package org.gcube.accounting.aggregator.persistence;

import java.io.Serializable;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Date;
import java.util.List;
import java.util.TimeZone;

import org.gcube.accounting.aggregator.aggregation.AggregationInfo;
import org.gcube.accounting.aggregator.aggregation.AggregationType;
import org.gcube.accounting.aggregator.status.AggregationStateEvent;
import org.gcube.accounting.aggregator.status.AggregationStatus;
import org.gcube.accounting.analytics.persistence.AccountingPersistenceBackendQueryConfiguration;
import org.gcube.accounting.analytics.persistence.postgresql.AccountingPersistenceQueryPostgreSQL;
import org.gcube.accounting.persistence.AccountingPersistenceConfiguration;
import org.postgresql.core.Utils;

public class PostgreSQLConnector extends AccountingPersistenceQueryPostgreSQL {

	private static final String UTC_TIME_ZONE = "UTC";
	public static final TimeZone DEFAULT_TIME_ZONE = TimeZone.getTimeZone(UTC_TIME_ZONE);
	
	public PostgreSQLConnector() throws Exception {
		this.configuration = new AccountingPersistenceBackendQueryConfiguration(AccountingPersistenceQueryPostgreSQL.class);
	}
	
	protected Connection getConnection() throws Exception {
		Class.forName("org.postgresql.Driver");
		String url = configuration.getProperty(AccountingPersistenceQueryPostgreSQL.URL_PROPERTY_KEY);
		String username = configuration.getProperty(AccountingPersistenceConfiguration.USERNAME_PROPERTY_KEY);
		String password = configuration.getProperty(AccountingPersistenceConfiguration.PASSWORD_PROPERTY_KEY);
		
		Connection connection = DriverManager.getConnection(url, username, password);
		logger.trace("Database {} opened successfully", url);
		connection.setAutoCommit(false);
		return connection;
	}
	
	protected String getQuotedString(String string) throws SQLException {
		StringBuilder builder = new StringBuilder();
		builder.append("'");
		Utils.escapeLiteral(builder, string, false);
		builder.append("'");
		return builder.toString();
	}
	
	protected String getValue(Serializable serializable) throws SQLException {
		if(serializable == null) {
			return "null";
		}
		
		if(serializable instanceof Number) {
			return serializable.toString();
		}
		
		if(serializable instanceof Calendar) {
			Calendar calendar = (Calendar) serializable;
			SimpleDateFormat simpleDateFormat = new SimpleDateFormat(DATETIME_PATTERN);
			simpleDateFormat.setTimeZone(DEFAULT_TIME_ZONE);
			String date = simpleDateFormat.format(calendar.getTime());
			return getQuotedString(date);
		}
		
		if(serializable instanceof Date) {
			Date date = (Date) serializable;
			SimpleDateFormat simpleDateFormat = new SimpleDateFormat(DATETIME_PATTERN);
			simpleDateFormat.setTimeZone(DEFAULT_TIME_ZONE);
			String dateString = simpleDateFormat.format(date);
			return getQuotedString(dateString);
		}
		
		
		if(serializable instanceof Enum) {
			Enum<?> e = (Enum<?>) serializable;
			return getQuotedString(e.name());
		}
		
		// String, URI etc
		return getQuotedString(serializable.toString());
	}
	
	public String getInsertAggregationStatusQuery(AggregationStatus aggregationStatus, boolean upsert) throws SQLException {
		StringBuffer stringBuffer = new StringBuffer();
		
		stringBuffer.append("INSERT INTO ");
		stringBuffer.append("aggregation_status");
		stringBuffer.append(" (id, ");
		stringBuffer.append("record_type, aggregation_type, aggregation_start_date, aggregation_end_date, ");
		stringBuffer.append("original_records_number, aggregated_records_number, recovered_records_number, malformed_records_number,  percentage, ");
		stringBuffer.append("context, current_aggregation_state, last_update_time, previous)");
		stringBuffer.append(" VALUES (");
		stringBuffer.append(getValue(aggregationStatus.getUUID().toString()));
		
		AggregationInfo aggregationInfo = aggregationStatus.getAggregationInfo();
		stringBuffer.append(", ");
		stringBuffer.append(getValue(aggregationInfo.getRecordType()));
		stringBuffer.append(", ");
		stringBuffer.append(getValue(aggregationInfo.getAggregationType()));
		stringBuffer.append(", ");
		stringBuffer.append(getValue(aggregationInfo.getAggregationStartDate()));
		stringBuffer.append(", ");
		stringBuffer.append(getValue(aggregationInfo.getAggregationEndDate()));
		stringBuffer.append(", ");
		
		stringBuffer.append(getValue(aggregationStatus.getOriginalRecordsNumber()));
		stringBuffer.append(", ");
		stringBuffer.append(getValue(aggregationStatus.getAggregatedRecordsNumber()));
		stringBuffer.append(", ");
		stringBuffer.append(getValue(aggregationStatus.getRecoveredRecordNumber()));
		stringBuffer.append(", ");
		stringBuffer.append(getValue(aggregationStatus.getMalformedRecordNumber()));
		stringBuffer.append(", ");
		stringBuffer.append(getValue(aggregationStatus.getPercentage()));
		
		stringBuffer.append(", ");
		stringBuffer.append(getValue(aggregationStatus.getContext()));
		stringBuffer.append(", ");
		stringBuffer.append(getValue(aggregationStatus.getAggregationState()));
		stringBuffer.append(", ");
		stringBuffer.append(getValue(aggregationStatus.getLastUpdateTime()));
		stringBuffer.append(", ");
		
		AggregationStatus previous = aggregationStatus.getPrevious();
		if(previous!=null) {
			stringBuffer.append(getValue(previous.getUUID().toString()));
		}else {
			stringBuffer.append(getValue(null));
		}
		
		if(upsert) {
			stringBuffer.append(") ON CONFLICT (id) DO UPDATE SET ");
			stringBuffer.append("original_records_number=EXCLUDED.original_records_number, aggregated_records_number=EXCLUDED.aggregated_records_number, recovered_records_number=EXCLUDED.recovered_records_number, malformed_records_number=EXCLUDED.malformed_records_number,  percentage=EXCLUDED.percentage, ");
			stringBuffer.append("current_aggregation_state=EXCLUDED.current_aggregation_state, last_update_time=EXCLUDED.last_update_time, previous=EXCLUDED.previous;");
		}else {
			stringBuffer.append(");");
		}
		
		return stringBuffer.toString();
	}
	
	public String getInsertAggregationStateQuery(AggregationStatus aggregationStatus) throws SQLException {
		StringBuffer stringBuffer = new StringBuffer();
		for(AggregationStateEvent aggregationStateEvent : aggregationStatus.getAggregationStateEvents()) {
			stringBuffer.append("INSERT INTO ");
			stringBuffer.append("aggregation_status_event");
			stringBuffer.append(" ( aggregation_state, start_time, end_time, aggregation_status)");
			stringBuffer.append(" VALUES (");
			stringBuffer.append(getValue(aggregationStateEvent.getAggregationState()));
			stringBuffer.append(", ");
			stringBuffer.append(getValue(aggregationStateEvent.getStartTime()));
			stringBuffer.append(", ");
			stringBuffer.append(getValue(aggregationStateEvent.getEndTime()));
			stringBuffer.append(", ");
			stringBuffer.append(getValue(aggregationStatus.getUUID().toString()));
			stringBuffer.append(") ON CONFLICT DO NOTHING;");
		}
		return stringBuffer.toString();
	}
	
	
	public void upsertAggregationStatus(AggregationStatus aggregationStatus) throws Exception {
		Connection connection = getConnection();
		Statement statement = connection.createStatement();
		String sqlCommand = getInsertAggregationStatusQuery(aggregationStatus, true);
		statement.executeUpdate(sqlCommand);
		sqlCommand = getInsertAggregationStateQuery(aggregationStatus);
		statement.executeUpdate(sqlCommand);
		statement.close();
		connection.commit();
		connection.close();
	}
	
	public AggregationStatus getLast(String recordType, AggregationType aggregationType, Date aggregationStartDate, Date aggregationEndDate) throws Exception{
		
		/*
		 * SELECT * 
		 * FROM aggregation_status
		 * WHERE 
		 * 		`aggregationInfo`.`recordType` = "ServiceUsageRecord" AND 
		 * 		`aggregationInfo`.`aggregationType` = "DAILY" AND
		 * 		`aggregationInfo`.`aggregationStartDate` >= "2017-05-01 00:00:00.000 +0000"
		 * 		`aggregationInfo`.`aggregationStartDate` <= "2017-05-31 00:00:00.000 +0000"
		 * ORDER BY `aggregationInfo`.`aggregationStartDate` DESC LIMIT 1
		 */
		
		return null;
		
	}
	
	public List<AggregationStatus> getUnterminated(Date aggregationStartDate, Date aggregationEndDate) throws Exception{
		return getUnterminated(null, null, aggregationStartDate, aggregationEndDate);
	}
	
	public List<AggregationStatus> getUnterminated(String recordType, AggregationType aggregationType, Date aggregationStartDate, Date aggregationEndDate) throws Exception{
		
		/*
		 * SELECT * 
		 * FROM AccountingManager
		 * WHERE 
		 * 		`aggregationState` != "COMPLETED" AND
		 * 		`lastUpdateTime` < "2017-07-31 09:31:10.984 +0000" AND
		 * 		`aggregationInfo`.`recordType` = "ServiceUsageRecord" AND 
		 * 		`aggregationInfo`.`aggregationType` = "DAILY" AND
		 * 		`aggregationInfo`.`aggregationStartDate` >= "2017-05-01 00:00:00.000 +0000"
		 * 		`aggregationInfo`.`aggregationStartDate` <= "2017-05-31 00:00:00.000 +0000"
		 * 		
		 * ORDER BY `aggregationInfo`.`aggregationStartDate` ASC
		 */
		
		List<AggregationStatus> aggregationStatuses = new ArrayList<>();
		
		return aggregationStatuses;
		
	}
	
	public static List<AggregationStatus> getAll() throws Exception{
		
		/*
		 * SELECT * 
		 * FROM AccountingManager
		 * ORDER BY `aggregationInfo`.`aggregationStartDate` ASC
		 */
		
		List<AggregationStatus> aggregationStatuses = new ArrayList<>();
		
		
		return aggregationStatuses;
		
	}
	
	
	public static AggregationStatus getAggregationStatus(String recordType, AggregationType aggregationType, Date aggregationStartDate) throws Exception{
		
		/*
		 * SELECT * 
		 * FROM AccountingManager 
		 * WHERE 
		 * 		`aggregationInfo`.`recordType` = "ServiceUsageRecord" AND 
		 * 		`aggregationInfo`.`aggregationType` = "DAILY" AND 
		 * 		`aggregationInfo`.`aggregationStartDate` = "2017-06-24 00:00:00.000 +0000"
		 */
		
				return null;
	}
	
}