package eu.dnetlib.oa.graph.usagestatsbuild.export;

import java.io.*;
import java.net.URLDecoder;
import java.sql.Connection;
import java.sql.SQLException;
import java.sql.Statement;
import java.text.SimpleDateFormat;
import java.util.*;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.LocatedFileStatus;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.fs.RemoteIterator;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.sql.Timestamp;

/**
 * @author D. Pierrakos, S. Zoupanos
 */
public class PiwikStatsDB {

	private String logPath;

	private Statement stmt = null;

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


	public PiwikStatsDB() throws Exception {

	}


	public void recreateDBAndTables() throws Exception {
		this.createDatabase();
		// The piwiklog table is not needed since it is built
		// on top of JSON files
		////////////this.createTmpTables();
	}

	private void createDatabase() throws Exception {
		try {
			stmt = ConnectDB.getHiveConnection().createStatement();

			logger.info("Dropping usagestats DB: " + ConnectDB.getUsageStatsDBSchema());
			String dropDatabase = "DROP DATABASE IF EXISTS " + ConnectDB.getUsageStatsDBSchema() + " CASCADE";
			stmt.executeUpdate(dropDatabase);
		} catch (Exception e) {
			logger.error("Failed to drop database: " + e);
			throw new Exception("Failed to drop database: " + e.toString(), e);
		}

		try {
			stmt = ConnectDB.getHiveConnection().createStatement();

			logger.info("Creating usagestats DB: " + ConnectDB.getUsageStatsDBSchema());
			String createDatabase = "CREATE DATABASE IF NOT EXISTS " + ConnectDB.getUsageStatsDBSchema();
			stmt.executeUpdate(createDatabase);

		} catch (Exception e) {
			logger.error("Failed to create database: " + e);
			throw new Exception("Failed to create database: " + e.toString(), e);
		}
	}


	public void processLogs() throws Exception {
		try {

			logger.info("ViewsStats processing starts at: "+new Timestamp(System.currentTimeMillis()));
			viewsStats();
			logger.info("ViewsStats processing ends at: "+new Timestamp(System.currentTimeMillis()));

			logger.info("DownloadsStats processing starts at: "+new Timestamp(System.currentTimeMillis()));
			downloadsStats();
			logger.info("DownloadsStats processing ends at: "+new Timestamp(System.currentTimeMillis()));

		} catch (Exception e) {
			logger.error("Failed to process logs: " + e);
			throw new Exception("Failed to process logs: " + e.toString(), e);
		}
	}

	
	
	public void viewsStats() throws Exception {
		Statement stmt = ConnectDB.getHiveConnection().createStatement();
		ConnectDB.getHiveConnection().setAutoCommit(false);

		logger.info("Dropping openaire_result_views_monthly_tmp view");
		String drop_result_views_monthly = "DROP VIEW IF EXISTS " +
			ConnectDB.getUsageStatsDBSchema() +
			".openaire_piwikresult_views_monthly_tmp";
		stmt.executeUpdate(drop_result_views_monthly);
		logger.info("Dropped openaire_result_views_monthly_tmp view");

		logger.info("Creating openaire_result_views_monthly_tmp view");
		String create_result_views_monthly = "CREATE OR REPLACE VIEW " + ConnectDB.getUsageStatsDBSchema()
			+ ".openaire_result_views_monthly_tmp " +
			"AS SELECT entity_id AS id, " +
			"COUNT(entity_id) as views, SUM(CASE WHEN referrer_name LIKE '%openaire%' THEN 1 ELSE 0 END) " +
			"AS openaire_referrer, " +
			"CONCAT(YEAR(timestamp), '/', LPAD(MONTH(timestamp), 2, '0')) AS month, source " +
			"FROM " + ConnectDB.getUsageRawDataDBSchema()
			+ ".piwiklog where action='action' and (source_item_type='oaItem' or " +
			"source_item_type='repItem') " +
			"GROUP BY entity_id, CONCAT(YEAR(timestamp), '/', LPAD(MONTH(timestamp), 2, '0')), " +
			"source ORDER BY source, entity_id";
		stmt.executeUpdate(create_result_views_monthly);
		logger.info("Created openaire_result_views_monthly_tmp table");

		logger.info("Dropping openaire_views_stats_tmp table");
		String drop_views_stats = "DROP TABLE IF EXISTS " +
			ConnectDB.getUsageStatsDBSchema() +
			".openaire_views_stats_tmp";
		stmt.executeUpdate(drop_views_stats);
		logger.info("Dropped openaire_views_stats_tmp table");

		logger.info("Creating openaire_views_stats_tmp table");
		String create_views_stats = "CREATE TABLE IF NOT EXISTS " + ConnectDB.getUsageStatsDBSchema()
			+ ".openaire_views_stats_tmp " +
			"AS SELECT 'OpenAIRE' as source, d.id as repository_id, ro.id as result_id, month as date, " +
			"max(views) AS count, max(openaire_referrer) AS openaire " +
			"FROM " + ConnectDB.getUsageStatsDBSchema() + ".openaire_result_views_monthly_tmp p, " +
			ConnectDB.getStatsDBSchema() + ".datasource d, " + ConnectDB.getStatsDBSchema() + ".result_oids ro " +
			"WHERE p.source=d.piwik_id AND p.id=ro.oid " +
			"GROUP BY d.id, ro.id, month " +
			"ORDER BY d.id, ro.id, month ";
		stmt.executeUpdate(create_views_stats);
		logger.info("Created openaire_views_stats_tmp table");

		logger.info("Creating openaire_pageviews_stats_tmp table");
		String create_pageviews_stats = "CREATE TABLE IF NOT EXISTS " + ConnectDB.getUsageStatsDBSchema()
			+ ".openaire_pageviews_stats_tmp AS SELECT " +
			"'OpenAIRE' as source, d.id as repository_id, ro.id as result_id, month as date, max(views) AS count " +
			"FROM " + ConnectDB.getUsageStatsDBSchema() + ".openaire_result_views_monthly_tmp p, " +
			ConnectDB.getStatsDBSchema() + ".datasource d, " + ConnectDB.getStatsDBSchema() + ".result_oids ro " +
			"WHERE p.source=" + ExecuteWorkflow.portalMatomoID + " AND p.source=d.piwik_id and p.id=ro.id \n" +
			"GROUP BY d.id, ro.id, month " +
			"ORDER BY d.id, ro.id, month ";
		stmt.executeUpdate(create_pageviews_stats);
		logger.info("Created pageviews_stats table");

		stmt.close();
		//ConnectDB.getHiveConnection().close();
	}

	private void downloadsStats() throws Exception {
		Statement stmt = ConnectDB.getHiveConnection().createStatement();
		ConnectDB.getHiveConnection().setAutoCommit(false);

		logger.info("Dropping openaire_result_downloads_monthly_tmp view");
		String drop_result_downloads_monthly = "DROP VIEW IF EXISTS " +
			ConnectDB.getUsageStatsDBSchema() +
			".openaire_result_downloads_monthly_tmp";
		stmt.executeUpdate(drop_result_downloads_monthly);
		logger.info("Dropped openaire_result_downloads_monthly_tmp view");

		logger.info("Creating openaire_result_downloads_monthly_tmp view");
		String sql = "CREATE OR REPLACE VIEW " + ConnectDB.getUsageStatsDBSchema() + ".openaire_result_downloads_monthly_tmp " +
			"AS SELECT entity_id AS id, COUNT(entity_id) as downloads, " +
			"SUM(CASE WHEN referrer_name LIKE '%openaire%' THEN 1 ELSE 0 END) AS openaire_referrer, " +
			"CONCAT(YEAR(timestamp), '/', LPAD(MONTH(timestamp), 2, '0')) AS month, source " +
			"FROM " + ConnectDB.getUsageRawDataDBSchema()+ ".piwiklog where action='download' " +
			"AND (source_item_type='oaItem' OR source_item_type='repItem') " +
			"GROUP BY entity_id, CONCAT(YEAR(timestamp), '/', LPAD(MONTH(timestamp), 2, '0')) , source " +
			"ORDER BY source, entity_id, month";
		stmt.executeUpdate(sql);
		logger.info("Created openaire_result_downloads_monthly_tmp view");

		logger.info("Dropping openaire_downloads_stats_tmp table");
		String drop_views_stats = "DROP TABLE IF EXISTS " +
			ConnectDB.getUsageStatsDBSchema() +
			".openaire_downloads_stats_tmp";
		stmt.executeUpdate(drop_views_stats);
		logger.info("Dropped openaire_downloads_stats_tmp table");

		logger.info("Creating openaire_downloads_stats_tmp table");
		sql = "CREATE TABLE IF NOT EXISTS " + ConnectDB.getUsageStatsDBSchema() + ".openaire_downloads_stats_tmp AS " +
			"SELECT 'OpenAIRE' as source, d.id as repository_id, ro.id as result_id, month as date, " +
			"max(downloads) AS count, max(openaire_referrer) AS openaire " +
			"FROM " + ConnectDB.getUsageStatsDBSchema() + ".openaire_result_downloads_monthly_tmp p, " +
			ConnectDB.getStatsDBSchema() + ".datasource d, " + ConnectDB.getStatsDBSchema() + ".result_oids ro " +
			"WHERE p.source=d.piwik_id and p.id=ro.oid " +
			"GROUP BY d.id, ro.id, month " +
			"ORDER BY d.id, ro.id, month ";
		stmt.executeUpdate(sql);
		logger.info("Created downloads_stats table");

                
		logger.info("Dropping openaire_result_downloads_monthly_tmp view");
		sql = "DROP VIEW IF EXISTS "+ConnectDB.getUsageStatsDBSchema() + ".openaire_result_downloads_monthly_tmp";
		logger.info("Dropped openaire_result_downloads_monthly_tmp view ");
		stmt.executeUpdate(sql);

		stmt.close();
		//ConnectDB.getHiveConnection().close();
	}

	public void finalizeStats() throws Exception {
		stmt = ConnectDB.getHiveConnection().createStatement();
		ConnectDB.getHiveConnection().setAutoCommit(false);

                //Dropping views_stats table
                logger.info("Dropping views_stats table");
		String sql = "DROP TABLE IF EXISTS "+ConnectDB.getUsageStatsDBSchema() + ".views_stats";
		logger.info("Dropped views_stats table ");
		stmt.executeUpdate(sql);

                //Dropping downloads_stats table
                logger.info("Dropping downloads_stats table");
		sql = "DROP TABLE IF EXISTS "+ConnectDB.getUsageStatsDBSchema() + ".downloads_stats";
		logger.info("Dropped downloads_stats table ");
		stmt.executeUpdate(sql);

                //Dropping page_views_stats table
                logger.info("Dropping pageviews_stats table");
		sql = "DROP TABLE IF EXISTS "+ConnectDB.getUsageStatsDBSchema() + ".pageviews_stats";
		logger.info("Dropped pageviews_stats table ");
		stmt.executeUpdate(sql);

                //Creating views_stats table
		logger.info("Creating views_stats table");
		String createViewsStats = "CREATE TABLE IF NOT EXISTS " +
			ConnectDB.getUsageStatsDBSchema() +
			".views_stats " +
			"LIKE " + ConnectDB.getUsageStatsDBSchema() + ".openaire_views_stats_tmp STORED AS PARQUET";
		stmt.executeUpdate(createViewsStats);
		logger.info("Created views_stats table");
                
                //Inserting OpenAIRE views stats
		logger.info("Inserting Openaire data to views_stats");
		sql = "INSERT INTO " + ConnectDB.getUsageStatsDBSchema() + ".views_stats " +
			"SELECT * FROM " + ConnectDB.getUsageStatsDBSchema() + ".openaire_views_stats_tmp";
		stmt.executeUpdate(sql);
                logger.info("Openaire views updated to views_stats");

                //Inserting Lareferencia views stats
		logger.info("Inserting LaReferencia data to views_stats");
		sql = "INSERT INTO " + ConnectDB.getUsageStatsDBSchema() + ".views_stats " +
			"SELECT * FROM " + ConnectDB.getUsageStatsDBSchema() + ".la_views_stats_tmp";
		stmt.executeUpdate(sql);
                logger.info("LaReferencia views updated to views_stats");
                

		logger.info("Creating downloads_stats table");
		String createDownloadsStats = "CREATE TABLE IF NOT EXISTS " +
			ConnectDB.getUsageStatsDBSchema() +
			".downloads_stats " +
			"LIKE " + ConnectDB.getUsageStatsDBSchema() + ".openaire_downloads_stats_tmp STORED AS PARQUET";
		stmt.executeUpdate(createDownloadsStats);
		logger.info("Created downloads_stats table");

                //Inserting OpenAIRE downloads stats
		logger.info("Inserting OpenAIRE data to downloads_stats");
		sql = "INSERT INTO " + ConnectDB.getUsageStatsDBSchema() + ".downloads_stats " +
			"SELECT * FROM " + ConnectDB.getUsageStatsDBSchema() + ".openaire_downloads_stats_tmp";
		stmt.executeUpdate(sql);

                //Inserting Lareferencia downloads stats
		logger.info("Inserting LaReferencia data to downloads_stats");
		sql = "INSERT INTO " + ConnectDB.getUsageStatsDBSchema() + ".downloads_stats " +
			"SELECT * FROM " + ConnectDB.getUsageStatsDBSchema() + ".la_downloads_stats_tmp";
		stmt.executeUpdate(sql);
                logger.info("Lareferencia downloads updated to downloads_stats");
                
                //Inserting IRUS downloads stats
		logger.info("Inserting IRUS data to downloads_stats");
		sql = "INSERT INTO " + ConnectDB.getUsageStatsDBSchema() + ".downloads_stats " +
			"SELECT * FROM " + ConnectDB.getUsageStatsDBSchema() + ".irus_downloads_stats_tmp";
		stmt.executeUpdate(sql);
                logger.info("IRUS downloads updated to downloads_stats");

                //Inserting SARC-OJS downloads stats
		logger.info("Inserting SARC data to downloads_stats");
		sql = "INSERT INTO " + ConnectDB.getUsageStatsDBSchema() + ".downloads_stats " +
			"SELECT * FROM " + ConnectDB.getUsageStatsDBSchema() + ".sarc_downloads_stats_tmp";
		stmt.executeUpdate(sql);
                logger.info("SARC-OJS downloads updated to downloads_stats");
                
                
                logger.info("Creating pageviews_stats table");
		String create_pageviews_stats = "CREATE TABLE IF NOT EXISTS " + ConnectDB.getUsageStatsDBSchema()
			+ ".pageviews_stats " +
			"LIKE " + ConnectDB.getUsageStatsDBSchema() + ".openaire_pageviews_stats_tmp STORED AS PARQUET";
		stmt.executeUpdate(create_pageviews_stats);
		logger.info("Created pageviews_stats table");
                
                //Inserting OpenAIRE views stats from Portal
		logger.info("Inserting data to page_views_stats");
		sql = "INSERT INTO " + ConnectDB.getUsageStatsDBSchema() + ".pageviews_stats " +
			"SELECT * FROM " + ConnectDB.getUsageStatsDBSchema() + ".openaire_pageviews_stats_tmp";
		stmt.executeUpdate(sql);
                
		logger.info("Dropping full_dates table");
		String dropFullDates = "DROP TABLE IF EXISTS " +
			ConnectDB.getUsageStatsDBSchema() +
			".full_dates";
		stmt.executeUpdate(dropFullDates);
		logger.info("Dropped full_dates table");

		Calendar startCalendar = Calendar.getInstance();
		startCalendar.setTime(new SimpleDateFormat("yyyy-MM-dd").parse("2016-01-01"));
		Calendar endCalendar = Calendar.getInstance();
		int diffYear = endCalendar.get(Calendar.YEAR) - startCalendar.get(Calendar.YEAR);
		int diffMonth = diffYear * 12 + endCalendar.get(Calendar.MONTH) - startCalendar.get(Calendar.MONTH);

		logger.info("Creating full_dates table");
		sql = "CREATE TABLE IF NOT EXISTS " + ConnectDB.getUsageStatsDBSchema() + ".full_dates AS " +
			"SELECT from_unixtime(unix_timestamp(cast(add_months(from_date,i) AS DATE)), 'yyyy/MM') AS txn_date " +
			"FROM (SELECT DATE '2016-01-01' AS from_date) p " +
			"LATERAL VIEW " +
			"posexplode(split(space(" + diffMonth + "),' ')) pe AS i,x";
		stmt.executeUpdate(sql);
		logger.info("Created full_dates table");
                

                logger.info("Inserting data to usage_stats");
		sql = "CREATE TABLE IF NOT EXISTS "+ConnectDB.getUsageStatsDBSchema() + ".usage_stats AS " +
                        "SELECT coalesce(ds.source, vs.source) as source, " +
			"coalesce(ds.repository_id, vs.repository_id) as repository_id, " +
			"coalesce(ds.result_id, vs.result_id) as result_id, coalesce(ds.date, vs.date) as date, " +
			"coalesce(ds.count, 0) as downloads, coalesce(vs.count, 0) as views, " +
			"coalesce(ds.openaire, 0) as openaire_downloads, " +
			"coalesce(vs.openaire, 0) as openaire_views " +
			"FROM " + ConnectDB.getUsageStatsDBSchema() + ".downloads_stats AS ds FULL OUTER JOIN " +
			ConnectDB.getUsageStatsDBSchema() + ".views_stats AS vs ON ds.source=vs.source " +
			"AND ds.repository_id=vs.repository_id AND ds.result_id=vs.result_id AND ds.date=vs.date";
                stmt.executeUpdate(sql);
                logger.info("Inserted data to usage_stats");


		stmt.close();
		ConnectDB.getHiveConnection().close();
	}

	
	private Connection getConnection() throws SQLException {
		return ConnectDB.getHiveConnection();
	}
}