/*

  * Tee pseudo-muxer

  * Copyright (c) 2012 Nicolas George
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public License
  * as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * FFmpeg 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 Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public License
  * along with FFmpeg; if not, write to the Free Software * Foundation, Inc.,
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 
 #include "libavutil/avutil.h"
 #include "libavutil/avstring.h"
 #include "libavutil/opt.h"

 #include "internal.h"

 #include "avformat.h"

 #include "avio_internal.h"

 #include "tee_common.h"

 typedef enum {
     ON_SLAVE_FAILURE_ABORT  = 1,
     ON_SLAVE_FAILURE_IGNORE = 2
 } SlaveFailurePolicy;
 
 #define DEFAULT_SLAVE_FAILURE_POLICY ON_SLAVE_FAILURE_ABORT
 

 typedef struct {
     AVFormatContext *avf;

     AVBSFContext **bsfs; ///< bitstream filters per stream

     SlaveFailurePolicy on_fail;

     int use_fifo;
     AVDictionary *fifo_options;

     /** map from input to output streams indexes,
      * disabled output streams are set to -1 */
     int *stream_map;

     int header_written;

 } TeeSlave;
 

 typedef struct TeeContext {
     const AVClass *class;
     unsigned nb_slaves;

     unsigned nb_alive;

     TeeSlave *slaves;

     int use_fifo;
     AVDictionary *fifo_options;
     char *fifo_options_str;

 } TeeContext;
 
 static const char *const slave_delim     = "|";

 static const char *const slave_bsfs_spec_sep = "/";

 static const char *const slave_select_sep = ",";

 #define OFFSET(x) offsetof(TeeContext, x)
 static const AVOption options[] = {
         {"use_fifo", "Use fifo pseudo-muxer to separate actual muxers from encoder",
          OFFSET(use_fifo), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, AV_OPT_FLAG_ENCODING_PARAM},
         {"fifo_options", "fifo pseudo-muxer options", OFFSET(fifo_options_str),
          AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, AV_OPT_FLAG_ENCODING_PARAM},
         {NULL}
 };
 

 static const AVClass tee_muxer_class = {
     .class_name = "Tee muxer",
     .item_name  = av_default_item_name,

     .option = options,

     .version    = LIBAVUTIL_VERSION_INT,
 };
 

 static inline int parse_slave_failure_policy_option(const char *opt, TeeSlave *tee_slave)
 {
     if (!opt) {
         tee_slave->on_fail = DEFAULT_SLAVE_FAILURE_POLICY;
         return 0;
     } else if (!av_strcasecmp("abort", opt)) {
         tee_slave->on_fail = ON_SLAVE_FAILURE_ABORT;
         return 0;
     } else if (!av_strcasecmp("ignore", opt)) {
         tee_slave->on_fail = ON_SLAVE_FAILURE_IGNORE;
         return 0;
     }
     /* Set failure behaviour to abort, so invalid option error will not be ignored */
     tee_slave->on_fail = ON_SLAVE_FAILURE_ABORT;
     return AVERROR(EINVAL);
 }
 

 static int parse_slave_fifo_options(const char *use_fifo,
                                     const char *fifo_options, TeeSlave *tee_slave)
 {
     int ret = 0;
 
     if (use_fifo) {
         /*TODO - change this to use proper function for parsing boolean
          *       options when there is one */
         if (av_match_name(use_fifo, "true,y,yes,enable,enabled,on,1")) {
             tee_slave->use_fifo = 1;
         } else if (av_match_name(use_fifo, "false,n,no,disable,disabled,off,0")) {
             tee_slave->use_fifo = 0;
         } else {
             return AVERROR(EINVAL);
         }
     }
 
     if (fifo_options)
         ret = av_dict_parse_string(&tee_slave->fifo_options, fifo_options, "=", ":", 0);
 
     return ret;
 }
 

 static int close_slave(TeeSlave *tee_slave)

 {
     AVFormatContext *avf;
     unsigned i;

     int ret = 0;

 
     avf = tee_slave->avf;

     if (!avf)
         return 0;
 
     if (tee_slave->header_written)
         ret = av_write_trailer(avf);
 
     if (tee_slave->bsfs) {

         for (i = 0; i < avf->nb_streams; ++i)
             av_bsf_free(&tee_slave->bsfs[i]);

     }
     av_freep(&tee_slave->stream_map);
     av_freep(&tee_slave->bsfs);
 
     ff_format_io_close(avf, &avf->pb);
     avformat_free_context(avf);
     tee_slave->avf = NULL;

     return ret;

 }
 
 static void close_slaves(AVFormatContext *avf)
 {
     TeeContext *tee = avf->priv_data;
     unsigned i;
 
     for (i = 0; i < tee->nb_slaves; i++) {
         close_slave(&tee->slaves[i]);
     }

     av_freep(&tee->slaves);

 }
 

 static int open_slave(AVFormatContext *avf, char *slave, TeeSlave *tee_slave)

 {
     int i, ret;
     AVDictionary *options = NULL;
     AVDictionaryEntry *entry;
     char *filename;

     char *format = NULL, *select = NULL, *on_fail = NULL;

     char *use_fifo = NULL, *fifo_options_str = NULL;

     AVFormatContext *avf2 = NULL;
     AVStream *st, *st2;

     int stream_count;

     int fullret;
     char *subselect = NULL, *next_subselect = NULL, *first_subselect = NULL, *tmp_select = NULL;

     if ((ret = ff_tee_parse_slave_options(avf, slave, &options, &filename)) < 0)

         return ret;

 
 #define STEAL_OPTION(option, field) do {                                \
         if ((entry = av_dict_get(options, option, NULL, 0))) {          \
             field = entry->value;                                       \
             entry->value = NULL; /* prevent it from being freed */      \
             av_dict_set(&options, option, NULL, 0);                     \
         }                                                               \
     } while (0)
 
     STEAL_OPTION("f", format);
     STEAL_OPTION("select", select);

     STEAL_OPTION("onfail", on_fail);

     STEAL_OPTION("use_fifo", use_fifo);
     STEAL_OPTION("fifo_options", fifo_options_str);

 
     ret = parse_slave_failure_policy_option(on_fail, tee_slave);
     if (ret < 0) {
         av_log(avf, AV_LOG_ERROR,
                "Invalid onfail option value, valid options are 'abort' and 'ignore'\n");
         goto end;
     }

     ret = parse_slave_fifo_options(use_fifo, fifo_options_str, tee_slave);
     if (ret < 0) {
         av_log(avf, AV_LOG_ERROR, "Error parsing fifo options: %s\n", av_err2str(ret));
         goto end;
     }
 
     if (tee_slave->use_fifo) {
 
         if (options) {
             char *format_options_str = NULL;
             ret = av_dict_get_string(options, &format_options_str, '=', ':');
             if (ret < 0)
                 goto end;
 

             ret = av_dict_set(&tee_slave->fifo_options, "format_opts", format_options_str,

                               AV_DICT_DONT_STRDUP_VAL);
             if (ret < 0)
                 goto end;
         }
 
         if (format) {
             ret = av_dict_set(&tee_slave->fifo_options, "fifo_format", format,
                               AV_DICT_DONT_STRDUP_VAL);
             format = NULL;
             if (ret < 0)
                 goto end;
         }
 
         av_dict_free(&options);
         options = tee_slave->fifo_options;
     }
     ret = avformat_alloc_output_context2(&avf2, NULL,
                                          tee_slave->use_fifo ? "fifo" :format, filename);

     if (ret < 0)

         goto end;

     tee_slave->avf = avf2;

     av_dict_copy(&avf2->metadata, avf->metadata, 0);

     avf2->opaque   = avf->opaque;
     avf2->io_open  = avf->io_open;
     avf2->io_close = avf->io_close;

     avf2->interrupt_callback = avf->interrupt_callback;
     avf2->flags = avf->flags;

     tee_slave->stream_map = av_calloc(avf->nb_streams, sizeof(*tee_slave->stream_map));
     if (!tee_slave->stream_map) {
         ret = AVERROR(ENOMEM);
         goto end;
     }
 
     stream_count = 0;

     for (i = 0; i < avf->nb_streams; i++) {
         st = avf->streams[i];

         if (select) {

             tmp_select = av_strdup(select);  // av_strtok is destructive so we regenerate it in each loop
             if (!tmp_select) {
                 ret = AVERROR(ENOMEM);

                 goto end;
             }

             fullret = 0;
             first_subselect = tmp_select;
             next_subselect = NULL;
             while (subselect = av_strtok(first_subselect, slave_select_sep, &next_subselect)) {
                 first_subselect = NULL;
 
                 ret = avformat_match_stream_specifier(avf, avf->streams[i], subselect);
                 if (ret < 0) {
                     av_log(avf, AV_LOG_ERROR,
                            "Invalid stream specifier '%s' for output '%s'\n",
                            subselect, slave);
                     goto end;
                 }
                 if (ret != 0) {
                     fullret = 1; // match
                     break;
                 }
             }
             av_freep(&tmp_select);

             if (fullret == 0) { /* no match */

                 tee_slave->stream_map[i] = -1;
                 continue;
             }
         }
         tee_slave->stream_map[i] = stream_count++;
 

         if (!(st2 = avformat_new_stream(avf2, NULL))) {
             ret = AVERROR(ENOMEM);

             goto end;

         }

 
         ret = ff_stream_encode_params_copy(st2, st);
         if (ret < 0)

             goto end;

     }
 

     ret = ff_format_output_open(avf2, filename, NULL);
     if (ret < 0) {
         av_log(avf, AV_LOG_ERROR, "Slave '%s': error opening: %s\n", slave,
                av_err2str(ret));
         goto end;

     }
 
     if ((ret = avformat_write_header(avf2, &options)) < 0) {
         av_log(avf, AV_LOG_ERROR, "Slave '%s': error writing header: %s\n",
                slave, av_err2str(ret));

         goto end;
     }

     tee_slave->header_written = 1;

     tee_slave->bsfs = av_calloc(avf2->nb_streams, sizeof(*tee_slave->bsfs));

     if (!tee_slave->bsfs) {
         ret = AVERROR(ENOMEM);
         goto end;
     }
 
     entry = NULL;
     while (entry = av_dict_get(options, "bsfs", NULL, AV_DICT_IGNORE_SUFFIX)) {
         const char *spec = entry->key + strlen("bsfs");
         if (*spec) {
             if (strspn(spec, slave_bsfs_spec_sep) != 1) {
                 av_log(avf, AV_LOG_ERROR,
                        "Specifier separator in '%s' is '%c', but only characters '%s' "
                        "are allowed\n", entry->key, *spec, slave_bsfs_spec_sep);

                 ret = AVERROR(EINVAL);
                 goto end;

             }
             spec++; /* consume separator */
         }
 
         for (i = 0; i < avf2->nb_streams; i++) {
             ret = avformat_match_stream_specifier(avf2, avf2->streams[i], spec);
             if (ret < 0) {
                 av_log(avf, AV_LOG_ERROR,
                        "Invalid stream specifier '%s' in bsfs option '%s' for slave "
                        "output '%s'\n", spec, entry->key, filename);
                 goto end;
             }
 
             if (ret > 0) {
                 av_log(avf, AV_LOG_DEBUG, "spec:%s bsfs:%s matches stream %d of slave "
                        "output '%s'\n", spec, entry->value, i, filename);
                 if (tee_slave->bsfs[i]) {
                     av_log(avf, AV_LOG_WARNING,
                            "Duplicate bsfs specification associated to stream %d of slave "
                            "output '%s', filters will be ignored\n", i, filename);
                     continue;
                 }

                 ret = av_bsf_list_parse_str(entry->value, &tee_slave->bsfs[i]);

                 if (ret < 0) {
                     av_log(avf, AV_LOG_ERROR,
                            "Error parsing bitstream filter sequence '%s' associated to "
                            "stream %d of slave output '%s'\n", entry->value, i, filename);
                     goto end;
                 }
             }
         }
 
         av_dict_set(&options, entry->key, NULL, 0);

     }

     for (i = 0; i < avf->nb_streams; i++){
         int target_stream = tee_slave->stream_map[i];
         if (target_stream < 0)
             continue;
 
         if (!tee_slave->bsfs[target_stream]) {
             /* Add pass-through bitstream filter */
             ret = av_bsf_get_null_filter(&tee_slave->bsfs[target_stream]);
             if (ret < 0) {
                 av_log(avf, AV_LOG_ERROR,
                        "Failed to create pass-through bitstream filter: %s\n",
                        av_err2str(ret));
                 goto end;
             }
         }
 
         tee_slave->bsfs[target_stream]->time_base_in = avf->streams[i]->time_base;
         ret = avcodec_parameters_copy(tee_slave->bsfs[target_stream]->par_in,
                                       avf->streams[i]->codecpar);
         if (ret < 0)
             goto end;
 
         ret = av_bsf_init(tee_slave->bsfs[target_stream]);
         if (ret < 0) {
             av_log(avf, AV_LOG_ERROR,
             "Failed to initialize bitstream filter(s): %s\n",
             av_err2str(ret));
             goto end;
         }
     }
 

     if (options) {
         entry = NULL;
         while ((entry = av_dict_get(options, "", entry, AV_DICT_IGNORE_SUFFIX)))
             av_log(avf2, AV_LOG_ERROR, "Unknown option '%s'\n", entry->key);
         ret = AVERROR_OPTION_NOT_FOUND;

         goto end;

     }
 

 end:
     av_free(format);

     av_free(select);

     av_free(on_fail);

     av_dict_free(&options);

     av_freep(&tmp_select);

     return ret;
 }
 

 static void log_slave(TeeSlave *slave, void *log_ctx, int log_level)
 {
     int i;
     av_log(log_ctx, log_level, "filename:'%s' format:%s\n",
            slave->avf->filename, slave->avf->oformat->name);
     for (i = 0; i < slave->avf->nb_streams; i++) {
         AVStream *st = slave->avf->streams[i];

         AVBSFContext *bsf = slave->bsfs[i];
         const char *bsf_name;

 
         av_log(log_ctx, log_level, "    stream:%d codec:%s type:%s",

                i, avcodec_get_name(st->codecpar->codec_id),
                av_get_media_type_string(st->codecpar->codec_type));

 
         bsf_name = bsf->filter->priv_class ?
                    bsf->filter->priv_class->item_name(bsf) : bsf->filter->name;
         av_log(log_ctx, log_level, " bsfs: %s\n", bsf_name);

     }
 }
 

 static int tee_process_slave_failure(AVFormatContext *avf, unsigned slave_idx, int err_n)
 {
     TeeContext *tee = avf->priv_data;
     TeeSlave *tee_slave = &tee->slaves[slave_idx];
 
     tee->nb_alive--;
 
     close_slave(tee_slave);
 
     if (!tee->nb_alive) {
         av_log(avf, AV_LOG_ERROR, "All tee outputs failed.\n");
         return err_n;
     } else if (tee_slave->on_fail == ON_SLAVE_FAILURE_ABORT) {
         av_log(avf, AV_LOG_ERROR, "Slave muxer #%u failed, aborting.\n", slave_idx);
         return err_n;
     } else {
         av_log(avf, AV_LOG_ERROR, "Slave muxer #%u failed: %s, continuing with %u/%u slaves.\n",
                slave_idx, av_err2str(err_n), tee->nb_alive, tee->nb_slaves);
         return 0;
     }
 }
 

 static int tee_write_header(AVFormatContext *avf)
 {
     TeeContext *tee = avf->priv_data;
     unsigned nb_slaves = 0, i;
     const char *filename = avf->filename;

     char **slaves = NULL;

     int ret;
 
     while (*filename) {

         char *slave = av_get_token(&filename, slave_delim);
         if (!slave) {
             ret = AVERROR(ENOMEM);

             goto fail;
         }

         ret = av_dynarray_add_nofree(&slaves, &nb_slaves, slave);
         if (ret < 0) {
             av_free(slave);

             goto fail;
         }
         if (strspn(filename, slave_delim))
             filename++;
     }
 

     if (tee->fifo_options_str) {
         ret = av_dict_parse_string(&tee->fifo_options, tee->fifo_options_str, "=", ":", 0);
         if (ret < 0)
             goto fail;
     }
 

     if (!(tee->slaves = av_mallocz_array(nb_slaves, sizeof(*tee->slaves)))) {
         ret = AVERROR(ENOMEM);
         goto fail;
     }

     tee->nb_slaves = tee->nb_alive = nb_slaves;

     for (i = 0; i < nb_slaves; i++) {

 
         tee->slaves[i].use_fifo = tee->use_fifo;
         ret = av_dict_copy(&tee->slaves[i].fifo_options, tee->fifo_options, 0);
         if (ret < 0)
             goto fail;
 

         if ((ret = open_slave(avf, slaves[i], &tee->slaves[i])) < 0) {
             ret = tee_process_slave_failure(avf, i, ret);
             if (ret < 0)
                 goto fail;
         } else {
             log_slave(&tee->slaves[i], avf, AV_LOG_VERBOSE);
         }

         av_freep(&slaves[i]);
     }
 

     for (i = 0; i < avf->nb_streams; i++) {
         int j, mapped = 0;
         for (j = 0; j < tee->nb_slaves; j++)

             if (tee->slaves[j].avf)
                 mapped += tee->slaves[j].stream_map[i] >= 0;

         if (!mapped)
             av_log(avf, AV_LOG_WARNING, "Input stream #%d is not mapped "
                    "to any slave.\n", i);
     }

     av_free(slaves);

     return 0;
 
 fail:
     for (i = 0; i < nb_slaves; i++)
         av_freep(&slaves[i]);
     close_slaves(avf);

     av_free(slaves);

     return ret;
 }
 
 static int tee_write_trailer(AVFormatContext *avf)
 {
     TeeContext *tee = avf->priv_data;
     int ret_all = 0, ret;
     unsigned i;
 
     for (i = 0; i < tee->nb_slaves; i++) {

         if ((ret = close_slave(&tee->slaves[i])) < 0) {
             ret = tee_process_slave_failure(avf, i, ret);
             if (!ret_all && ret < 0)

                 ret_all = ret;

         }

     }

     av_freep(&tee->slaves);

     return ret_all;
 }
 
 static int tee_write_packet(AVFormatContext *avf, AVPacket *pkt)
 {
     TeeContext *tee = avf->priv_data;
     AVFormatContext *avf2;

     AVBSFContext *bsfs;

     AVPacket pkt2;
     int ret_all = 0, ret;
     unsigned i, s;

     int s2;

 
     for (i = 0; i < tee->nb_slaves; i++) {

         if (!(avf2 = tee->slaves[i].avf))
             continue;
 

         /* Flush slave if pkt is NULL*/
         if (!pkt) {
             ret = av_interleaved_write_frame(avf2, NULL);
             if (ret < 0) {
                 ret = tee_process_slave_failure(avf, i, ret);
                 if (!ret_all && ret < 0)
                     ret_all = ret;
             }
             continue;
         }
 

         s = pkt->stream_index;

         s2 = tee->slaves[i].stream_map[s];
         if (s2 < 0)

             continue;

         memset(&pkt2, 0, sizeof(AVPacket));
         if ((ret = av_packet_ref(&pkt2, pkt)) < 0)

             if (!ret_all) {

                 ret_all = ret;

                 continue;
             }

         bsfs = tee->slaves[i].bsfs[s2];

         pkt2.stream_index = s2;

         ret = av_bsf_send_packet(bsfs, &pkt2);
         if (ret < 0) {
             av_log(avf, AV_LOG_ERROR, "Error while sending packet to bitstream filter: %s\n",
                    av_err2str(ret));
             ret = tee_process_slave_failure(avf, i, ret);
             if (!ret_all && ret < 0)
                 ret_all = ret;
         }
 
         while(1) {
             ret = av_bsf_receive_packet(bsfs, &pkt2);
             if (ret == AVERROR(EAGAIN)) {
                 ret = 0;
                 break;
             } else if (ret < 0) {
                 break;
             }
 
             av_packet_rescale_ts(&pkt2, bsfs->time_base_out,
                                  avf2->streams[s2]->time_base);
             ret = av_interleaved_write_frame(avf2, &pkt2);
             if (ret < 0)
                 break;
         };
 
         if (ret < 0) {

             ret = tee_process_slave_failure(avf, i, ret);
             if (!ret_all && ret < 0)

                 ret_all = ret;

         }

     }
     return ret_all;
 }
 
 AVOutputFormat ff_tee_muxer = {
     .name              = "tee",
     .long_name         = NULL_IF_CONFIG_SMALL("Multiple muxer tee"),
     .priv_data_size    = sizeof(TeeContext),
     .write_header      = tee_write_header,
     .write_trailer     = tee_write_trailer,
     .write_packet      = tee_write_packet,
     .priv_class        = &tee_muxer_class,

     .flags             = AVFMT_NOFILE | AVFMT_ALLOW_FLUSH,

 };