/* The MIT License
 * 
 * Copyright (c) 2021 KikooDX
 * 
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 * 
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE. */

#include <stdio.h>
#include <stdlib.h>

static const int kble_fmt_version = 0;

static int read_byte(FILE *file);
static int read_byte_group(FILE *file, int number);

int main(int argc, char **argv) {
	FILE *file = NULL;
	int byte = 0;
	int width = 0;
	int height = 0;
	int cell_size = 0;
	int i = 0;

	if (argc != 2) {
		fprintf(stderr, "ERROR: Wrong argument count. "
			"Expected 1, got %d.\n", argc - 1);
		return EXIT_FAILURE;
	}

	file = fopen(argv[1], "rb");
	if (file == NULL) {
		fprintf(stderr, "ERROR: Cannot open input file.\n");
		return EXIT_FAILURE;
	}

	/* Check KBLE format ID. */
	byte = read_byte(file);
	if (byte != kble_fmt_version) {
		fprintf(stderr, "ERROR: KBLE format ID doesn't match. "
			"Expected %d, got %d.\n", kble_fmt_version, byte);
		return EXIT_FAILURE;
	}

	/* Get cell size (in bytes). */
	cell_size = read_byte(file);

	/* Get width and height of level. */
	width = read_byte_group(file, 2);
	height = read_byte_group(file, 2);

	/* Output Lua code. */
	printf(
		"return {\n"
		"  width = %d,\n"
		"  height = %d,\n"
		"  data = {\n    ", width, height);
	for (i = 0; i < width * height; i++) {
		byte = read_byte_group(file, cell_size);
		printf("%d", byte);
		printf(", ");
		if (i % width == width - 1 && i != width * height - 1)
			printf("\n    ");
	}
	printf("\n"
		"  }\n"
		"}\n");
	/* End output Lua code. */

	fclose(file);

	return EXIT_SUCCESS;
}

static int read_byte(FILE *file) {
	const int byte = getc(file);
	if (byte == EOF) {
		fprintf(stderr, "ERROR: Unexpected EOF.\n");
		exit(EXIT_FAILURE);
	}
	return byte;
}

static int read_byte_group(FILE *file, int number) {
	int byte = 0;
	int merged = 0;
	int i = 0;
	int shift = number * 8;
	for (i = 0; i < number; i += 1) {
		shift -= 8;
		byte = read_byte(file);
		merged |= byte << shift;
	}
	return merged;
}