#include <stdio.h>
#include <ctype.h>
#include <errno.h>
#include <sys/file.h>
#include <unistd.h>
#include <time.h>
#include <limits.h>
#include <string.h>
#include <stdlib.h>

#if 0
static char *strip_end(char *str)
{
	int len = strlen(str);
	for (str += len - 1
		; len > 0 && (isspace(*str) || *str == 26)
		; len--, str--) *str = '\0';
	return str+1;
}
#endif

static int popauth_getip (char ip[20])
{
	int ret = -1;
	char lineip[PATH_MAX];
	if (fgets(lineip,sizeof(lineip)-1,stdin)!=NULL){
		char *paren = strchr(lineip,'(');
		if (paren != NULL){
			paren++;
			char *endparen = strchr(paren,')');
			if (endparen != NULL){
				*endparen = '\0';
				if (strlen(paren) < 20){
					strcpy (ip,paren);
					ret = 0;
				}
			}
		}
	}
	return ret;
}

static void usage()
{
	fprintf (stderr,"popauth --setip map_path map_format\n");
	fprintf (stderr,"Normal usage: popauth --setip /etc/mail/popauth hash\n");
	fprintf (stderr,"\n");
	fprintf (stderr,"popauth --clean map_path format seconds\n");
	fprintf (stderr,"\tRemove old entries from the table\n");
}

static int popauth_makemap(
	const char *db,
	const char *format,
	const char *key,
	const char *val)
{
	int ret = -1;
	char cmd[PATH_MAX];
	if (key == NULL){
		snprintf (cmd,sizeof(cmd)-1,"makemap -o %s %s <%s",format,db,db);
		ret = system  (cmd);
	}else{
		snprintf (cmd,sizeof(cmd)-1,"makemap -o %s %s",format,db);
		FILE *fout = popen (cmd,"w");
		if (fout != NULL){
			fprintf (fout,"%s\t%s\n",key,val);
			ret = pclose (fout);
		}
	}
	return ret;
}

static FILE *fopen_lock (const char *fname, const char *mode)
{
	FILE *ret = fopen (fname,mode);
	if (ret != NULL){
		flock (fileno(ret),LOCK_EX);
	}
	return ret;
}

int main (int argc, char *argv[])
{
	int ret = -1;
	if (argc < 2){
		usage();
	}else if (strcmp(argv[1],"--setip")==0){
		if (argc != 4){
			usage();
		}else{
			const char *db = argv[2];
			const char *format = argv[3];
			char ip[20];
			while (popauth_getip(ip)!=-1){
				char date[20];
				snprintf (date,sizeof(date)-1,"%lu",time(NULL));
				FILE *fin = fopen_lock (db,"r+");
				if (fin == NULL){
					if (errno == ENOENT){
						FILE *fout = fopen (db,"w");
						if (fout == NULL){
							fprintf (stderr,"Can't open %s (%s)\n",db,strerror(errno));
						}else{
							fprintf (fout,"%s\t%s\n",ip,date);
							fclose (fout);
							ret = popauth_makemap (db,format,ip,date);
						}
					}else{
						fprintf (stderr,"Can't open %s (%s)\n",db,strerror(errno));
					}
				}else{
					char line[1000];
					bool found = false;
					while (fgets(line,sizeof(line)-1,fin)!=NULL){
						char key[1000],tmp[1000];
						if (sscanf (line,"%s %s",key,tmp)==2){
							if (strcmp(key,ip)==0){
								found = true;
							}
						}
					}
					if (!found){
						if (fseek (fin,0,SEEK_END) != -1){
							fprintf (fin,"%s\t%s\n",ip,date);
							fflush (fin);
							ret = popauth_makemap (db,format,ip,date);
						}
					}else{
						ret = 0;
					}
					fclose (fin);
				}
			}
		}
	}else if (strcmp(argv[1],"--clean")==0){
		if (argc != 5){
			usage();
		}else{
			const char *db = argv[2];
			char dbtmp[PATH_MAX];
			snprintf (dbtmp,sizeof(dbtmp)-1,"%s.tmp",db);
			const char *format = argv[3];
			time_t ti = time(NULL)-atoi(argv[4]);
			FILE *fin = fopen_lock (db,"r");
			if (fin != NULL){
				FILE *fout = fopen (dbtmp,"w");
				if (fout != NULL){
					char line[1000];
					bool removed = false;
					while (fgets(line,sizeof(line)-1,fin)!=NULL){
						time_t t;
						char ip[1000];
						if (sscanf(line,"%s %lu",ip,&t)==2
							&& t >= ti){
							fputs (line,fout);
						}else{
							removed = true;
						}
					}
					fclose (fout);
					if (removed){
						rename (dbtmp,db);
						ret = popauth_makemap (db,format,NULL,NULL);
					}else{
						ret = 0;
						unlink (dbtmp);
					}
				}
				fclose (fin);
			}
		}
	}
	return ret;
}