transmission/libtransmission/transmission.h

/******************************************************************************
 * $Id$
 *
 * Copyright (c) Transmission authors and contributors
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 *****************************************************************************/

/*
 * This file defines the public API for the libtransmission library.
 *
 * Other headers with a public API are bencode.h and utils.h.
 * Most of the remaining headers in libtransmission are private.
 */
#ifndef TR_TRANSMISSION_H
#define TR_TRANSMISSION_H 1

#ifdef __cplusplus
extern "C" {
#endif

/***
****
****  Basic Types
****
***/

#include <inttypes.h> /* uintN_t */
#include <time.h> /* time_t */

#if !defined (__cplusplus)
 #ifdef HAVE_STDBOOL_H
  #include <stdbool.h>
 #elif !defined (__bool_true_false_are_defined)
  #define bool uint8_t
  #define true 1
  #define false 0
 #endif
#endif

#ifndef PRId64
 #define PRId64 "lld"
#endif
#ifndef PRIu64
 #define PRIu64 "llu"
#endif
#ifndef PRIu32
 #define PRIu32 "lu"
#endif

#if defined (WIN32) && defined (_MSC_VER)
 #define inline __inline
#endif

#define SHA_DIGEST_LENGTH 20
#define TR_INET6_ADDRSTRLEN 46

typedef uint32_t tr_file_index_t;
typedef uint32_t tr_piece_index_t;
/* assuming a 16 KiB block, a 32-bit block index gives us a maximum torrent size of 63 TiB.
 * if we ever need to grow past that, change this to uint64_t ;) */
typedef uint32_t tr_block_index_t;
typedef uint16_t tr_port;

typedef struct tr_ctor tr_ctor;
typedef struct tr_info tr_info;
typedef struct tr_torrent tr_torrent;
typedef struct tr_session tr_session;

struct tr_variant;

typedef int8_t tr_priority_t;

#define TR_RPC_SESSION_ID_HEADER "X-Transmission-Session-Id"

typedef enum
{
    TR_PREALLOCATE_NONE   = 0,
    TR_PREALLOCATE_SPARSE = 1,
    TR_PREALLOCATE_FULL   = 2
}
tr_preallocation_mode;

typedef enum
{
    TR_CLEAR_PREFERRED,
    TR_ENCRYPTION_PREFERRED,
    TR_ENCRYPTION_REQUIRED
}
tr_encryption_mode;


/***
****
****  Startup & Shutdown
****
***/

/**
 * @addtogroup tr_session Session
 *
 * A libtransmission session is created by calling tr_sessionInit ().
 * libtransmission creates a thread for itself so that it can operate
 * independently of the caller's event loop. The session will continue
 * until tr_sessionClose () is called.
 *
 * @{
 */

/**
 * @brief returns Transmission's default configuration file directory.
 *
 * The default configuration directory is determined this way:
 * -# If the TRANSMISSION_HOME environment variable is set, its value is used.
 * -# On Darwin, "${HOME}/Library/Application Support/${appname}" is used.
 * -# On Windows, "${CSIDL_APPDATA}/${appname}" is used.
 * -# If XDG_CONFIG_HOME is set, "${XDG_CONFIG_HOME}/${appname}" is used.
 * -# ${HOME}/.config/${appname}" is used as a last resort.
 */
const char* tr_getDefaultConfigDir (const char * appname);

/**
 * @brief returns Transmisson's default download directory.
 *
 * The default download directory is determined this way:
 * -# If the HOME environment variable is set, "${HOME}/Downloads" is used.
 * -# On Windows, "${CSIDL_MYDOCUMENTS}/Downloads" is used.
 * -# Otherwise, getpwuid (getuid ())->pw_dir + "/Downloads" is used.
 */
const char* tr_getDefaultDownloadDir (void);


#define TR_DEFAULT_BIND_ADDRESS_IPV4        "0.0.0.0"
#define TR_DEFAULT_BIND_ADDRESS_IPV6             "::"
#define TR_DEFAULT_RPC_WHITELIST          "127.0.0.1"
#define TR_DEFAULT_RPC_PORT_STR                "9091"
#define TR_DEFAULT_RPC_URL_STR       "/transmission/"
#define TR_DEFAULT_PEER_PORT_STR              "51413"
#define TR_DEFAULT_PEER_SOCKET_TOS_STR      "default"
#define TR_DEFAULT_PEER_LIMIT_GLOBAL_STR        "200"
#define TR_DEFAULT_PEER_LIMIT_TORRENT_STR        "50"

/**
 * Add libtransmission's default settings to the benc dictionary.
 *
 * Example:
 * @code
 *     tr_variant settings;
 *     int64_t i;
 *
 *     tr_variantInitDict (&settings, 0);
 *     tr_sessionGetDefaultSettings (&settings);
 *     if (tr_variantDictFindInt (&settings, TR_PREFS_KEY_PEER_PORT, &i))
 *         fprintf (stderr, "the default peer port is %d\n", (int)i);
 *     tr_variantFree (&settings);
 * @endcode
 *
 * @param initme pointer to a tr_variant dictionary
 * @see tr_sessionLoadSettings ()
 * @see tr_sessionInit ()
 * @see tr_getDefaultConfigDir ()
 */
void tr_sessionGetDefaultSettings (struct tr_variant * dictionary);

/**
 * Add the session's current configuration settings to the benc dictionary.
 *
 * FIXME: this probably belongs in libtransmissionapp
 *
 * @param session
 * @param dictionary
 * @see tr_sessionGetDefaultSettings ()
 */
void tr_sessionGetSettings (tr_session *, struct tr_variant * dictionary);

/**
 * Load settings from the configuration directory's settings.json file,
 * using libtransmission's default settings as fallbacks for missing keys.
 *
 * FIXME: this belongs in libtransmissionapp
 *
 * @param dictionary pointer to an uninitialized tr_variant
 * @param configDir the configuration directory to find settings.json
 * @param appName if configDir is empty, appName is used to find the default dir.
 * @return success true if the settings were loaded, false otherwise
 * @see tr_sessionGetDefaultSettings ()
 * @see tr_sessionInit ()
 * @see tr_sessionSaveSettings ()
 */
bool tr_sessionLoadSettings (struct tr_variant  * dictionary,
                             const char         * configDir,
                             const char         * appName);

/**
 * Add the session's configuration settings to the benc dictionary
 * and save it to the configuration directory's settings.json file.
 *
 * FIXME: this belongs in libtransmissionapp
 *
 * @param session
 * @param dictionary
 * @see tr_sessionLoadSettings ()
 */
void tr_sessionSaveSettings (tr_session              * session,
                             const char              * configDir,
                             const struct tr_variant * dictonary);

/**
 * @brief Initialize a libtransmission session.
 *
 * For example, this will instantiate a session with all the default values:
 * @code
 *     tr_variant settings;
 *     tr_session * session;
 *     const char * configDir;
 *
 *     tr_variantInitDict (&settings, 0);
 *     tr_sessionGetDefaultSettings (&settings);
 *     configDir = tr_getDefaultConfigDir ("Transmission");
 *     session = tr_sessionInit ("mac", configDir, true, &settings);
 *
 *     tr_variantFree (&settings);
 * @endcode
 *
 * @param tag "gtk", "macosx", "daemon", etc... this is only for pre-1.30 resume files
 * @param configDir where Transmission will look for resume files, blocklists, etc.
 * @param messageQueueingEnabled if false, messages will be dumped to stderr
 * @param settings libtransmission settings
 * @see tr_sessionGetDefaultSettings ()
 * @see tr_sessionLoadSettings ()
 * @see tr_getDefaultConfigDir ()
 */
tr_session * tr_sessionInit (const char        * tag,
                             const char        * configDir,
                             bool                messageQueueingEnabled,
                             struct tr_variant * settings);

/** @brief Update a session's settings from a benc dictionary
           like to the one used in tr_sessionInit () */
void tr_sessionSet (tr_session         * session,
                    struct tr_variant  * settings);

/** @brief Rescan the blocklists directory and
           reload whatever blocklist files are found there */
void tr_sessionReloadBlocklists (tr_session * session);


/** @brief End a libtransmission session
    @see tr_sessionInit () */
void tr_sessionClose (tr_session *);

/**
 * @brief Return the session's configuration directory.
 *
 * This is where transmission stores its .torrent files, .resume files,
 * blocklists, etc. It's set in tr_transmissionInit () and is immutable
 * during the session.
 */
const char * tr_sessionGetConfigDir (const tr_session *);

/**
 * @brief Set the per-session default download folder for new torrents.
 * @see tr_sessionInit ()
 * @see tr_sessionGetDownloadDir ()
 * @see tr_ctorSetDownloadDir ()
 */
void tr_sessionSetDownloadDir (tr_session * session, const char * downloadDir);

/**
 * @brief Get the default download folder for new torrents.
 *
 * This is set by tr_sessionInit () or tr_sessionSetDownloadDir (),
 * and can be overridden on a per-torrent basis by tr_ctorSetDownloadDir ().
 */
const char * tr_sessionGetDownloadDir (const tr_session * session);

/**
 * @brief Get available disk space (in bytes) for the default download folder.
 * @return zero or positive integer on success, -1 in case of error.
 */
int64_t tr_sessionGetDownloadDirFreeSpace (tr_session * session);

/**
 * @brief Set the torrent's bandwidth priority.
 */
void tr_ctorSetBandwidthPriority (tr_ctor * ctor, tr_priority_t priority);

/**
 * @brief Get the torrent's bandwidth priority.
 */
tr_priority_t tr_ctorGetBandwidthPriority (const tr_ctor * ctor);


/**
 * @brief set the per-session incomplete download folder.
 *
 * When you add a new torrent and the session's incomplete directory is enabled,
 * the new torrent will start downloading into that directory, and then be moved
 * to tr_torrent.downloadDir when the torrent is finished downloading.
 *
 * Torrents aren't moved as a result of changing the session's incomplete dir --
 * it's applied to new torrents, not existing ones.
 *
 * tr_torrentSetLocation () overrules the incomplete dir: when a user specifies
 * a new location, that becomes the torrent's new downloadDir and the torrent
 * is moved there immediately regardless of whether or not it's complete.
 *
 * @see tr_sessionInit ()
 * @see tr_sessionGetIncompleteDir ()
 * @see tr_sessionSetIncompleteDirEnabled ()
 * @see tr_sessionGetIncompleteDirEnabled ()
 */
void tr_sessionSetIncompleteDir (tr_session * session, const char * dir);

/** @brief get the per-session incomplete download folder */
const char* tr_sessionGetIncompleteDir (const tr_session * session);

/** @brief enable or disable use of the incomplete download folder */
void tr_sessionSetIncompleteDirEnabled (tr_session * session, bool);

/** @brief get whether or not the incomplete download folder is enabled */
bool tr_sessionIsIncompleteDirEnabled (const tr_session * session);


/**
 * @brief When enabled, newly-created files will have ".part" appended
 *        to their filename until the file is fully downloaded
 *
 * This is not retroactive -- toggling this will not rename existing files.
 * It only applies to new files created by Transmission after this API call.
 *
 * @see tr_sessionIsIncompleteFileNamingEnabled ()
 */
void tr_sessionSetIncompleteFileNamingEnabled (tr_session * session, bool);

/** @brief return true if files will end in ".part" until they're complete */
bool tr_sessionIsIncompleteFileNamingEnabled (const tr_session * session);

/**
 * @brief Set whether or not RPC calls are allowed in this session.
 *
 * @details If true, libtransmission will open a server socket to listen
 * for incoming http RPC requests as described in docs/rpc-spec.txt.
 *
 * This is intially set by tr_sessionInit () and can be
 * queried by tr_sessionIsRPCEnabled ().
 */
void tr_sessionSetRPCEnabled (tr_session  * session,
                              bool          isEnabled);

/** @brief Get whether or not RPC calls are allowed in this session.
    @see tr_sessionInit ()
    @see tr_sessionSetRPCEnabled () */
bool tr_sessionIsRPCEnabled (const tr_session * session);

/** @brief Specify which port to listen for RPC requests on.
    @see tr_sessionInit ()
    @see tr_sessionGetRPCPort */
void tr_sessionSetRPCPort (tr_session  * session,
                           tr_port       port);

/** @brief Get which port to listen for RPC requests on.
    @see tr_sessionInit ()
    @see tr_sessionSetRPCPort */
tr_port tr_sessionGetRPCPort (const tr_session * session);

/**
 * @brief Specify which base URL to use.
 *
 * @detail The RPC API is accessible under <url>/rpc, the web interface under
 * <url>/web.
 *
 *  @see tr_sessionGetRPCUrl
 */
void tr_sessionSetRPCUrl (tr_session  * session,
                          const char * url);

/**
 * @brief Get the base URL.
 * @see tr_sessionInit ()
 * @see tr_sessionSetRPCUrl
 */
const char* tr_sessionGetRPCUrl (const tr_session * session);

/**
 * @brief Specify a whitelist for remote RPC access
 *
 * The whitelist is a comma-separated list of dotted-quad IP addresses
 * to be allowed. Wildmat notation is supported, meaning that
 * '?' is interpreted as a single-character wildcard and
 * '*' is interprted as a multi-character wildcard.
 */
void   tr_sessionSetRPCWhitelist (tr_session * session,
                                  const char * whitelist);

/** @brief get the Access Control List for allowing/denying RPC requests.
    @return a comma-separated string of whitelist domains.
    @see tr_sessionInit
    @see tr_sessionSetRPCWhitelist */
const char* tr_sessionGetRPCWhitelist (const tr_session *);

void  tr_sessionSetRPCWhitelistEnabled (tr_session * session,
                                        bool         isEnabled);

bool tr_sessionGetRPCWhitelistEnabled (const tr_session * session);

void  tr_sessionSetRPCPassword (tr_session * session,
                                const char * password);

void  tr_sessionSetRPCUsername (tr_session * session,
                                const char * username);

/** @brief get the password used to restrict RPC requests.
    @return the password string.
    @see tr_sessionInit ()
    @see tr_sessionSetRPCPassword () */
const char* tr_sessionGetRPCPassword (const tr_session * session);

const char* tr_sessionGetRPCUsername (const tr_session * session);

void  tr_sessionSetRPCPasswordEnabled (tr_session * session,
                                       bool         isEnabled);

bool tr_sessionIsRPCPasswordEnabled (const tr_session * session);

const char* tr_sessionGetRPCBindAddress (const tr_session * session);


typedef enum
{
    TR_RPC_TORRENT_ADDED,
    TR_RPC_TORRENT_STARTED,
    TR_RPC_TORRENT_STOPPED,
    TR_RPC_TORRENT_REMOVING,
    TR_RPC_TORRENT_TRASHING, /* _REMOVING + delete local data */
    TR_RPC_TORRENT_CHANGED, /* catch-all for the "torrent-set" rpc method */
    TR_RPC_TORRENT_MOVED,
    TR_RPC_SESSION_CHANGED,
    TR_RPC_SESSION_QUEUE_POSITIONS_CHANGED, /* catch potentially multiple torrents being moved in the queue */
    TR_RPC_SESSION_CLOSE
}
tr_rpc_callback_type;

typedef enum
{
    /* no special handling is needed by the caller */
    TR_RPC_OK            = 0,

    /* indicates to the caller that the client will take care of
     * removing the torrent itself. For example the client may
     * need to keep the torrent alive long enough to cleanly close
     * some resources in another thread. */
    TR_RPC_NOREMOVE   = (1 << 1)
}
tr_rpc_callback_status;

typedef tr_rpc_callback_status (*tr_rpc_func)(tr_session          * session,
                                              tr_rpc_callback_type  type,
                                              struct tr_torrent   * tor_or_null,
                                              void                * user_data);

/**
 * Register to be notified whenever something is changed via RPC,
 * such as a torrent being added, removed, started, stopped, etc.
 *
 * func is invoked FROM LIBTRANSMISSION'S THREAD!
 * This means func must be fast (to avoid blocking peers),
 * shouldn't call libtransmission functions (to avoid deadlock),
 * and shouldn't modify client-level memory without using a mutex!
 */
void tr_sessionSetRPCCallback (tr_session   * session,
                               tr_rpc_func    func,
                               void         * user_data);

/**
***
**/

/** @brief Used by tr_sessionGetStats () and tr_sessionGetCumulativeStats () */
typedef struct tr_session_stats
{
    float       ratio;        /* TR_RATIO_INF, TR_RATIO_NA, or total up/down */
    uint64_t    uploadedBytes; /* total up */
    uint64_t    downloadedBytes; /* total down */
    uint64_t    filesAdded;   /* number of files added */
    uint64_t    sessionCount; /* program started N times */
    uint64_t    secondsActive; /* how long Transmisson's been running */
}
tr_session_stats;

/** @brief Get bandwidth use statistics for the current session */
void tr_sessionGetStats (const tr_session * session,
                         tr_session_stats * setme);

/** @brief Get cumulative bandwidth statistics for current and past sessions */
void tr_sessionGetCumulativeStats (const tr_session * session,
                                   tr_session_stats * setme);

void tr_sessionClearStats (tr_session * session);

/**
 * @brief Set whether or not torrents are allowed to do peer exchanges.
 *
 * PEX is always disabled in private torrents regardless of this.
 * In public torrents, PEX is enabled by default.
 */
void  tr_sessionSetPexEnabled (tr_session  * session, bool isEnabled);
bool  tr_sessionIsPexEnabled (const tr_session * session);

bool  tr_sessionIsDHTEnabled (const tr_session * session);
void  tr_sessionSetDHTEnabled (tr_session * session, bool);

bool  tr_sessionIsUTPEnabled (const tr_session * session);
void  tr_sessionSetUTPEnabled (tr_session * session, bool);

bool  tr_sessionIsLPDEnabled (const tr_session * session);
void  tr_sessionSetLPDEnabled (tr_session * session, bool enabled);

void  tr_sessionSetCacheLimit_MB (tr_session * session, int mb);
int   tr_sessionGetCacheLimit_MB (const tr_session * session);

tr_encryption_mode tr_sessionGetEncryption (tr_session * session);
void               tr_sessionSetEncryption (tr_session * session,
                                            tr_encryption_mode    mode);


/***********************************************************************
** Incoming Peer Connections Port
*/

void  tr_sessionSetPortForwardingEnabled (tr_session  * session,
                                          bool          enabled);

bool tr_sessionIsPortForwardingEnabled (const tr_session  * session);

void  tr_sessionSetPeerPort (tr_session  * session,
                             tr_port       port);

tr_port tr_sessionGetPeerPort (const tr_session * session);

tr_port tr_sessionSetPeerPortRandom (tr_session  * session);

void  tr_sessionSetPeerPortRandomOnStart (tr_session * session, bool random);

bool  tr_sessionGetPeerPortRandomOnStart (tr_session * session);

typedef enum
{
    TR_PORT_ERROR,
    TR_PORT_UNMAPPED,
    TR_PORT_UNMAPPING,
    TR_PORT_MAPPING,
    TR_PORT_MAPPED
}
tr_port_forwarding;

tr_port_forwarding tr_sessionGetPortForwarding (const tr_session * session);

typedef enum
{
    TR_CLIENT_TO_PEER = 0, TR_UP = 0,
    TR_PEER_TO_CLIENT = 1, TR_DOWN = 1
}
tr_direction;

/***
****
***/

/***
****  Primary session speed limits
***/

void         tr_sessionSetSpeedLimit_KBps (tr_session *, tr_direction, unsigned int KBps);
unsigned int tr_sessionGetSpeedLimit_KBps (const tr_session *, tr_direction);

void  tr_sessionLimitSpeed       (tr_session *, tr_direction, bool);
bool  tr_sessionIsSpeedLimited   (const tr_session *, tr_direction);


/***
****  Alternative speed limits that are used during scheduled times
***/

void         tr_sessionSetAltSpeed_KBps (tr_session *, tr_direction, unsigned int Bps);
unsigned int tr_sessionGetAltSpeed_KBps (const tr_session *, tr_direction);

void     tr_sessionUseAltSpeed      (tr_session *, bool);
bool     tr_sessionUsesAltSpeed     (const tr_session *);

void     tr_sessionUseAltSpeedTime  (tr_session *, bool);
bool  tr_sessionUsesAltSpeedTime    (const tr_session *);

void     tr_sessionSetAltSpeedBegin (tr_session *, int minsSinceMidnight);
int      tr_sessionGetAltSpeedBegin (const tr_session *);

void     tr_sessionSetAltSpeedEnd   (tr_session *, int minsSinceMidnight);
int      tr_sessionGetAltSpeedEnd   (const tr_session *);

typedef enum
{
    TR_SCHED_SUN      = (1<<0),
    TR_SCHED_MON      = (1<<1),
    TR_SCHED_TUES     = (1<<2),
    TR_SCHED_WED      = (1<<3),
    TR_SCHED_THURS    = (1<<4),
    TR_SCHED_FRI      = (1<<5),
    TR_SCHED_SAT      = (1<<6),
    TR_SCHED_WEEKDAY  = (TR_SCHED_MON|TR_SCHED_TUES|TR_SCHED_WED|
                         TR_SCHED_THURS|TR_SCHED_FRI),
    TR_SCHED_WEEKEND  = (TR_SCHED_SUN|TR_SCHED_SAT),
    TR_SCHED_ALL      = (TR_SCHED_WEEKDAY|TR_SCHED_WEEKEND)
}
tr_sched_day;

void         tr_sessionSetAltSpeedDay (tr_session *, tr_sched_day day);
tr_sched_day tr_sessionGetAltSpeedDay (const tr_session *);

typedef void (tr_altSpeedFunc)(tr_session *,
                                  bool active,
                                  bool userDriven,
                                  void *);

void  tr_sessionClearAltSpeedFunc (tr_session *);
void  tr_sessionSetAltSpeedFunc  (tr_session *, tr_altSpeedFunc *, void *);


bool  tr_sessionGetActiveSpeedLimit_KBps (const tr_session  * session,
                                          tr_direction        dir,
                                          double            * setme);

/***
****
***/

double     tr_sessionGetRawSpeed_KBps (const tr_session *, tr_direction);

void       tr_sessionSetRatioLimited (tr_session *, bool isLimited);
bool       tr_sessionIsRatioLimited (const tr_session *);

void       tr_sessionSetRatioLimit  (tr_session *, double desiredRatio);
double     tr_sessionGetRatioLimit  (const tr_session *);

void       tr_sessionSetIdleLimited (tr_session *, bool isLimited);
bool       tr_sessionIsIdleLimited (const tr_session *);

void       tr_sessionSetIdleLimit (tr_session *, uint16_t idleMinutes);
uint16_t   tr_sessionGetIdleLimit (const tr_session *);

void       tr_sessionSetPeerLimit (tr_session *, uint16_t maxGlobalPeers);
uint16_t   tr_sessionGetPeerLimit (const tr_session *);

void       tr_sessionSetPeerLimitPerTorrent (tr_session *, uint16_t maxPeers);
uint16_t   tr_sessionGetPeerLimitPerTorrent (const tr_session *);

void       tr_sessionSetPaused      (tr_session *, bool isPaused);
bool       tr_sessionGetPaused      (const tr_session *);

void       tr_sessionSetDeleteSource (tr_session *, bool deleteSource);
bool       tr_sessionGetDeleteSource (const tr_session *);

tr_priority_t   tr_torrentGetPriority (const tr_torrent *);
void            tr_torrentSetPriority (tr_torrent *, tr_priority_t);

/***
****
****  Torrent Queueing
****
****  There are independent queues for seeding (TR_UP) and leeching (TR_DOWN).
****
****  If the session already has enough non-stalled seeds/leeches when
****  tr_torrentStart () is called, the torrent will be moved into the
****  appropriate queue and its state will be TR_STATUS_{DOWNLOAD,SEED}_WAIT.
****
****  To bypass the queue and unconditionally start the torrent use
****  tr_torrentStartNow ().
****
****  Torrents can be moved in the queue using the simple functions
****  tr_torrentQueueMove{Top,Up,Down,Bottom}. They can be moved to
****  arbitrary points in the queue with tr_torrentSetQueuePosition ().
****
***/


/** @brief Like tr_torrentStart (), but resumes right away regardless of the queues. */
void tr_torrentStartNow       (tr_torrent *);

/** @brief Return the queued torrent's position in the queue it's in. [0...n) */
int  tr_torrentGetQueuePosition (const tr_torrent *);

/** @brief Set the queued torrent's position in the queue it's in.
 * Special cases: pos <= 0 moves to the front; pos >= queue length moves to the back */
void tr_torrentSetQueuePosition (tr_torrent *, int queuePosition);

/**
**/

/** @brief Convenience function for moving a batch of torrents to the front of their queue (s) */
void tr_torrentsQueueMoveTop  (tr_torrent ** torrents, int torrentCount);

/** @brief Convenience function for moving a batch of torrents ahead one step in their queue (s) */
void tr_torrentsQueueMoveUp   (tr_torrent ** torrents, int torrentCount);

/** @brief Convenience function for moving a batch of torrents back one step in their queue (s) */
void tr_torrentsQueueMoveDown (tr_torrent ** torrents, int torrentCount);

/** @brief Convenience function for moving a batch of torrents to the back of their queue (s) */
void tr_torrentsQueueMoveBottom (tr_torrent ** torrents, int torrentCount);

/**
**/

/** @brief Set the number of torrents allowed to download (if direction is TR_DOWN) or seed (if direction is TR_UP) at the same time */
void tr_sessionSetQueueSize   (tr_session *, tr_direction, int max_simultaneous_seed_torrents);

/** @brief Return the number of torrents allowed to download (if direction is TR_DOWN) or seed (if direction is TR_UP) at the same time */
int  tr_sessionGetQueueSize   (const tr_session *, tr_direction);

/** @brief Set whether or not to limit how many torrents can download (TR_DOWN) or seed (TR_UP) at the same time  */
void tr_sessionSetQueueEnabled (tr_session *, tr_direction, bool do_limit_simultaneous_seed_torrents);

/** @brief Return true if we're limiting how many torrents can concurrently download (TR_DOWN) or seed (TR_UP) at the same time */
bool tr_sessionGetQueueEnabled (const tr_session *, tr_direction);

/**
**/

/** @brief Consider torrent as 'stalled' when it's been inactive for N minutes.
    Stalled torrents are left running but are not counted by tr_sessionGetQueueSize (). */
void tr_sessionSetQueueStalledMinutes (tr_session *, int minutes);

/** @return the number of minutes a torrent can be idle before being considered as stalled */
int  tr_sessionGetQueueStalledMinutes (const tr_session *);

/** @brief Set whether or not to count torrents idle for over N minutes as 'stalled' */
void tr_sessionSetQueueStalledEnabled (tr_session *, bool);

/** @return true if we're torrents idle for over N minutes will be flagged as 'stalled' */
bool tr_sessionGetQueueStalledEnabled (const tr_session *);

/**
**/

/** @brief Set a callback that is invoked when the queue starts a torrent */
void tr_torrentSetQueueStartCallback (tr_torrent * torrent, void (*callback)(tr_torrent *, void *), void * user_data);


/***
****
****
***/

/**
 *  Load all the torrents in tr_getTorrentDir ().
 *  This can be used at startup to kickstart all the torrents
 *  from the previous session.
 */
tr_torrent ** tr_sessionLoadTorrents (tr_session  * session,
                                      tr_ctor     * ctor,
                                      int         * setmeCount);

/**
***
**/

bool tr_sessionIsTorrentDoneScriptEnabled (const tr_session *);

void tr_sessionSetTorrentDoneScriptEnabled (tr_session *, bool isEnabled);

const char * tr_sessionGetTorrentDoneScript (const tr_session *);

void tr_sessionSetTorrentDoneScript (tr_session *, const char * scriptFilename);


/** @} */

/**
***
**/


/***********************************************************************
** Message Logging
*/

typedef enum
{
    TR_MSG_ERR = 1,
    TR_MSG_INF = 2,
    TR_MSG_DBG = 3
}
tr_msg_level;

void tr_setMessageLevel (tr_msg_level);

typedef struct tr_msg_list
{
    /* TR_MSG_ERR, TR_MSG_INF, or TR_MSG_DBG */
    tr_msg_level level;

    /* The line number in the source file where this message originated */
    int line;

    /* Time the message was generated */
    time_t when;

    /* The torrent associated with this message,
     * or a module name such as "Port Forwarding" for non-torrent messages,
     * or NULL. */
    char *  name;

    /* The message */
    char *  message;

    /* The source file where this message originated */
    const char * file;

    /* linked list of messages */
    struct tr_msg_list * next;
}
tr_msg_list;

void          tr_setMessageQueuing (bool isEnabled);

bool          tr_getMessageQueuing (void);

tr_msg_list * tr_getQueuedMessages (void);

void          tr_freeMessageList (tr_msg_list * freeme);

/** @addtogroup Blocklists
    @{ */

/**
 * Specify a range of IPs for Transmission to block.
 *
 * Filename must be an uncompressed ascii file.
 *
 * libtransmission does not keep a handle to `filename'
 * after this call returns, so the caller is free to
 * keep or delete `filename' as it wishes.
 * libtransmission makes its own copy of the file
 * massaged into a binary format easier to search.
 *
 * The caller only needs to invoke this when the blocklist
 * has changed.
 *
 * Passing NULL for a filename will clear the blocklist.
 */
int     tr_blocklistSetContent (tr_session       * session,
                                   const char       * filename);

int     tr_blocklistGetRuleCount (const tr_session * session);

bool    tr_blocklistExists     (const tr_session * session);

bool    tr_blocklistIsEnabled  (const tr_session * session);

void    tr_blocklistSetEnabled (tr_session       * session,
                                   bool               isEnabled);

/** @brief The blocklist that ges updated when an RPC client
           invokes the "blocklist-update" method */
void tr_blocklistSetURL       (tr_session *, const char * url);

const char * tr_blocklistGetURL (const tr_session *);

/** @brief the file in the $config/blocklists/ directory that's
           used by tr_blocklistSetContent () and "blocklist-update" */
#define DEFAULT_BLOCKLIST_FILENAME "blocklist.bin"

/** @} */


/** @addtogroup tr_ctor Torrent Constructors
    @{

    Instantiating a tr_torrent had gotten more complicated as features were
    added. At one point there were four functions to check metainfo and five
    to create a tr_torrent object.

    To remedy this, a Torrent Constructor (struct tr_ctor) has been introduced:
    - Simplifies the API to two functions: tr_torrentParse () and tr_torrentNew ()
    - You can set the fields you want; the system sets defaults for the rest.
    - You can specify whether or not your fields should supercede resume's.
    - We can add new features to tr_ctor without breaking tr_torrentNew ()'s API.

    All the tr_ctor{Get,Set}* () functions with a return value return
    an error number, or zero if no error occurred.

    You must call one of the SetMetainfo () functions before creating
    a torrent with a tr_ctor. The other functions are optional.

    You can reuse a single tr_ctor to create a batch of torrents --
    just call one of the SetMetainfo () functions between each
    tr_torrentNew () call.

    Every call to tr_ctorSetMetainfo* () frees the previous metainfo.
 */

typedef enum
{
    TR_FALLBACK, /* indicates the ctor value should be used only
                    in case of missing resume settings */

    TR_FORCE, /* indicates the ctor value should be used
                 regardless of what's in the resume settings */
}
tr_ctorMode;

/** @brief Create a torrent constructor object used to instantiate a tr_torrent
    @param session the tr_session. This is required if you're going to call
                   tr_torrentNew (), but you can use NULL for tr_torrentParse ().
    @see tr_torrentNew (), tr_torrentParse () */
tr_ctor* tr_ctorNew (const tr_session * session_or_NULL);

/** @brief Free a torrent constructor object */
void  tr_ctorFree (tr_ctor * ctor);

/** @brief Set whether or not to delete the source .torrent file
           when the torrent is added. (Default: False) */
void  tr_ctorSetDeleteSource (tr_ctor * ctor, bool doDelete);

/** @brief Set the constructor's metainfo from a magnet link */
int tr_ctorSetMetainfoFromMagnetLink (tr_ctor * ctor, const char * magnet);

/** @brief Set the constructor's metainfo from a raw benc already in memory */
int tr_ctorSetMetainfo (tr_ctor * ctor, const uint8_t * metainfo, size_t len);

/** @brief Set the constructor's metainfo from a local .torrent file */
int tr_ctorSetMetainfoFromFile (tr_ctor * ctor, const char * filename);

/**
 * @brief Set the metainfo from an existing file in tr_getTorrentDir ().
 *
 * This is used by the Mac client on startup to pick and choose which
 * torrents to load
 */
int tr_ctorSetMetainfoFromHash (tr_ctor * ctor, const char * hashString);

/** @brief Set how many peers this torrent can connect to. (Default: 50) */
void tr_ctorSetPeerLimit (tr_ctor * ctor, tr_ctorMode mode, uint16_t limit);

/** @brief Set the download folder for the torrent being added with this ctor.
    @see tr_ctorSetDownloadDir ()
    @see tr_sessionInit () */
void  tr_ctorSetDownloadDir (tr_ctor      * ctor,
                             tr_ctorMode    mode,
                             const char   * directory);

/**
 * @brief Set the incompleteDir for this torrent.
 *
 * This is not a supported API call.
 * It only exists so the mac client can migrate
 * its older incompleteDir settings, and that's
 * the only place where it should be used.
 */
void tr_ctorSetIncompleteDir (tr_ctor * ctor, const char * directory);

/** Set whether or not the torrent begins downloading/seeding when created.
  (Default: not paused) */
void        tr_ctorSetPaused (tr_ctor      * ctor,
                              tr_ctorMode    mode,
                              bool           isPaused);

/** @brief Set the priorities for files in a torrent */
void        tr_ctorSetFilePriorities (tr_ctor                * ctor,
                                      const tr_file_index_t  * files,
                                      tr_file_index_t          fileCount,
                                      tr_priority_t            priority);

/** @brief Set the download flag for files in a torrent */
void        tr_ctorSetFilesWanted (tr_ctor                * ctor,
                                   const tr_file_index_t  * fileIndices,
                                   tr_file_index_t          fileCount,
                                   bool                     wanted);


/** @brief Get this peer constructor's peer limit */
int         tr_ctorGetPeerLimit (const tr_ctor * ctor,
                                 tr_ctorMode     mode,
                                 uint16_t *      setmeCount);

/** @brief Get the "isPaused" flag from this peer constructor */
int         tr_ctorGetPaused (const tr_ctor * ctor,
                              tr_ctorMode     mode,
                              bool          * setmeIsPaused);

/** @brief Get the download path from this peer constructor */
int         tr_ctorGetDownloadDir (const tr_ctor  * ctor,
                                   tr_ctorMode      mode,
                                   const char    ** setmeDownloadDir);

/** @brief Get the incomplete directory from this peer constructor */
int         tr_ctorGetIncompleteDir (const tr_ctor  * ctor,
                                     const char    ** setmeIncompleteDir);

/** @brief Get the metainfo from this peer constructor */
int         tr_ctorGetMetainfo (const tr_ctor            * ctor,
                                const struct tr_variant ** setme);

/** @brief Get the "delete .torrent file" flag from this peer constructor */
int         tr_ctorGetDeleteSource (const tr_ctor  * ctor,
                                    bool           * setmeDoDelete);

/** @brief Get the tr_session poiner from this peer constructor */
tr_session* tr_ctorGetSession (const tr_ctor * ctor);

/** @brief Get the .torrent file that this ctor's metainfo came from,
           or NULL if tr_ctorSetMetainfoFromFile () wasn't used */
const char* tr_ctorGetSourceFile (const tr_ctor * ctor);

typedef enum
{
    TR_PARSE_OK,
    TR_PARSE_ERR,
    TR_PARSE_DUPLICATE
}
tr_parse_result;

/**
 * @brief Parses the specified metainfo
 *
 * @return TR_PARSE_ERR if parsing failed;
 *         TR_PARSE_OK if parsing succeeded and it's not a duplicate;
 *         TR_PARSE_DUPLICATE if parsing succeeded but it's a duplicate.
 *
 * @param setme_info If parsing is successful and setme_info is non-NULL,
 *                   the parsed metainfo is stored there and sould be freed
 *                   by calling tr_metainfoFree () when no longer needed.
 *
 * Notes:
 *
 * 1. tr_torrentParse () won't be able to check for duplicates -- and therefore
 *    won't return TR_PARSE_DUPLICATE -- unless ctor's "download-dir" and
 *    session variable is set.
 *
 * 2. setme_info->torrent's value can't be set unless ctor's session variable
 *    is set.
 */
tr_parse_result  tr_torrentParse (const tr_ctor  * ctor,
                                  tr_info        * setme_info_or_NULL);

/** @brief free a metainfo
    @see tr_torrentParse */
void tr_metainfoFree (tr_info * inf);


/** Instantiate a single torrent.
    @return 0 on success,
            TR_EINVALID if the torrent couldn't be parsed, or
            TR_EDUPLICATE if there's already a matching torrent object. */
tr_torrent * tr_torrentNew (const tr_ctor   * ctor,
                            int             * setmeError);

/** @} */

/***********************************************************************
 ***
 ***  TORRENTS
 **/

/** @addtogroup tr_torrent Torrents
    @{ */

typedef int tr_fileFunc (const char * filename);

/** @brief Removes our .torrent and .resume files for this torrent */
void tr_torrentRemove (tr_torrent  * torrent,
                       bool          removeLocalData,
                       tr_fileFunc   removeFunc);

/** @brief Start a torrent */
void tr_torrentStart (tr_torrent * torrent);

/** @brief Stop (pause) a torrent */
void tr_torrentStop (tr_torrent * torrent);


typedef void (tr_torrent_rename_done_func)(tr_torrent  * torrent,
                                           const char  * oldpath,
                                           const char  * newname,
                                           int           error,
                                           void        * user_data);

/**
 * @brief Rename a file or directory in a torrent.
 *
 * @tor: the torrent whose path will be renamed.
 * @oldpath: the path to the file or folder that will be renamed
 * @newname: the file or folder's new name
 * @callback: the callback invoked when the renaming finishes, or NULL
 * @callback_data: the pointer to pass in the callback's user_data arg
 *
 * As a special case, renaming the root file in a torrent will allso
 * update tr_info.name.
 *
 * EXAMPLES
 *
 *   Consider a tr_torrent where its
 *   info.files[0].name is "frobnitz-linux/checksum" and
 *   info.files[1].name is "frobnitz-linux/frobnitz.iso".
 *
 *   1. tr_torrentRenamePath (tor, "frobnitz-linux", "foo") will rename
 *      the "frotbnitz-linux" folder as "foo", and update both info.name
 *      and info.files[*].name.
 *
 *   2. tr_torrentRenamePath (tor, "frobnitz-linux/checksum", "foo") will
 *      rename the "frobnitz-linux/checksum" file as "foo" and update
 *      files[0].name to "frobnitz-linux/foo".
 *
 * RETURN
 *
 *   Changing tr_info's contents requires a session lock, so this function
 *   returns asynchronously to avoid blocking. If you don't want to be notified
 *   when the function has finished, you can pass NULL as the callback arg.
 *
 *   On success, the callback's error argument will be 0.
 *
 *   If oldpath can't be found in files[*].name, or if newname is already
 *   in files[*].name, or contains a directory separator, or is NULL, "",
 *   ".", or "..", the error argument will be EINVAL.
 *
 *   If the path exists on disk but can't be renamed, the error argument
 *   will be the errno set by rename().
 */
void tr_torrentRenamePath (tr_torrent                  * tor,
                           const char                  * oldpath,
                           const char                  * newname,
                           tr_torrent_rename_done_func   callback,
                           void                        * callback_user_data);

enum
{
    TR_LOC_MOVING,
    TR_LOC_DONE,
    TR_LOC_ERROR
};

/**
 * @brief Tell transmsision where to find this torrent's local data.
 *
 * if move_from_previous_location is `true', the torrent's incompleteDir
 * will be clobberred s.t. additional files being added will be saved
 * to the torrent's downloadDir.
 */
void tr_torrentSetLocation (tr_torrent       * torrent,
                            const char       * location,
                            bool               move_from_previous_location,
                            volatile double  * setme_progress,
                            volatile int     * setme_state);

uint64_t tr_torrentGetBytesLeftToAllocate (const tr_torrent * torrent);

/**
 * @brief Returns this torrent's unique ID.
 *
 * IDs are good as simple lookup keys, but are not persistent
 * between sessions. If you need that, use tr_info.hash or
 * tr_info.hashString.
 */
int tr_torrentId (const tr_torrent * torrent);

tr_torrent* tr_torrentFindFromId (tr_session * session, int id);

tr_torrent* tr_torrentFindFromHash (tr_session     * session,
                                    const uint8_t  * hash);

/** @brief Convenience function similar to tr_torrentFindFromHash () */
tr_torrent* tr_torrentFindFromMagnetLink (tr_session * session,
                                          const char * link);

/**
 * @return this torrent's name.
 */
const char* tr_torrentName (const tr_torrent *);

/**
 * @brief find the location of a torrent's file by looking with and without
 *        the ".part" suffix, looking in downloadDir and incompleteDir, etc.
 * @return a newly-allocated string (that must be tr_freed () by the caller
 *         when done) that gives the location of this file on disk,
 *         or NULL if no file exists yet.
 * @param tor the torrent whose file we're looking for
 * @param fileNum the fileIndex, in [0...tr_info.fileCount)
 */
char* tr_torrentFindFile (const tr_torrent * tor, tr_file_index_t fileNo);


/***
****  Torrent speed limits
****
***/

void         tr_torrentSetSpeedLimit_KBps (tr_torrent *, tr_direction, unsigned int KBps);
unsigned int tr_torrentGetSpeedLimit_KBps (const tr_torrent *, tr_direction);

void         tr_torrentUseSpeedLimit      (tr_torrent *, tr_direction, bool);
bool         tr_torrentUsesSpeedLimit     (const tr_torrent *, tr_direction);

void         tr_torrentUseSessionLimits   (tr_torrent *, bool);
bool         tr_torrentUsesSessionLimits  (const tr_torrent *);


/****
*****  Ratio Limits
****/

typedef enum
{
    /* follow the global settings */
    TR_RATIOLIMIT_GLOBAL    = 0,

    /* override the global settings, seeding until a certain ratio */
    TR_RATIOLIMIT_SINGLE    = 1,

    /* override the global settings, seeding regardless of ratio */
    TR_RATIOLIMIT_UNLIMITED = 2
}
tr_ratiolimit;

void          tr_torrentSetRatioMode (tr_torrent         * tor,
                                      tr_ratiolimit        mode);

tr_ratiolimit tr_torrentGetRatioMode (const tr_torrent   * tor);

void          tr_torrentSetRatioLimit (tr_torrent        * tor,
                                       double              ratio);

double        tr_torrentGetRatioLimit (const tr_torrent  * tor);


bool          tr_torrentGetSeedRatio  (const tr_torrent *, double * ratio);


/****
*****  Idle Time Limits
****/

typedef enum
{
    /* follow the global settings */
    TR_IDLELIMIT_GLOBAL    = 0,

    /* override the global settings, seeding until a certain idle time */
    TR_IDLELIMIT_SINGLE    = 1,

    /* override the global settings, seeding regardless of activity */
    TR_IDLELIMIT_UNLIMITED = 2
}
tr_idlelimit;

void          tr_torrentSetIdleMode (tr_torrent         * tor,
                                      tr_idlelimit         mode);

tr_idlelimit  tr_torrentGetIdleMode (const tr_torrent   * tor);

void          tr_torrentSetIdleLimit (tr_torrent         * tor,
                                      uint16_t             idleMinutes);

uint16_t      tr_torrentGetIdleLimit (const tr_torrent   * tor);


bool          tr_torrentGetSeedIdle (const tr_torrent *, uint16_t * minutes);

/****
*****  Peer Limits
****/

void          tr_torrentSetPeerLimit (tr_torrent * tor, uint16_t peerLimit);

uint16_t      tr_torrentGetPeerLimit (const tr_torrent * tor);

/****
*****  File Priorities
****/

enum
{
    TR_PRI_LOW    = -1,
    TR_PRI_NORMAL =  0, /* since NORMAL is 0, memset initializes nicely */
    TR_PRI_HIGH   =  1
};

/**
 * @brief Set a batch of files to a particular priority.
 *
 * @param priority must be one of TR_PRI_NORMAL, _HIGH, or _LOW
 */
void tr_torrentSetFilePriorities (tr_torrent             * torrent,
                                  const tr_file_index_t  * files,
                                  tr_file_index_t          fileCount,
                                  tr_priority_t            priority);

/**
 * @brief Get this torrent's file priorities.
 *
 * @return A malloc ()ed array of tor->info.fileCount items,
 *         each holding a TR_PRI_NORMAL, TR_PRI_HIGH, or TR_PRI_LOW.
 *         It's the caller's responsibility to free () this.
 */
tr_priority_t*  tr_torrentGetFilePriorities (const tr_torrent * torrent);

/** @brief Set a batch of files to be downloaded or not. */
void tr_torrentSetFileDLs (tr_torrent             * torrent,
                           const tr_file_index_t  * files,
                           tr_file_index_t          fileCount,
                           bool                     do_download);


const tr_info * tr_torrentInfo (const tr_torrent * torrent);

/* Raw function to change the torrent's downloadDir field.
   This should only be used by libtransmission or to bootstrap
   a newly-instantiated tr_torrent object. */
void tr_torrentSetDownloadDir (tr_torrent  * torrent, const char * path);

const char * tr_torrentGetDownloadDir (const tr_torrent * torrent);

/**
 * Returns the root directory of where the torrent is.
 *
 * This will usually be the downloadDir. However if the torrent
 * has an incompleteDir enabled and hasn't finished downloading
 * yet, that will be returned instead.
 */
const char * tr_torrentGetCurrentDir (const tr_torrent * tor);


char* tr_torrentInfoGetMagnetLink (const tr_info * inf);

/**
 * Returns a newly-allocated string with a magnet link of the torrent.
 * Use tr_free () to free the string when done.
 */
static inline
char* tr_torrentGetMagnetLink (const tr_torrent * tor)
{
    return tr_torrentInfoGetMagnetLink (tr_torrentInfo (tor));
}

/**
***
**/


/** @brief a part of tr_info that represents a single tracker */
typedef struct tr_tracker_info
{
    int      tier;
    char *   announce;
    char *   scrape;
    uint32_t id; /* unique identifier used to match to a tr_tracker_stat */
}
tr_tracker_info;

/**
 * @brief Modify a torrent's tracker list.
 *
 * This updates both the `torrent' object's tracker list
 * and the metainfo file in tr_sessionGetConfigDir ()'s torrent subdirectory.
 *
 * @param torrent The torrent whose tracker list is to be modified
 * @param trackers An array of trackers, sorted by tier from first to last.
 *                 NOTE: only the `tier' and `announce' fields are used.
 *                 libtransmission derives `scrape' from `announce'
 *                 and reassigns 'id'.
 * @param trackerCount size of the `trackers' array
 */
bool
tr_torrentSetAnnounceList (tr_torrent             * torrent,
                           const tr_tracker_info  * trackers,
                           int                      trackerCount);


/**
***
**/

typedef enum
{
    TR_LEECH,        /* doesn't have all the desired pieces */
    TR_SEED,         /* has the entire torrent */
    TR_PARTIAL_SEED  /* has the desired pieces, but not the entire torrent */
}
tr_completeness;

/**
 * @param wasRunning whether or not the torrent was running when
 *                   it changed its completeness state
 */
typedef void (tr_torrent_completeness_func)(tr_torrent       * torrent,
                                            tr_completeness    completeness,
                                            bool               wasRunning,
                                            void             * user_data);

typedef void (tr_torrent_ratio_limit_hit_func)(tr_torrent   * torrent,
                                               void         * user_data);

typedef void (tr_torrent_idle_limit_hit_func)(tr_torrent   * torrent,
                                              void         * user_data);


/**
 * Register to be notified whenever a torrent's "completeness"
 * changes. This will be called, for example, when a torrent
 * finishes downloading and changes from TR_LEECH to
 * either TR_SEED or TR_PARTIAL_SEED.
 *
 * func is invoked FROM LIBTRANSMISSION'S THREAD!
 * This means func must be fast (to avoid blocking peers),
 * shouldn't call libtransmission functions (to avoid deadlock),
 * and shouldn't modify client-level memory without using a mutex!
 *
 * @see tr_completeness
 */
void tr_torrentSetCompletenessCallback (
         tr_torrent                    * torrent,
         tr_torrent_completeness_func    func,
         void                          * user_data);

void tr_torrentClearCompletenessCallback (tr_torrent * torrent);



typedef void (tr_torrent_metadata_func)(tr_torrent  * torrent,
                                           void        * user_data);
/**
 * Register to be notified whenever a torrent changes from
 * having incomplete metadata to having complete metadata.
 * This happens when a magnet link finishes downloading
 * metadata from its peers.
 */
void tr_torrentSetMetadataCallback (
         tr_torrent                * tor,
         tr_torrent_metadata_func     func,
         void                      * user_data);

/**
 * Register to be notified whenever a torrent's ratio limit
 * has been hit. This will be called when the torrent's
 * ul/dl ratio has met or exceeded the designated ratio limit.
 *
 * Has the same restrictions as tr_torrentSetCompletenessCallback
 */
void tr_torrentSetRatioLimitHitCallback (
     tr_torrent                     * torrent,
     tr_torrent_ratio_limit_hit_func  func,
     void                           * user_data);

void tr_torrentClearRatioLimitHitCallback (tr_torrent * torrent);

/**
 * Register to be notified whenever a torrent's idle limit
 * has been hit. This will be called when the seeding torrent's
 * idle time has met or exceeded the designated idle limit.
 *
 * Has the same restrictions as tr_torrentSetCompletenessCallback
 */
void tr_torrentSetIdleLimitHitCallback (
     tr_torrent                          * torrent,
     tr_torrent_idle_limit_hit_func        func,
     void                                * user_data);

void tr_torrentClearIdleLimitHitCallback (tr_torrent * torrent);


/**
 * MANUAL ANNOUNCE
 *
 * Trackers usually set an announce interval of 15 or 30 minutes.
 * Users can send one-time announce requests that override this
 * interval by calling tr_torrentManualUpdate ().
 *
 * The wait interval for tr_torrentManualUpdate () is much smaller.
 * You can test whether or not a manual update is possible
 * (for example, to desensitize the button) by calling
 * tr_torrentCanManualUpdate ().
 */

void tr_torrentManualUpdate (tr_torrent * torrent);

bool tr_torrentCanManualUpdate (const tr_torrent * torrent);

/***
****  tr_peer_stat
***/

typedef struct tr_peer_stat
{
    bool  isUTP;

    bool  isEncrypted;
    bool  isDownloadingFrom;
    bool  isUploadingTo;
    bool  isSeed;

    bool  peerIsChoked;
    bool  peerIsInterested;
    bool  clientIsChoked;
    bool  clientIsInterested;
    bool  isIncoming;

    uint8_t  from;
    tr_port  port;

    char     addr[TR_INET6_ADDRSTRLEN];
    char     client[80];
    char     flagStr[32];

    float    progress;
    double   rateToPeer_KBps;
    double   rateToClient_KBps;


/***
****  THESE NEXT FOUR FIELDS ARE EXPERIMENTAL.
****  Don't rely on them; they'll probably go away
***/
    /* how many blocks we've sent to this peer in the last 120 seconds */
    uint32_t  blocksToPeer;
    /* how many blocks this client's sent to us in the last 120 seconds */
    uint32_t  blocksToClient;
    /* how many requests to this peer that we've cancelled in the last 120 seconds */
    uint32_t  cancelsToPeer;
    /* how many requests this peer made of us, then cancelled, in the last 120 seconds */
    uint32_t  cancelsToClient;

    /* how many requests the peer has made that we haven't responded to yet */
    int      pendingReqsToClient;

    /* how many requests we've made and are currently awaiting a response for */
    int      pendingReqsToPeer;
}
tr_peer_stat;

tr_peer_stat * tr_torrentPeers (const tr_torrent * torrent,
                                int              * peerCount);

void           tr_torrentPeersFree (tr_peer_stat * peerStats,
                                    int            peerCount);

/***
****  tr_tracker_stat
***/

typedef enum
{
    /* we won't (announce,scrape) this torrent to this tracker because
     * the torrent is stopped, or because of an error, or whatever */
    TR_TRACKER_INACTIVE = 0,

    /* we will (announce,scrape) this torrent to this tracker, and are
     * waiting for enough time to pass to satisfy the tracker's interval */
    TR_TRACKER_WAITING = 1,

    /* it's time to (announce,scrape) this torrent, and we're waiting on a
     * a free slot to open up in the announce manager */
    TR_TRACKER_QUEUED = 2,

    /* we're (announcing,scraping) this torrent right now */
    TR_TRACKER_ACTIVE = 3
}
tr_tracker_state;

typedef struct
{
    /* how many downloads this tracker knows of (-1 means it does not know) */
    int downloadCount;

    /* whether or not we've ever sent this tracker an announcement */
    bool hasAnnounced;

    /* whether or not we've ever scraped to this tracker */
    bool hasScraped;

    /* human-readable string identifying the tracker */
    char host[1024];

    /* the full announce URL */
    char announce[1024];

    /* the full scrape URL */
    char scrape[1024];

    /* Transmission uses one tracker per tier,
     * and the others are kept as backups */
    bool isBackup;

    /* is the tracker announcing, waiting, queued, etc */
    tr_tracker_state announceState;

    /* is the tracker scraping, waiting, queued, etc */
    tr_tracker_state scrapeState;

    /* number of peers the tracker told us about last time.
     * if "lastAnnounceSucceeded" is false, this field is undefined */
    int lastAnnouncePeerCount;

    /* human-readable string with the result of the last announce.
       if "hasAnnounced" is false, this field is undefined */
    char lastAnnounceResult[128];

    /* when the last announce was sent to the tracker.
     * if "hasAnnounced" is false, this field is undefined */
    time_t lastAnnounceStartTime;

    /* whether or not the last announce was a success.
       if "hasAnnounced" is false, this field is undefined */
    bool lastAnnounceSucceeded;

    /* whether or not the last announce timed out. */
    bool lastAnnounceTimedOut;

    /* when the last announce was completed.
       if "hasAnnounced" is false, this field is undefined */
    time_t lastAnnounceTime;

    /* human-readable string with the result of the last scrape.
     * if "hasScraped" is false, this field is undefined */
    char lastScrapeResult[128];

    /* when the last scrape was sent to the tracker.
     * if "hasScraped" is false, this field is undefined */
    time_t lastScrapeStartTime;

    /* whether or not the last scrape was a success.
       if "hasAnnounced" is false, this field is undefined */
    bool lastScrapeSucceeded;

    /* whether or not the last scrape timed out. */
    bool lastScrapeTimedOut;

    /* when the last scrape was completed.
       if "hasScraped" is false, this field is undefined */
    time_t lastScrapeTime;

    /* number of leechers this tracker knows of (-1 means it does not know) */
    int leecherCount;

    /* when the next periodic announce message will be sent out.
       if announceState isn't TR_TRACKER_WAITING, this field is undefined */
    time_t nextAnnounceTime;

    /* when the next periodic scrape message will be sent out.
       if scrapeState isn't TR_TRACKER_WAITING, this field is undefined */
    time_t nextScrapeTime;

    /* number of seeders this tracker knows of (-1 means it does not know) */
    int seederCount;

    /* which tier this tracker is in */
    int tier;

    /* used to match to a tr_tracker_info */
    uint32_t id;
}
tr_tracker_stat;

tr_tracker_stat * tr_torrentTrackers (const tr_torrent * torrent,
                                      int              * setmeTrackerCount);

void tr_torrentTrackersFree (tr_tracker_stat * trackerStats,
                             int               trackerCount);



/**
 * @brief get the download speeds for each of this torrent's webseed sources.
 *
 * @return an array of tor->info.webseedCount floats giving download speeds.
 *         Each speed in the array corresponds to the webseed at the same
 *         array index in tor->info.webseeds.
 *         To differentiate "idle" and "stalled" status, idle webseeds will
 *         return -1 instead of 0 KiB/s.
 *         NOTE: always free this array with tr_free () when you're done with it.
 */
double*  tr_torrentWebSpeeds_KBps (const tr_torrent * torrent);

typedef struct tr_file_stat
{
    uint64_t    bytesCompleted;
    float       progress;
}
tr_file_stat;

tr_file_stat * tr_torrentFiles (const tr_torrent  * torrent,
                                tr_file_index_t   * fileCount);

void tr_torrentFilesFree (tr_file_stat     * files,
                          tr_file_index_t    fileCount);


/***********************************************************************
 * tr_torrentAvailability
 ***********************************************************************
 * Use this to draw an advanced progress bar which is 'size' pixels
 * wide. Fills 'tab' which you must have allocated: each byte is set
 * to either -1 if we have the piece, otherwise it is set to the number
 * of connected peers who have the piece.
 **********************************************************************/
void tr_torrentAvailability (const tr_torrent  * torrent,
                             int8_t            * tab,
                             int                 size);

void tr_torrentAmountFinished (const tr_torrent  * torrent,
                               float             * tab,
                               int                 size);

void tr_torrentVerify (tr_torrent * torrent);

/***********************************************************************
 * tr_info
 **********************************************************************/

/** @brief a part of tr_info that represents a single file of the torrent's content */
typedef struct tr_file
{
    uint64_t          length;      /* Length of the file, in bytes */
    char *            name;        /* Path to the file */
    int8_t            priority;    /* TR_PRI_HIGH, _NORMAL, or _LOW */
    int8_t            dnd;         /* "do not download" flag */
    int8_t            is_renamed;  /* true if we're using a different path from the one in the metainfo; ie, if the user has renamed it */
    tr_piece_index_t  firstPiece;  /* We need pieces [firstPiece... */
    tr_piece_index_t  lastPiece;   /* ...lastPiece] to dl this file */
    uint64_t          offset;      /* file begins at the torrent's nth byte */
}
tr_file;

/** @brief a part of tr_info that represents a single piece of the torrent's content */
typedef struct tr_piece
{
    time_t   timeChecked;              /* the last time we tested this piece */
    uint8_t  hash[SHA_DIGEST_LENGTH];  /* pieces hash */
    int8_t   priority;                 /* TR_PRI_HIGH, _NORMAL, or _LOW */
    int8_t   dnd;                      /* "do not download" flag */
}
tr_piece;

/** @brief information about a torrent that comes from its metainfo file */
struct tr_info
{
    /* total size of the torrent, in bytes */
    uint64_t           totalSize;

    /* The original name that came in this torrent's metainfo.
     * CLIENT CODE: NOT USE THIS FIELD. */
    char             * originalName;

    /* The torrent's name. */
    char             * name;

    /* Path to torrent Transmission's internal copy of the .torrent file. */
    char             * torrent;

    char            ** webseeds;

    char             * comment;
    char             * creator;
    tr_file          * files;
    tr_piece         * pieces;

    /* these trackers are sorted by tier */
    tr_tracker_info  * trackers;

    /* Torrent info */
    time_t             dateCreated;

    unsigned int       trackerCount;
    unsigned int       webseedCount;
    tr_file_index_t    fileCount;
    uint32_t           pieceSize;
    tr_piece_index_t   pieceCount;

    /* General info */
    uint8_t            hash[SHA_DIGEST_LENGTH];
    char               hashString[2 * SHA_DIGEST_LENGTH + 1];

    /* Flags */
    bool               isPrivate;
    bool               isMultifile;
};

static inline bool tr_torrentHasMetadata (const tr_torrent * tor)
{
    return tr_torrentInfo (tor)->fileCount > 0;
}

/**
 * What the torrent is doing right now.
 *
 * Note: these values will become a straight enum at some point in the future.
 * Do not rely on their current `bitfield' implementation
 */
typedef enum
{
    TR_STATUS_STOPPED        = 0, /* Torrent is stopped */
    TR_STATUS_CHECK_WAIT     = 1, /* Queued to check files */
    TR_STATUS_CHECK          = 2, /* Checking files */
    TR_STATUS_DOWNLOAD_WAIT  = 3, /* Queued to download */
    TR_STATUS_DOWNLOAD       = 4, /* Downloading */
    TR_STATUS_SEED_WAIT      = 5, /* Queued to seed */
    TR_STATUS_SEED           = 6  /* Seeding */
}
tr_torrent_activity;

enum
{
    TR_PEER_FROM_INCOMING  = 0, /* connections made to the listening port */
    TR_PEER_FROM_LPD,           /* peers found by local announcements */
    TR_PEER_FROM_TRACKER,       /* peers found from a tracker */
    TR_PEER_FROM_DHT,           /* peers found from the DHT */
    TR_PEER_FROM_PEX,           /* peers found from PEX */
    TR_PEER_FROM_RESUME,        /* peers found in the .resume file */
    TR_PEER_FROM_LTEP,          /* peer address provided in an LTEP handshake */
    TR_PEER_FROM__MAX
};

typedef enum
{
    /* everything's fine */
    TR_STAT_OK               = 0,

    /* when we anounced to the tracker, we got a warning in the response */
    TR_STAT_TRACKER_WARNING  = 1,

    /* when we anounced to the tracker, we got an error in the response */
    TR_STAT_TRACKER_ERROR    = 2,

    /* local trouble, such as disk full or permissions error */
    TR_STAT_LOCAL_ERROR      = 3
}
tr_stat_errtype;

/** @brief Used by tr_torrentStat () to tell clients about a torrent's state and statistics */
typedef struct tr_stat
{
    /** The torrent's unique Id.
        @see tr_torrentId () */
    int    id;

    /** What is this torrent doing right now? */
    tr_torrent_activity activity;

    /** Defines what kind of text is in errorString.
        @see errorString */
    tr_stat_errtype error;

    /** A warning or error message regarding the torrent.
        @see error */
    char errorString[512];

    /** When tr_stat.activity is TR_STATUS_CHECK or TR_STATUS_CHECK_WAIT,
        this is the percentage of how much of the files has been
        verified. When it gets to 1, the verify process is done.
        Range is [0..1]
        @see tr_stat.activity */
    float recheckProgress;

    /** How much has been downloaded of the entire torrent.
        Range is [0..1] */
    float percentComplete;

    /** How much of the metadata the torrent has.
        For torrents added from a .torrent this will always be 1.
        For magnet links, this number will from from 0 to 1 as the metadata is downloaded.
        Range is [0..1] */
    float metadataPercentComplete;

    /** How much has been downloaded of the files the user wants. This differs
        from percentComplete if the user wants only some of the torrent's files.
        Range is [0..1]
        @see tr_stat.leftUntilDone */
    float percentDone;

    /** How much has been uploaded to satisfy the seed ratio.
        This is 1 if the ratio is reached or the torrent is set to seed forever.
        Range is [0..1] */
    float seedRatioPercentDone;

    /** Speed all data being sent for this torrent.
        This includes piece data, protocol messages, and TCP overhead */
    float rawUploadSpeed_KBps;

    /** Speed all data being received for this torrent.
        This includes piece data, protocol messages, and TCP overhead */
    float rawDownloadSpeed_KBps;

    /** Speed all piece being sent for this torrent.
        This ONLY counts piece data. */
    float pieceUploadSpeed_KBps;

    /** Speed all piece being received for this torrent.
        This ONLY counts piece data. */
    float pieceDownloadSpeed_KBps;

#define TR_ETA_NOT_AVAIL -1
#define TR_ETA_UNKNOWN -2
    /** If downloading, estimated number of seconds left until the torrent is done.
        If seeding, estimated number of seconds left until seed ratio is reached. */
    int    eta;
    /** If seeding, number of seconds left until the idle time limit is reached. */
    int    etaIdle;

    /** Number of peers that we're connected to */
    int    peersConnected;

    /** How many peers we found out about from the tracker, or from pex,
        or from incoming connections, or from our resume file. */
    int    peersFrom[TR_PEER_FROM__MAX];

    /** Number of peers that are sending data to us. */
    int    peersSendingToUs;

    /** Number of peers that we're sending data to */
    int    peersGettingFromUs;

    /** Number of webseeds that are sending data to us. */
    int    webseedsSendingToUs;

    /** Byte count of all the piece data we'll have downloaded when we're done,
        whether or not we have it yet. This may be less than tr_info.totalSize
        if only some of the torrent's files are wanted.
        [0...tr_info.totalSize] */
    uint64_t    sizeWhenDone;

    /** Byte count of how much data is left to be downloaded until we've got
        all the pieces that we want. [0...tr_info.sizeWhenDone] */
    uint64_t    leftUntilDone;

    /** Byte count of all the piece data we want and don't have yet,
        but that a connected peer does have. [0...leftUntilDone] */
    uint64_t    desiredAvailable;

    /** Byte count of all the corrupt data you've ever downloaded for
        this torrent. If you're on a poisoned torrent, this number can
        grow very large. */
    uint64_t    corruptEver;

    /** Byte count of all data you've ever uploaded for this torrent. */
    uint64_t    uploadedEver;

    /** Byte count of all the non-corrupt data you've ever downloaded
        for this torrent. If you deleted the files and downloaded a second
        time, this will be 2*totalSize.. */
    uint64_t    downloadedEver;

    /** Byte count of all the checksum-verified data we have for this torrent.
      */
    uint64_t    haveValid;

    /** Byte count of all the partial piece data we have for this torrent.
        As pieces become complete, this value may decrease as portions of it
        are moved to `corrupt' or `haveValid'. */
    uint64_t    haveUnchecked;

    /** time when one or more of the torrent's trackers will
        allow you to manually ask for more peers,
        or 0 if you can't */
    time_t manualAnnounceTime;

#define TR_RATIO_NA  -1
#define TR_RATIO_INF -2
    /** TR_RATIO_INF, TR_RATIO_NA, or a regular ratio */
    float    ratio;

    /** When the torrent was first added. */
    time_t    addedDate;

    /** When the torrent finished downloading. */
    time_t    doneDate;

    /** When the torrent was last started. */
    time_t    startDate;

    /** The last time we uploaded or downloaded piece data on this torrent. */
    time_t    activityDate;

    /** Number of seconds since the last activity (or since started).
        -1 if activity is not seeding or downloading. */
    int    idleSecs;

    /** Cumulative seconds the torrent's ever spent downloading */
    int    secondsDownloading;

    /** Cumulative seconds the torrent's ever spent seeding */
    int    secondsSeeding;

    /** A torrent is considered finished if it has met its seed ratio.
        As a result, only paused torrents can be finished. */
    bool   finished;

    /** This torrent's queue position.
        All torrents have a queue position, even if it's not queued. */
    int queuePosition;

    /** True if the torrent is running, but has been idle for long enough
        to be considered stalled.  @see tr_sessionGetQueueStalledMinutes () */
    bool isStalled;
}
tr_stat;

/** Return a pointer to an tr_stat structure with updated information
    on the torrent. This is typically called by the GUI clients every
    second or so to get a new snapshot of the torrent's status. */
const tr_stat * tr_torrentStat (tr_torrent * torrent);

/** Like tr_torrentStat (), but only recalculates the statistics if it's
    been longer than a second since they were last calculated. This can
    reduce the CPU load if you're calling tr_torrentStat () frequently. */
const tr_stat * tr_torrentStatCached (tr_torrent * torrent);

/** @deprecated */
void tr_torrentSetAddedDate (tr_torrent * torrent,
                             time_t       addedDate);

/** @deprecated */
void tr_torrentSetActivityDate (tr_torrent * torrent,
                                time_t       activityDate);

/** @deprecated */
void tr_torrentSetDoneDate (tr_torrent * torrent, time_t doneDate);

/** @} */

/** @brief Sanity checker to test that the direction is TR_UP or TR_DOWN */
static inline bool tr_isDirection (tr_direction d) { return d==TR_UP || d==TR_DOWN; }

/** @brief Sanity checker to test that a bool is true or false */
static inline bool tr_isBool (bool b) { return b==1 || b==0; }

#ifdef __cplusplus
}
#endif

#endif