#ifndef SOCKET_H
#define SOCKET_H

#include <sys/socket.h>
#include <vector>
#include <errno.h>
#include <netinet/in.h>

#include "NetworkAddress.h"
#include "../exception.h"

class SocketUDP {

private:

    static constexpr int MAX_DATAGRAM_SIZE = 64*1024;

    bool bound = false;

public:

	/** ctor */
	SocketUDP() : handle(0) {

		// create socket
		handle = socket(AF_INET, SOCK_DGRAM, 0);
		if (handle == -1) {throw Exception("error while creating socket");}

	}

	/** dtor */
	~SocketUDP() {
		close();
	}

	/**
	 * @brief bind the socket to receive all datagrams sent to the given (local) port
	 * a localPort of 0 will let the OS determine a free one.
	 * @param localPort the local endpoint for datagrams sent from a remote
	 */
	void bind(const uint16_t localPort) {

		if (bound) {throw Exception("socket already bound!");}

		// local endpoint AF_INET struct
		struct sockaddr_in srvAddr;
		memset((char*)&srvAddr, 0, sizeof(srvAddr));
		srvAddr.sin_family = AF_INET;
		srvAddr.sin_addr.s_addr = htonl(INADDR_ANY);	// every interface
		srvAddr.sin_port = htons(localPort);

		// bind the socket to the given port
		int ret = ::bind(handle, (struct sockaddr*) &srvAddr, sizeof(srvAddr));
        if (ret < 0) {throw Exception("error while binding socket");}

		// mark as bound
		bound = true;

	}

	/** close the socket */
	void close() {

		// cleanup
		if (handle) {
			::close(handle);
			handle = 0;
		}

	}

//	/** is the socket currently closed? */
//	bool isClosed() const {
//		return handle == 0;
//	}

//	/** allow to broadcast packets using this socket? */
//	void allowBroadcast(const bool allow) {

//		#if defined(__GNUC__)
//			const int broadcastEnable = (allow) ? (1) : (0);
//			const int ret = setsockopt(handle, SOL_SOCKET, SO_BROADCAST, &broadcastEnable, sizeof(broadcastEnable));
//			if (ret < 0) { throw SocketException("error while enabling broadcast", errno); }
//		#elif defined(_WIN32)
//			;
//		#endif

//	}

	/**
	 * @brief send a datagram to the given destination address
	 * @param data the data to send
	 * @param len the length of the data to send (max 64k!)
	 * @param addr the destination address
	 */
	void sendDatagram(const uint8_t* data, uint32_t len, const NetworkAddress& addr) {

		// sanity check
        if (!bound) {throw Exception("bind() the socket first!");}

		// ensure max datagram size
        if (len > MAX_DATAGRAM_SIZE)	{throw Exception("max datagram size is " + std::to_string(MAX_DATAGRAM_SIZE)+ " bytes!");}

		// ensure correct destination address
        if (!addr.isValidTargetPort())	{throw Exception("the given destination address has no valid port number");}
        if (!addr.isValidTargetHost())	{throw Exception("the given destination address has no valid hostname");}

		// send datagram to the given destionation
		const struct sockaddr_in& sockAddr = addr.getAsSocketAddress();
		const int options = 0;
		const int res = sendto(handle, (const char*)data, len, options, (struct sockaddr*) &sockAddr, sizeof(sockaddr));

		// check
        if (res < 0) {throw Exception("error while sending datagram");}

	}

	/**
	 * @brief send a datagram to the given destination address
	 * @param data the data to send (max 64k!)
	 * @param addr the destination address
	 */
	void sendDatagram(const std::vector<uint8_t>& data, const NetworkAddress& addr) {
		sendDatagram(data.data(), (uint32_t) data.size(), addr);
	}

    void sendDatagram(const std::string& data, const NetworkAddress& addr) {
        sendDatagram((const uint8_t*)data.data(), data.length(), addr);
    }

//	/**
//	 * @brief send the given datagram to its internal destination address
//	 * @param d the datagram to send
//	 */
//	void sendDatagram(const Datagram& d) {
//		sendDatagram(d.getData(), d.getLength(), d.getAddress());
//	}


//	/**
//	 * @brief convenience function for receiveDatagram(d) which returns a new
//	 * datagram instead of reusing an existing one.
//	 * @return a newly created datagram holding the received message
//	 */
//	DefaultDatagram receiveDatagram() {
//		DefaultDatagram dd;
//		receiveDatagram(dd);
//		return dd;
//	}

//	/**
//	 * @brief this method will block until a new datagram is received on the bound
//	 * port of the underlying socket. the received data will be stored within the
//	 * given datagram
//	 * @param d the buffer to store the received datagram to
//	 */
//	void receiveDatagram(Datagram& d) {

//		const int flags = 0;
//		const int maxSize = MAX_DATAGRAM_SIZE;

//		// sanity check
//		if (!bound) {throw SocketException("bind() the socket first!");}

//		// ensure the target buffer may hold the largest possible datagram
//		d.ensureSpace(maxSize);

//		// the datagrams sender will be stored here
//		struct sockaddr_in senderAddr;
//		socklen_t senderLength = sizeof(senderAddr);

//		// receive datagram from socket and store sender information
//		int len = recvfrom(handle, (char*) d.getDataWriteable(), maxSize, flags, (struct sockaddr*) &senderAddr, &senderLength);
//		if (len < 0) {throw SocketException("error while receiving datagram", errno);}

//		// store senders network-address in the datagram
//		NetworkAddress na(senderAddr);
//		d.setAddress(na);

//		// inform buffer about the actual size of the datagram
//		d.setLength( (uint32_t) len );

//	}



private:

	/** the socket handle */
	int handle;

	/** the local address the socket is bound to */
	NetworkAddress localAddress;

};



#endif // SOCKET_H