package org.gcube.documentstore.persistence;

import java.sql.Connection;
import java.sql.Statement;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;

import org.gcube.accounting.utility.postgresql.RecordToDBConnection;
import org.gcube.accounting.utility.postgresql.RecordToDBMapping;
import org.gcube.documentstore.records.AggregatedRecord;
import org.gcube.documentstore.records.Record;
import org.gcube.documentstore.records.RecordUtility;

public class StatementMap {

	private static final InheritableThreadLocal<Map<String, Statement>> statementsThreadLocal = new InheritableThreadLocal<Map<String, Statement>>() {
		
		@Override
		protected Map<String, Statement> initialValue() {
			return new HashMap<String, Statement>();
		}
		
	};
	
	private PersistenceBackendConfiguration configuration;
	private RecordToDBMapping recordToDBMapping;
	
	public StatementMap(PersistenceBackendConfiguration configuration) {
		this.configuration = configuration;
		this.recordToDBMapping = new RecordToDBMapping();
		Map<String, Class<? extends AggregatedRecord<?,?>>> aggregatedRecords = RecordUtility.getAggregatedRecordClassesFound();
		for(String typeName : aggregatedRecords.keySet()) {
			try {
				Class<? extends AggregatedRecord<?,?>> clz = aggregatedRecords.get(typeName); 
				recordToDBMapping.addRecordToDB(clz, configuration);
			} catch (Exception e) {
				new RuntimeException(e);
			}
		}
	}
	
	protected Connection getConnection(Class<? extends AggregatedRecord<?, ?>> clz) throws Exception {
		RecordToDBConnection recordDBInfo = recordToDBMapping.getRecordDBInfo(clz);
		if(recordDBInfo == null) {
			recordToDBMapping.addRecordToDB(clz, configuration);
			recordDBInfo = recordToDBMapping.getRecordDBInfo(clz);
		}
		return recordDBInfo.getConnection();
	}
	
	public synchronized Statement getStatement(Record record) throws Exception {
		Map<String, Statement> map = statementsThreadLocal.get();
		String type = record.getRecordType();
		Statement statement = map.get(type);
		if(statement == null) {
			Class<? extends AggregatedRecord<?, ?>> clz = RecordUtility.getAggregatedRecordClass(type);
			Connection connection = getConnection(clz);
			statement = connection.createStatement();
			map.put(type, statement);
		}
		return statement;
	}

	public synchronized void close() throws Exception {
		Map<String, Statement> map = statementsThreadLocal.get();
		Collection<Statement> statements = map.values();
		statementsThreadLocal.remove();
		for(Statement statement : statements) {
			statement.close();
			Connection connection = statement.getConnection();
			connection.commit();
			connection.close();
		}
		
	}
	
}