/*
 * This file Copyright (C) 2007-2014 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 <assert.h>

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

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

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

enum ReadState
{
    READ_NOW,
    READ_LATER,
    READ_ERR
};

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

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

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

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

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

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

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

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

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

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

#define PEER_IO_MAGIC_NUMBER 206745

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

/**
***
**/

constexpr void tr_peerIoEnableFEXT(tr_peerIo* io, bool flag)
{
    io->fastExtensionSupported = flag;
}

constexpr bool tr_peerIoSupportsFEXT(tr_peerIo const* io)
{
    return io->fastExtensionSupported;
}

constexpr void tr_peerIoEnableLTEP(tr_peerIo* io, bool flag)
{
    io->extendedProtocolSupported = flag;
}

constexpr bool tr_peerIoSupportsLTEP(tr_peerIo const* io)
{
    return io->extendedProtocolSupported;
}

constexpr void tr_peerIoEnableDHT(tr_peerIo* io, bool flag)
{
    io->dhtSupported = flag;
}

constexpr bool tr_peerIoSupportsDHT(tr_peerIo const* io)
{
    return io->dhtSupported;
}

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

/**
***
**/

constexpr tr_session* tr_peerIoGetSession(tr_peerIo* io)
{
    TR_ASSERT(tr_isPeerIo(io));
    TR_ASSERT(io->session != nullptr);

    return io->session;
}

char const* tr_peerIoGetAddrStr(tr_peerIo const* io, char* buf, size_t buflen);

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

uint8_t const* tr_peerIoGetTorrentHash(tr_peerIo* io);

bool tr_peerIoHasTorrentHash(tr_peerIo const* io);

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

int tr_peerIoReconnect(tr_peerIo* io);

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

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

/**
***
**/

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

constexpr uint8_t const* tr_peerIoGetPeersId(tr_peerIo const* io)
{
    TR_ASSERT(tr_isPeerIo(io));
    TR_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, void const* writeme, size_t writemeLen, bool isPieceData);

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

/**
***
**/

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

void tr_peerIoSetEncryption(tr_peerIo* io, tr_encryption_type encryption_type);

constexpr bool tr_peerIoIsEncrypted(tr_peerIo const* io)
{
    return io != nullptr && 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(tr_peerIo const* io, uint64_t now);

static inline void tr_peerIoSetParent(tr_peerIo* io, struct tr_bandwidth* parent)
{
    TR_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(tr_peerIo const* io, tr_direction dir)
{
    return tr_bandwidthClamp(&io->bandwidth, dir, 1024) > 0;
}

static inline unsigned int tr_peerIoGetPieceSpeed_Bps(tr_peerIo const* 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);

/**
***
**/

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

/* @} */