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

///////////
struct	s_client
{
	int	fd;
	int	id;
	struct s_client	*next;
} typedef t_client;

t_client	*g_clients = NULL;
int			g_id = 0;
int			lsocket = -1;
fd_set		rfds;
fd_set		wfds;
////////////
int		extract_message(char **buf, char **msg);
char	*str_join(char *buf, char *add);

void		init(int port);
t_client	*new_client(int fd);
t_client	*close_client(t_client *client_to_close);
void		broadcast(t_client *client, char *str);
int			read_client(t_client *client);
void		free_all();
void		fatal_error();
ssize_t 	ft_print(int fd, char *buf);
////////////

int	main(int argc, char** argv)
{
	// int	count = 0; // force exit debug
	int			fd_max;
	t_client	*clients;
	int			new_fd;
	int			client_id;
	t_client	*last_connected;
	char		announce_msg[420];
	int			ret;

	if (argc != 2) {
		ft_print(STDERR_FILENO, "Wrong number of arguments\n");
		exit(1);
	}
	init(atoi(argv[1]));
	fcntl(lsocket, F_SETFL, O_NONBLOCK); // debug

	while (1)
	{
	// reset rfds and wfds
		fd_max = lsocket;
		FD_ZERO(&rfds);
		FD_ZERO(&wfds);
		FD_SET(lsocket, &rfds);
		clients = g_clients;
		while (clients)
		{
			if (clients->fd > fd_max)
				fd_max = clients->fd;
			FD_SET(clients->fd, &rfds);
			FD_SET(clients->fd, &wfds);
			clients = clients->next;
		}

	// multiplexing (select) 
		select(fd_max + 1, &rfds, &wfds, NULL, NULL);

	// accept new connection
		if (FD_ISSET(lsocket, &rfds))
		{
			new_fd = accept(lsocket, NULL, NULL);
			fcntl(new_fd, F_SETFL, O_NONBLOCK); // debug
			last_connected = new_client(new_fd);
			sprintf(announce_msg, "server: client %d just arrived\n", last_connected->id);
			broadcast(last_connected, announce_msg);

			// debug
			// ++count;
			// printf("count: %d\n", count);
			// if (count == 7)
			// 	break;
		}

	// read incoming clients messages
		clients = g_clients;
		while (clients)
		{
			ret = 1;
			if (FD_ISSET(clients->fd, &rfds))
				ret = read_client(clients);

			if (ret == 0)
			{
				client_id = clients->id;
				clients = close_client(clients);
				sprintf(announce_msg, "server: client %d just left\n", client_id);
				broadcast(NULL, announce_msg);
			}
			else
				clients = clients->next;
		}
	}

	free_all();
	return (0);
}

void	init(int port)
{
	struct sockaddr_in	servaddr; 

	lsocket = socket(AF_INET, SOCK_STREAM, 0);
	if (lsocket == -1)
		fatal_error();

	bzero(&servaddr, sizeof(servaddr));
	servaddr.sin_family = AF_INET; 
	servaddr.sin_addr.s_addr = htonl(2130706433); //127.0.0.1
	servaddr.sin_port = htons(port);

	if (bind(lsocket, (const struct sockaddr *)&servaddr, sizeof(servaddr)) != 0)
		fatal_error();
	if (listen(lsocket, 10) != 0)
		fatal_error();
}

t_client	*new_client(int fd)
{
	t_client *new;

	new = calloc(1, sizeof (t_client));
	if (!new)
		fatal_error();
	new->fd = fd;
	new->id = g_id++;

	if (!g_clients)
		g_clients = new;
	else
	{
		t_client *last = g_clients;
		while (last->next)
			last = last->next;
		last->next = new;
	}
	return (new);
}


t_client	*close_client(t_client *client_to_close)
{
	t_client	*next_client = client_to_close->next;
	t_client	*clients = g_clients;

	if (g_clients == client_to_close)
	{
		g_clients = next_client;
	}
	else
	{
		while (clients->next != client_to_close)
			clients = clients->next;
		clients->next = next_client;
	}
	close(client_to_close->fd);
	free(client_to_close);
	return (next_client);
}

void	broadcast(t_client *client, char *str)
{
	t_client	*clients = g_clients;

	while (clients)
	{
		if (clients != client && FD_ISSET(clients->fd, &wfds))
		{
			send(clients->fd, str, strlen(str), 0);
		}
		clients = clients->next;
	}
}

int	read_client(t_client *client)
{
	char	*buf;
	int		recv_ret;

	buf = malloc(420000);
	if (!buf)
		fatal_error();

	recv_ret = recv(client->fd, buf, 420000, 0);
	if (recv_ret > 0)
	{
		buf[recv_ret] = '\0';
		if (recv_ret == 420000) // debug
			ft_print(STDERR_FILENO, "Oupsi, ca depasse. Il faut malloc mon petit\n");

		char	buf_sprintf[420];
		char	*msg;
		char	*final_msg;
		int ret = 1;
		while (ret == 1)
		{
			msg = NULL;
			ret = extract_message(&buf, &msg);
			if (ret == -1)
			{
				free(buf);
				fatal_error();
			}
			if (!msg)
				msg = buf;
			if (msg && msg[0] != 0)
			{
				sprintf(buf_sprintf, "client %d: ", client->id);
				final_msg = str_join(buf_sprintf, msg);
				free(msg);
				if (!final_msg)
				{
					free(buf);
					fatal_error();
				}
				broadcast(client, final_msg);
				free(final_msg);
			}
			else
				free(msg);
		}
	}
	else
	{
		free(buf);
	}

	return (recv_ret);
}

void	free_all()
{
	if (lsocket != -1)
		close(lsocket);
	while (g_clients)
		close_client(g_clients);
}

void	fatal_error()
{
	ft_print(STDERR_FILENO, "Fatal error\n");
	free_all();
	exit(1);
}

ssize_t 	ft_print(int fd, char *buf)
{
	return write(fd, buf, strlen(buf));
}

// Base example function
int extract_message(char **buf, char **msg)
{
	char	*newbuf;
	int	i;

	*msg = 0;
	if (*buf == 0)
		return (0);
	i = 0;
	while ((*buf)[i])
	{
		if ((*buf)[i] == '\n')
		{
			newbuf = calloc(1, sizeof(*newbuf) * (strlen(*buf + i + 1) + 1));
			if (newbuf == 0)
				return (-1);
			strcpy(newbuf, *buf + i + 1);
			*msg = *buf;
			(*msg)[i + 1] = 0;
			*buf = newbuf;
			return (1);
		}
		i++;
	}
	return (0);
}

// Base example function, minus the commented free()
char *str_join(char *buf, char *add)
{
	char	*newbuf;
	int		len;

	if (buf == 0)
		len = 0;
	else
		len = strlen(buf);
	newbuf = malloc(sizeof(*newbuf) * (len + strlen(add) + 1));
	if (newbuf == 0)
		return (0);
	newbuf[0] = 0;
	if (buf != 0)
		strcat(newbuf, buf);
	// free(buf);
	strcat(newbuf, add);
	return (newbuf);
}