/*
* ============LICENSE_START=======================================================
* ONAP : DataLake
* ================================================================================
* Copyright 2019 China Mobile
*=================================================================================
* 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.datalake.feeder.domain;

import java.util.Set;
import java.util.function.Predicate;

import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.JoinTable;
import javax.persistence.ManyToMany;
import javax.persistence.ManyToOne;
import javax.persistence.Table;

import org.apache.commons.lang3.StringUtils;
import org.json.JSONObject;
import org.onap.datalake.feeder.enumeration.DataFormat;

import com.fasterxml.jackson.annotation.JsonBackReference;

import lombok.Getter;
import lombok.Setter;
 
/**
 * Domain class representing topic 
 * 
 * @author Guobiao Mo
 *
 */
@Setter
@Getter
@Entity
@Table(name = "topic")
public class Topic {
	@Id
	private String name;//topic name 

	@ManyToOne(fetch = FetchType.EAGER, cascade = CascadeType.ALL) 
	@JoinColumn(name = "default_topic", nullable = true)
	private Topic defaultTopic;

	//for protected Kafka topics
	private String login;
	private String pass;

	//@ManyToMany(mappedBy = "topics", cascade=CascadeType.ALL)
	@JsonBackReference
	//@JsonManagedReference
    @ManyToMany(cascade=CascadeType.ALL, fetch=FetchType.EAGER) 
    @JoinTable(	name 				= "map_db_topic",
    			joinColumns 		= {  @JoinColumn(name="topic_name")  },
    			inverseJoinColumns 	= {  @JoinColumn(name="db_name")  }
    )
	protected Set<Db> dbs;
	
	/**
	 *  indicate if we should monitor this topic
	 */
	private Boolean enabled;
	
	/**
	 * save raw message text
	 */
	@Column(name = "save_raw")
	private Boolean saveRaw;

	/**
	 * need to explicitly tell feeder the data format of the message.
	 * support JSON, XML, YAML, TEXT
	 */
	private String dataFormat;

	/**
	 * TTL in day
	 */
	private Integer ttl; 
	
	//if this flag is true, need to correlate alarm cleared message to previous alarm 
	@Column(name = "correlate_cleared_message")
	private Boolean correlateClearedMessage;
	
	//the value in the JSON with this path will be used as DB id
	@Column(name = "message_id_path")
	private String messageIdPath;

	public Topic() {
	}

	public Topic(String name) {
		this.name = name;
	}

	public boolean isDefault() {
		return "_DL_DEFAULT_".equals(name);
	}
	
	public boolean isEnabled() {
		return is(enabled, Topic::isEnabled);	
	}

	public boolean isCorrelateClearedMessage() {
		return is(correlateClearedMessage, Topic::isCorrelateClearedMessage);
	}
	
	public int getTtl() {
		if (ttl != null) {
			return ttl;
		} else if (defaultTopic != null) {
			return defaultTopic.getTtl();
		} else {
			return 3650;//default to 10 years for safe
		}		
	}
	
	public DataFormat getDataFormat() {
		if (dataFormat != null) {
			return DataFormat.fromString(dataFormat);
		} else if (defaultTopic != null) {
			return defaultTopic.getDataFormat();
		} else {
			return null;
		}
	}

	//if 'this' Topic does not have the setting, use default Topic's
	private boolean is(Boolean b, Predicate<Topic> pre) {
		return is(b, pre, false);
	}
	
	private boolean is(Boolean b, Predicate<Topic> pre, boolean defaultValue) {
		if (b != null) {
			return b;
		} else if (defaultTopic != null) {
			return pre.test(defaultTopic);
		} else {
			return defaultValue;
		}
	}

	public boolean isSaveRaw() {
		return is(saveRaw, Topic::isSaveRaw);
	}

	public boolean supportElasticsearch() {
		return containDb("Elasticsearch");//TODO string hard codes
	}

	public boolean supportCouchbase() {
		return containDb("Couchbase");
	}

	public boolean supportDruid() {
		return containDb("Druid");
	}

	public boolean supportMongoDB() {
		return containDb("MongoDB");
	}

	private boolean containDb(String dbName) {		
		Db db = new Db(dbName);
		
		if(dbs!=null && dbs.contains(db)) {
			return true;
		}
		
		if (defaultTopic != null) {
			return defaultTopic.containDb(dbName);
		} else {
			return false;
		}
	}
	
	//extract DB id from JSON attributes, support multiple attributes
	public String getMessageId(JSONObject json) {
		String id = null;
		
		if(StringUtils.isNotBlank(messageIdPath)) {
			String[] paths=messageIdPath.split(",");
			
			StringBuilder sb= new StringBuilder();
			for(int i=0; i<paths.length; i++) {
				if(i>0) {
					sb.append('^');					
				}
				sb.append(json.query(paths[i]).toString());				
			}
			id = sb.toString();
		}
		
		return id;
	}
	
	@Override
	public String toString() {
		return name;
	}

	@Override
	public boolean equals(Object obj) {		
		return name.equals(((Topic)obj).getName());		
	}

	@Override
	public int hashCode() {
		return name.hashCode();		
	}
	
}