/*
Copyright (C) 1997-2001 Id Software, Inc.

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

*/

//
// cl_download.c -- queue manager and UDP downloads
//

#include "cl_local.h"
#include "d_md2.h"
#include "d_sp2.h"

typedef enum {
    PRECACHE_MODELS,
    PRECACHE_OTHER,
    PRECACHE_MAP,
    PRECACHE_FINAL
} precache_t;

static precache_t precache_check;
static int precache_sexed_sounds[MAX_SOUNDS];
static int precache_sexed_total;

/*
===============
CL_QueueDownload

Adds new download path into queue, incrementing pending count.
Entry will stay in queue for entire lifetime of server connection,
to make sure each path is tried exactly once.
===============
*/
qerror_t CL_QueueDownload( const char *path, dltype_t type ) {
    dlqueue_t *q;
    size_t len;

    FOR_EACH_DLQ( q ) {
        // avoid sending duplicate requests
        if( !FS_pathcmp( path, q->path ) ) {
            Com_DPrintf( "%s: %s [DUP]\n", __func__, path );
            return Q_ERR_EXIST;
        }
    }

    len = strlen( path );
    if( len >= MAX_QPATH ) {
        Com_Error( ERR_DROP, "%s: oversize quake path", __func__ );
    }

    q = Z_Malloc( sizeof( *q ) + len );
    memcpy( q->path, path, len + 1 );
    q->type = type;
    q->state = DL_PENDING;

#if USE_CURL
    // paks get bumped to the top and HTTP switches to single downloading.
    // this prevents someone on 28k dialup trying to do both the main .pak
    // and referenced configstrings data at once.
    if( type == DL_PAK )
        List_Insert( &cls.download.queue, &q->entry );
    else
#endif
        List_Append( &cls.download.queue, &q->entry );

    cls.download.pending++;
    Com_DPrintf( "%s: %s [%d]\n", __func__, path, cls.download.pending );
    return Q_ERR_SUCCESS;
}

/*
===============
CL_FinishDownload

Mark the queue entry as done, decrementing pending count.
===============
*/
void CL_FinishDownload( dlqueue_t *q ) {
    if( q->state == DL_DONE ) {
        Com_Error( ERR_DROP, "%s: already done", __func__ );
    }
    if( !cls.download.pending ) {
        Com_Error( ERR_DROP, "%s: bad pending count", __func__ );
    }

    q->state = DL_DONE;
    cls.download.pending--;
    Com_DPrintf( "%s: %s [%d]\n", __func__, q->path, cls.download.pending );
}

/*
===============
CL_CleanupDownloads

Disconnected from server, clean up.
===============
*/
void CL_CleanupDownloads( void ) {
    dlqueue_t *q, *n;

#if USE_CURL
    HTTP_CleanupDownloads();
#endif

    FOR_EACH_DLQ_SAFE( q, n ) {
        Z_Free( q );
    }

    List_Init( &cls.download.queue );
    cls.download.pending = 0;

    cls.download.current = NULL;
    cls.download.percent = 0;

    if( cls.download.file ) {
        FS_FCloseFile( cls.download.file );
        cls.download.file = 0;
    }

    cls.download.temp[0] = 0;
}

// start legacy UDP download
static qboolean start_download( dlqueue_t *q ) {
    size_t len;
    qhandle_t f;
    ssize_t ret;

    len = strlen( q->path );
    if( len >= MAX_QPATH ) {
        Com_Error( ERR_DROP, "%s: oversize quake path", __func__ );
    }

    // download to a temp name, and only rename
    // to the real name when done, so if interrupted
    // a runt file wont be left
    memcpy( cls.download.temp, q->path, len );
    memcpy( cls.download.temp + len, ".tmp", 5 );

//ZOID
    // check to see if we already have a tmp for this file, if so, try to resume
    // open the file if not opened yet
    ret = FS_FOpenFile( cls.download.temp, &f, FS_MODE_RDWR );
    if( ret >= 0 ) { // it exists
        cls.download.file = f;
        // give the server an offset to start the download
        Com_DPrintf( "[UDP] Resuming %s\n", q->path );
        CL_ClientCommand( va( "download \"%s\" %d", q->path, (int)ret ) );
    } else if( ret == Q_ERR_NOENT ) { // it doesn't exist
        Com_DPrintf( "[UDP] Downloading %s\n", q->path );
        CL_ClientCommand( va( "download \"%s\"", q->path ) );
    } else { // error happened
        Com_EPrintf( "[UDP] Couldn't open %s for appending: %s\n",
            cls.download.temp, Q_ErrorString( ret ) );
        CL_FinishDownload( q );
        return qfalse;
    }

    q->state = DL_RUNNING;
    cls.download.current = q;
    return qtrue;
}

/*
===============
CL_StartNextDownload

Start another UDP download if possible
===============
*/
void CL_StartNextDownload( void ) {
    dlqueue_t *q;

    if( !cls.download.pending || cls.download.current ) {
        return;
    }

    FOR_EACH_DLQ( q ) {
        if( q->state == DL_PENDING ) {
            if( start_download( q ) ) {
                break;
            }
        }
    }
}

/*
=====================
CL_HandleDownload

A download data has been received from the server
=====================
*/
void CL_HandleDownload( const byte *data, int size, int percent ) {
    dlqueue_t *q = cls.download.current;
    const char *msg = NULL;
    qerror_t ret;

    if( !q ) {
        Com_Error( ERR_DROP, "%s: no download requested", __func__ );
    }

    if( size == -1 ) {
        if( !percent ) {
            msg = "FAIL";
        } else {
            msg = "STOP";
        }
        if( cls.download.file ) {
            // if here, we tried to resume a file but the server said no
            FS_FCloseFile( cls.download.file );
        }
        goto another;
    }

    // open the file if not opened yet
    if( !cls.download.file ) {
        ret = FS_FOpenFile( cls.download.temp, &cls.download.file, FS_MODE_WRITE );
        if( !cls.download.file ) {
            Com_EPrintf( "[UDP] Couldn't open %s for writing: %s\n",
                cls.download.temp, Q_ErrorString( ret ) );
            goto another;
        }
    }

    FS_Write( data, size, cls.download.file );

    if( percent != 100 ) {
        // request next block
        // change display routines by zoid
        cls.download.percent = percent;

        CL_ClientCommand( "nextdl" );
    } else {
        FS_FCloseFile( cls.download.file );

        // rename the temp file to it's final name
        ret = FS_RenameFile( cls.download.temp, q->path );
        if( ret ) {
            Com_EPrintf( "[UDP] Couldn't rename %s to %s: %s\n",
                cls.download.temp, q->path, Q_ErrorString( ret ) );
        } else {
            msg = "DONE";
        }

another:
        // finished with current path
        CL_FinishDownload( q );
        cls.download.current = NULL;
        cls.download.percent = 0;
        cls.download.file = 0;
        cls.download.temp[0] = 0;

        if( msg ) {
            Com_Printf( "[UDP] %s [%s] [%d remaining file%s]\n",
                q->path, msg, cls.download.pending, cls.download.pending == 1 ? "" : "s" );
        }

        // get another file if needed
        CL_RequestNextDownload();
        CL_StartNextDownload();
    }
}


/*
===============
CL_CheckDownloadExtension

Only predefined set of filename extensions is allowed,
to prevent the server from uploading arbitrary files.
===============
*/
qboolean CL_CheckDownloadExtension( const char *ext ) {
    static const char allowed[][4] = {
        "pcx", "wal", "wav", "md2", "sp2", "tga", "png",
        "jpg", "bsp", "ent", "txt", "dm2", "loc", "md3"
    };
    static const int total = sizeof( allowed ) / sizeof( allowed[0] );
    int i;

    for( i = 0; i < total; i++ )
        if( !Q_stricmp( ext, allowed[i] ) )
            return qtrue;

    return qfalse;
}

// attempts to start a download from the server if file doesn't exist.
static qerror_t check_file_len( const char *path, size_t len, dltype_t type ) {
    char *ext;
    qerror_t ret;

    // check path
    if( len < 1 || len >= MAX_QPATH
        || !Q_ispath( path[0] )
        || !Q_ispath( path[ len - 1 ] )
        || strchr( path, '\\' )
        || strchr( path, ':' )
        || !strchr( path, '/' )
        || strstr( path, ".." ) )
    {
        return Q_ERR_INVALID_PATH;
    }

    // check extension
    ext = COM_FileExtension( path );
    if( *ext != '.' || !CL_CheckDownloadExtension( ext + 1 ) ) {
        return Q_ERR_INVALID_PATH;
    }

    if( FS_FileExists( path ) ) {
        // it exists, no need to download
        return Q_ERR_EXIST;
    }

#if USE_CURL
    ret = HTTP_QueueDownload( path, type );
    if( ret != Q_ERR_NOSYS ) {
        return ret;
    }
#endif

    // queue and start legacy UDP download
    ret = CL_QueueDownload( path, type );
    if( ret == Q_ERR_SUCCESS ) {
        CL_StartNextDownload();
    }

    return ret;
}

#define check_file( path, type ) \
    check_file_len( path, strlen( path ), type )

static void check_skins( const char *name ) {
    size_t          i, num_skins, ofs_skins, end_skins;
    byte            *model;
    size_t          len;
    dmd2header_t    *md2header;
    dsp2header_t    *sp2header;
    char            *md2skin;
    dsp2frame_t     *sp2frame;
    uint32_t        ident;
    char            fn[ MAX_QPATH ];

    len = FS_LoadFile( name, ( void ** )&model );
    if( !model ) {
        // couldn't load it
        return;
    }

    if( len < sizeof( ident ) ) {
        // file too small
        goto done;
    }

    // check ident
    ident = LittleLong( *( uint32_t * )model );
    switch( ident ) {
    case MD2_IDENT:
        // alias model
        md2header = ( dmd2header_t * )model;
        if( len < sizeof( *md2header ) ||
            LittleLong( md2header->ident ) != MD2_IDENT ||
            LittleLong( md2header->version ) != MD2_VERSION )
        {
            // not an alias model
            goto done;
        }

        num_skins = LittleLong( md2header->num_skins );
        ofs_skins = LittleLong( md2header->ofs_skins );
        end_skins = ofs_skins + num_skins * MD2_MAX_SKINNAME;
        if( num_skins > MD2_MAX_SKINS || end_skins < ofs_skins || end_skins > len ) {
            // bad alias model
            goto done;
        }

        md2skin = ( char * )model + ofs_skins;
        for( i = 0; i < num_skins; i++ ) {
            if( !Q_memccpy( fn, md2skin, 0, sizeof( fn ) ) ) {
                // bad alias model
                goto done;
            }
            check_file( fn, DL_OTHER );
            md2skin += MD2_MAX_SKINNAME;
        }
        break;

    case SP2_IDENT:
        // sprite model
        sp2header = ( dsp2header_t * )model;
        if( len < sizeof( *sp2header ) ||
            LittleLong( sp2header->ident ) != SP2_IDENT ||
            LittleLong( sp2header->version ) != SP2_VERSION )
        {
            // not a sprite model
            goto done;
        }

        num_skins = LittleLong( sp2header->numframes );
        ofs_skins = sizeof( *sp2header );
        end_skins = ofs_skins + num_skins * sizeof( dsp2frame_t );
        if( num_skins > SP2_MAX_FRAMES || end_skins < ofs_skins || end_skins > len ) {
            // bad sprite model
            goto done;
        }

        sp2frame = ( dsp2frame_t * )( model + ofs_skins );
        for( i = 0; i < num_skins; i++ ) {
            if( !Q_memccpy( fn, sp2frame->name, 0, sizeof( fn ) ) ) {
                // bad sprite model
                goto done;
            }
            check_file( fn, DL_OTHER );
            sp2frame++;
        }
        break;

    default:
        // unknown file format
        goto done;
    }

done:
    FS_FreeFile( model );
}

static void check_player( const char *name ) {
    char fn[ MAX_QPATH ], model[ MAX_QPATH ], skin[ MAX_QPATH ], *p;
    size_t len;
    int i, j;

    CL_ParsePlayerSkin( NULL, model, skin, name );

    // model
    len = Q_concat( fn, sizeof( fn ), "players/", model, "/tris.md2", NULL );
    check_file_len( fn, len, DL_OTHER );

    // weapon models
    for( i = 0; i < cl.numWeaponModels; i++ ) {
        len = Q_concat( fn, sizeof( fn ), "players/", model, "/", cl.weaponModels[i], NULL );
        check_file_len( fn, len, DL_OTHER );
    }

    // default weapon skin
    len = Q_concat( fn, sizeof( fn ), "players/", model, "/weapon.pcx", NULL );
    check_file_len( fn, len, DL_OTHER );

    // skin
    len = Q_concat( fn, sizeof( fn ), "players/", model, "/", skin, ".pcx", NULL );
    check_file_len( fn, len, DL_OTHER );

    // skin_i
    len = Q_concat( fn, sizeof( fn ), "players/", model, "/", skin, "_i.pcx", NULL );
    check_file_len( fn, len, DL_OTHER );

    // sexed sounds
    for( i = 0; i < precache_sexed_total; i++ ) {
        j = precache_sexed_sounds[ i ];
        p = cl.configstrings[ CS_SOUNDS + j ];

        if( *p == '*' ) {
            len = Q_concat( fn, sizeof( fn ), "players/", model, "/", p + 1, NULL );
            check_file_len( fn, len, DL_OTHER );
        }
    }
}

// for precaching dependencies
static qboolean downloads_pending( dltype_t type ) {
    dlqueue_t *q;

    // DL_OTHER just checks for any download
    if( type == DL_OTHER ) {
        return !!cls.download.pending;
    }

    // see if there are pending downloads of the given type
    FOR_EACH_DLQ( q ) {
        if( q->state != DL_DONE && q->type == type ) {
            return qtrue;
        }
    }

    return qfalse;
}

/*
=====================
CL_RequestNextDownload

Runs precache check and dispatches downloads.
=====================
*/
void CL_RequestNextDownload( void ) {
    char fn[ MAX_QPATH ], *name;
    size_t len;
    int i;

    if( cls.state != ca_connected && cls.state != ca_loading )
        return;

    if( !allow_download->integer || NET_IsLocalAddress( &cls.serverAddress ) ) {
        if( precache_check <= PRECACHE_MAP ) {
            CL_RegisterModels();
        }

        CL_Begin();
        return;
    }

    switch( precache_check ) {
    case PRECACHE_MODELS:
        // confirm map
        if( allow_download_maps->integer )
            check_file( cl.configstrings[ CS_MODELS + 1 ], DL_MAP );

        // checking for models
        if( allow_download_models->integer ) {
            for( i = 2; i < MAX_MODELS; i++ ) {
                name = cl.configstrings[ CS_MODELS + i ];
                if( !name[0] ) {
                    break;
                }
                if( name[0] == '*' || name[0] == '#' ) {
                    continue;
                }
                check_file( name, DL_MODEL );
            }
        }

        precache_check = PRECACHE_OTHER;
        // fall through

    case PRECACHE_OTHER:
        if( allow_download_models->integer ) {
            if( downloads_pending( DL_MODEL ) ) {
                // pending downloads (models), let's wait here before we can check skins.
                Com_DPrintf( "%s: waiting for models...\n", __func__ );
                return;
            }

            for( i = 2; i < MAX_MODELS; i++ ) {
                name = cl.configstrings[ CS_MODELS + i ];
                if( !name[0] ) {
                    break;
                }
                if( name[0] == '*' || name[0] == '#' ) {
                    continue;
                }
                check_skins( name );
            }
        }

        if( allow_download_sounds->integer ) {
            for( i = 1; i < MAX_SOUNDS; i++ ) {
                name = cl.configstrings[ CS_SOUNDS + i ];
                if( !name[0] ) {
                    break;
                }
                if( name[0] == '*' ) {
                    continue;
                }
                if( name[0] == '#' ) {
                    len = Q_strlcpy( fn, name + 1, sizeof( fn ) );
                } else {
                    len = Q_concat( fn, sizeof( fn ), "sound/", name, NULL );
                }
                check_file_len( fn, len, DL_OTHER );
            }
        }

        if( allow_download_pics->integer ) {
            for( i = 1; i < MAX_IMAGES; i++ ) {
                name = cl.configstrings[ CS_IMAGES + i ];
                if( !name[0] ) {
                    break;
                }
                if( name[0] == '/' || name[0] == '\\' ) {
                    len = Q_strlcpy( fn, name + 1, sizeof( fn ) );
                } else {
                    len = Q_concat( fn, sizeof( fn ), "pics/", name, ".pcx", NULL );
                }
                check_file_len( fn, len, DL_OTHER );
            }
        }

        if( allow_download_players->integer ) {
            // find sexed sounds
            precache_sexed_total = 0;
            for( i = 1; i < MAX_SOUNDS; i++ ) {
                if( cl.configstrings[ CS_SOUNDS + i ][ 0 ] == '*' ) {
                    precache_sexed_sounds[precache_sexed_total++] = i;
                }
            }

            for( i = 0; i < MAX_CLIENTS; i++ ) {
                name = cl.configstrings[ CS_PLAYERSKINS + i ];
                if( !name[0] ) {
                    continue;
                }
                check_player( name );
            }
        }

        if( allow_download_textures->integer ) {
            static const char env_suf[6][3] = {
                "rt", "bk", "lf", "ft", "up", "dn"
            };

            for( i = 0; i < 12; i++ ) {
                if( i & 1 )
                    len = Q_concat( fn, sizeof( fn ),
                        "env/", cl.configstrings[ CS_SKY ], env_suf[ i >> 1 ], ".pcx", NULL );
                else
                    len = Q_concat( fn, sizeof( fn ),
                        "env/", cl.configstrings[ CS_SKY ], env_suf[ i >> 1 ], ".tga", NULL );
                check_file_len( fn, len, DL_OTHER );
            }
        }

        precache_check = PRECACHE_MAP;
        // fall through

    case PRECACHE_MAP:
        if( downloads_pending( DL_MAP ) ) {
            // map might still be downloading?
            Com_DPrintf( "%s: waiting for map...\n", __func__ );
            return;
        }

        // load the map file before checking textures
        CL_RegisterModels();

        if( allow_download_textures->integer ) {
            for( i = 0; i < cl.bsp->numtexinfo; i++ ) {
                name = cl.bsp->texinfo[ i ].name;

                len = Q_concat( fn, sizeof( fn ), "textures/", name, ".wal", NULL );
                check_file_len( fn, len, DL_OTHER );
            }
        }

        precache_check = PRECACHE_FINAL;
        // fall through

    case PRECACHE_FINAL:
        if( downloads_pending( DL_OTHER ) ) {
            // pending downloads (possibly textures), let's wait here.
            Com_DPrintf( "%s: waiting for others...\n", __func__ );
            return;
        }

        // all done, tell server we are ready
        CL_Begin();
        break;

    default:
        Com_Error( ERR_DROP, "%s: bad precache_check\n", __func__ );
    }
}

void CL_ResetPrecacheCheck( void ) {
    precache_check = PRECACHE_MODELS;
}

/*
===============
CL_Download_f

Request a download from the server
===============
*/
static void CL_Download_f( void ) {
    char *path;
    qerror_t ret;

    if( cls.state < ca_connected ) {
        Com_Printf( "Must be connected to a server.\n" );
        return;
    }

    if( Cmd_Argc() != 2 ) {
        Com_Printf( "Usage: download <filename>\n" );
        return;
    }

    path = Cmd_Argv( 1 );

    ret = check_file( path, DL_OTHER );
    if( ret ) {
        Com_Printf( "Couldn't download %s: %s\n", path, Q_ErrorString( ret ) );
    }
}

void CL_InitDownloads( void ) {
    Cmd_AddCommand( "download", CL_Download_f );

    List_Init( &cls.download.queue );
}