/*
 *
 * Copyright (c) 2013 - 2017 Lijun Liao
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License version 3
 * as published by the Free Software Foundation with the addition of the
 * following permission added to Section 15 as permitted in Section 7(a):
 *
 * FOR ANY PART OF THE COVERED WORK IN WHICH THE COPYRIGHT IS OWNED BY
 * THE AUTHOR LIJUN LIAO. LIJUN LIAO DISCLAIMS THE WARRANTY OF NON INFRINGEMENT
 * OF THIRD PARTY RIGHTS.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 *
 * The interactive user interfaces in modified source and object code versions
 * of this program must display Appropriate Legal Notices, as required under
 * Section 5 of the GNU Affero General Public License.
 *
 * You can be released from the requirements of the license by purchasing
 * a commercial license. Buying such a license is mandatory as soon as you
 * develop commercial activities involving the XiPKI software without
 * disclosing the source code of your own applications.
 *
 * For more information, please contact Lijun Liao at this
 * address: lijun.liao@gmail.com
 */

package org.xipki.pki.ocsp.client.impl;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;

import org.bouncycastle.util.encoders.Base64;
import org.xipki.commons.common.util.IoUtil;
import org.xipki.commons.common.util.ParamUtil;
import org.xipki.pki.ocsp.client.api.RequestOptions;

/**
 * @author Lijun Liao
 * @since 2.0.0
 */

public class DefaultHttpOcspRequestor extends AbstractOcspRequestor {

    // result in maximal 254 Base-64 encoded octets
    private static final int MAX_LEN_GET = 190;

    private static final String CT_REQUEST = "application/ocsp-request";

    private static final String CT_RESPONSE = "application/ocsp-response";

    public DefaultHttpOcspRequestor() {
    }

    @Override
    protected byte[] send(final byte[] request, final URL responderUrl,
            final RequestOptions requestOptions) throws IOException {
        ParamUtil.requireNonNull("request", request);
        ParamUtil.requireNonNull("responderUrl", responderUrl);
        ParamUtil.requireNonNull("requestOptions", requestOptions);

        int size = request.length;
        HttpURLConnection httpUrlConnection;
        if (size <= MAX_LEN_GET && requestOptions.isUseHttpGetForRequest()) {
            String b64Request = Base64.toBase64String(request);
            String urlEncodedReq = URLEncoder.encode(b64Request, "UTF-8");
            StringBuilder urlBuilder = new StringBuilder();
            String baseUrl = responderUrl.toString();
            urlBuilder.append(baseUrl);
            if (!baseUrl.endsWith("/")) {
                urlBuilder.append('/');
            }
            urlBuilder.append(urlEncodedReq);

            URL newUrl = new URL(urlBuilder.toString());
            httpUrlConnection = IoUtil.openHttpConn(newUrl);;
            httpUrlConnection.setRequestMethod("GET");
        } else {
            httpUrlConnection = IoUtil.openHttpConn(responderUrl);;
            httpUrlConnection.setDoOutput(true);
            httpUrlConnection.setUseCaches(false);

            httpUrlConnection.setRequestMethod("POST");
            httpUrlConnection.setRequestProperty("Content-Type", CT_REQUEST);
            httpUrlConnection.setRequestProperty("Content-Length", Integer.toString(size));
            OutputStream outputstream = httpUrlConnection.getOutputStream();
            outputstream.write(request);
            outputstream.flush();
        }

        InputStream inputstream = httpUrlConnection.getInputStream();
        if (httpUrlConnection.getResponseCode() != HttpURLConnection.HTTP_OK) {
            inputstream.close();
            throw new IOException("bad response: "
                    + httpUrlConnection.getResponseCode() + "    "
                    + httpUrlConnection.getResponseMessage());
        }
        String responseContentType = httpUrlConnection.getContentType();
        boolean isValidContentType = false;
        if (responseContentType != null) {
            if (responseContentType.equalsIgnoreCase(CT_RESPONSE)) {
                isValidContentType = true;
            }
        }
        if (!isValidContentType) {
            inputstream.close();
            throw new IOException("bad response: mime type " + responseContentType
                    + " not supported!");
        }

        return IoUtil.read(inputstream);
    } // method send

}