/*-
 * ============LICENSE_START=======================================================
 * PNF-REGISTRATION-HANDLER
 * ================================================================================
 * Copyright (C) 2018 NOKIA Intellectual Property. 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
 *
 * 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.
 * ============LICENSE_END=========================================================
 */

package org.onap.dcaegen2.services.service.producer;

import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.methods.HttpRequestBase;
import org.apache.http.client.utils.URIBuilder;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.onap.dcaegen2.services.config.DmaapPublisherConfiguration;
import org.onap.dcaegen2.services.service.CommonMethods;
import org.onap.dcaegen2.services.service.DmaapHttpClientImpl;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.Optional;

public class ExtendedDmaapProducerHttpClientImpl {

    private static Logger logger = LoggerFactory.getLogger(ExtendedDmaapProducerHttpClientImpl.class);

    private final CloseableHttpClient closeableHttpClient;
    private final String dmaapHostName;
    private final String dmaapProtocol;
    private final Integer dmaapPortNumber;
    private final String dmaapTopicName;
    private final String dmaapContentType;


    ExtendedDmaapProducerHttpClientImpl(DmaapPublisherConfiguration configuration) {
        this.closeableHttpClient = new DmaapHttpClientImpl(configuration).getHttpClient();
        this.dmaapHostName = configuration.dmaapHostName();
        this.dmaapProtocol = configuration.dmaapProtocol();
        this.dmaapPortNumber = configuration.dmaapPortNumber();
        this.dmaapTopicName = configuration.dmaapTopicName();
        this.dmaapContentType = configuration.dmaapContentType();
    }

     Optional<String> getHttpProducerResponse(DmaapPublisherRequestDetails requestDetails) {

        Optional<String> extendedDetails = Optional.empty();
        Optional<HttpRequestBase> request = createRequest(requestDetails);

        try {
            extendedDetails = closeableHttpClient.execute(request.get(), CommonMethods.dmaapResponseHandler());
        } catch (IOException | NullPointerException e) {
            logger.error("Exception while executing HTTP request: {}", e);
        }

        return extendedDetails;
    }

    private Boolean isExtendedURINotNull(URI extendedURI) {
        return extendedURI != null;
    }

    private Optional<StringEntity> createStringEntity(Optional<String> jsonBody) {
        return Optional.of(parseJson(jsonBody).get());
    }

    private Optional<StringEntity> parseJson(Optional<String> jsonBody) {
        Optional<StringEntity> stringEntity = Optional.empty();

        try {
            stringEntity = Optional.of(new StringEntity(jsonBody.get()));
        } catch (UnsupportedEncodingException e) {
            logger.error("Exception while parsing JSON: {}", e);
        }

        return stringEntity;
    }

    private Optional<HttpRequestBase> createRequest (DmaapPublisherRequestDetails requestDetails) {

        Optional<HttpRequestBase> request = Optional.empty();
        final URI extendedURI = createDmaapPublisherExtendedURI(requestDetails);

        if ("application/json".equals(dmaapContentType)) {
            request = Optional.ofNullable(createRequest(extendedURI, requestDetails));
            request.get().addHeader("Content-type", dmaapContentType);
        }

        return request;
    }

    private URI createDmaapPublisherExtendedURI(DmaapPublisherRequestDetails requestDetails) {
        URI extendedURI = null;

        final URIBuilder uriBuilder = new URIBuilder()
                .setScheme(dmaapProtocol)
                .setHost(dmaapHostName)
                .setPort(dmaapPortNumber)
                .setPath(requestDetails.dmaapAPIPath() + "/" + dmaapTopicName);

        try {
            extendedURI = uriBuilder.build();
            logger.info("Building extended URI: {}",extendedURI);
        } catch (URISyntaxException e) {
            logger.error("Exception while building extended URI: {}", e);
        }

        return extendedURI;
    }

    private HttpRequestBase createRequest(URI extendedURI, DmaapPublisherRequestDetails requestDetails) {
        if (isExtendedURINotNull(extendedURI) && requestDetails.jsonBody().isPresent()) {
            return createHttpPost(extendedURI, requestDetails.jsonBody());
        } else {
            return null;
        }
    }

    private HttpPost createHttpPost(URI extendedURI, Optional<String> jsonBody) {
        HttpPost post = new HttpPost(extendedURI);
        Optional<StringEntity> stringEntity = createStringEntity(jsonBody);
        post.setEntity(stringEntity.get());
        return post;
    }
}