#include<sys/socket.h>
#include<sys/types.h>
#include<netinet/ip.h>
#include<arpa/inet.h>
#include<stdio.h>
#include<unistd.h>
#include<signal.h>
#include<fcntl.h>

int skt; // Global.  This is the socket that the server will listen on

void close_server(int signal_number){
	printf("Closing down the server\n");
	close(skt);
}

void handle_sigpipe(int signal_number){
	printf("SIGPIPE received\n");
}

int main(int argc, char ** argv){
	struct sockaddr_in sad;
	sad.sin_port = htons(5141);
	sad.sin_addr.s_addr = INADDR_ANY;
	sad.sin_family = AF_INET;

	skt = socket(AF_INET, SOCK_STREAM, 0);
	if(skt == -1){
		perror("socket");
		return 1;
	}
	struct sigaction close_action;
	close_action.sa_handler = close_server;
	if(sigaction(SIGINT, &close_action, 0)){
		perror("sigaction");
		return 1;
	}

	close_action.sa_handler = handle_sigpipe;
	sigaction(SIGPIPE, &close_action, 0);

	if( bind(skt, (struct sockaddr *)(&sad), sizeof(struct sockaddr_in)) ){
		perror("bind");
		return 1;
	}
	if( listen(skt, 5) ){
		perror("listen");
		return 1;
	}	
	int client_fd;
	struct sockaddr_in client_address;
	socklen_t address_size = sizeof(struct sockaddr_in);
	char buffer[1024*16];
	for(;;){
		client_fd = accept(skt, (struct sockaddr *)(&client_address), &address_size);
		if(client_fd == -1){
			perror("accept");
			break;
		}
		printf("Connection made from address %s\n", inet_ntoa(client_address.sin_addr));
		int file_fd = open("/home/seth/gene.fna", O_RDONLY);
		if(file_fd == -1)
			perror("open");

		int readlen;
		int sent_so_far = 0;
		while(readlen = read(file_fd, buffer, sizeof(buffer))){
			if(readlen == -1){
				perror("read from file_fd error");
				break;
			}
			sent_so_far += readlen;
			printf("readlen = %d, so far %d\n", readlen, sent_so_far);
			ssize_t write_return = write(client_fd, buffer, readlen);
			if(write_return == -1)
				break;
			printf("write returned %ld\n", write_return);
		}
		close(file_fd);
		close(client_fd);
	}
	return 0;
}