#ifndef RDBMSDATASOURCE_H
#define RDBMSDATASOURCE_H

#include <boost/shared_ptr.hpp>
#include <map>
#include <set>
#include <thread>
#include <mutex>
#include "dataSource.h"
#include <connection.h>
#include <error.h>
#include "scriptLoader.h"
#include "connectionLoader.h"

/// Project2 component to provide access to transactional RDBMS data sources
class RdbmsDataSource : public DataSource {
	public:
		class ConnectionRef;

		class RdbmsConnection {
			public:
				RdbmsConnection(const DB::Connection * connection, time_t kat);
				~RdbmsConnection();

				void touch() const;
				bool isExpired() const;
				const DB::Connection * const connection;
				bool txOpen;
				boost::optional<std::thread::id> threadId;

			private:
				friend class ConnectionRef;
				friend class RdbmsDataSource;
				mutable time_t lastUsedTime;
				void incRef();
				void decRef();
				unsigned int users;
				const time_t keepAliveTime;
		};
		typedef boost::shared_ptr<RdbmsConnection> ConnectionPtr;

		class ConnectionRef {
			public:
				ConnectionRef();
				ConnectionRef(const ConnectionPtr &);
				~ConnectionRef();

				ConnectionRef & operator=(const ConnectionRef &);
				const DB::Connection * operator->() const;
				const DB::Connection & operator*() const;
				const DB::Connection * get() const;
			private:
				ConnectionPtr conn;
		};

		class ConnectionInfo {
			public:
				ConnectionInfo(ScriptNodePtr);

				DB::Connection * connect() const;

				bool operator<(const ConnectionInfo & o) const;

				const std::string dsn;
				const boost::shared_ptr<ConnectionLoader> typeId;
		};

		typedef std::map<std::string, ConnectionInfo> ReadonlyDSNs; // Map hostname to DSN string
		typedef std::multimap<ConnectionInfo, ConnectionPtr> DBHosts; // Map DSN strings to connections
		typedef std::map<ConnectionInfo, const DB::ConnectionError> FailedHosts; // Map DSN strings to failures

		RdbmsDataSource(ScriptNodePtr p);
		~RdbmsDataSource();

		ConnectionRef getReadonly() const;
		ConnectionRef getWritable() const;
		virtual void close() override;
		virtual void commit() override;
		virtual void rollback() override;

		const ConnectionInfo masterDsn;
		const bool preferLocal;

	protected:
		static ConnectionPtr connectTo(const ConnectionInfo & dsn);
		ReadonlyDSNs roDSNs;

	private:
		mutable std::mutex ilock;
		static std::mutex glock;
		mutable std::string localhost;
		static DBHosts dbhosts;
		static FailedHosts failedhosts;
		typedef std::pair<std::string, std::thread::id> ChangedDSN;
		typedef std::set<ChangedDSN> ChangedDSNs;
		static ChangedDSNs changedDSNs;

		friend class RdbmsDataSourceLoader;
};

#endif