/*
 * This file Copyright (C) 2010-2014 Mnemosyne LLC
 *
 * It may be used under the GNU GPL versions 2 or 3
 * or any future license endorsed by Mnemosyne LLC.
 *
 * $Id$
 */

#ifndef __LIBTRANSMISSION_ANNOUNCER_MODULE__
 #error only the libtransmission announcer module should #include this header.
#endif

#ifndef _TR_ANNOUNCER_COMMON_H_
#define _TR_ANNOUNCER_COMMON_H_

#include "transmission.h" /* SHA_DIGEST_LENGTH */
#include "session.h" /* PEER_ID_LEN */

/***
****  SCRAPE
***/

enum
{
  /* pick a number small enough for common tracker software:
   *  - ocelot has no upper bound
   *  - opentracker has an upper bound of 64
   *  - udp protocol has an upper bound of 74
   *  - xbtt has no upper bound */
  TR_MULTISCRAPE_MAX = 64
};

typedef struct
{
  /* the scrape URL */
  char * url;

  /* the name to use when deep logging is enabled */
  char log_name[128];

  /* info hashes of the torrents to scrape */
  uint8_t info_hash[TR_MULTISCRAPE_MAX][SHA_DIGEST_LENGTH];

  /* how many hashes to use in the info_hash field */
  int info_hash_count;
}
tr_scrape_request;

struct tr_scrape_response_row
{
  /* the torrent's info_hash */
  uint8_t info_hash[SHA_DIGEST_LENGTH];

  /* how many peers are seeding this torrent */
  int seeders;

  /* how many peers are downloading this torrent */
  int leechers;

  /* how many times this torrent has been downloaded */
  int downloads;

  /* the number of active downloaders in the swarm.
   * this is a BEP 21 extension that some trackers won't support.
   * http://www.bittorrent.org/beps/bep_0021.html#tracker-scrapes  */
  int downloaders;
};

typedef struct
{
  /* whether or not we managed to connect to the tracker */
  bool did_connect;

  /* whether or not the scrape timed out */
  bool did_timeout;

  /* how many info hashes are in the 'rows' field */
  int row_count;

  /* the individual torrents' scrape results */
  struct tr_scrape_response_row rows[TR_MULTISCRAPE_MAX];

  /* the raw scrape url */
  char * url;

  /* human-readable error string on failure, or NULL */
  char * errmsg;

  /* minimum interval (in seconds) allowed between scrapes.
   * this is an unofficial extension that some trackers won't support. */
  int min_request_interval;
}
tr_scrape_response;

typedef void (*tr_scrape_response_func) (const tr_scrape_response  * response,
                                         void                      * user_data);

void tr_tracker_http_scrape (tr_session               * session,
                             const tr_scrape_request  * req,
                             tr_scrape_response_func    response_func,
                             void                     * user_data);

void tr_tracker_udp_scrape (tr_session               * session,
                            const tr_scrape_request  * req,
                            tr_scrape_response_func    response_func,
                            void                     * user_data);

/***
****  ANNOUNCE
***/

typedef enum
{
  TR_ANNOUNCE_EVENT_NONE,
  TR_ANNOUNCE_EVENT_COMPLETED,
  TR_ANNOUNCE_EVENT_STARTED,
  TR_ANNOUNCE_EVENT_STOPPED
}
tr_announce_event;

const char * tr_announce_event_get_string (tr_announce_event);

typedef struct
{
  tr_announce_event event;
  bool partial_seed;

  /* the port we listen for incoming peers on */
  int port;

  /* per-session key */
  int key;

  /* the number of peers we'd like to get back in the response */
  int numwant;

  /* the number of bytes we uploaded since the last 'started' event */
  uint64_t up;

  /* the number of good bytes we downloaded since the last 'started' event */
  uint64_t down;

  /* the number of bad bytes we downloaded since the last 'started' event */
  uint64_t corrupt;

  /* the total size of the torrent minus the number of bytes completed */
  uint64_t leftUntilComplete;

  /* the tracker's announce URL */
  char * url;

  /* key generated by and returned from an http tracker.
   * see tr_announce_response.tracker_id_str */
  char * tracker_id_str;

  /* the torrent's peer id.
   * this changes when a torrent is stopped -> restarted. */
  char peer_id[PEER_ID_LEN];

  /* the torrent's info_hash */
  uint8_t info_hash[SHA_DIGEST_LENGTH];

  /* the name to use when deep logging is enabled */
  char log_name[128];
}
tr_announce_request;

struct tr_pex;

typedef struct
{
  /* the torrent's info hash */
  uint8_t info_hash[SHA_DIGEST_LENGTH];

  /* whether or not we managed to connect to the tracker */
  bool did_connect;

  /* whether or not the scrape timed out */
  bool did_timeout;

  /* preferred interval between announces.
   * transmission treats this as the interval for periodic announces */
  int interval;

  /* minimum interval between announces. (optional)
   * transmission treats this as the min interval for manual announces */
  int min_interval;

  /* how many peers are seeding this torrent */
  int seeders;

  /* how many peers are downloading this torrent */
  int leechers;

  /* how many times this torrent has been downloaded */
  int downloads;

  /* number of items in the 'pex' field */
  size_t pex_count;

  /* IPv4 peers that we acquired from the tracker */
  struct tr_pex * pex;

  /* number of items in the 'pex6' field */
  size_t pex6_count;

  /* IPv6 peers that we acquired from the tracker */
  struct tr_pex * pex6;

  /* human-readable error string on failure, or NULL */
  char * errmsg;

  /* human-readable warning string or NULL */
  char * warning;

  /* key generated by and returned from an http tracker.
   * if this is provided, subsequent http announces must include this. */
  char * tracker_id_str;
}
tr_announce_response;

typedef void (*tr_announce_response_func) (const tr_announce_response * response,
                                           void                       * userdata);

void tr_tracker_http_announce (tr_session                 * session,
                               const tr_announce_request  * req,
                               tr_announce_response_func    response_func,
                               void                       * user_data);

void tr_tracker_udp_announce (tr_session                 * session,
                              const tr_announce_request  * req,
                              tr_announce_response_func    response_func,
                              void                       * user_data);

void tr_tracker_udp_start_shutdown (tr_session * session);

#endif /* _TR_ANNOUNCER_COMMON_H_ */
