/*
 * This file Copyright (C) Mnemosyne LLC
 *
 * This file is licensed by the GPL version 2. Works owned by the
 * Transmission project are granted a special exemption to clause 2 (b)
 * so that the bulk of its code can remain under the MIT license.
 * This exemption does not extend to derived works not owned by
 * the Transmission project.
 *
 * $Id$
 */

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

#ifndef TR_PEER_IO_H
#define TR_PEER_IO_H

/**
***
**/

#include <assert.h>

#include "transmission.h"
#include "bandwidth.h"
#include "crypto.h"
#include "net.h" /* tr_address */
#include "utils.h" /* tr_time () */

struct evbuffer;
struct tr_bandwidth;
struct tr_datatype;
struct tr_peerIo;

/**
 * @addtogroup networked_io Networked IO
 * @{
 */

typedef enum
{
    READ_NOW,
    READ_LATER,
    READ_ERR
}
ReadState;

typedef enum
{
    /* these match the values in MSE's crypto_select */
    PEER_ENCRYPTION_NONE  = (1 << 0),
    PEER_ENCRYPTION_RC4   = (1 << 1)
}
tr_encryption_type;


typedef ReadState (*tr_can_read_cb)(struct tr_peerIo * io,
                                    void             * user_data,
                                    size_t           * setme_piece_byte_count);

typedef void (*tr_did_write_cb)(struct tr_peerIo * io,
                                size_t             bytesWritten,
                                bool               wasPieceData,
                                void             * userData);

typedef void (*tr_net_error_cb)(struct tr_peerIo * io,
                                short              what,
                                void             * userData);

typedef struct tr_peerIo
{
    bool                  isEncrypted;
    bool                  isIncoming;
    bool                  peerIdIsSet;
    bool                  extendedProtocolSupported;
    bool                  fastExtensionSupported;
    bool                  dhtSupported;
    bool                  utpSupported;

    tr_priority_t         priority;

    short int             pendingEvents;

    int                   magicNumber;

    tr_encryption_type    encryption_type;
    bool                  isSeed;

    tr_port               port;
    int                   socket;
    struct UTPSocket      *utp_socket;

    int                   refCount;

    uint8_t               peerId[SHA_DIGEST_LENGTH];
    time_t                timeCreated;

    tr_session          * session;

    tr_address            addr;

    tr_can_read_cb        canRead;
    tr_did_write_cb       didWrite;
    tr_net_error_cb       gotError;
    void *                userData;

    struct tr_bandwidth   bandwidth;
    tr_crypto             crypto;

    struct evbuffer     * inbuf;
    struct evbuffer     * outbuf;
    struct tr_datatype  * outbuf_datatypes;

    struct event        * event_read;
    struct event        * event_write;
}
tr_peerIo;

/**
***
**/

tr_peerIo*  tr_peerIoNewOutgoing (tr_session              * session,
                                  struct tr_bandwidth     * parent,
                                  const struct tr_address * addr,
                                  tr_port                   port,
                                  const  uint8_t          * torrentHash,
                                  bool                      isSeed,
                                  bool                      utp);


tr_peerIo*  tr_peerIoNewIncoming (tr_session              * session,
                                  struct tr_bandwidth     * parent,
                                  const struct tr_address * addr,
                                  tr_port                   port,
                                  int                       socket,
                                  struct UTPSocket *        utp_socket);

void tr_peerIoRefImpl         (const char              * file,
                                  int                       line,
                                  tr_peerIo               * io);

#define tr_peerIoRef(io) tr_peerIoRefImpl (__FILE__, __LINE__, (io));

void tr_peerIoUnrefImpl       (const char              * file,
                                  int                       line,
                                  tr_peerIo               * io);

#define tr_peerIoUnref(io) tr_peerIoUnrefImpl (__FILE__, __LINE__, (io));

#define PEER_IO_MAGIC_NUMBER 206745

static inline bool
tr_isPeerIo (const tr_peerIo * io)
{
    return (io != NULL)
        && (io->magicNumber == PEER_IO_MAGIC_NUMBER)
        && (io->refCount >= 0)
        && (tr_isBandwidth (&io->bandwidth))
        && (tr_address_is_valid (&io->addr));
}

/**
***
**/

static inline void tr_peerIoEnableFEXT (tr_peerIo * io, bool flag)
{
    io->fastExtensionSupported = flag;
}
static inline bool tr_peerIoSupportsFEXT (const tr_peerIo * io)
{
    return io->fastExtensionSupported;
}

static inline void tr_peerIoEnableLTEP (tr_peerIo * io, bool flag)
{
    io->extendedProtocolSupported = flag;
}
static inline bool tr_peerIoSupportsLTEP (const tr_peerIo * io)
{
    return io->extendedProtocolSupported;
}

static inline void tr_peerIoEnableDHT (tr_peerIo * io, bool flag)
{
    io->dhtSupported = flag;
}
static inline bool tr_peerIoSupportsDHT (const tr_peerIo * io)
{
    return io->dhtSupported;
}

static inline bool tr_peerIoSupportsUTP (const tr_peerIo * io)
{
    return io->utpSupported;
}

/**
***
**/

static inline tr_session* tr_peerIoGetSession (tr_peerIo * io)
{
    assert (tr_isPeerIo (io));
    assert (io->session);

    return io->session;
}

const char* tr_peerIoAddrStr (const struct tr_address * addr,
                              tr_port                   port);

const char* tr_peerIoGetAddrStr (const tr_peerIo * io);

const struct tr_address * tr_peerIoGetAddress (const tr_peerIo * io,
                                               tr_port         * port);

const uint8_t*       tr_peerIoGetTorrentHash (tr_peerIo * io);

int                  tr_peerIoHasTorrentHash (const tr_peerIo * io);

void                 tr_peerIoSetTorrentHash (tr_peerIo *     io,
                                              const uint8_t * hash);

int                  tr_peerIoReconnect (tr_peerIo * io);

static inline bool tr_peerIoIsIncoming (const tr_peerIo * io)
{
    return io->isIncoming;
}

static inline int    tr_peerIoGetAge (const tr_peerIo * io)
{
    return tr_time () - io->timeCreated;
}


/**
***
**/

void                 tr_peerIoSetPeersId (tr_peerIo *     io,
                                          const uint8_t * peer_id);

static inline const uint8_t* tr_peerIoGetPeersId (const tr_peerIo * io)
{
    assert (tr_isPeerIo (io));
    assert (io->peerIdIsSet);

    return io->peerId;
}

/**
***
**/

void    tr_peerIoSetIOFuncs   (tr_peerIo        * io,
                               tr_can_read_cb     readcb,
                               tr_did_write_cb    writecb,
                               tr_net_error_cb    errcb,
                               void             * user_data);

void    tr_peerIoClear        (tr_peerIo        * io);

/**
***
**/

void    tr_peerIoWriteBytes   (tr_peerIo         * io,
                               const void        * writeme,
                               size_t              writemeLen,
                               bool                isPieceData);

void    tr_peerIoWriteBuf     (tr_peerIo         * io,
                               struct evbuffer   * buf,
                               bool                isPieceData);

/**
***
**/

static inline tr_crypto * tr_peerIoGetCrypto (tr_peerIo * io)
{
    return &io->crypto;
}

void tr_peerIoSetEncryption (tr_peerIo * io, tr_encryption_type encryption_type);

static inline bool
tr_peerIoIsEncrypted (const tr_peerIo * io)
{
    return (io != NULL) && (io->encryption_type == PEER_ENCRYPTION_RC4);
}

void evbuffer_add_uint8 (struct evbuffer * outbuf, uint8_t byte);
void evbuffer_add_uint16 (struct evbuffer * outbuf, uint16_t hs);
void evbuffer_add_uint32 (struct evbuffer * outbuf, uint32_t hl);
void evbuffer_add_uint64 (struct evbuffer * outbuf, uint64_t hll);

static inline void
evbuffer_add_hton_16 (struct evbuffer * buf, uint16_t val)
{
   evbuffer_add_uint16 (buf, val);
}
static inline void
evbuffer_add_hton_32 (struct evbuffer * buf, uint32_t val)
{
   evbuffer_add_uint32 (buf, val);
}
static inline void
evbuffer_add_hton_64 (struct evbuffer * buf, uint64_t val)
{
   evbuffer_add_uint64 (buf, val);
}

void tr_peerIoReadBytesToBuf (tr_peerIo       * io,
                              struct evbuffer * inbuf,
                              struct evbuffer * outbuf,
                              size_t            byteCount);

void tr_peerIoReadBytes (tr_peerIo        * io,
                         struct evbuffer  * inbuf,
                         void             * bytes,
                         size_t             byteCount);

static inline void tr_peerIoReadUint8 (tr_peerIo        * io,
                                          struct evbuffer  * inbuf,
                                          uint8_t          * setme)
{
    tr_peerIoReadBytes (io, inbuf, setme, sizeof (uint8_t));
}

void tr_peerIoReadUint16 (tr_peerIo        * io,
                          struct evbuffer  * inbuf,
                          uint16_t         * setme);

void tr_peerIoReadUint32 (tr_peerIo        * io,
                          struct evbuffer  * inbuf,
                          uint32_t         * setme);

void      tr_peerIoDrain (tr_peerIo        * io,
                          struct evbuffer  * inbuf,
                          size_t             byteCount);

/**
***
**/

size_t    tr_peerIoGetWriteBufferSpace (const tr_peerIo * io, uint64_t now);

static inline void tr_peerIoSetParent (tr_peerIo            * io,
                                          struct tr_bandwidth  * parent)
{
    assert (tr_isPeerIo (io));

    tr_bandwidthSetParent (&io->bandwidth, parent);
}

void      tr_peerIoBandwidthUsed (tr_peerIo           * io,
                                  tr_direction          direction,
                                  size_t                byteCount,
                                  int                   isPieceData);

static inline bool
tr_peerIoHasBandwidthLeft (const tr_peerIo * io, tr_direction dir)
{
    return tr_bandwidthClamp (&io->bandwidth, dir, 1024) > 0;
}

static inline unsigned int
tr_peerIoGetPieceSpeed_Bps (const tr_peerIo * io, uint64_t now, tr_direction dir)
{
    return tr_bandwidthGetPieceSpeed_Bps (&io->bandwidth, now, dir);
}

/**
***
**/

void      tr_peerIoSetEnabled (tr_peerIo    * io,
                               tr_direction   dir,
                               bool           isEnabled);

int       tr_peerIoFlush (tr_peerIo     * io,
                          tr_direction    dir,
                          size_t          byteLimit);

int       tr_peerIoFlushOutgoingProtocolMsgs (tr_peerIo * io);

/**
***
**/

static inline struct evbuffer * tr_peerIoGetReadBuffer (tr_peerIo * io)
{
    return io->inbuf;
}

/* @} */

#endif