#include <stdio.h>
#include <time.h>

#include <getopt.h>

#include <file.h>
#include <image.h>
#include <macros.h>
#include <option.h>
#include <pack.h>

enum {
	OPTION_HELP = 'h',
	OPTION_OUTPUT = 'o',
};

struct args {
	const char *input, *output;
};

static struct opt_desc opt_descs[] = {
	{ "-o", "--output", "the file to contain the image in ROTS format" },
	{ "-h", "--help", "display this help and exit" },
	{ NULL, NULL, NULL },
};

static int parse_args(struct args *args, int argc, char *argv[])
{
	struct option options[] = {
		{ "help", no_argument, NULL, OPTION_HELP },
		{ "output", required_argument, 0, OPTION_OUTPUT },
		{ NULL, 0, 0, 0 },
	};
	int ret;

	while ((ret = getopt_long(argc, (char * const *)argv, "ho:", options,
		NULL)) >= 0) {
		switch (ret) {
		case OPTION_HELP: return -1;
		case OPTION_OUTPUT: args->output = optarg; break;
		default: return -1;
		}
	}

	if (!args->output)
		return -1;

	if (optind >= argc)
		return -1;

	++optind;

	if (optind >= argc)
		return -1;

	args->input = argv[optind];

	return 0;
}

void show_pack_usage(const char *prog_name, const char *cmd)
{
	fprintf(stderr, "usage: %s %s [option]...\n\n"
		"pack the payload within an image\n\n", prog_name, cmd);
	format_options(opt_descs);
}

int do_pack(int argc, char *argv[])
{
	char data[4096];
	struct rots_hdr hdr;
	struct args args;
	FILE *input, *output;
	size_t nbytes, size;

	if (parse_args(&args, argc, argv) < 0) {
		show_pack_usage(argv[0], argv[1]);
		return -1;
	}

	if (!(input = fopen(args.input, "rb"))) {
		fprintf(stderr, "unable to open '%s' for reading.\n", args.input);
		return -1;
	}

	if (!(output = fopen(args.output, "wb"))) {
		fprintf(stderr, "unable to open '%s' for writing.\n", args.output);
		goto err_close_input;
	}

	get_file_size(&size, args.input);
	hdr.timestamp = (uint64_t)time(NULL);
	hdr.size = size;
	printf("%zu\n", hdr.size);

	if (rots_write_hdr(output, &hdr) < 0)
		goto err_close_output;

	while (size) {
		nbytes = fread(data, sizeof *data, min(sizeof data, size), input);

		if (nbytes == 0) {
			fprintf(stderr, "unable to read the next chunk\n");
			goto err_close_output;
		}

		if (fwrite(data, sizeof *data, nbytes, output) < nbytes) {
			fprintf(stderr, "unable to write the current chunk\n");
			goto err_close_output;
		}

		size -= nbytes;
	}

	fclose(output);
	fclose(input);

	return 0;

err_close_output:
	fclose(output);
err_close_input:
	fclose(input);
	return -1;
}