS IS* BASIS, WITHOUT WARRANTIES OR CONDITIONS
 * OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION
 * ANY IMPLIED WARRANTIES OR CONDITIONS OF TITLE, FITNESS FOR A
 * PARTICULAR PURPOSE, MERCHANTABILITY OR NON-INFRINGEMENT.
 *
 * See the Apache License, Version 2.0 for the specific language
 * governing permissions and limitations under the License.
 */
package com.msopentech.odatajclient.testauthproxy.esigate;

import java.io.IOException;
import java.io.Writer;
import org.apache.http.HttpEntityEnclosingRequest;
import org.esigate.Renderer;

public class LinkRewriteRenderer implements Renderer {

    private static final char SLASH = '/';

    private String baseUrl;

    private String replacementUrl;

    public LinkRewriteRenderer(final String baseUrl, final String visibleBaseUrl) {
        if (visibleBaseUrl == null || visibleBaseUrl.isEmpty()) {
            throw new IllegalArgumentException("Need to specify baseUrl and visibleBaseUrl");
        }

        this.baseUrl = removeLeadingSlash(baseUrl);
        this.replacementUrl = removeLeadingSlash(visibleBaseUrl);
    }

    private String removeLeadingSlash(final String src) {
        final int lastCharPosition = src.length() - 1;
        return src.charAt(lastCharPosition) == SLASH
                ? src.substring(0, lastCharPosition)
                : src;
    }

    @Override
    public void render(final HttpEntityEnclosingRequest httpRequest, final String src, final Writer out)
            throws IOException {

        out.write(src.replaceAll(baseUrl, replacementUrl));
    }
}