/*

Compile with
	gcc -oserver_seq server_seq.c

*/


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


int main()
{
	const char* PORT = "7000";
	struct addrinfo hint;
	hint.ai_flags = AI_PASSIVE;
	hint.ai_family = AF_UNSPEC;
	hint.ai_socktype = SOCK_STREAM;
	struct addrinfo* addrinfo_list;
	if (getaddrinfo(NULL, PORT, &hint, &addrinfo_list) != 0)
	{
		fprintf(stderr, "main():error with call to 'getaddrinfo()'\n");
		exit(EXIT_FAILURE);
	}

	int server_fd;
	struct addrinfo* it;
	for (it = addrinfo_list; it != NULL; it = it->ai_next)
	{
		server_fd = socket(PF_INET, SOCK_STREAM, 0);
		if (server_fd == -1)
		{
			fprintf(stderr, "main(): cannot create socket");
			continue;
		}

		if (bind(server_fd, it->ai_addr, it->ai_addrlen) == -1)
		{
			fprintf(stderr, "main(): cannot bind the address, exiting program\n");
			continue;
		}
		int yes = 1;
		setsockopt(server_fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(int));
		break;
	}


	const unsigned int PENDING_SIZE = 5;
	if (listen(server_fd, PENDING_SIZE) == -1)
	{
		fprintf(stderr, "main(): cannot listen the address, exiting program\n");
		exit(EXIT_FAILURE);
	}

	while (1)
	{
		struct sockaddr_in client_address;
		socklen_t client_address_len = sizeof(client_address);
		int client_fd = accept(server_fd, (struct sockaddr*)&client_address, &client_address_len);
		if (client_fd == -1)
		{
			printf("main(): cannot accept client, sleeping...\n");
			sleep(5);
		}
		
		char addr_buf[INET_ADDRSTRLEN];
		const char* client_address_s = inet_ntop(AF_INET, (const void*)&client_address, addr_buf, INET_ADDRSTRLEN);
		if (client_address_s == NULL)
			printf("main(): cannot read client address\n");
		else
			printf("main(): client accepted from %s\n", client_address_s);
		
		sleep(10);
		const char* request = "Hello, World!";
		if (send(client_fd, request, strlen(request), 0) == -1)
		{
			printf("main(): cannot send response\n");
			close(client_fd);
			continue;
		}
		close(client_fd);
	}

	return EXIT_SUCCESS;
}