/*
 * ================================================================================
 * Copyright (c) 2018 AT&T 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.dcae.analytics.web.config;

import com.fasterxml.jackson.databind.ObjectMapper;

import java.util.Map;

import org.onap.dcae.analytics.model.AnalyticsHttpConstants;
import org.onap.dcae.analytics.model.AnalyticsProfile;
import org.onap.dcae.analytics.model.DmaapMrConstants;
import org.onap.dcae.analytics.web.dmaap.MrMessageSplitter;
import org.onap.dcae.analytics.web.dmaap.MrPublisherPreferences;
import org.onap.dcae.analytics.web.dmaap.MrSubscriberPollingAdvice;
import org.onap.dcae.analytics.web.dmaap.MrSubscriberPreferences;
import org.onap.dcae.analytics.web.dmaap.MrTriggerMessageProvider;
import org.onap.dcae.analytics.web.http.HttpClientPreferencesCustomizer;
import org.onap.dcae.analytics.web.util.AnalyticsWebUtils;
import org.springframework.boot.web.client.RestTemplateBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Import;
import org.springframework.context.annotation.Profile;
import org.springframework.http.HttpMethod;
import org.springframework.integration.channel.DirectChannel;
import org.springframework.integration.channel.QueueChannel;
import org.springframework.integration.core.MessageSource;
import org.springframework.integration.dsl.IntegrationFlow;
import org.springframework.integration.dsl.IntegrationFlows;
import org.springframework.integration.dsl.channel.MessageChannels;
import org.springframework.integration.endpoint.MethodInvokingMessageSource;
import org.springframework.integration.handler.advice.RequestHandlerRetryAdvice;
import org.springframework.integration.http.dsl.Http;
import org.springframework.integration.scheduling.PollerMetadata;
import org.springframework.integration.store.BasicMessageGroupStore;
import org.springframework.integration.store.MessageGroupQueue;
import org.springframework.integration.support.MessageBuilder;
import org.springframework.web.client.RestTemplate;

/**
 * @author Rajiv Singla
 */
@Configuration
@Import(value = {DmaapPollerConfig.class, DmaapRetryConfig.class})
@Profile(AnalyticsProfile.DMAAP_PROFILE_NAME)
public class DmaapMrConfig {

    private static final String[] DMAAP_MAPPED_REQUEST_HEADERS =
            DmaapMrConstants.getDmaapmappedHeaders().toArray(new String[DmaapMrConstants.getDmaapmappedHeaders().size()]);

    @Bean(name = DmaapMrConstants.DMAAP_MR_SUBSCRIBER_OUTPUT_CHANNEL_NAME)
    public QueueChannel mrSubscriberOutputChannel(final BasicMessageGroupStore basicMessageGroupStore) {
        return MessageChannels.queue(new MessageGroupQueue(basicMessageGroupStore,
                DmaapMrConstants.DMAAP_MR_SUBSCRIBER_OUTPUT_MESSAGE_STORE_GROUP_ID)).get();
    }

    @Bean(name = DmaapMrConstants.DMAAP_MR_PUBLISHER_INPUT_CHANNEL)
    public DirectChannel mrPublisherInputChannel() {
        return MessageChannels.direct().get();
    }


    @Bean
    public RestTemplate mrSubscriberRestTemplate(final MrSubscriberPreferences mrSubscriberPreferences,
                                                 final RestTemplateBuilder restTemplateBuilder) {
        return restTemplateBuilder
                .additionalCustomizers(new HttpClientPreferencesCustomizer<>(mrSubscriberPreferences))
                .build();
    }

    @Bean
    public RestTemplate mrPublisherRestTemplate(final MrPublisherPreferences mrPublisherPreferences,
                                                final RestTemplateBuilder restTemplateBuilder) {
        return restTemplateBuilder
                .additionalCustomizers(new HttpClientPreferencesCustomizer<>(mrPublisherPreferences))
                .build();
    }

    @Bean
    public MrMessageSplitter mrMessageSplitter(final ObjectMapper objectMapper,
                                               final Integer processingBatchSize) {
        final Integer batchSize = processingBatchSize != null ? processingBatchSize :
                DmaapMrConstants.SUBSCRIBER_DEFAULT_PROCESSING_BATCH_SIZE;
        return new MrMessageSplitter(objectMapper, batchSize);
    }


    @Bean
    public MrTriggerMessageProvider mrTriggerMessageProvider(
            final MrSubscriberPreferences mrSubscriberPreferences) {
        return new MrTriggerMessageProvider(mrSubscriberPreferences);
    }

    @Bean
    public MessageSource mrMessageSource(final MrTriggerMessageProvider mrTriggerMessageProvider) {
        final MethodInvokingMessageSource source = new MethodInvokingMessageSource();
        source.setObject(mrTriggerMessageProvider);
        source.setMethodName(MrTriggerMessageProvider.TRIGGER_METHOD_NAME);
        return source;
    }

    @Bean
    public IntegrationFlow mrSubscriberFlow(final PollerMetadata pollerMetadata,
                                            final RestTemplate mrSubscriberRestTemplate,
                                            final MessageSource mrMessageSource,
                                            final QueueChannel mrSubscriberOutputChannel,
                                            final MrMessageSplitter mrMessageSplitter,
                                            final MrSubscriberPollingAdvice mrSubscriberPollingAdvice) {
        return IntegrationFlows.from(mrMessageSource, c -> c.poller(pollerMetadata))
                .handle(Http.outboundGateway(m -> String.class.cast(m.getPayload()), mrSubscriberRestTemplate)
                        .mappedRequestHeaders(DMAAP_MAPPED_REQUEST_HEADERS)
                        .httpMethod(HttpMethod.GET)
                        .expectedResponseType(String.class), c -> c.advice(mrSubscriberPollingAdvice))
                .split(mrMessageSplitter)
                .channel(mrSubscriberOutputChannel)
                .get();
    }


    @Bean
    public IntegrationFlow mrPublisherFlow(final MrPublisherPreferences mrPublisherPreferences,
                                           final RestTemplate mrPublisherRestTemplate,
                                           final DirectChannel mrPublisherInputChannel,
                                           final RequestHandlerRetryAdvice requestHandlerRetryAdvice) {

        return IntegrationFlows.from(mrPublisherInputChannel)
                .handle(Http.outboundGateway(mrPublisherPreferences.getRequestURL(), mrPublisherRestTemplate)
                        .mappedRequestHeaders(DMAAP_MAPPED_REQUEST_HEADERS)
                        .httpMethod(HttpMethod.POST)
                        .extractPayload(true)
                        .expectedResponseType(String.class), c -> c.advice(requestHandlerRetryAdvice))
                // add end timestamp
                .handle((String p, Map<String, Object> headers) ->
                        MessageBuilder.withPayload(p).copyHeaders(headers)
                                .setHeader(AnalyticsHttpConstants.REQUEST_END_TS_HEADER_KEY,
                                        AnalyticsWebUtils.CREATION_TIMESTAMP_SUPPLIER.get()).build()
                )
                .channel(DmaapMrConstants.DMAAP_MR_PUBLISHER_OUTPUT_CHANNEL)
                .get();
    }

}