/*
  * Copyright (c) 2012 Stefano Sabatini
  *
  * 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
  */
 
 /**
  * @file
  * flite voice synth source
  */
 
 #include <flite/flite.h>

 #include "libavutil/channel_layout.h"

 #include "libavutil/file.h"
 #include "libavutil/opt.h"
 #include "avfilter.h"
 #include "audio.h"
 #include "formats.h"
 #include "internal.h"
 
 typedef struct {
     const AVClass *class;
     char *voice_str;
     char *textfile;
     char *text;
     cst_wave *wave;
     int16_t *wave_samples;
     int      wave_nb_samples;
     int list_voices;
     cst_voice *voice;

     struct voice_entry *voice_entry;

     int64_t pts;
     int frame_nb_samples; ///< number of samples per frame
 } FliteContext;
 
 #define OFFSET(x) offsetof(FliteContext, x)

 #define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM

 
 static const AVOption flite_options[] = {

     { "list_voices", "list voices and exit",              OFFSET(list_voices), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, FLAGS },
     { "nb_samples",  "set number of samples per frame",   OFFSET(frame_nb_samples), AV_OPT_TYPE_INT, {.i64=512}, 0, INT_MAX, FLAGS },
     { "n",           "set number of samples per frame",   OFFSET(frame_nb_samples), AV_OPT_TYPE_INT, {.i64=512}, 0, INT_MAX, FLAGS },

     { "text",        "set text to speak",                 OFFSET(text),      AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS },
     { "textfile",    "set filename of the text to speak", OFFSET(textfile),  AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS },
     { "v",           "set voice",                         OFFSET(voice_str), AV_OPT_TYPE_STRING, {.str="kal"}, CHAR_MIN, CHAR_MAX, FLAGS },
     { "voice",       "set voice",                         OFFSET(voice_str), AV_OPT_TYPE_STRING, {.str="kal"}, CHAR_MIN, CHAR_MAX, FLAGS },

     { NULL }
 };
 
 AVFILTER_DEFINE_CLASS(flite);
 
 static volatile int flite_inited = 0;
 
 /* declare functions for all the supported voices */

 #define DECLARE_REGISTER_VOICE_FN(name) \
     cst_voice *register_cmu_us_## name(const char *); \
     void     unregister_cmu_us_## name(cst_voice *);

 DECLARE_REGISTER_VOICE_FN(awb);
 DECLARE_REGISTER_VOICE_FN(kal);
 DECLARE_REGISTER_VOICE_FN(kal16);
 DECLARE_REGISTER_VOICE_FN(rms);
 DECLARE_REGISTER_VOICE_FN(slt);
 
 struct voice_entry {
     const char *name;
     cst_voice * (*register_fn)(const char *);

     void (*unregister_fn)(cst_voice *);
     cst_voice *voice;
     unsigned usage_count;

 } voice_entry;
 

 #define MAKE_VOICE_STRUCTURE(voice_name) {             \
     .name          =                      #voice_name, \
     .register_fn   =   register_cmu_us_ ## voice_name, \
     .unregister_fn = unregister_cmu_us_ ## voice_name, \
 }

 static struct voice_entry voice_entries[] = {

     MAKE_VOICE_STRUCTURE(awb),
     MAKE_VOICE_STRUCTURE(kal),
     MAKE_VOICE_STRUCTURE(kal16),
     MAKE_VOICE_STRUCTURE(rms),
     MAKE_VOICE_STRUCTURE(slt),

 };
 
 static void list_voices(void *log_ctx, const char *sep)
 {
     int i, n = FF_ARRAY_ELEMS(voice_entries);
     for (i = 0; i < n; i++)
         av_log(log_ctx, AV_LOG_INFO, "%s%s",
                voice_entries[i].name, i < (n-1) ? sep : "\n");
 }
 

 static int select_voice(struct voice_entry **entry_ret, const char *voice_name, void *log_ctx)

 {
     int i;
 
     for (i = 0; i < FF_ARRAY_ELEMS(voice_entries); i++) {
         struct voice_entry *entry = &voice_entries[i];
         if (!strcmp(entry->name, voice_name)) {

             if (!entry->voice)
                 entry->voice = entry->register_fn(NULL);
             if (!entry->voice) {

                 av_log(log_ctx, AV_LOG_ERROR,
                        "Could not register voice '%s'\n", voice_name);
                 return AVERROR_UNKNOWN;
             }

             entry->usage_count++;
             *entry_ret = entry;

             return 0;
         }
     }
 
     av_log(log_ctx, AV_LOG_ERROR, "Could not find voice '%s'\n", voice_name);
     av_log(log_ctx, AV_LOG_INFO, "Choose between the voices: ");
     list_voices(log_ctx, ", ");
 
     return AVERROR(EINVAL);
 }
 
 static av_cold int init(AVFilterContext *ctx, const char *args)
 {
     FliteContext *flite = ctx->priv;
     int ret = 0;
 
     flite->class = &flite_class;
     av_opt_set_defaults(flite);
 

     if ((ret = av_set_options_string(flite, args, "=", ":")) < 0)

         return ret;
 
     if (flite->list_voices) {
         list_voices(ctx, "\n");
         return AVERROR_EXIT;
     }
 
     if (!flite_inited) {
         if (flite_init() < 0) {
             av_log(ctx, AV_LOG_ERROR, "flite initialization failed\n");
             return AVERROR_UNKNOWN;
         }
         flite_inited++;
     }
 

     if ((ret = select_voice(&flite->voice_entry, flite->voice_str, ctx)) < 0)

         return ret;

     flite->voice = flite->voice_entry->voice;

 
     if (flite->textfile && flite->text) {
         av_log(ctx, AV_LOG_ERROR,
                "Both text and textfile options set: only one must be specified\n");
         return AVERROR(EINVAL);
     }
 
     if (flite->textfile) {
         uint8_t *textbuf;
         size_t textbuf_size;
 
         if ((ret = av_file_map(flite->textfile, &textbuf, &textbuf_size, 0, ctx)) < 0) {
             av_log(ctx, AV_LOG_ERROR,
                    "The text file '%s' could not be read: %s\n",
                    flite->textfile, av_err2str(ret));
             return ret;
         }
 
         if (!(flite->text = av_malloc(textbuf_size+1)))
             return AVERROR(ENOMEM);
         memcpy(flite->text, textbuf, textbuf_size);
         flite->text[textbuf_size] = 0;
         av_file_unmap(textbuf, textbuf_size);
     }
 
     if (!flite->text) {
         av_log(ctx, AV_LOG_ERROR,
                "No speech text specified, specify the 'text' or 'textfile' option\n");
         return AVERROR(EINVAL);
     }
 
     /* synth all the file data in block */
     flite->wave = flite_text_to_wave(flite->text, flite->voice);
     flite->wave_samples    = flite->wave->samples;
     flite->wave_nb_samples = flite->wave->num_samples;
     return 0;
 }
 
 static av_cold void uninit(AVFilterContext *ctx)
 {
     FliteContext *flite = ctx->priv;
 
     av_opt_free(flite);
 

     if (!--flite->voice_entry->usage_count)
         flite->voice_entry->unregister_fn(flite->voice);

     flite->voice = NULL;

     flite->voice_entry = NULL;

     delete_wave(flite->wave);
     flite->wave = NULL;
 }
 
 static int query_formats(AVFilterContext *ctx)
 {
     FliteContext *flite = ctx->priv;
 
     AVFilterChannelLayouts *chlayouts = NULL;
     int64_t chlayout = av_get_default_channel_layout(flite->wave->num_channels);
     AVFilterFormats *sample_formats = NULL;
     AVFilterFormats *sample_rates = NULL;
 
     ff_add_channel_layout(&chlayouts, chlayout);
     ff_set_common_channel_layouts(ctx, chlayouts);
     ff_add_format(&sample_formats, AV_SAMPLE_FMT_S16);
     ff_set_common_formats(ctx, sample_formats);
     ff_add_format(&sample_rates, flite->wave->sample_rate);
     ff_set_common_samplerates (ctx, sample_rates);
 
     return 0;
 }
 
 static int config_props(AVFilterLink *outlink)
 {
     AVFilterContext *ctx = outlink->src;
     FliteContext *flite = ctx->priv;
 
     outlink->sample_rate = flite->wave->sample_rate;
     outlink->time_base = (AVRational){1, flite->wave->sample_rate};
 
     av_log(ctx, AV_LOG_VERBOSE, "voice:%s fmt:%s sample_rate:%d\n",
            flite->voice_str,
            av_get_sample_fmt_name(outlink->format), outlink->sample_rate);
     return 0;
 }
 
 static int request_frame(AVFilterLink *outlink)
 {
     AVFilterBufferRef *samplesref;
     FliteContext *flite = outlink->src->priv;
     int nb_samples = FFMIN(flite->wave_nb_samples, flite->frame_nb_samples);
 
     if (!nb_samples)
         return AVERROR_EOF;
 
     samplesref = ff_get_audio_buffer(outlink, AV_PERM_WRITE, nb_samples);
     if (!samplesref)
         return AVERROR(ENOMEM);
 
     memcpy(samplesref->data[0], flite->wave_samples,
            nb_samples * flite->wave->num_channels * 2);
     samplesref->pts = flite->pts;
     samplesref->pos = -1;
     samplesref->audio->sample_rate = flite->wave->sample_rate;
     flite->pts += nb_samples;
     flite->wave_samples += nb_samples * flite->wave->num_channels;
     flite->wave_nb_samples -= nb_samples;
 

     return ff_filter_frame(outlink, samplesref);

 }
 

 static const AVFilterPad flite_outputs[] = {
     {
         .name          = "default",
         .type          = AVMEDIA_TYPE_AUDIO,
         .config_props  = config_props,
         .request_frame = request_frame,
     },
     { NULL }
 };
 

 AVFilter avfilter_asrc_flite = {
     .name        = "flite",
     .description = NULL_IF_CONFIG_SMALL("Synthesize voice from text using libflite."),
     .query_formats = query_formats,
     .init        = init,
     .uninit      = uninit,
     .priv_size   = sizeof(FliteContext),

     .inputs      = NULL,
     .outputs     = flite_outputs,
     .priv_class  = &flite_class,

 };