/*
 * ===============================LICENSE_START======================================
 *  dcae-analytics
 * ================================================================================
 *    Copyright © 2017 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.apod.analytics.cdap.plugins.streaming.dmaap;

import co.cask.cdap.api.annotation.Description;
import co.cask.cdap.api.annotation.Name;
import co.cask.cdap.api.annotation.Plugin;
import co.cask.cdap.api.data.format.StructuredRecord;
import co.cask.cdap.etl.api.PipelineConfigurer;
import co.cask.cdap.etl.api.streaming.StreamingContext;
import co.cask.cdap.etl.api.streaming.StreamingSource;
import org.apache.spark.storage.StorageLevel;
import org.apache.spark.streaming.api.java.JavaDStream;
import org.onap.dcae.apod.analytics.cdap.common.utils.ValidationUtils;
import org.onap.dcae.apod.analytics.cdap.plugins.domain.config.dmaap.DMaaPMRSourcePluginConfig;
import org.onap.dcae.apod.analytics.cdap.plugins.domain.schema.dmaap.DMaaPSourceOutputSchema;
import org.onap.dcae.apod.analytics.cdap.plugins.validator.DMaaPMRSourcePluginConfigValidator;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * DMaaP MR Source Plugin which polls DMaaP MR topic at frequent intervals
 * <p>
 * @author Rajiv Singla . Creation Date: 1/18/2017.
 */
@Plugin(type = StreamingSource.PLUGIN_TYPE)
@Name("DMaaPMRSource")
@Description("Fetches DMaaP MR Messages at regular intervals")
public class DMaaPMRSource extends StreamingSource<StructuredRecord> {

    private static final Logger LOG = LoggerFactory.getLogger(DMaaPMRSource.class);
    private static final long serialVersionUID = 1L;

    private final DMaaPMRSourcePluginConfig pluginConfig;

    public DMaaPMRSource(final DMaaPMRSourcePluginConfig pluginConfig) {
        LOG.debug("Creating DMaaP MR Source plugin with plugin Config: {}", pluginConfig);
        this.pluginConfig = pluginConfig;
    }

    @Override
    public void configurePipeline(PipelineConfigurer pipelineConfigurer) {
        ValidationUtils.validateSettings(pluginConfig, new DMaaPMRSourcePluginConfigValidator());
        pipelineConfigurer.getStageConfigurer().setOutputSchema(DMaaPSourceOutputSchema.getSchema());
    }

    @Override
    public JavaDStream<StructuredRecord> getStream(final StreamingContext streamingContext) throws Exception {
        return streamingContext.getSparkStreamingContext().receiverStream(
                new DMaaPMRReceiver(StorageLevel.MEMORY_ONLY(), pluginConfig, streamingContext.getMetrics()));
    }
}