#include <stdio.h>
#include <netdb.h>
#include <netinet/in.h>
#include <stdlib.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <string.h>

#include <unistd.h>

#define bufferSize 1024
int main(int argc, char *argv[])
{
	if(argc<2)
	{
		printf("Error. No port was entered.\n");
		fflush(stdout);
		exit(1);
	}
	int port = atoi(argv[1]);
	char buffer[bufferSize];

	/*int server_fd = socket(AF_INET,SOCK_DGRAM,0);
	struct sockaddr_in server,client;
	if(server_fd<0)
	{
		if(server_fd)
		{
			close(server_fd);
		}
		printf("Error. Couldn't create socket on server.\n");
		exit(1);
	}

	server.sin_family = AF_INET;
	server.sin_port = htons(port);
	server.sin_addr.s_addr=htonl(INADDRY_ANY);

	if(bind(server_fd,(struct sockaddr *) &server, sizeof(server))<0)
	{
		printf("Error. Binding datagram socket server_fd to port %d failed.\n",port);
		if(server_fd)
		{
			close(server_fd);
		}
		exit(1);
	}
	while(1)
	{
		socklen_t client_len = sizeof(client);

		while(1)
		{
			int readBytes = recvfrom(server_fd,buffer,bufferSize,0,(struct sockaddr *)&client,&client_len);
			if(readBytes<=0)
			{
				printf("Error. Could not read data from client.\n");

				break;
			}
			buffer[readBytes]='\0';
			int sentBytes = sendto(server_fd,buffer,strlen(buffer)+1,0,(struct sockaddr *)&client, &client_len);
			if(sentBytes<=0)
			{
				printf("Error. Could not send data to client.\n");
				break;
			}
		}
	}*/


	int server_fd, client_fd, checker;
	struct sockaddr_in server, client;

	server_fd = socket(AF_INET,SOCK_STREAM,0);
	if(server_fd < 0)
	{
		printf("Couldn't create socket.\n");
		fflush(stdout);
		exit(EXIT_FAILURE);
	}
	server.sin_family=AF_INET;
	server.sin_port=htons(port);
	server.sin_addr.s_addr = htonl(INADDR_ANY);

	int reuseOn=1;
	if(setsockopt(server_fd,SOL_SOCKET,SO_REUSEADDR,&reuseOn,sizeof(reuseOn)) < 0)
	{
		printf("Error. setsockopt(SO_REUSEADDR) failed.\n");
		fflush(stdout);
		exit(EXIT_FAILURE);
	}

	if(bind(server_fd,(struct sockaddr *) &server, sizeof(server))<0)
	{
		printf("Error. Binding server_fd to port %d failed.\n",port);
		fflush(stdout);
		exit(EXIT_FAILURE);
	}

	checker = listen(server_fd,128);
	if(checker<0)
	{
		printf("Error. Listening on socket failed.\n");
		fflush(stdout);
	}

	printf("Echo server is listening on port %d.\n",port);
	fflush(stdout);


	int dataSendCounter=0;
	int dataReceivedCounter=0;
	while(1)
	{
		socklen_t client_len = sizeof(client);
		client_fd = accept(server_fd,(struct sockaddr*) &client,&client_len);
		if(client_fd<0)
		{
			printf("Error. Failed to establish new connection.");
			fflush(stdout);
			continue;
		}
		while(1)
		{
			printf("\nReceiving new data.\n");
			int readBytes = recv(client_fd,buffer,bufferSize,0);
			dataReceivedCounter++;
			printf("\n Times received data = %d \n",dataReceivedCounter);
			if(readBytes<=0)
			{
				printf("Error. Connection with client lost. Could not read message. readBytes = %d \n",readBytes);
				fflush(stdout);
				break;
			}
			printf("\nREADBYTES = %d\n",readBytes);
			buffer[readBytes]='\0';
			printf("From client: %s ",buffer);
			fflush(stdout);
			int timesSent=0;
			int bytesSent=0;
			int totalBytesSent=0;
			while(1)
			{
				bytesSent=totalBytesSent;
				if(totalBytesSent<readBytes)
				{
					timesSent++;
					printf("\nSending data.\n");
					totalBytesSent+=send(client_fd,buffer+bytesSent,readBytes-bytesSent,0);
					dataSendCounter++;
					printf("\nTimes sent data = %d\n",dataSendCounter);
					if(totalBytesSent<=bytesSent)
					{
						printf("Error. Could not send message.\n");
						fflush(stdout);
						close(client_fd);
						break;
					}
					printf("bytesSent = %d\n",bytesSent);
					printf("debug %d\n",timesSent);
					//close(client_fd);
				}
				else
				{
					break;
				}
			}

			printf("To client: %s \n", buffer);
			fflush(stdout);
			if(strncmp(buffer,"over",4)==0)
			{
				printf("Exchange with client ended successfully.\n");
				fflush(stdout);
				break;
			}
		}
		close(client_fd);

	}

	return 0;
}