#ifndef TRANSPORT_H
#define TRANSPORT_H

#include "cache.h"
#include "remote.h"

struct git_transport_options {
        unsigned thin : 1;
        unsigned keep : 1;
        unsigned followtags : 1;
        int depth;
        const char *uploadpack;
        const char *receivepack;
};

struct transport {
        struct remote *remote;
        const char *url;
        void *data;
        const struct ref *remote_refs;

        /**
         * Indicates whether we already called get_refs_list(); set by
         * transport.c::transport_get_remote_refs().
         */
        unsigned got_remote_refs : 1;

        /**
         * Returns 0 if successful, positive if the option is not
         * recognized or is inapplicable, and negative if the option
         * is applicable but the value is invalid.
         **/
        int (*set_option)(struct transport *connection, const char *name,
                          const char *value);

        /**
         * Returns a list of the remote side's refs. In order to allow
         * the transport to try to share connections, for_push is a
         * hint as to whether the ultimate operation is a push or a fetch.
         *
         * If the transport is able to determine the remote hash for
         * the ref without a huge amount of effort, it should store it
         * in the ref's old_sha1 field; otherwise it should be all 0.
         **/
        struct ref *(*get_refs_list)(struct transport *transport, int for_push);

        /**
         * Fetch the objects for the given refs. Note that this gets
         * an array, and should ignore the list structure.
         *
         * If the transport did not get hashes for refs in
         * get_refs_list(), it should set the old_sha1 fields in the
         * provided refs now.
         **/
        int (*fetch)(struct transport *transport, int refs_nr, struct ref **refs);

        /**
         * Push the objects and refs. Send the necessary objects, and
         * then, for any refs where peer_ref is set and
         * peer_ref->new_sha1 is different from old_sha1, tell the
         * remote side to update each ref in the list from old_sha1 to
         * peer_ref->new_sha1.
         *
         * Where possible, set the status for each ref appropriately.
         *
         * The transport must modify new_sha1 in the ref to the new
         * value if the remote accepted the change. Note that this
         * could be a different value from peer_ref->new_sha1 if the
         * process involved generating new commits.
         **/
        int (*push_refs)(struct transport *transport, struct ref *refs, int flags);
        int (*push)(struct transport *connection, int refspec_nr, const char **refspec, int flags);
        int (*connect)(struct transport *connection, const char *name,
                       const char *executable, int fd[2]);

        /** get_refs_list(), fetch(), and push_refs() can keep
         * resources (such as a connection) reserved for futher
         * use. disconnect() releases these resources.
         **/
        int (*disconnect)(struct transport *connection);
        char *pack_lockfile;
        signed verbose : 3;
        /**
         * Transports should not set this directly, and should use this
         * value without having to check isatty(2), -q/--quiet
         * (transport->verbose < 0), etc. - checking has already been done
         * in transport_set_verbosity().
         **/
        unsigned progress : 1;
        /*
         * If transport is at least potentially smart, this points to
         * git_transport_options structure to use in case transport
         * actually turns out to be smart.
         */
        struct git_transport_options *smart_options;
};

#define TRANSPORT_PUSH_ALL 1
#define TRANSPORT_PUSH_FORCE 2
#define TRANSPORT_PUSH_DRY_RUN 4
#define TRANSPORT_PUSH_MIRROR 8
#define TRANSPORT_PUSH_PORCELAIN 16
#define TRANSPORT_PUSH_SET_UPSTREAM 32

#define TRANSPORT_SUMMARY_WIDTH (2 * DEFAULT_ABBREV + 3)

/* Returns a transport suitable for the url */
struct transport *transport_get(struct remote *, const char *);

/* Transport options which apply to git:// and scp-style URLs */

/* The program to use on the remote side to send a pack */
#define TRANS_OPT_UPLOADPACK "uploadpack"

/* The program to use on the remote side to receive a pack */
#define TRANS_OPT_RECEIVEPACK "receivepack"

/* Transfer the data as a thin pack if not null */
#define TRANS_OPT_THIN "thin"

/* Keep the pack that was transferred if not null */
#define TRANS_OPT_KEEP "keep"

/* Limit the depth of the fetch if not null */
#define TRANS_OPT_DEPTH "depth"

/* Aggressively fetch annotated tags if possible */
#define TRANS_OPT_FOLLOWTAGS "followtags"

/**
 * Returns 0 if the option was used, non-zero otherwise. Prints a
 * message to stderr if the option is not used.
 **/
int transport_set_option(struct transport *transport, const char *name,
                         const char *value);
void transport_set_verbosity(struct transport *transport, int verbosity,
        int force_progress);

int transport_push(struct transport *connection,
                   int refspec_nr, const char **refspec, int flags,
                   int * nonfastforward);

const struct ref *transport_get_remote_refs(struct transport *transport);

int transport_fetch_refs(struct transport *transport, struct ref *refs);
void transport_unlock_pack(struct transport *transport);
int transport_disconnect(struct transport *transport);
char *transport_anonymize_url(const char *url);
void transport_take_over(struct transport *transport,
                         struct child_process *child);

int transport_connect(struct transport *transport, const char *name,
                      const char *exec, int fd[2]);

/* Transport methods defined outside transport.c */
int transport_helper_init(struct transport *transport, const char *name);
int bidirectional_transfer_loop(int input, int output);

/* common methods used by transport.c and builtin-send-pack.c */
void transport_verify_remote_names(int nr_heads, const char **heads);

void transport_update_tracking_ref(struct remote *remote, struct ref *ref, int verbose);

int transport_refs_pushed(struct ref *ref);

void transport_print_push_status(const char *dest, struct ref *refs,
                  int verbose, int porcelain, int *nonfastforward);

typedef void alternate_ref_fn(const struct ref *, void *);
extern void for_each_alternate_ref(alternate_ref_fn, void *);

#endif