// Standard C
#include <stdio.h>
#include <stdlib.h>

// System
#include <unistd.h>

// zlib
#include <zlib.h>

static void
usage(void)
{
	(void) fprintf(stderr, "compress [-d] infile outfile\n");
	exit(EXIT_FAILURE);
}

int
main(int argc, char *argv[])
{
	// int compress = 1;
	int level = 5;

	int opt = 0;
	while ( (opt = getopt(argc, argv, "dl")) != -1 ) {
		switch ( opt ) {
		case 'd':
			// compress = 0; // decompress
			break;

		case 'l':
			level = 9;
			break;

		case '?':
		default:
			usage();
			break;
		}
	}
	argc -= optind;
	argv += optind;

	if ( argc != 2 ) {
		usage();
	}

	FILE *in_file  = fopen(argv[0], "rb");
	FILE *out_file = fopen(argv[1], "wb");

	(void) fseek(in_file, 0, SEEK_END);
	unsigned long insize = ftell(in_file); // max 2GB...
	(void) fseek(in_file, 0, SEEK_SET);

	unsigned char *indata = malloc(insize);
	(void) fread(indata, 1, insize, in_file);

	unsigned long  outsize = compressBound(insize);
	unsigned char *outdata = malloc(outsize);

	int res = compress2(outdata, &outsize, indata, insize, level);

	if ( res == Z_OK ) {
		(void) fwrite(outdata, 1, outsize, out_file);
	}
	else {
		printf("Error: %d\n", res);
	}

	free(outdata);
	free(indata);

	(void) fclose(out_file);
	(void) fclose(in_file);

	return EXIT_SUCCESS;
}