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

#include "configfile.h"
#include "list.h"
#include "logging.h"
#include "network.h"
#include "plugins.h"
#include "rrdtool.h"

#define BUFSIZE 1024

static LIST_HEAD(fwd_list);

struct fwd_entry {
	struct list_head list;
	struct sockaddr_in sa;
	int sock;
};

// todo: never freed..
static char *tx_buf, *rx_buf;

void net_submit(char *hostname, char *plugin, char *filename, int ds_id, char *data)
{
	int size = snprintf(tx_buf, BUFSIZE, "%s:%s:%s:%d %s", hostname, plugin, filename, ds_id, data);
	if (size < 0 || size >= BUFSIZE) {
		log_print(LOG_ERROR, "net_submit(): arguments too long");
		return;
	}

	struct fwd_entry *entry;
	list_for_each_entry(entry, &fwd_list, list)
		sendto(entry->sock, tx_buf, size +1, 0, (struct sockaddr *)&entry->sa, sizeof(entry->sa));

//	log_print(LOG_DEBUG, "net_submit: %s", tx_buf);
}

int net_receive(int socket)
{
	char *hostname, *plugin, *filename, *ds_id, *data;
	int size, num;

	size = recv(socket, rx_buf, BUFSIZE, 0);

	hostname = rx_buf;
	plugin = strchr(rx_buf, ':');
	if (plugin == NULL)
		return 0;

	*plugin++ = '\0';
	filename = strchr(plugin, ':');
	if (filename == NULL)
		return 0;

	*filename++ = '\0';
	ds_id = strchr(filename, ':');
	if (ds_id == NULL)
		return 0;

	*ds_id++ = '\0';

	data = strchr(ds_id, ' ');
	if (data == NULL)
		return 0;

	*data++ = '\0';

//	log_print(LOG_DEBUG, "net_receive: %s|%s|%s|%d|%s", hostname, plugin, filename, atoi(ds_id), data);
	rrd_submit(hostname, plugin, filename, atoi(ds_id), data);

	return 0;
}

static int parse_address(char *addr, struct sockaddr_in *sa)
{
	if (addr == NULL)
		return -1;

	char *port = strchr(addr, ':');
	if (port == NULL)
		return -1;

	*port = '\0';

	sa->sin_family = AF_INET;
	sa->sin_port = htons(atoi(port +1));
	inet_aton(addr, &sa->sin_addr);

	*port = ':';

	return 0;
}

static int net_add_cli(char *addr)
{
	struct fwd_entry *entry;

	entry = malloc(sizeof(struct fwd_entry));
	if (entry == NULL) {
		log_print(LOG_ERROR, "net_add_cli(): out of memory");
		return -1;
	}

	if (parse_address(addr, &entry->sa) == -1) {
		free(entry);
		return -1;
	}

	if ((entry->sock = socket(PF_INET, SOCK_DGRAM, 0)) < 0) {
		log_print(LOG_ERROR, "net_add_cli(): socket()");
		free(entry);
		return -1;
	}

	log_print(LOG_INFO, "forwarding to %s:%d", inet_ntoa(entry->sa.sin_addr), ntohs(entry->sa.sin_port));
	list_add_tail(&entry->list, &fwd_list);
	return 0;
}

int net_init_cli()
{
	struct conf_section *section;
	struct conf_tupel *tupel;

	section = config_get_section("global");
	if (section == NULL)
		return 0;

	int retval = 0;
	list_for_each_entry(tupel, &section->tupel, list) {
		if (!strcmp(tupel->option, "forward"))
			retval |= (net_add_cli(tupel->parameter) != -1);
	}

	if (retval) {
		tx_buf = malloc(BUFSIZE);
		if (tx_buf == NULL) {
			log_print(LOG_ERROR, "net_init_cli(): out of memory");
			return 0;
		}
	}

	return retval;
}

int net_init_srv()
{
	struct sockaddr_in sa_srv;
	int srv_sock;

	char *listen = config_get_string("global", "listen", NULL);
	if (parse_address(listen, &sa_srv) == -1)
		return -1;

	if ((srv_sock = socket(PF_INET, SOCK_DGRAM, 0)) < 0) {
		log_print(LOG_ERROR, "net_init_src(): socket()");
		return -1;
	}

	if (bind(srv_sock, (struct sockaddr *)&sa_srv, sizeof(sa_srv)) < 0) {
		log_print(LOG_ERROR, "net_init_src(): bind()");
		close(srv_sock);
		return -1;
	}

	rx_buf = malloc(BUFSIZE);
	if (rx_buf == NULL) {
		log_print(LOG_ERROR, "net_init_srv(): out of memory");
		return 0;
	}

	log_print(LOG_INFO, "listen on %s:%d", inet_ntoa(sa_srv.sin_addr), ntohs(sa_srv.sin_port));

	return srv_sock;
}