/*

 * Copyright (C) the libgit2 contributors. All rights reserved.

 *

 * This file is part of libgit2, distributed under the GNU GPL v2 with

 * a Linking Exception. For full terms see the included COPYING file.

 */

#include "git2/errors.h"

#include "common.h"

#include "refspec.h"

#include "util.h"

#include "posix.h"

#include "refs.h"

#include "vector.h"

int git_refspec__parse(git_refspec *refspec, const char *input, bool is_fetch)

{

	// Ported from https://github.com/git/git/blob/f06d47e7e0d9db709ee204ed13a8a7486149f494/remote.c#L518-636

	size_t llen;

	int is_glob = 0;

	const char *lhs, *rhs;

	int flags;

	assert(refspec && input);

	memset(refspec, 0x0, sizeof(git_refspec));

	refspec->push = !is_fetch;

	lhs = input;

	if (*lhs == '+') {

		refspec->force = 1;

		lhs++;

	}

	rhs = strrchr(lhs, ':');

	/*

	 * Before going on, special case ":" (or "+:") as a refspec

	 * for matching refs.

	 */

	if (!is_fetch && rhs == lhs && rhs[1] == '\0') {

		refspec->matching = 1;

		refspec->string = git__strdup(input);

		GITERR_CHECK_ALLOC(refspec->string);

		refspec->src = git__strdup("");

		GITERR_CHECK_ALLOC(refspec->src);

		refspec->dst = git__strdup("");

		GITERR_CHECK_ALLOC(refspec->dst);

		return 0;

	}

	if (rhs) {

		size_t rlen = strlen(++rhs);

		if (rlen || !is_fetch) {

			is_glob = (1 <= rlen && strchr(rhs, '*'));

			refspec->dst = git__strndup(rhs, rlen);

		}

	}

	llen = (rhs ? (size_t)(rhs - lhs - 1) : strlen(lhs));

	if (1 <= llen && memchr(lhs, '*', llen)) {

		if ((rhs && !is_glob) || (!rhs && is_fetch))

			goto invalid;

		is_glob = 1;

	} else if (rhs && is_glob)

		goto invalid;

	refspec->pattern = is_glob;

	refspec->src = git__strndup(lhs, llen);

	flags = GIT_REF_FORMAT_ALLOW_ONELEVEL | GIT_REF_FORMAT_REFSPEC_SHORTHAND

		| (is_glob ? GIT_REF_FORMAT_REFSPEC_PATTERN : 0);

	if (is_fetch) {

		/*

			* LHS

			* - empty is allowed; it means HEAD.

			* - otherwise it must be a valid looking ref.

			*/

		if (!*refspec->src)

			; /* empty is ok */

		else if (!git_reference__is_valid_name(refspec->src, flags))

			goto invalid;

		/*

			* RHS

			* - missing is ok, and is same as empty.

			* - empty is ok; it means not to store.

			* - otherwise it must be a valid looking ref.

			*/

		if (!refspec->dst)

			; /* ok */

		else if (!*refspec->dst)

			; /* ok */

		else if (!git_reference__is_valid_name(refspec->dst, flags))

			goto invalid;

	} else {

		/*

			* LHS

			* - empty is allowed; it means delete.

			* - when wildcarded, it must be a valid looking ref.

			* - otherwise, it must be an extended SHA-1, but

			*   there is no existing way to validate this.

			*/

		if (!*refspec->src)

			; /* empty is ok */

		else if (is_glob) {

			if (!git_reference__is_valid_name(refspec->src, flags))

				goto invalid;

		}

		else {

			; /* anything goes, for now */

		}

		/*

			* RHS

			* - missing is allowed, but LHS then must be a

			*   valid looking ref.

			* - empty is not allowed.

			* - otherwise it must be a valid looking ref.

			*/

		if (!refspec->dst) {

			if (!git_reference__is_valid_name(refspec->src, flags))

				goto invalid;

		} else if (!*refspec->dst) {

			goto invalid;

		} else {

			if (!git_reference__is_valid_name(refspec->dst, flags))

				goto invalid;

		}

		/* if the RHS is empty, then it's a copy of the LHS */

		if (!refspec->dst) {

			refspec->dst = git__strdup(refspec->src);

			GITERR_CHECK_ALLOC(refspec->dst);

		}

	}

	refspec->string = git__strdup(input);

	GITERR_CHECK_ALLOC(refspec->string);

	return 0;

 invalid:

        giterr_set(

                GITERR_INVALID,

                "'%s' is not a valid refspec.", input);

        git_refspec__free(refspec);

	return -1;

}

void git_refspec__free(git_refspec *refspec)

{

	if (refspec == NULL)

		return;

	git__free(refspec->src);

	git__free(refspec->dst);

	git__free(refspec->string);

	memset(refspec, 0x0, sizeof(git_refspec));

}

const char *git_refspec_src(const git_refspec *refspec)

{

	return refspec == NULL ? NULL : refspec->src;

}

const char *git_refspec_dst(const git_refspec *refspec)

{

	return refspec == NULL ? NULL : refspec->dst;

}

const char *git_refspec_string(const git_refspec *refspec)

{

	return refspec == NULL ? NULL : refspec->string;

}

int git_refspec_force(const git_refspec *refspec)

{

	assert(refspec);

	return refspec->force;

}

int git_refspec_src_matches(const git_refspec *refspec, const char *refname)

{

	if (refspec == NULL || refspec->src == NULL)

		return false;

	return (p_fnmatch(refspec->src, refname, 0) == 0);

}

int git_refspec_dst_matches(const git_refspec *refspec, const char *refname)

{

	if (refspec == NULL || refspec->dst == NULL)

		return false;

	return (p_fnmatch(refspec->dst, refname, 0) == 0);

}

static int refspec_transform(

	git_buf *out, const char *from, const char *to, const char *name)

{

	const char *from_star, *to_star;

	const char *name_slash, *from_slash;

	size_t replacement_len, star_offset;

	git_buf_sanitize(out);

	git_buf_clear(out);

	/*

	 * There are two parts to each side of a refspec, the bit

	 * before the star and the bit after it. The star can be in

	 * the middle of the pattern, so we need to look at each bit

	 * individually.

	 */

	from_star = strchr(from, '*');

	to_star = strchr(to, '*');

	assert(from_star && to_star);

	/* star offset, both in 'from' and in 'name' */

	star_offset = from_star - from;

	/* the first half is copied over */

	git_buf_put(out, to, to_star - to);

	/* then we copy over the replacement, from the star's offset to the next slash in 'name' */

	name_slash = strchr(name + star_offset, '/');

	if (!name_slash)

		name_slash = strrchr(name, '\0');

	/* if there is no slash after the star in 'from', we want to copy everything over */

	from_slash = strchr(from + star_offset, '/');

	if (!from_slash)

		name_slash = strrchr(name, '\0');

	replacement_len = (name_slash - name) - star_offset;

	git_buf_put(out, name + star_offset, replacement_len);

	return git_buf_puts(out, to_star + 1);

}

int git_refspec_transform(git_buf *out, const git_refspec *spec, const char *name)

{

	assert(out && spec && name);

	git_buf_sanitize(out);

	if (!git_refspec_src_matches(spec, name)) {

		giterr_set(GITERR_INVALID, "ref '%s' doesn't match the source", name);

		return -1;

	}

	if (!spec->pattern)

		return git_buf_puts(out, spec->dst);

	return refspec_transform(out, spec->src, spec->dst, name);

}

int git_refspec_rtransform(git_buf *out, const git_refspec *spec, const char *name)

{

	assert(out && spec && name);

	git_buf_sanitize(out);

	if (!git_refspec_dst_matches(spec, name)) {

		giterr_set(GITERR_INVALID, "ref '%s' doesn't match the destination", name);

		return -1;

	}

	if (!spec->pattern)

		return git_buf_puts(out, spec->src);

	return refspec_transform(out, spec->dst, spec->src, name);

}

int git_refspec__serialize(git_buf *out, const git_refspec *refspec)

{

	if (refspec->force)

		git_buf_putc(out, '+');

	git_buf_printf(out, "%s:%s",

		refspec->src != NULL ? refspec->src : "",

		refspec->dst != NULL ? refspec->dst : "");

	return git_buf_oom(out) == false;

}

int git_refspec_is_wildcard(const git_refspec *spec)

{

	assert(spec && spec->src);

	return (spec->src[strlen(spec->src) - 1] == '*');

}

git_direction git_refspec_direction(const git_refspec *spec)

{

	assert(spec);

	return spec->push;

}

int git_refspec__dwim_one(git_vector *out, git_refspec *spec, git_vector *refs)

{

	git_buf buf = GIT_BUF_INIT;

	size_t j, pos;

	git_remote_head key;

	const char* formatters[] = {

		GIT_REFS_DIR "%s",

		GIT_REFS_TAGS_DIR "%s",

		GIT_REFS_HEADS_DIR "%s",

		NULL

	};

	git_refspec *cur = git__calloc(1, sizeof(git_refspec));

	GITERR_CHECK_ALLOC(cur);

	cur->force = spec->force;

	cur->push = spec->push;

	cur->pattern = spec->pattern;

	cur->matching = spec->matching;

	cur->string = git__strdup(spec->string);

	/* shorthand on the lhs */

	if (git__prefixcmp(spec->src, GIT_REFS_DIR)) {

		for (j = 0; formatters[j]; j++) {

			git_buf_clear(&buf;;

			git_buf_printf(&buf, formatters[j], spec->src);

			GITERR_CHECK_ALLOC_BUF(&buf;;

			key.name = (char *) git_buf_cstr(&buf;;

			if (!git_vector_search(&pos, refs, &key)) {

				/* we found something to match the shorthand, set src to that */

				cur->src = git_buf_detach(&buf;;

			}

		}

	}

	/* No shorthands found, copy over the name */

	if (cur->src == NULL && spec->src != NULL) {

		cur->src = git__strdup(spec->src);

		GITERR_CHECK_ALLOC(cur->src);

	}

	if (spec->dst && git__prefixcmp(spec->dst, GIT_REFS_DIR)) {

		/* if it starts with "remotes" then we just prepend "refs/" */

		if (!git__prefixcmp(spec->dst, "remotes/")) {

			git_buf_puts(&buf, GIT_REFS_DIR);

		} else {

			git_buf_puts(&buf, GIT_REFS_HEADS_DIR);

		}

		git_buf_puts(&buf, spec->dst);

		GITERR_CHECK_ALLOC_BUF(&buf;;

		cur->dst = git_buf_detach(&buf;;

	}

	git_buf_free(&buf;;

	if (cur->dst == NULL && spec->dst != NULL) {

		cur->dst = git__strdup(spec->dst);

		GITERR_CHECK_ALLOC(cur->dst);

	}

	return git_vector_insert(out, cur);

}