#include "unix.h"

#include "conf.h"
#include "irc.h"

static int
sock_perms(char fname[])
{
	// first get group by name
	struct group *group;
	if ((group = getgrnam(SOCKETGROUP)) == NULL) {
		fprintf(stderr,"no such group: %s\n",SOCKETGROUP);
		return -1;
	}
	// set group on socket
	if (chown(fname, -1, group->gr_gid) == -1) {
		perror("chown");
		return -1;
	}

	// get current permissions, so we can modify them.
	struct stat sb;
	if (stat(fname, &sb) == -1) {
		perror("stat");
		return -1;
	}
	if (chmod(fname, sb.st_mode|S_IWGRP) == -1) {
		perror("chmod");
		return -1;
	}

	return 0;
}

// takes filename, returns socket fd
// or -1 or whatever
int
unix_setup(char filename[])
{
	unlink(filename);

	int sock = socket(AF_UNIX, SOCK_DGRAM, 0);
	if (sock == -1) {
		perror("(unix) socket");
		return -1;
	}

	struct sockaddr_un name;
	memset(&name, 0, sizeof name);
	name.sun_family = AF_UNIX;
	strncpy(name.sun_path, filename, (sizeof name.sun_path)-1);
	if (bind(sock, (struct sockaddr *)&name, sizeof name) == -1) {
		perror("(unix) bind");
		return -1;
	}

	if (sock_perms(filename) == -1) {
		fprintf(stderr,"warning: couldn't correctly set up permissions on %s\n",filename);
	}

	return sock;
}

// reads a message from the fd in question, and sends it to irc
int
unix_handle(int fd, char chname[])
{
	// PRIVMSG #{chname} :{message}<CR><LF>
	// 123456789        12         3   4
	// 512 >= 13 + strlen(chname) + length of message 
	// chname can be max 16 bytes, so worst case
	// 512 >= 13 + 16 + length of message
	// 483 >= length of message
	// 480 is slightly pessimistic but it's a rounder number. 
	// (one more byte for null terminator needed by snprintf)
	unsigned char buf[481];

	if (strlen(chname) > 16) {
		fprintf(stderr,"channel name %s is longer than 16 bytes, ignoring\n",chname);
		return -1;
	}

	ssize_t amt;
	if ((amt = recv(fd, buf, sizeof buf-1,0)) == -1) {
		perror("recv");
		return -1;
	} else if (amt == 0) {
		fputs("unix eof\n",stderr);
		return -1;
	} else {
		int i;
		for (i=0;i<amt;i++) {
			if (buf[i] < ' ') {
				buf[i] = ' ';
			}
		}
		buf[amt] = '\0';
		char msg[512];
		int s;
		if ((s=snprintf(msg,512,"PRIVMSG #%s :%s\r\n",chname,buf)) > 512) {
			fprintf(stderr,"irc message was somehow too long (this should never happen) (%d)/512\n",s);
			return -1;
		}
		if (irc_sendall(msg, s) == -1) {
			perror("sendall");
			return -1;
		};

		return 0;
	}
}