// SPDX-License-Identifier: GPL-2.0
#include <errno.h>
#include <stdlib.h>
#include "strbuf.h"
#include "quote.h"
#include "util.h"

/* Help to copy the thing properly quoted for the shell safety.
 * any single quote is replaced with '\'', any exclamation point
 * is replaced with '\!', and the whole thing is enclosed in a
 *
 * E.g.
 *  original     sq_quote     result
 *  name     ==> name      ==> 'name'
 *  a b      ==> a b       ==> 'a b'
 *  a'b      ==> a'\''b    ==> 'a'\''b'
 *  a!b      ==> a'\!'b    ==> 'a'\!'b'
 */
static inline int need_bs_quote(char c)
{
	return (c == '\'' || c == '!');
}

static int sq_quote_buf(struct strbuf *dst, const char *src)
{
	char *to_free = NULL;
	int ret;

	if (dst->buf == src)
		to_free = strbuf_detach(dst, NULL);

	ret = strbuf_addch(dst, '\'');
	while (!ret && *src) {
		size_t len = strcspn(src, "'!");
		ret = strbuf_add(dst, src, len);
		src += len;
		while (!ret && need_bs_quote(*src))
			ret = strbuf_addf(dst, "'\\%c\'", *src++);
	}
	if (!ret)
		ret = strbuf_addch(dst, '\'');
	free(to_free);

	return ret;
}

int sq_quote_argv(struct strbuf *dst, const char** argv, size_t maxlen)
{
	int i, ret;

	/* Copy into destination buffer. */
	ret = strbuf_grow(dst, 255);
	for (i = 0; !ret && argv[i]; ++i) {
		ret = strbuf_addch(dst, ' ');
		if (ret)
			break;
		ret = sq_quote_buf(dst, argv[i]);
		if (maxlen && dst->len > maxlen)
			return -ENOSPC;
	}
	return ret;
}