/*

 * 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/oid.h"

#include "git2/refs.h"

#include "git2/revwalk.h"

#include "git2/transport.h"

#include "common.h"

#include "remote.h"

#include "refspec.h"

#include "pack.h"

#include "fetch.h"

#include "netops.h"

#include "repository.h"

#include "refs.h"

static int maybe_want(git_remote *remote, git_remote_head *head, git_odb *odb, git_refspec *tagspec, git_remote_autotag_option_t tagopt)

{

	int match = 0;

	if (!git_reference_is_valid_name(head->name))

		return 0;

	if (tagopt == GIT_REMOTE_DOWNLOAD_TAGS_ALL) {

		/*

		 * If tagopt is --tags, always request tags

		 * in addition to the remote's refspecs

		 */

		if (git_refspec_src_matches(tagspec, head->name))

			match = 1;

	}

	if (!match && git_remote__matching_refspec(remote, head->name))

		match = 1;

	if (!match)

		return 0;

	/* If we have the object, mark it so we don't ask for it */

	if (git_odb_exists(odb, &head->oid)) {

		head->local = 1;

	}

	else

		remote->need_pack = 1;

	return git_vector_insert(&remote->refs, head);

}

static int filter_wants(git_remote *remote, const git_fetch_options *opts)

{

	git_remote_head **heads;

	git_refspec tagspec, head;

	int error = 0;

	git_odb *odb;

	size_t i, heads_len;

	git_remote_autotag_option_t tagopt = remote->download_tags;

	if (opts && opts->download_tags != GIT_REMOTE_DOWNLOAD_TAGS_UNSPECIFIED)

		tagopt = opts->download_tags;

	git_vector_clear(&remote->refs);

	if ((error = git_refspec__parse(&tagspec, GIT_REFSPEC_TAGS, true)) < 0)

		return error;

	/*

	 * The fetch refspec can be NULL, and what this means is that the

	 * user didn't specify one. This is fine, as it means that we're

	 * not interested in any particular branch but just the remote's

	 * HEAD, which will be stored in FETCH_HEAD after the fetch.

	 */

	if (remote->active_refspecs.length == 0) {

		if ((error = git_refspec__parse(&head, "HEAD", true)) < 0)

			goto cleanup;

		error = git_refspec__dwim_one(&remote->active_refspecs, &head, &remote->refs);

		git_refspec__free(&head;;

		if (error < 0)

			goto cleanup;

	}

	if (git_repository_odb__weakptr(&odb, remote->repo) < 0)

		goto cleanup;

	if (git_remote_ls((const git_remote_head ***)&heads, &heads_len, remote) < 0)

		goto cleanup;

	for (i = 0; i < heads_len; i++) {

		if ((error = maybe_want(remote, heads[i], odb, &tagspec, tagopt)) < 0)

			break;

	}

cleanup:

	git_refspec__free(&tagspec);

	return error;

}

/*

 * In this first version, we push all our refs in and start sending

 * them out. When we get an ACK we hide that commit and continue

 * traversing until we're done

 */

int git_fetch_negotiate(git_remote *remote, const git_fetch_options *opts)

{

	git_transport *t = remote->transport;

	remote->need_pack = 0;

	if (filter_wants(remote, opts) < 0) {

		giterr_set(GITERR_NET, "failed to filter the reference list for wants");

		return -1;

	}

	/* Don't try to negotiate when we don't want anything */

	if (!remote->need_pack)

		return 0;

	/*

	 * Now we have everything set up so we can start tell the

	 * server what we want and what we have.

	 */

	return t->negotiate_fetch(t,

		remote->repo,

		(const git_remote_head * const *)remote->refs.contents,

		remote->refs.length);

}

int git_fetch_download_pack(git_remote *remote, const git_remote_callbacks *callbacks)

{

	git_transport *t = remote->transport;

	git_transfer_progress_cb progress = NULL;

	void *payload = NULL;

	if (!remote->need_pack)

		return 0;

	if (callbacks) {

		progress = callbacks->transfer_progress;

		payload  = callbacks->payload;

	}

	return t->download_pack(t, remote->repo, &remote->stats, progress, payload);

}

int git_fetch_init_options(git_fetch_options *opts, unsigned int version)

{

	GIT_INIT_STRUCTURE_FROM_TEMPLATE(

		opts, version, git_fetch_options, GIT_FETCH_OPTIONS_INIT);

	return 0;

}