#include "cache.h"

#include "remote.h"

#include "refspec.h"

#include "checkout.h"

#include "config.h"

struct tracking_name_data {

	/* const */ char *src_ref;

	char *dst_ref;

	struct object_id *dst_oid;

	int num_matches;

	const char *default_remote;

	char *default_dst_ref;

	struct object_id *default_dst_oid;

};

#define TRACKING_NAME_DATA_INIT { NULL, NULL, NULL, 0, NULL, NULL, NULL }

static int check_tracking_name(struct remote *remote, void *cb_data)

{

	struct tracking_name_data *cb = cb_data;

	struct refspec_item query;

	memset(&query, 0, sizeof(struct refspec_item));

	query.src = cb->src_ref;

	if (remote_find_tracking(remote, &query) ||

	    get_oid(query.dst, cb->dst_oid)) {

		free(query.dst);

		return 0;

	}

	cb->num_matches++;

	if (cb->default_remote && !strcmp(remote->name, cb->default_remote)) {

		struct object_id *dst = xmalloc(sizeof(*cb->default_dst_oid));

		cb->default_dst_ref = xstrdup(query.dst);

		oidcpy(dst, cb->dst_oid);

		cb->default_dst_oid = dst;

	}

	if (cb->dst_ref) {

		free(query.dst);

		return 0;

	}

	cb->dst_ref = query.dst;

	return 0;

}

const char *unique_tracking_name(const char *name, struct object_id *oid,

				 int *dwim_remotes_matched)

{

	struct tracking_name_data cb_data = TRACKING_NAME_DATA_INIT;

	const char *default_remote = NULL;

	if (!git_config_get_string_const("checkout.defaultremote", &default_remote))

		cb_data.default_remote = default_remote;

	cb_data.src_ref = xstrfmt("refs/heads/%s", name);

	cb_data.dst_oid = oid;

	for_each_remote(check_tracking_name, &cb_data);

	if (dwim_remotes_matched)

		*dwim_remotes_matched = cb_data.num_matches;

	free(cb_data.src_ref);

	free((char *)default_remote);

	if (cb_data.num_matches == 1) {

		free(cb_data.default_dst_ref);

		free(cb_data.default_dst_oid);

		return cb_data.dst_ref;

	}

	free(cb_data.dst_ref);

	if (cb_data.default_dst_ref) {

		oidcpy(oid, cb_data.default_dst_oid);

		free(cb_data.default_dst_oid);

		return cb_data.default_dst_ref;

	}

	return NULL;

}