#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <ctype.h>

#define GUESTBOOK_FILE "/home/fria/gemini/guestbook.gmi"

int ishex(int x) {
	return	(x >= '0' && x <= '9')	||
		(x >= 'a' && x <= 'f')	||
		(x >= 'A' && x <= 'F');
}

int urldecode(const char *s, char *dec)
{
	char *o;
	const char *end = s + strlen(s);
	int c;

	for (o = dec; s <= end; o++) {
		c = *s++;
		if (c == '+') c = ' ';
		else if (c == '%' && (	!ishex(*s++)	||
					!ishex(*s++)	||
					!sscanf(s - 2, "%2x", &c)))
			return -1;

		if (dec) *o = c;
	}

	return o - dec;
}

int main() {
	char *input=getenv("QUERY_STRING");
	FILE *fp=NULL;
	time_t t = time(NULL);
	struct tm tm = *localtime(&t);
	char *output=NULL;
	
	if(!(input && *input)) {
		printf("10 Enter message?\r\n");
		exit(0);
	}

	output=malloc(sizeof(*output)*strlen(input)+1);
	if(output==NULL) exit(1);
	if(urldecode(input,output)==-1) exit(1);

	if((fp=fopen(GUESTBOOK_FILE,"a"))==NULL) exit(1);
	
	fprintf(fp,"### %d-%02d-%02d %02d:%02d:%02d\n%s\n",tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec,output);
	fclose(fp);

	free(output);
	output=NULL;
	
	printf("30 /cgi-bin/guestbook/view.cgi\r\n");
	
	return 0;
}