/******************************************************************************
 * $Id$
 *
 * Copyright (c) 2005-2006 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.
 *****************************************************************************/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <signal.h>

#include <libtransmission/transmission.h>
#include <libtransmission/bencode.h>
#include <libtransmission/makemeta.h>
#include <libtransmission/metainfo.h> /* tr_metainfoFree */
#include <libtransmission/tr-getopt.h>
#include <libtransmission/utils.h> /* tr_wait */
#include <libtransmission/web.h> /* tr_webRun */

#define MY_NAME "transmission-cli"

static int           showInfo      = 0;
static int           showScrape    = 0;
static int           isPrivate     = 0;
static int           verboseLevel  = 0;
static int           peerPort      = TR_DEFAULT_PORT;
static int           peerSocketTOS = TR_DEFAULT_PEER_SOCKET_TOS;
static int           uploadLimit   = 20;
static int           downloadLimit = -1;
static int           natTraversal  = 0;
static int           verify        = 0;
static sig_atomic_t  gotsig        = 0;
static sig_atomic_t  manualUpdate  = 0;

static const char   * torrentPath   = NULL;
static const char   * downloadDir   = NULL;
static const char   * finishCall   = NULL;
static const char   * announce     = NULL;
static const char   * configdir    = NULL;
static const char   * sourceFile   = NULL;
static const char   * comment      = NULL;

static int  parseCommandLine ( int argc, const char ** argv );
static void sigHandler       ( int signal );

static char *
getStringRatio( float ratio )
{
    static char string[20];

    if( ratio == TR_RATIO_NA )
        return "n/a";
    snprintf( string, sizeof string, "%.3f", ratio );
    return string;
}

static int
is_rfc2396_alnum( char ch )
{
    return     ( '0' <= ch && ch <= '9' )
            || ( 'A' <= ch && ch <= 'Z' )
            || ( 'a' <= ch && ch <= 'z' );
}

static void
escape( char * out, const uint8_t * in, int in_len ) /* rfc2396 */
{
    const uint8_t *end = in + in_len;
    while( in != end )
        if( is_rfc2396_alnum(*in) )
            *out++ = (char) *in++;
        else
            out += snprintf( out, 4, "%%%02X", (unsigned int)*in++ );
    *out = '\0';
}


#define LINEWIDTH 80

static void
torrentStateChanged( tr_torrent   * torrent UNUSED,
                     cp_status_t    status UNUSED,
                     void         * user_data UNUSED )
{
    system( finishCall );
}

static int leftToScrape = 0;

static void
scrapeDoneFunc( struct tr_handle    * session UNUSED,
                long                  response_code,
                const void          * response,
                size_t                response_byte_count,
                void                * host )
{
    tr_benc top, *files;

    if( !tr_bencLoad( response, response_byte_count, &top, NULL ) 
        && tr_bencDictFindDict( &top, "files", &files )
        && files->val.l.count >= 2 )
    {
        int64_t complete=-1, incomplete=-1, downloaded=-1;
        tr_benc * hash = &files->val.l.vals[1];
        tr_bencDictFindInt( hash, "complete", &complete );
        tr_bencDictFindInt( hash, "incomplete", &incomplete );
        tr_bencDictFindInt( hash, "downloaded", &downloaded );
        printf( "%4d seeders, %4d leechers, %5d downloads at %s\n",
                (int)complete, (int)incomplete, (int)downloaded, (char*)host );
        tr_bencFree( &top );
    }
    else
        printf( "unable to parse response (http code %lu) at %s", response_code, (char*)host );

    --leftToScrape;
}

int
main( int argc, char ** argv )
{
    int i, error;
    tr_handle  * h;
    tr_ctor * ctor;
    tr_torrent * tor = NULL;
    char cwd[MAX_PATH_LENGTH];

    printf( "Transmission %s - http://www.transmissionbt.com/\n",
            LONG_VERSION_STRING );

    /* Get options */
    if( parseCommandLine( argc, (const char**)argv ) )
        return EXIT_FAILURE;

    /* Check the options for validity */
    if( !torrentPath ) {
        printf( "No torrent specified!\n" );
        return EXIT_FAILURE;
    }
    if( peerPort < 1 || peerPort > 65535 ) {
        printf( "Invalid port '%d'\n", peerPort );
        return EXIT_FAILURE;
    }
    if( peerSocketTOS < 0 || peerSocketTOS > 255 ) {
        printf( "Invalid TOS '%d'\n", peerSocketTOS );
        return EXIT_FAILURE;
    }

    /* don't bind the port if we're just running the CLI 
     * to get metainfo or to create a torrent */
    if( showInfo || showScrape || ( sourceFile != NULL ) )
        peerPort = -1;

    if( configdir == NULL )
        configdir = tr_getDefaultConfigDir( );

    /* if no download directory specified, use cwd instead */
    if( !downloadDir ) {
        getcwd( cwd, sizeof( cwd ) );
        downloadDir = cwd;
    }


    /* Initialize libtransmission */
    h = tr_sessionInitFull(
            configdir,
            "cli",                         /* tag */
            downloadDir,                   /* where to download torrents */
            TR_DEFAULT_PEX_ENABLED,
            natTraversal,                  /* nat enabled */
            peerPort,
            TR_ENCRYPTION_PREFERRED,
            uploadLimit >= 0,
            uploadLimit,
            downloadLimit >= 0,
            downloadLimit,
            TR_DEFAULT_GLOBAL_PEER_LIMIT,
            verboseLevel + 1,              /* messageLevel */
            0,                             /* is message queueing enabled? */
            TR_DEFAULT_BLOCKLIST_ENABLED,
            peerSocketTOS,
            TR_DEFAULT_RPC_ENABLED,
            TR_DEFAULT_RPC_PORT,
            TR_DEFAULT_RPC_ACL,
            FALSE, "fnord", "potzrebie",
            TR_DEFAULT_PROXY_ENABLED,
            TR_DEFAULT_PROXY,
            TR_DEFAULT_PROXY_TYPE,
            TR_DEFAULT_PROXY_AUTH_ENABLED,
            TR_DEFAULT_PROXY_USERNAME,
            TR_DEFAULT_PROXY_PASSWORD );

    if( sourceFile && *sourceFile ) /* creating a torrent */
    {
        int err;
        tr_metainfo_builder * builder = tr_metaInfoBuilderCreate( h, sourceFile );
        tr_tracker_info ti;
        ti.tier = 0;
        ti.announce = (char*) announce;
        tr_makeMetaInfo( builder, torrentPath, &ti, 1, comment, isPrivate );
        while( !builder->isDone ) {
            tr_wait( 1000 );
            printf( "." );
        }
        err = builder->result;
        tr_metaInfoBuilderFree( builder );
        return err;
    }

    ctor = tr_ctorNew( h );
    tr_ctorSetMetainfoFromFile( ctor, torrentPath );
    tr_ctorSetPaused( ctor, TR_FORCE, showScrape );
    tr_ctorSetDownloadDir( ctor, TR_FORCE, downloadDir );

    if( showScrape )
    {
        tr_info info;

        if( !tr_torrentParse( h, ctor, &info ) )
        {
            int i;
            const time_t start = time( NULL );
            for( i=0; i<info.trackerCount; ++i )
            {
                if( info.trackers[i].scrape )
                {
                    const char * scrape = info.trackers[i].scrape;
                    char escaped[SHA_DIGEST_LENGTH*3 + 1];
                    char *url, *host;
                    escape( escaped, info.hash, SHA_DIGEST_LENGTH );
                    url = tr_strdup_printf( "%s%cinfo_hash=%s",
                                            scrape,
                                            strchr(scrape,'?')?'&':'?',
                                            escaped );
                    tr_httpParseURL( scrape, -1, &host, NULL, NULL );
                    ++leftToScrape;
                    tr_webRun( h, url, NULL, scrapeDoneFunc, host );
                    tr_free( url );
                }
            }

            fprintf( stderr, "scraping %d trackers:\n", leftToScrape );

            while( leftToScrape>0 && ((time(NULL)-start)<20) )
                tr_wait( 250 );
        }
        goto cleanup;
    }

    if( showInfo )
    {
        tr_info info;

        if( !tr_torrentParse( h, ctor, &info ) )
        {
            int prevTier = -1;
            tr_file_index_t ff;

            printf( "hash:\t" );
            for( i=0; i<SHA_DIGEST_LENGTH; ++i )
                printf( "%02x", info.hash[i] );
            printf( "\n" );

            printf( "name:\t%s\n", info.name );

            for( i=0; i<info.trackerCount; ++i ) {
                if( prevTier != info.trackers[i].tier ) {
                    prevTier = info.trackers[i].tier;
                    printf( "\ntracker tier #%d:\n", (prevTier+1) );
                }
                printf( "\tannounce:\t%s\n", info.trackers[i].announce );
            }

            printf( "size:\t%"PRIu64" (%"PRIu64" * %d + %"PRIu64")\n",
                    info.totalSize, info.totalSize / info.pieceSize,
                    info.pieceSize, info.totalSize % info.pieceSize );

            if( info.comment[0] )
                printf( "comment:\t%s\n", info.comment );
            if( info.creator[0] )
                printf( "creator:\t%s\n", info.creator );
            if( info.isPrivate )
                printf( "private flag set\n" );

            printf( "file(s):\n" );
            for( ff=0; ff<info.fileCount; ++ff )
                printf( "\t%s (%"PRIu64")\n", info.files[ff].name, info.files[ff].length );

            tr_metainfoFree( &info );
        }

        tr_ctorFree( ctor );
        goto cleanup;
    }

    tor = tr_torrentNew( h, ctor, &error );
    tr_ctorFree( ctor );
    if( tor == NULL )
    {
        printf( "Failed opening torrent file `%s'\n", torrentPath );
        tr_sessionClose( h );
        return EXIT_FAILURE;
    }

    signal( SIGINT, sigHandler );
    signal( SIGHUP, sigHandler );

    tr_torrentSetStatusCallback( tor, torrentStateChanged, NULL );
    tr_torrentStart( tor );

    for( ;; )
    {
        char string[LINEWIDTH];
        int  chars = 0;
        const struct tr_stat * s;

        tr_wait( 1000 );

        if( gotsig )
        {
            gotsig = 0;
            tr_torrentStop( tor );
            tr_sessionSetPortForwardingEnabled( h, 0 );
        }
        
        if( manualUpdate )
        {
            manualUpdate = 0;
            if ( !tr_torrentCanManualUpdate( tor ) )
                fprintf( stderr, "\rReceived SIGHUP, but can't send a manual update now\n" );
            else {
                fprintf( stderr, "\rReceived SIGHUP: manual update scheduled\n" );
                tr_torrentManualUpdate( tor );
            }
        }
        
        if( verify )
        {
            verify = 0;
            tr_torrentVerify( tor );
        }

        s = tr_torrentStat( tor );

        if( s->status & TR_STATUS_CHECK_WAIT )
        {
            chars = snprintf( string, sizeof string,
                "Waiting to verify local files..." );
        }
        else if( s->status & TR_STATUS_CHECK )
        {
            chars = snprintf( string, sizeof string,
                "Verifying local files... %.2f%%, found %.2f%% valid", 100 * s->recheckProgress, 100.0 * s->percentDone );
        }
        else if( s->status & TR_STATUS_DOWNLOAD )
        {
            chars = snprintf( string, sizeof string,
                "Progress: %.2f %%, %d peer%s, dl from %d (%.2f KB/s), "
                "ul to %d (%.2f KB/s) [%s]", 100.0 * s->percentDone,
                s->peersConnected, ( s->peersConnected == 1 ) ? "" : "s",
                s->peersSendingToUs, s->rateDownload,
                s->peersGettingFromUs, s->rateUpload,
                getStringRatio(s->ratio) );
        }
        else if( s->status & TR_STATUS_SEED )
        {
            chars = snprintf( string, sizeof string,
                "Seeding, uploading to %d of %d peer(s), %.2f KB/s [%s]",
                s->peersGettingFromUs, s->peersConnected,
                s->rateUpload, getStringRatio(s->ratio) );
        }
        else if( s->status & TR_STATUS_STOPPED )
        {
            break;
        }
        if( ( signed )sizeof string > chars )
        {
            memset( &string[chars], ' ', sizeof string - 1 - chars );
        }
        string[sizeof string - 1] = '\0';
        fprintf( stderr, "\r%s", string );

        if( s->error )
        {
            fprintf( stderr, "\n%s\n", s->errorString );
        }
        else if( verboseLevel > 0 )
        {
            fprintf( stderr, "\n" );
        }
    }
    fprintf( stderr, "\n" );

    /* try for 5 seconds to delete any port mappings for nat traversal */
    tr_sessionSetPortForwardingEnabled( h, 0 );
    for( i=0; i<10; ++i ) {
        const tr_port_forwarding f = tr_sessionGetPortForwarding( h );
        if( f == TR_PORT_UNMAPPED )
            break;
        tr_wait( 500 );
    }
    
cleanup:
    tr_sessionClose( h );

    return EXIT_SUCCESS;
}

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

static const char *
getUsage( void )
{
    return "A fast and easy BitTorrent client\n"
           "\n"
           "Usage: "MY_NAME" [options] <torrent-filename>";
}

const struct tr_option options[] = {
    { 'a', "announce",     "When creating a new torrent, set its announce URL",   "a", 1, "<url>" },
    { 'c', "comment",      "When creating a new torrent, set its comment field",  "c", 1, "<comment>" },
    { 'd', "downlimit",    "Set the maxiumum download speed in KB/s",             "d", 1, "<number>" },
    { 'D', "no-downlimit", "Don't limit the download speed",                      "D", 0, NULL },
    { 'f', "finish",       "Set a script to run when the torrent finishes",       "f", 1, "<script>" },
    { 'g', "config-dir",   "Where to look for configuration files",               "g", 1, "<path>" },
    { 'i', "info",         "Show torrent details and exit",                       "i", 0, NULL },
    { 'm', "portmap",      "Enable portmapping via NAT-PMP or UPnP",              "m", 0, NULL },
    { 'M', "no-portmap",   "Disable portmapping",                                 "M", 0, NULL },
    { 'n', "new",          "Create a new torrent from a file or directory",       "n", 1, "<path>" },
    { 'p', "port",         "Port to listen for incoming peers (Default: "TR_DEFAULT_PORT_STR")", "p", 1, "<port>" },
    { 'r', "private",      "When creating a new torrent, set its 'private' flag", "r", 0, NULL },
    { 's', "scrape",       "Scrape the torrent and exit",                         "s", 0, NULL },
    { 't', "tos",          "Peer socket TOS (0 to 255, default="TR_DEFAULT_PEER_SOCKET_TOS_STR")", "t", 1, "<number>"},
    { 'u', "uplimit",      "Set the maxiumum upload speed in KB/s",               "u", 1, "<number>" },
    { 'U', "no-uplimit",   "Don't limit the upload speed",                        "U", 0, NULL },
    { 'v', "verify",       "Verify the specified torrent",                        "v", 0, NULL },
    { 'w', "download-dir", "Where to save downloaded data",                       "w", 1, "<path>" },
    { 0, NULL, NULL, NULL, 0, NULL }
};

static void
showUsage( void )
{
    tr_getopt_usage( MY_NAME, getUsage(), options );
    exit( 0 );
}

static int
numarg( const char * arg )
{
    char * end = NULL;
    const long num = strtol( arg, &end, 10 );
    if( *end ) {
        fprintf( stderr, "Not a number: \"%s\"\n", arg );
        showUsage( );
    }
    return num;
}

static int
parseCommandLine( int argc, const char ** argv )
{
    int c;
    const char * optarg;

    while(( c = tr_getopt( getUsage(), argc, argv, options, &optarg )))
    {
        switch( c )
        {
            case 'a': announce = optarg; break;
            case 'c': comment = optarg; break;
            case 'd': downloadLimit = numarg( optarg ); break;
            case 'D': downloadLimit = -1; break;
            case 'f': finishCall = optarg; break;
            case 'g': configdir = optarg; break;
            case 'i': showInfo = 1; break;
            case 'm': natTraversal = 1; break;
            case 'M': natTraversal = 0; break;
            case 'n': sourceFile = optarg; break;
            case 'p': peerPort = numarg( optarg ); break;
            case 'r': isPrivate = 1; break;
            case 's': showScrape = 1; break;
            case 't': peerSocketTOS = numarg( optarg ); break;
            case 'u': uploadLimit = numarg( optarg ); break;
            case 'U': uploadLimit = -1; break;
            case 'v': verify = 1; break;
            case 'w': downloadDir = optarg; break;
            case TR_OPT_UNK: torrentPath = optarg; break;
            default: return 1;
        }
    }

    return 0;
}

static void
sigHandler( int signal )
{
    switch( signal )
    {
        case SIGINT: gotsig = 1; break;
        case SIGHUP: manualUpdate = 1; break;
        default: break;
    }
}