/* SPDX-License-Identifier: LGPL-3.0-or-later */
/*
 * alloc.c
 *
 * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
 */
#include "config.h"

#include "util/parse.h"
#include "sqfs/error.h"

#include <ctype.h>

static int parse(const char *in, size_t len, size_t *diff,
		 sqfs_u64 base, sqfs_u64 vmin, sqfs_u64 vmax, sqfs_u64 *out)
{
	/* init result */
	if (diff != NULL)
		*diff = 0;
	*out = 0;

	/* sequence has at least 1 digit */
	if (len == 0 || !isdigit(*in))
		return SQFS_ERROR_CORRUPTED;

	/* parse sequence */
	while (len > 0 && isdigit(*in)) {
		sqfs_u64 x = *in - '0';
		if (x >= base)
			break;

		if ((*out) >= (0xFFFFFFFFFFFFFFFFULL / base))
			return SQFS_ERROR_OVERFLOW;

		(*out) *= base;

		if ((*out) > (0xFFFFFFFFFFFFFFFFULL - x))
			return SQFS_ERROR_OVERFLOW;

		(*out) += x;

		--len;
		++in;
		if (diff != NULL)
			++(*diff);
	}

	/* range check */
	if ((vmin < vmax) && ((*out < vmin) || (*out > vmax)))
		return SQFS_ERROR_OUT_OF_BOUNDS;

	/* if diff is not used, entire  must have been processed */
	if (diff == NULL && (len > 0 && *in != '\0'))
		return SQFS_ERROR_CORRUPTED;

	return 0;
}

int parse_uint(const char *in, size_t len, size_t *diff,
	       sqfs_u64 vmin, sqfs_u64 vmax, sqfs_u64 *out)
{
	return parse(in, len, diff, 10, vmin, vmax, out);
}

int parse_uint_oct(const char *in, size_t len, size_t *diff,
		   sqfs_u64 vmin, sqfs_u64 vmax, sqfs_u64 *out)
{
	return parse(in, len, diff, 8, vmin, vmax, out);
}

int parse_int(const char *in, size_t len, size_t *diff,
	      sqfs_s64 vmin, sqfs_s64 vmax, sqfs_s64 *out)
{
	bool negative = false;
	sqfs_u64 temp;
	int ret;

	if (len > 0 && *in == '-') {
		++in;
		--len;
		negative = true;
	}

	ret = parse_uint(in, len, diff, 0, 0, &temp);
	if (ret)
		return ret;

	if (temp >= 0x7FFFFFFFFFFFFFFFULL)
		return SQFS_ERROR_OVERFLOW;

	if (negative) {
		if (diff != NULL)
			(*diff) += 1;
		*out = -((sqfs_s64)temp);
	} else {
		*out = (sqfs_s64)temp;
	}

	if ((vmin < vmax) && ((*out < vmin) || (*out > vmax)))
		return SQFS_ERROR_OUT_OF_BOUNDS;

	return 0;
}