/*
 * This file Copyright (C) 2008-2014 Mnemosyne LLC
 *
 * It may be used under the GNU GPL versions 2 or 3
 * or any future license endorsed by Mnemosyne LLC.
 *
 */

#pragma once

#ifndef __TRANSMISSION__
#error only libtransmission should #include this header.
#endif

#include "transmission.h"
#include "bitfield.h"
#include "history.h"
#include "quark.h"

/**
 * @addtogroup peers Peers
 * @{
 */

struct tr_peer;
struct tr_swarm;

enum
{
    /* this is the maximum size of a block request.
       most bittorrent clients will reject requests
       larger than this size. */
    MAX_BLOCK_SIZE = (1024 * 16)
};

/**
***  Peer Publish / Subscribe
**/

typedef enum
{
    TR_PEER_CLIENT_GOT_BLOCK,
    TR_PEER_CLIENT_GOT_CHOKE,
    TR_PEER_CLIENT_GOT_PIECE_DATA,
    TR_PEER_CLIENT_GOT_ALLOWED_FAST,
    TR_PEER_CLIENT_GOT_SUGGEST,
    TR_PEER_CLIENT_GOT_PORT,
    TR_PEER_CLIENT_GOT_REJ,
    TR_PEER_CLIENT_GOT_BITFIELD,
    TR_PEER_CLIENT_GOT_HAVE,
    TR_PEER_CLIENT_GOT_HAVE_ALL,
    TR_PEER_CLIENT_GOT_HAVE_NONE,
    TR_PEER_PEER_GOT_PIECE_DATA,
    TR_PEER_ERROR
} PeerEventType;

typedef struct
{
    PeerEventType eventType;

    uint32_t pieceIndex; /* for GOT_BLOCK, GOT_HAVE, CANCEL, ALLOWED, SUGGEST */
    struct tr_bitfield* bitfield; /* for GOT_BITFIELD */
    uint32_t offset; /* for GOT_BLOCK */
    uint32_t length; /* for GOT_BLOCK + GOT_PIECE_DATA */
    int err; /* errno for GOT_ERROR */
    tr_port port; /* for GOT_PORT */
} tr_peer_event;

extern tr_peer_event const TR_PEER_EVENT_INIT;

typedef void (*tr_peer_callback)(struct tr_peer* peer, tr_peer_event const* event, void* client_data);

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

typedef void (*tr_peer_destruct_func)(struct tr_peer* peer);
typedef bool (
    *tr_peer_is_transferring_pieces_func)(struct tr_peer const* peer, uint64_t now, tr_direction direction, unsigned int* Bps);

struct tr_peer_virtual_funcs
{
    tr_peer_destruct_func destruct;
    tr_peer_is_transferring_pieces_func is_transferring_pieces;
};

/**
 * State information about a connected peer.
 *
 * @see struct peer_atom
 * @see tr_peerMsgs
 */
typedef struct tr_peer
{
    /* whether or not we should free this peer soon.
       NOTE: private to peer-mgr.c */
    bool doPurge;

    /* number of bad pieces they've contributed to */
    uint8_t strikes;

    /* 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;

    /* Hook to private peer-mgr information */
    struct peer_atom* atom;

    struct tr_swarm* swarm;

    /** how complete the peer's copy of the torrent is. [0.0...1.0] */
    float progress;

    struct tr_bitfield blame;
    struct tr_bitfield have;

    /* the client name.
       For BitTorrent peers, this is the app name derived from the `v' string in LTEP's handshake dictionary */
    tr_quark client;

    tr_recentHistory blocksSentToClient;
    tr_recentHistory blocksSentToPeer;

    tr_recentHistory cancelsSentToClient;
    tr_recentHistory cancelsSentToPeer;

    struct tr_peer_virtual_funcs const* funcs;
} tr_peer;

void tr_peerConstruct(struct tr_peer* peer, tr_torrent const* tor);

void tr_peerDestruct(struct tr_peer* peer);

/** Update the tr_peer.progress field based on the 'have' bitset. */
void tr_peerUpdateProgress(tr_torrent* tor, struct tr_peer*);

bool tr_peerIsSeed(struct tr_peer const* peer);

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

typedef struct tr_swarm_stats
{
    int activePeerCount[2];
    int activeWebseedCount;
    int peerCount;
    int peerFromCount[TR_PEER_FROM__MAX];
} tr_swarm_stats;

extern tr_swarm_stats const TR_SWARM_STATS_INIT;

void tr_swarmGetStats(struct tr_swarm const* swarm, tr_swarm_stats* setme);

void tr_swarmIncrementActivePeers(struct tr_swarm* swarm, tr_direction direction, bool is_active);

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

#ifdef _WIN32
#undef EMSGSIZE
#define EMSGSIZE WSAEMSGSIZE
#endif

/** @} */