/*

 * 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 "config.h"

#include <stddef.h>

#include <string.h>

#include "libavutil/avassert.h"

#include "libavutil/error.h"

#include "libavutil/mem.h"

#include "libavutil/opt.h"

#include "bsf.h"

#include "bsf_internal.h"

#define OFFSET(x) offsetof(AVBitStreamFilterGraph, x)

#define FLAGS (AV_OPT_FLAG_BSF_PARAM|AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_VIDEO_PARAM)

static const AVOption filtergraph_options[] = {

    {"max_buffered_packets"  , "maximum number of buffered packets allowed", OFFSET(max_buffered_packets),

        AV_OPT_TYPE_UINT,   {.i64 = 0}, 0, UINT_MAX, FLAGS },

    { NULL },

};

static const AVClass filtergraph_class = {

    .class_name = "AVBitStreamFilterGraph",

    .item_name  = av_default_item_name,

    .version    = LIBAVUTIL_VERSION_INT,

    .option     = filtergraph_options,

    .category   = AV_CLASS_CATEGORY_BITSTREAM_FILTER,

};

AVBitStreamFilterGraph *av_bsf_graph_alloc(void)

{

    FFBitStreamFilterGraph *graph = av_mallocz(sizeof(*graph));

    AVBitStreamFilterGraph *ret;

    if (!graph)

        return NULL;

    ret = &graph->p;

    ret->av_class = &filtergraph_class;

    av_opt_set_defaults(ret);

    graph->max_packet_queue = SIZE_MAX;

    return ret;

}

void ff_bsf_graph_remove_filter(AVBitStreamFilterGraph *graph, AVBitStreamFilterContext *filter)

{

    int i, j;

    for (i = 0; i < graph->nb_filters; i++) {

        if (graph->filters[i] == filter) {

            FFSWAP(AVBitStreamFilterContext*, graph->filters[i],

                   graph->filters[graph->nb_filters - 1]);

            graph->nb_filters--;

            filter->graph = NULL;

            for (j = 0; j<filter->nb_outputs; j++)

                if (filter->outputs[j])

                    filter->outputs[j]->graph = NULL;

            return;

        }

    }

}

AVBitStreamFilterContext *av_bsf_graph_get_filter(AVBitStreamFilterGraph *graph, const char *name)

{

    int i;

    for (i = 0; i < graph->nb_filters; i++)

        if (graph->filters[i]->name && !strcmp(name, graph->filters[i]->name))

            return graph->filters[i];

    return NULL;

}

void av_bsf_graph_free(AVBitStreamFilterGraph **graphp)

{

    AVBitStreamFilterGraph *graph = *graphp;

    FFBitStreamFilterGraph *graphi = ffbsffiltergraph(graph);

    if (!graph)

        return;

    while (graph->nb_filters)

        ff_bsf_free(graph->filters[0]);

    av_freep(&graphi->sink_links);

    av_freep(&graphi->source_links);

    av_opt_free(graph);

    av_freep(&graph->filters);

    av_freep(graphp);

}

int av_bsf_graph_create_filter(AVBitStreamFilterContext **filt_ctx, const AVBitStreamFilter *filt,

                               const char *name, AVDictionary **options, AVBitStreamFilterGraph *graph_ctx)

{

    AVBitStreamFilterContext *s;

    int ret;

    ret = av_bsf_graph_alloc_filter(&s, filt, name, graph_ctx);

    if (ret < 0)

        return ret;

    ret = av_bsf_init_dict(s, options);

    if (ret < 0)

        goto fail;

    if (filt_ctx)

        *filt_ctx = s;

    return 0;

fail:

    ff_bsf_free(s);

    if (filt_ctx)

        *filt_ctx = NULL;

    return ret;

}

int av_bsf_graph_alloc_filter(AVBitStreamFilterContext **filt_ctx,

                              const AVBitStreamFilter *filter,

                              const char *name,

                              AVBitStreamFilterGraph *graph)

{

    AVBitStreamFilterContext **filters, *s;

    int ret;

    if (!ff_bsf(filter)->activate && !ff_bsf(filter)->nb_inputs && !ff_bsf(filter)->nb_outputs)

        return AVERROR(ENOTSUP);

    filters = av_realloc_array(graph->filters, graph->nb_filters + 1, sizeof(*filters));

    if (!filters)

        return AVERROR(ENOMEM);

    graph->filters = filters;

    ret = ff_bsf_alloc(filter, name, &s);

    if (ret < 0)

        return ret;

    graph->filters[graph->nb_filters++] = s;

    s->graph = graph;

    if (filt_ctx)

        *filt_ctx = s;

    return ret;

}

/**

 * Check for the validity of graph.

 *

 * A graph is considered valid if all its input and output pads are

 * connected.

 *

 * @return >= 0 in case of success, a negative value otherwise

 */

static int graph_check_validity(AVBitStreamFilterGraph *graph, void *log_ctx)

{

    AVBitStreamFilterContext *filt;

    int i, j;

    for (i = 0; i < graph->nb_filters; i++) {

        const AVBitStreamFilterPad *pad;

        filt = graph->filters[i];

        for (j = 0; j < filt->nb_inputs; j++) {

            if (!filt->inputs[j] || !filt->inputs[j]->src) {

                pad = &filt->input_pads[j];

                av_log(log_ctx, AV_LOG_ERROR,

                       "Input pad \"%s\" of the filter instance \"%s\" of %s not connected to any source\n",

                       pad->name, filt->name, filt->filter->name);

                return AVERROR(EINVAL);

            }

        }

        for (j = 0; j < filt->nb_outputs; j++) {

            if (!filt->outputs[j] || !filt->outputs[j]->dst) {

                pad = &filt->output_pads[j];

                av_log(log_ctx, AV_LOG_ERROR,

                       "Output pad \"%s\" of the filter instance \"%s\" of %s not connected to any destination\n",

                       pad->name, filt->name, filt->filter->name);

                return AVERROR(EINVAL);

            }

        }

    }

    return 0;

}

/**

 * Configure all the links of graphctx.

 *

 * @return >= 0 in case of success, a negative value otherwise

 */

static int graph_config_links(AVBitStreamFilterGraph *graph, void *log_ctx)

{

    AVBitStreamFilterContext *filt;

    int i, ret;

    for (i = 0; i < graph->nb_filters; i++) {

        filt = graph->filters[i];

        if (!filt->nb_outputs) {

            if ((ret = ff_bsf_config_links(filt)))

                return ret;

        }

    }

    return 0;

}

static int graph_config_pointers(AVBitStreamFilterGraph *graph, void *log_ctx)

{

    unsigned i, j;

    int sink_links_count = 0, source_links_count = 0, n = 0;

    AVBitStreamFilterContext *f;

    BitStreamFilterLinkInternal **sinks, **sources;

    for (i = 0; i < graph->nb_filters; i++) {

        f = graph->filters[i];

        for (j = 0; j < f->nb_inputs; j++) {

            ff_link_internal(f->inputs[j])->age_index  = -1;

        }

        for (j = 0; j < f->nb_outputs; j++) {

            ff_link_internal(f->outputs[j])->age_index = -1;

        }

        if (!f->nb_outputs) {

            if (f->nb_inputs > INT_MAX - sink_links_count)

                return AVERROR(EINVAL);

            sink_links_count += f->nb_inputs;

        }

        if (!f->nb_inputs && !strcmp(f->filter->name, "source")) {

            if (f->nb_outputs > INT_MAX - source_links_count)

                return AVERROR(EINVAL);

            source_links_count += f->nb_outputs;

        }

    }

    sinks = av_calloc(sink_links_count, sizeof(*sinks));

    if (!sinks)

        return AVERROR(ENOMEM);

    for (i = 0; i < graph->nb_filters; i++) {

        f = graph->filters[i];

        if (!f->nb_outputs) {

            for (j = 0; j < f->nb_inputs; j++) {

                sinks[n] = ff_link_internal(f->inputs[j]);

                sinks[n]->age_index = n;

                n++;

            }

        }

    }

    av_assert0(n == sink_links_count);

    ffbsffiltergraph(graph)->sink_links       = sinks;

    ffbsffiltergraph(graph)->sink_links_count = sink_links_count;

    sources = av_calloc(source_links_count, sizeof(*sources));

    if (!sources)

        return AVERROR(ENOMEM);

    for (i = 0, n = 0; i < graph->nb_filters; i++) {

        f = graph->filters[i];

        if (!f->nb_inputs && !strcmp(f->filter->name, "source")) {

            for (j = 0; j < f->nb_outputs; j++) {

                sources[n] = ff_link_internal(f->outputs[j]);

                n++;

            }

        }

    }

    av_assert0(n == source_links_count);

    ffbsffiltergraph(graph)->source_links       = sources;

    ffbsffiltergraph(graph)->source_links_count = source_links_count;

    return 0;

}

int av_bsf_graph_config(AVBitStreamFilterGraph *graphctx, void *log_ctx)

{

    int ret;

    if (graphctx->max_buffered_packets)

        ffbsffiltergraph(graphctx)->max_packet_queue = graphctx->max_buffered_packets;

    if ((ret = graph_check_validity(graphctx, log_ctx)))

        return ret;

    if ((ret = graph_config_links(graphctx, log_ctx)))

        return ret;

    if ((ret = graph_config_pointers(graphctx, log_ctx)))

        return ret;

    return 0;

}

static void heap_bubble_up(FFBitStreamFilterGraph *graph,

                           BitStreamFilterLinkInternal *li, int index)

{

    BitStreamFilterLinkInternal **links = graph->sink_links;

    av_assert0(index >= 0);

    while (index) {

        int parent = (index - 1) >> 1;

        if (links[parent]->l.current_pts_us >= li->l.current_pts_us)

            break;

        links[index] = links[parent];

        links[index]->age_index = index;

        index = parent;

    }

    links[index] = li;

    li->age_index = index;

}

static void heap_bubble_down(FFBitStreamFilterGraph *graph,

                             BitStreamFilterLinkInternal *li, int index)

{

    BitStreamFilterLinkInternal **links = graph->sink_links;

    av_assert0(index >= 0);

    while (1) {

        int child = 2 * index + 1;

        if (child >= graph->sink_links_count)

            break;

        if (child + 1 < graph->sink_links_count &&

            links[child + 1]->l.current_pts_us < links[child]->l.current_pts_us)

            child++;

        if (li->l.current_pts_us < links[child]->l.current_pts_us)

            break;

        links[index] = links[child];

        links[index]->age_index = index;

        index = child;

    }

    links[index] = li;

    li->age_index = index;

}

void ff_bsf_graph_update_heap(AVBitStreamFilterGraph *graph, BitStreamFilterLinkInternal *li)

{

    FFBitStreamFilterGraph  *graphi = ffbsffiltergraph(graph);

    heap_bubble_up  (graphi, li, li->age_index);

    heap_bubble_down(graphi, li, li->age_index);

}

int ff_bsf_graph_run_once(AVBitStreamFilterGraph *graph)

{

    FFBitStreamFilterContext *ctxi;

    unsigned i;

    av_assert0(graph->nb_filters);

    ctxi = ffbsfctx(graph->filters[0]);

    for (i = 1; i < graph->nb_filters; i++) {

        FFBitStreamFilterContext *ctxi_other = ffbsfctx(graph->filters[i]);

        if (ctxi_other->ready > ctxi->ready)

            ctxi = ctxi_other;

    }

    if (!ctxi->ready)

        return AVERROR(EAGAIN);

    ctxi->ready = 0;

    return ff_bsf_activate(&ctxi->p);

}

int av_bsf_graph_source_needs_input(const AVBitStreamFilterGraph *graph)

{

    const FFBitStreamFilterGraph *graphi = cffbsffiltergraph(graph);

    int nb_requests, nb_requests_max = -1;

    int best_input = AVERROR(EOF);

    for (int i = 0; i < graphi->source_links_count; i++) {

        const BitStreamFilterLinkInternal *sourcei = graphi->source_links[i];

        const AVBitStreamFilterLink *source = &sourcei->l;

        if (av_bsf_source_get_status(source->src) == AVERROR(EOF))

            continue;

        nb_requests = ff_bsf_source_get_nb_failed_requests(source->src);

        if (nb_requests > nb_requests_max) {

            nb_requests_max = nb_requests;

            best_input = i;

        }

    }

    return best_input;

}