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

#define MOD_GZIP_LOG "MOD_GZIP_LOG"

char *gzip_ok[] = { "mod_gzip: OK", "mod_gzip: DECHUNK:OK",
	"mod_gzip: DECHUNK:TRANSMIT_ERROR:32" };


unsigned long long in, out, nr, tnr;

void parse(char *s) 
{
	char *p, *t;
	int i, found = 0;
	unsigned int cin, cout;
	for(i = 0; i < sizeof gzip_ok/sizeof(char *); i++) {
		p = strstr(s, gzip_ok[i]);
		if(p) {
			found = 1;
			break;
		}	
	}
	if(!found) return;
	t = strstr(p, "In:");
	if(!t) return;
	t += 3;
	if(sscanf(t, "%d ", &cin) != 1) return;
	p = strstr(t, "Out:");
	if(!p) return;
	p += 4;
	if(sscanf(p, "%d", &cout) != 1) return;
	in += cin;
	out += cout;
	nr++;
}

void header()
{
	printf("Content-type: text/plain\n\n");
}

void noenv()
{
	printf("MOD_GZIP_LOG environment variable not set\n");
	exit(0);
}

int main(int argc, char **argv)
{
	char *mod_gzip_log;
	char buf[512];
	struct timeval start, end;
	unsigned long long tmp;
	FILE *f;

	header();

	mod_gzip_log = getenv(MOD_GZIP_LOG);

	if (mod_gzip_log == NULL)
		noenv();

	f = fopen(mod_gzip_log, "r");

	if (!f) {
		printf("Cannot open %s\n", mod_gzip_log);
		exit(0);
	}

	gettimeofday(&start, 0);

	if (!fgets(buf, sizeof buf, f)) {
		printf("File seems to be empty.\n");
		exit(0);
	}

	if (!strstr(buf, "mod_gzip")) 
		printf("\nHmm...it doesn't look like mod_gzip log, but continuing anyway...\n");

	tnr++;
	parse(buf);	
	while(fgets(buf, sizeof buf, f)) {
		tnr++;
		parse(buf);
	}
	fclose(f);
	gettimeofday(&end, 0);
	printf("\nNumber of all requests: %lld\n", tnr);
	printf("Number of requests that were compressed: %lld ", nr);
	if(tnr) printf("(%lld%%)\n", nr*100/tnr);
	printf("Without compression it would be: %lld mb (%lld kb -> %lld bytes)\n",
		in/(1024*1024), in/1024, in);
	printf("Effective amount of bytes sent: %lld mb (%lld kb -> %lld bytes)", 
		out/(1024*1024), out/1024, out);
	if(in) printf("\n\nOnly %lld%% of real amount of bytes was sent to the clients.", out*100/in);
	tmp = in - out;
	printf("\nSaved bytes by mod_gzip: %lld mb (%lld kb -> %lld bytes)",
		tmp/(1024*1024), tmp/1024, tmp);
	printf("\n\n");
	printf("Log was analyzed in %ld.%.06ld sec\n", 
		end.tv_sec-start.tv_sec, end.tv_usec-start.tv_usec/1000);
	
	return 0;
}