/*
 * 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: clients.c 13954 2013-02-04 16:23:33Z jordan $
 */

/* thanks amc1! */

#include <ctype.h> /* isprint () */
#include <stdlib.h> /* strtol () */
#include <string.h>

#include "transmission.h"
#include "clients.h"
#include "utils.h" /* tr_snprintf (), tr_strlcpy () */

static int
charint (uint8_t ch)
{
    if ('0' <= ch && ch <= '9') return      ch - '0';
    if ('A' <= ch && ch <= 'Z') return 10 + ch - 'A';
    if ('a' <= ch && ch <= 'z') return 36 + ch - 'a';
    return 0;
}

static int
getShadowInt (uint8_t ch, int * setme)
{
    const char * str = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz.-";
    const char * pch = strchr (str, ch);
    if (!pch)
        return 0;
    *setme = pch - str;
    return 1;
}

static int
strint (const void * pch, int span)
{
    char tmp[64];
    memcpy (tmp, pch, span);
    tmp[span] = '\0';
    return strtol (tmp, NULL, 0);
}

static const char*
getMnemonicEnd (uint8_t ch)
{
    switch (ch)
    {
        case 'b': case 'B': return " (Beta)";
        case 'd': return " (Debug)";
        case 'x': case 'X': case 'Z': return " (Dev)";
        default: return "";
    }
}

static void
three_digits (char * buf, size_t buflen, const char * name, const uint8_t * digits)
{
    tr_snprintf (buf, buflen, "%s %d.%d.%d", name,
                 charint (digits[0]),
                 charint (digits[1]),
                 charint (digits[2]));
}
static void
four_digits (char * buf, size_t buflen, const char * name, const uint8_t * digits)
{
    tr_snprintf (buf, buflen, "%s %d.%d.%d.%d", name,
                 charint (digits[0]),
                 charint (digits[1]),
                 charint (digits[2]),
                 charint (digits[3]));
}
static void
two_major_two_minor (char * buf, size_t buflen, const char * name, const uint8_t * digits)
{
    tr_snprintf (buf, buflen, "%s %d.%02d", name,
                 strint (digits, 2),
                 strint (digits+2, 2));
}
static void
no_version (char * buf, size_t buflen, const char * name)
{
    tr_strlcpy (buf, name, buflen);
}

static void
mainline_style (char * buf, size_t buflen, const char * name, const uint8_t * id)
{
    if (id[4] == '-' && id[6] == '-')
        tr_snprintf (buf, buflen, "%s %c.%c.%c", name, id[1], id[3], id[5]);
    else if (id[5] == '-')
        tr_snprintf (buf, buflen, "%s %c.%c%c.%c", name, id[1], id[3], id[4], id[6]);
}

static int
isMainlineStyle (const uint8_t * peer_id)
{
    /**
     * One of the following styles will be used:
     *   Mx-y-z--
     *   Mx-yy-z-
     */
    return peer_id[2]=='-'
        && peer_id[7]=='-'
        && (peer_id[4]=='-' || peer_id[5]=='-');
}

static int
decodeBitCometClient (char * buf, size_t buflen, const uint8_t * id)
{
    int is_bitlord;
    int major, minor;
    const char * name;
    const char * mod = NULL;

    if (!memcmp (id, "exbc", 4)) mod = "";
    else if (!memcmp (id, "FUTB", 4)) mod = " (Solidox Mod) ";
    else if (!memcmp (id, "xUTB", 4)) mod = " (Mod 2) ";
    else return false;

    is_bitlord = !memcmp (id+6, "LORD", 4);
    name = (is_bitlord) ? "BitLord " : "BitComet ";
    major = id[4];
    minor = id[5];

    /**
     * Bitcomet, and older versions of BitLord, are of the form x.yy.
     * Bitcoment 1.0 and onwards are of the form x.y.
     */
    if (is_bitlord && major>0)
        tr_snprintf (buf, buflen, "%s%s%d.%d", name, mod, major, minor);
    else
        tr_snprintf (buf, buflen, "%s%s%d.%02d", name, mod, major, minor);

    return true;
}

char *
tr_clientForId (char * buf, size_t buflen, const void * id_in)
{
    const uint8_t * id = id_in;

    *buf = '\0';

    if (!id)
        return buf;

    /* Azureus-style */
    if (id[0] == '-' && id[7] == '-')
    {
        if (!memcmp (id+1, "TR", 2))
        {
            if (!memcmp (id+3, "000", 3)) /* very old client style: -TR0006- is 0.6 */
                tr_snprintf (buf, buflen, "Transmission 0.%c", id[6]);
            else if (!memcmp (id+3, "00", 2)) /* previous client style: -TR0072- is 0.72 */
                tr_snprintf (buf, buflen, "Transmission 0.%02d", strint (id+5,2));
            else /* current client style: -TR111Z- is 1.11+ */
                tr_snprintf (buf, buflen, "Transmission %d.%02d%s", strint (id+3,1), strint (id+4,2),
                          id[6]=='Z' || id[6]=='X' ? "+" : "");
        }

        else if (!memcmp (id+1, "UT", 2))
        {
            tr_snprintf (buf, buflen, "\xc2\xb5Torrent %d.%d.%d%s",
                         strint (id+3,1), strint (id+4,1), strint (id+5,1), getMnemonicEnd (id[6]));
        }
        else if (!memcmp (id+1, "UM", 2))
        {
            tr_snprintf (buf, buflen, "\xc2\xb5Torrent Mac %d.%d.%d%s",
                         strint (id+3,1), strint (id+4,1), strint (id+5,1), getMnemonicEnd (id[6]));
        }
        else if (!memcmp (id+1, "UE", 2))
        {
            tr_snprintf (buf, buflen, "\xc2\xb5Torrent Embedded %d.%d.%d%s",
                        strint (id+3,1), strint (id+4,1), strint (id+5,1), getMnemonicEnd (id[6]));
        }

        else if (!memcmp (id+1, "AZ", 2))
        {
            if (id[3] > '3' || (id[3] == '3' && id[4] >= '1')) /* Vuze starts at version 3.1.0.0 */
                four_digits (buf, buflen, "Vuze", id+3);
            else
                four_digits (buf, buflen, "Azureus", id+3);
        }

        else if (!memcmp (id+1, "KT", 2))
        {
            if (id[5] == 'D')
                tr_snprintf (buf, buflen, "KTorrent %d.%d Dev %d", charint (id[3]), charint (id[4]), charint (id[6]));
            else if (id[5] == 'R')
                tr_snprintf (buf, buflen, "KTorrent %d.%d RC %d", charint (id[3]), charint (id[4]), charint (id[6]));
            else
                three_digits (buf, buflen, "KTorrent", id+3);
        }

        else if (!memcmp (id+1, "AG", 2)) four_digits (buf, buflen, "Ares", id+3);
        else if (!memcmp (id+1, "AR", 2)) four_digits (buf, buflen, "Arctic", id+3);
        else if (!memcmp (id+1, "AT", 2)) four_digits (buf, buflen, "Artemis", id+3);
        else if (!memcmp (id+1, "AV", 2)) four_digits (buf, buflen, "Avicora", id+3);
        else if (!memcmp (id+1, "BB", 2)) four_digits (buf, buflen, "BitBuddy", id+3);
        else if (!memcmp (id+1, "BE", 2)) four_digits (buf, buflen, "BitTorrent SDK", id+3);
        else if (!memcmp (id+1, "BG", 2)) four_digits (buf, buflen, "BTGetit", id+3);
        else if (!memcmp (id+1, "BH", 2)) four_digits (buf, buflen, "BitZilla", id+3);
        else if (!memcmp (id+1, "BM", 2)) four_digits (buf, buflen, "BitMagnet", id+3);
        else if (!memcmp (id+1, "BP", 2)) four_digits (buf, buflen, "BitTorrent Pro (Azureus + Spyware)", id+3);
        else if (!memcmp (id+1, "BX", 2)) four_digits (buf, buflen, "BittorrentX", id+3);
        else if (!memcmp (id+1, "bk", 2)) four_digits (buf, buflen, "BitKitten (libtorrent)", id+3);
        else if (!memcmp (id+1, "BS", 2)) four_digits (buf, buflen, "BTSlave", id+3);
        else if (!memcmp (id+1, "BW", 2)) four_digits (buf, buflen, "BitWombat", id+3);
        else if (!memcmp (id+1, "BX", 2)) four_digits (buf, buflen, "BittorrentX", id+3);
        else if (!memcmp (id+1, "EB", 2)) four_digits (buf, buflen, "EBit", id+3);
        else if (!memcmp (id+1, "DE", 2)) four_digits (buf, buflen, "Deluge", id+3);
        else if (!memcmp (id+1, "DP", 2)) four_digits (buf, buflen, "Propogate Data Client", id+3);
        else if (!memcmp (id+1, "FC", 2)) four_digits (buf, buflen, "FileCroc", id+3);
        else if (!memcmp (id+1, "FT", 2)) four_digits (buf, buflen, "FoxTorrent/RedSwoosh", id+3);
        else if (!memcmp (id+1, "GR", 2)) four_digits (buf, buflen, "GetRight", id+3);
        else if (!memcmp (id+1, "GS", 2)) four_digits (buf, buflen, "GSTorrent", id+3);
        else if (!memcmp (id+1, "HK", 2)) four_digits (buf, buflen, "Hekate", id+3);
        else if (!memcmp (id+1, "HN", 2)) four_digits (buf, buflen, "Hydranode", id+3);
        else if (!memcmp (id+1, "KG", 2)) four_digits (buf, buflen, "KGet", id+3);
        else if (!memcmp (id+1, "LC", 2)) four_digits (buf, buflen, "LeechCraft", id+3);
        else if (!memcmp (id+1, "LH", 2)) four_digits (buf, buflen, "LH-ABC", id+3);
        else if (!memcmp (id+1, "NX", 2)) four_digits (buf, buflen, "Net Transport", id+3);
        else if (!memcmp (id+1, "MK", 2)) four_digits (buf, buflen, "Meerkat", id+3);
        else if (!memcmp (id+1, "MO", 2)) four_digits (buf, buflen, "MonoTorrent", id+3);
        else if (!memcmp (id+1, "MR", 2)) four_digits (buf, buflen, "Miro", id+3);
        else if (!memcmp (id+1, "MT", 2)) four_digits (buf, buflen, "Moonlight", id+3);
        else if (!memcmp (id+1, "OS", 2)) four_digits (buf, buflen, "OneSwarm", id+3);
        else if (!memcmp (id+1, "OT", 2)) four_digits (buf, buflen, "OmegaTorrent", id+3);
        else if (!memcmp (id+1, "PD", 2)) four_digits (buf, buflen, "Pando", id+3);
        else if (!memcmp (id+1, "QD", 2)) four_digits (buf, buflen, "QQDownload", id+3);
        else if (!memcmp (id+1, "RS", 2)) four_digits (buf, buflen, "Rufus", id+3);
        else if (!memcmp (id+1, "RT", 2)) four_digits (buf, buflen, "Retriever", id+3);
        else if (!memcmp (id+1, "RZ", 2)) four_digits (buf, buflen, "RezTorrent", id+3);
        else if (!memcmp (id+1, "SD", 2)) four_digits (buf, buflen, "Thunder", id+3);
        else if (!memcmp (id+1, "SM", 2)) four_digits (buf, buflen, "SoMud", id+3);
        else if (!memcmp (id+1, "SS", 2)) four_digits (buf, buflen, "SwarmScope", id+3);
        else if (!memcmp (id+1, "ST", 2)) four_digits (buf, buflen, "SymTorrent", id+3);
        else if (!memcmp (id+1, "SZ", 2)) four_digits (buf, buflen, "Shareaza", id+3);
        else if (!memcmp (id+1, "S~", 2)) four_digits (buf, buflen, "Shareaza", id+3);
        else if (!memcmp (id+1, "st", 2)) four_digits (buf, buflen, "SharkTorrent", id+3);
        else if (!memcmp (id+1, "TN", 2)) four_digits (buf, buflen, "Torrent .NET", id+3);
        else if (!memcmp (id+1, "TS", 2)) four_digits (buf, buflen, "TorrentStorm", id+3);
        else if (!memcmp (id+1, "TT", 2)) four_digits (buf, buflen, "TuoTu", id+3);
        else if (!memcmp (id+1, "UL", 2)) four_digits (buf, buflen, "uLeecher!", id+3);
        else if (!memcmp (id+1, "VG", 2)) four_digits (buf, buflen, "Vagaa", id+3);
        else if (!memcmp (id+1, "WT", 2)) four_digits (buf, buflen, "BitLet", id+3);
        else if (!memcmp (id+1, "WY", 2)) four_digits (buf, buflen, "FireTorrent", id+3);
        else if (!memcmp (id+1, "XL", 2)) four_digits (buf, buflen, "Xunlei", id+3);
        else if (!memcmp (id+1, "XS", 2)) four_digits (buf, buflen, "XSwifter", id+3);
        else if (!memcmp (id+1, "XT", 2)) four_digits (buf, buflen, "XanTorrent", id+3);
        else if (!memcmp (id+1, "XX", 2)) four_digits (buf, buflen, "Xtorrent", id+3);
        else if (!memcmp (id+1, "ZT", 2)) four_digits (buf, buflen, "Zip Torrent", id+3);
        else if (!memcmp (id+1, "ZO", 2)) four_digits (buf, buflen, "Zona", id+3);

        else if (!memcmp (id+1, "AG", 2)) three_digits (buf, buflen, "Ares", id+3);
        else if (!memcmp (id+1, "A~", 2)) three_digits (buf, buflen, "Ares", id+3);
        else if (!memcmp (id+1, "ES", 2)) three_digits (buf, buflen, "Electric Sheep", id+3);
        else if (!memcmp (id+1, "HL", 2)) three_digits (buf, buflen, "Halite", id+3);
        else if (!memcmp (id+1, "LT", 2)) three_digits (buf, buflen, "libtorrent (Rasterbar)", id+3);
        else if (!memcmp (id+1, "lt", 2)) three_digits (buf, buflen, "libTorrent (Rakshasa)", id+3);
        else if (!memcmp (id+1, "MP", 2)) three_digits (buf, buflen, "MooPolice", id+3);
        else if (!memcmp (id+1, "pb", 2)) three_digits (buf, buflen, "pbTorrent", id+3);
        else if (!memcmp (id+1, "TT", 2)) three_digits (buf, buflen, "TuoTu", id+3);
        else if (!memcmp (id+1, "qB", 2)) three_digits (buf, buflen, "qBittorrent", id+3);

        else if (!memcmp (id+1, "AX", 2)) two_major_two_minor (buf, buflen, "BitPump", id+3);
        else if (!memcmp (id+1, "BC", 2)) two_major_two_minor (buf, buflen, "BitComet", id+3);
        else if (!memcmp (id+1, "CD", 2)) two_major_two_minor (buf, buflen, "Enhanced CTorrent", id+3);
        else if (!memcmp (id+1, "LP", 2)) two_major_two_minor (buf, buflen, "Lphant", id+3);

        else if (!memcmp (id+1, "BF", 2)) no_version (buf, buflen, "BitFlu");
        else if (!memcmp (id+1, "LW", 2)) no_version (buf, buflen, "LimeWire");

        else if (!memcmp (id+1, "BB", 2))
        {
            tr_snprintf (buf, buflen, "BitBuddy %c.%c%c%c", id[3], id[4], id[5], id[6]);
        }
        else if (!memcmp (id+1, "BR", 2))
        {
            tr_snprintf (buf, buflen, "BitRocket %c.%c (%c%c)", id[3], id[4], id[5], id[6]);
        }
        else if (!memcmp (id+1, "CT", 2))
        {
            tr_snprintf (buf, buflen, "CTorrent %d.%d.%02d", charint (id[3]), charint (id[4]), strint (id+5,2));
        }
        else if (!memcmp (id+1, "XC", 2) || !memcmp (id+1, "XX", 2))
        {
            tr_snprintf (buf, buflen, "Xtorrent %d.%d (%d)", charint (id[3]), charint (id[4]), strint (id+5,2));
        }
        else if (!memcmp (id+1, "BOW", 3))
        {
                 if (!memcmp (&id[4], "A0B", 3)) tr_snprintf (buf, buflen, "Bits on Wheels 1.0.5");
            else if (!memcmp (&id[4], "A0C", 3)) tr_snprintf (buf, buflen, "Bits on Wheels 1.0.6");
            else                                   tr_snprintf (buf, buflen, "Bits on Wheels %c.%c.%c", id[4], id[5], id[5]);
        }
        else if (!memcmp (id+1, "MG", 2))
        {
            tr_snprintf (buf, buflen, "MediaGet %d.%02d", charint (id[3]), charint (id[4]));
        }

        if (*buf)
            return buf;
    }

    /* uTorrent will replace the trailing dash with an extra digit for longer version numbers */
    if (id[0] == '-')
    {
        if (!memcmp (id+1, "UT", 2))
        {
            tr_snprintf (buf, buflen, "\xc2\xb5Torrent %d.%d.%d%s",
                        strint (id+3,1), strint (id+4,1), strint (id+5,2), getMnemonicEnd (id[7]));
        }
        else if (!memcmp (id+1, "UM", 2))
        {
            tr_snprintf (buf, buflen, "\xc2\xb5Torrent Mac %d.%d.%d%s",
                        strint (id+3,1), strint (id+4,1), strint (id+5,2), getMnemonicEnd (id[7]));
        }
        else if (!memcmp (id+1, "UE", 2))
        {
            tr_snprintf (buf, buflen, "\xc2\xb5Torrent Embedded %d.%d.%d%s",
                        strint (id+3,1), strint (id+4,1), strint (id+5,2), getMnemonicEnd (id[7]));
        }

        if (*buf)
            return buf;
    }

    /* Mainline */
    if (isMainlineStyle (id))
    {
        if (*id=='M') mainline_style (buf, buflen, "BitTorrent", id);
        if (*id=='Q') mainline_style (buf, buflen, "Queen Bee", id);
        if (*buf) return buf;
    }

    if (decodeBitCometClient (buf, buflen, id))
        return buf;

    /* Clients with no version */
         if (!memcmp (id, "AZ2500BT", 8))  no_version (buf, buflen, "BitTyrant (Azureus Mod)");
    else if (!memcmp (id, "LIME", 4))      no_version (buf, buflen, "Limewire");
    else if (!memcmp (id, "martini", 7))   no_version (buf, buflen, "Martini Man");
    else if (!memcmp (id, "Pando", 5))     no_version (buf, buflen, "Pando");
    else if (!memcmp (id, "a00---0", 7))   no_version (buf, buflen, "Swarmy");
    else if (!memcmp (id, "a02---0", 7))   no_version (buf, buflen, "Swarmy");
    else if (!memcmp (id, "-G3", 3))       no_version (buf, buflen, "G3 Torrent");
    else if (!memcmp (id, "10-------", 9)) no_version (buf, buflen, "JVtorrent");
    else if (!memcmp (id, "346-", 4))      no_version (buf, buflen, "TorrentTopia");
    else if (!memcmp (id, "eX", 2))        no_version (buf, buflen, "eXeem");
    else if (!memcmp (id, "aria2-", 6))    no_version (buf, buflen, "aria2");
    else if (!memcmp (id, "-WT-", 4))      no_version (buf, buflen, "BitLet");
    else if (!memcmp (id, "-FG", 3))       two_major_two_minor (buf, buflen, "FlashGet", id+3);

    /* Everything else */
    else if (!memcmp (id, "S3", 2) && id[2] == '-' && id[4] == '-' && id[6] == '-')
    {
        tr_snprintf (buf, buflen, "Amazon S3 %c.%c.%c", id[3], id[5], id[7]);
    }
    else if (!memcmp (id, "OP", 2))
    {
        tr_snprintf (buf, buflen, "Opera (Build %c%c%c%c)", id[2], id[3], id[4], id[5]);
    }
    else if (!memcmp (id, "-ML", 3))
    {
        tr_snprintf (buf, buflen, "MLDonkey %c%c%c%c%c", id[3], id[4], id[5], id[6], id[7]);
    }
    else if (!memcmp (id, "DNA", 3))
    {
        tr_snprintf (buf, buflen, "BitTorrent DNA %d.%d.%d", strint (id+3,2),
                                                             strint (id+5,2),
                                                             strint (id+7,2));
    }
    else if (!memcmp (id, "Plus", 4))
    {
        tr_snprintf (buf, buflen, "Plus! v2 %c.%c%c", id[4], id[5], id[6]);
    }
    else if (!memcmp (id, "XBT", 3))
    {
        tr_snprintf (buf, buflen, "XBT Client %c.%c.%c%s", id[3], id[4], id[5], getMnemonicEnd (id[6]));
    }
    else if (!memcmp (id, "Mbrst", 5))
    {
        tr_snprintf (buf, buflen, "burst! %c.%c.%c", id[5], id[7], id[9]);
    }
    else if (!memcmp (id, "btpd", 4))
    {
        tr_snprintf (buf, buflen, "BT Protocol Daemon %c%c%c", id[5], id[6], id[7]);
    }
    else if (!memcmp (id, "BLZ", 3))
    {
        tr_snprintf (buf, buflen, "Blizzard Downloader %d.%d", id[3]+1, id[4]);
    }
    else if (!memcmp (id, "-SP", 3))
    {
        three_digits (buf, buflen, "BitSpirit", id+3);
    }
    else if ('\0' == id[0] && !memcmp (id+2, "BS", 2))
    {
        tr_snprintf (buf, buflen, "BitSpirit %u", (id[1] == 0 ? 1 : id[1]));
    }
    else if (!memcmp (id, "QVOD", 4))
    {
        four_digits (buf, buflen, "QVOD", id+4);
    }
    else if (!memcmp (id, "-NE", 3))
    {
        four_digits (buf, buflen, "BT Next Evolution", id+3);
    }

    /* Shad0w-style */
    {
        int a, b, c;
        if (strchr ("AOQRSTU", id[0])
            && getShadowInt (id[1], &a)
            && getShadowInt (id[2], &b)
            && getShadowInt (id[3], &c))
        {
            const char * name = NULL;

            switch (id[0])
            {
                case 'A': name = "ABC"; break;
                case 'O': name = "Osprey"; break;
                case 'Q': name = "BTQueue"; break;
                case 'R': name = "Tribler"; break;
                case 'S': name = "Shad0w"; break;
                case 'T': name = "BitTornado"; break;
                case 'U': name = "UPnP NAT Bit Torrent"; break;
            }

            if (name)
            {
                tr_snprintf (buf, buflen, "%s %d.%d.%d", name, a, b, c);
                return buf;
            }
        }
    }

    /* No match */
    if (!*buf)
    {
        char out[32], *walk=out;
        const char *in, *in_end;
        for (in= (const char*)id, in_end=in+8; in!=in_end; ++in) {
            if (isprint (*in))
                *walk++ = *in;
            else {
                tr_snprintf (walk, out+sizeof (out)-walk, "%%%02X", (unsigned int)*in);
                walk += 3;
            }
        }
        *walk = '\0';
        tr_strlcpy (buf, out, buflen);
    }

  return buf;
}
