#define USE_THE_REPOSITORY_VARIABLE

#include "git-compat-util.h"
#include "hash.h"
#include "hex.h"
#include "strbuf.h"

static int get_hash_hex_algop(const char *hex, unsigned char *hash,
			      const struct git_hash_algo *algop)
{
	for (size_t i = 0; i < algop->rawsz; i++) {
		int val = hex2chr(hex);
		if (val < 0)
			return -1;
		*hash++ = val;
		hex += 2;
	}
	return 0;
}

int get_hash_hex(const char *hex, unsigned char *sha1)
{
	return get_hash_hex_algop(hex, sha1, the_hash_algo);
}

int get_oid_hex_algop(const char *hex, struct object_id *oid,
		      const struct git_hash_algo *algop)
{
	int ret = get_hash_hex_algop(hex, oid->hash, algop);
	if (!ret) {
		oid_set_algo(oid, algop);
		if (algop->rawsz != GIT_MAX_RAWSZ)
			memset(oid->hash + algop->rawsz, 0,
			       GIT_MAX_RAWSZ - algop->rawsz);
	}
	return ret;
}

/*
 * NOTE: This function relies on hash algorithms being in order from shortest
 * length to longest length.
 */
int get_oid_hex_any(const char *hex, struct object_id *oid)
{
	int i;
	for (i = GIT_HASH_NALGOS - 1; i > 0; i--) {
		if (!get_oid_hex_algop(hex, oid, &hash_algos[i]))
			return i;
	}
	return GIT_HASH_UNKNOWN;
}

int get_oid_hex(const char *hex, struct object_id *oid)
{
	return get_oid_hex_algop(hex, oid, the_hash_algo);
}

int parse_oid_hex_algop_impl(const char *hex, struct object_id *oid,
			     const char **end,
			     const struct git_hash_algo *algop)
{
	int ret = get_oid_hex_algop(hex, oid, algop);
	if (!ret)
		*end = hex + algop->hexsz;
	return ret;
}

int parse_oid_hex_any(const char *hex, struct object_id *oid, const char **end)
{
	int ret = get_oid_hex_any(hex, oid);
	if (ret)
		*end = hex + hash_algos[ret].hexsz;
	return ret;
}

int parse_oid_hex(const char *hex, struct object_id *oid, const char **end)
{
	return parse_oid_hex_algop(hex, oid, end, the_hash_algo);
}

char *hash_to_hex_algop_r(char *buffer, const unsigned char *hash,
			  const struct git_hash_algo *algop)
{
	static const char hex[] = "0123456789abcdef";
	char *buf = buffer;

	/*
	 * Our struct object_id has been memset to 0, so default to printing
	 * using the default hash.
	 */
	if (algop == &hash_algos[0])
		algop = the_hash_algo;

	for (size_t i = 0; i < algop->rawsz; i++) {
		unsigned int val = *hash++;
		*buf++ = hex[val >> 4];
		*buf++ = hex[val & 0xf];
	}
	*buf = '\0';

	return buffer;
}

char *oid_to_hex_r(char *buffer, const struct object_id *oid)
{
	return hash_to_hex_algop_r(buffer, oid->hash, &hash_algos[oid->algo]);
}

char *hash_to_hex_algop(const unsigned char *hash, const struct git_hash_algo *algop)
{
	static int bufno;
	static char hexbuffer[4][GIT_MAX_HEXSZ + 1];
	bufno = (bufno + 1) % ARRAY_SIZE(hexbuffer);
	return hash_to_hex_algop_r(hexbuffer[bufno], hash, algop);
}

char *hash_to_hex(const unsigned char *hash)
{
	return hash_to_hex_algop(hash, the_hash_algo);
}

char *oid_to_hex(const struct object_id *oid)
{
	return hash_to_hex_algop(oid->hash, &hash_algos[oid->algo]);
}

void strbuf_add_oid_hex(struct strbuf *sb, const struct object_id *oid)
{
	const struct git_hash_algo *algop = oid->algo ?
		&hash_algos[oid->algo] : the_hash_algo;
	strbuf_grow(sb, algop->hexsz);
	hash_to_hex_algop_r(sb->buf + sb->len, oid->hash, algop);
	strbuf_setlen(sb, sb->len + algop->hexsz);
}