/*
 * 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/opt.h"
#include "libavutil/pixdesc.h"
#include "libavcodec/codec.h"
#include "libavcodec/codec_desc.h"
#include "libavcodec/codec_internal.h"

static const char *get_type_string(enum AVMediaType type)
{
    const char *ret = av_get_media_type_string(type);
    return ret ? ret : "unknown";
}

#define AV_LOG(...) av_log(NULL, AV_LOG_FATAL, __VA_ARGS__)
#define ERR_INTERNAL(msg, ...)                                  \
do {                                                            \
    AV_LOG(msg, codec->name __VA_ARGS__);                       \
    ret = 1;                                                    \
} while (0)
#define ERR(msg)           ERR_INTERNAL(msg, )
#define ERR_EXT(msg, ...)  ERR_INTERNAL(msg, , __VA_ARGS__)

static int priv_data_size_wrong(const FFCodec *codec)
{
    if (codec->priv_data_size < 0 ||
        codec->p.priv_class && codec->priv_data_size < sizeof(AVClass*))
        return 1;
    if (!codec->p.priv_class || !codec->p.priv_class->option)
        return 0;
    for (const AVOption *opt = codec->p.priv_class->option; opt->name; opt++) {
        if (opt->offset >= codec->priv_data_size ||
            opt->type == AV_OPT_TYPE_CONST && opt->offset != 0 ||
            opt->type != AV_OPT_TYPE_CONST && (opt->offset < sizeof(AVClass*) || opt->offset < 0)) {
            AV_LOG("Option %s offset %d nonsensical\n",
                   opt->name, opt->offset);
            return 1;
        }
    }
    return 0;
}

#define ARRAY_CHECK(field, var, type, is_sentinel, check, sentinel_check) \
do {                                                                      \
    const type *ptr = codec2->field;                                      \
    if (!ptr)                                                             \
        break;                                                            \
    type var = *ptr;                                                      \
    if (is_sentinel) {                                                    \
        ERR("Codec %s sets " #field ", but without valid elements.\n");   \
        break;                                                            \
    }                                                                     \
    do {                                                                  \
        if (!(check)) {                                                   \
            ERR("Codec's %s " #field " array contains invalid element\n");\
            break;                                                        \
        }                                                                 \
        ++ptr;                                                            \
        var = *ptr;                                                       \
    } while (!(is_sentinel));                                             \
    if (!(sentinel_check)) {                                              \
        ERR("Codec's %s " #field " array has malformed sentinel\n");      \
        break;                                                            \
    }                                                                     \
} while (0)

int main(void){
    void *iter = NULL;
    const AVCodec *codec = NULL;
    int ret = 0;

    while (codec = av_codec_iterate(&iter)) {
        const FFCodec *const codec2 = ffcodec(codec);
        const AVCodecDescriptor *desc;
        int is_decoder = 0, is_encoder = 0;

        if (!codec->name) {
            AV_LOG("Codec for format %s has no name\n",
                   avcodec_get_name(codec->id));
            ret = 1;
            continue;
        }
        if (codec->type != AVMEDIA_TYPE_VIDEO &&
            codec->type != AVMEDIA_TYPE_AUDIO &&
            codec->type != AVMEDIA_TYPE_SUBTITLE)
            ERR_EXT("Codec %s has unsupported type %s\n",
                    get_type_string(codec->type));
        if (codec->type != AVMEDIA_TYPE_AUDIO) {
#if defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
            if (codec2->ch_layouts || codec2->sample_fmts ||
                codec2->supported_samplerates)
                ERR("Non-audio codec %s has audio-only fields set\n");
#endif
            if (codec->capabilities & (AV_CODEC_CAP_SMALL_LAST_FRAME |
                                       AV_CODEC_CAP_CHANNEL_CONF     |
                                       AV_CODEC_CAP_VARIABLE_FRAME_SIZE))
                ERR("Non-audio codec %s has audio-only capabilities set\n");
        } else {
            ARRAY_CHECK(supported_samplerates, sample_rate, int, sample_rate == 0,
                        sample_rate > 0, 1);
            ARRAY_CHECK(sample_fmts, sample_fmt, enum AVSampleFormat, sample_fmt == AV_SAMPLE_FMT_NONE,
                        (unsigned)sample_fmt < AV_SAMPLE_FMT_NB, 1);
            static const AVChannelLayout zero_channel_layout = { 0 };
            ARRAY_CHECK(ch_layouts, ch_layout, AVChannelLayout, ch_layout.nb_channels == 0,
                        av_channel_layout_check(&ch_layout), !memcmp(ptr, &zero_channel_layout, sizeof(ch_layout)));
        }
        if (codec->type != AVMEDIA_TYPE_VIDEO) {
            if (codec2->color_ranges ||
#if defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
                codec2->pix_fmts || codec2->supported_framerates ||
#endif
                codec2->alpha_modes)
                ERR("Non-video codec %s has video-only fields set\n");
            if (codec2->caps_internal & FF_CODEC_CAP_EXPORTS_CROPPING)
                ERR("Non-video codec %s exports cropping\n");
        }
        if (codec2->caps_internal  & FF_CODEC_CAP_SLICE_THREAD_HAS_MF &&
            !(codec->capabilities & AV_CODEC_CAP_SLICE_THREADS))
            ERR("Codec %s wants mainfunction despite not being "
                "slice-threading capable");
        if (codec2->caps_internal  & FF_CODEC_CAP_AUTO_THREADS &&
            !(codec->capabilities & (AV_CODEC_CAP_FRAME_THREADS |
                                     AV_CODEC_CAP_SLICE_THREADS |
                                     AV_CODEC_CAP_OTHER_THREADS)))
            ERR("Codec %s has private-only threading support\n");

        switch (codec2->cb_type) {
        case FF_CODEC_CB_TYPE_DECODE:
        case FF_CODEC_CB_TYPE_DECODE_SUB:
        case FF_CODEC_CB_TYPE_RECEIVE_FRAME:
            is_decoder = 1;
            break;
        case FF_CODEC_CB_TYPE_ENCODE:
        case FF_CODEC_CB_TYPE_ENCODE_SUB:
        case FF_CODEC_CB_TYPE_RECEIVE_PACKET:
            is_encoder = 1;
            break;
        default:
            ERR("Codec %s has unknown cb_type\n");
            continue;
        }
        if (is_decoder != av_codec_is_decoder(codec) ||
            is_encoder != av_codec_is_encoder(codec)) {
            ERR("Codec %s cb_type and av_codec_is_(de|en)coder inconsistent.\n");
            continue;
        }
#define CHECK(TYPE, type) (codec2->cb_type == FF_CODEC_CB_TYPE_ ## TYPE && !codec2->cb.type)
        if (CHECK(DECODE, decode) || CHECK(DECODE_SUB, decode_sub) ||
            CHECK(RECEIVE_PACKET, receive_packet) ||
            CHECK(ENCODE, encode) || CHECK(ENCODE_SUB, encode_sub) ||
            CHECK(RECEIVE_FRAME, receive_frame)) {
            ERR_EXT("Codec %s does not implement its %s callback.\n",
                    is_decoder ? "decoding" : "encoding");
        }
#undef CHECK
        if (is_encoder) {
            if ((codec->type == AVMEDIA_TYPE_SUBTITLE) != (codec2->cb_type == FF_CODEC_CB_TYPE_ENCODE_SUB))
                ERR("Encoder %s is both subtitle encoder and not subtitle encoder.");
            if (codec2->update_thread_context || codec2->update_thread_context_for_user || codec2->bsfs)
                ERR("Encoder %s has decoder-only thread functions or bsf.\n");
            if (codec->type == AVMEDIA_TYPE_AUDIO) {
                if (!codec2->sample_fmts) {
                    av_log(NULL, AV_LOG_FATAL, "Encoder %s is missing the sample_fmts field\n", codec->name);
                    ret = 1;
                }
            } else if (codec->type == AVMEDIA_TYPE_VIDEO) {
                ARRAY_CHECK(pix_fmts, pix_fmt, enum AVPixelFormat, pix_fmt == AV_PIX_FMT_NONE,
                            av_pix_fmt_desc_get(pix_fmt), 1);
                ARRAY_CHECK(supported_framerates, framerate, AVRational, framerate.num == 0,
                            framerate.num > 0 && framerate.den > 0, framerate.den == 0);
            }
            if (codec2->caps_internal & (FF_CODEC_CAP_USES_PROGRESSFRAMES |
                                        FF_CODEC_CAP_SETS_PKT_DTS |
                                        FF_CODEC_CAP_SKIP_FRAME_FILL_PARAM |
                                        FF_CODEC_CAP_EXPORTS_CROPPING |
                                        FF_CODEC_CAP_SETS_FRAME_PROPS) ||
                codec->capabilities  & (AV_CODEC_CAP_AVOID_PROBING |
                                        AV_CODEC_CAP_CHANNEL_CONF  |
                                        AV_CODEC_CAP_DRAW_HORIZ_BAND))
                ERR("Encoder %s has decoder-only capabilities set\n");
            if (codec->capabilities & AV_CODEC_CAP_FRAME_THREADS &&
                codec->capabilities & AV_CODEC_CAP_ENCODER_FLUSH)
                ERR("Frame-threaded encoder %s claims to support flushing\n");
            if (codec->capabilities & AV_CODEC_CAP_FRAME_THREADS &&
                codec->capabilities & AV_CODEC_CAP_DELAY)
                ERR("Frame-threaded encoder %s claims to have delay\n");

            if (codec2->caps_internal & FF_CODEC_CAP_EOF_FLUSH &&
                !(codec->capabilities & AV_CODEC_CAP_DELAY))
                ERR("EOF_FLUSH encoder %s is not marked as having delay\n");
        } else {
            if ((codec2->update_thread_context || codec2->update_thread_context_for_user) &&
                !(codec->capabilities & AV_CODEC_CAP_FRAME_THREADS))
                ERR("Non-frame-threaded decoder %s has update_thread_context set");
            if ((codec->type == AVMEDIA_TYPE_SUBTITLE) != (codec2->cb_type == FF_CODEC_CB_TYPE_DECODE_SUB))
                ERR("Subtitle decoder %s does not implement decode_sub callback\n");
            if (codec->type == AVMEDIA_TYPE_SUBTITLE && codec2->bsfs)
                ERR("Automatic bitstream filtering unsupported for subtitles; "
                    "yet decoder %s has it set\n");
            if (codec->capabilities & (AV_CODEC_CAP_SMALL_LAST_FRAME    |
                                       AV_CODEC_CAP_VARIABLE_FRAME_SIZE |
                                       AV_CODEC_CAP_ENCODER_REORDERED_OPAQUE |
                                       AV_CODEC_CAP_ENCODER_FLUSH))
                ERR("Decoder %s has encoder-only capabilities\n");
            if (codec2->cb_type != FF_CODEC_CB_TYPE_DECODE &&
                codec2->caps_internal & FF_CODEC_CAP_SETS_PKT_DTS)
                ERR("Decoder %s is marked as setting pkt_dts when it doesn't have"
                    "any effect\n");
            if (codec->type == AVMEDIA_TYPE_VIDEO && (codec2->pix_fmts || codec2->supported_framerates))
                ERR("Decoder %s sets pix_fmts or supported_framerates.\n");
        }
        if (priv_data_size_wrong(codec2))
            ERR_EXT("Private context of codec %s is impossibly-sized (size %d).",
                    codec2->priv_data_size);
        if (!(desc = avcodec_descriptor_get(codec->id))) {
            ERR("Codec %s lacks a corresponding descriptor\n");
        } else {
            if (desc->type != codec->type)
                ERR_EXT("The type of AVCodec %s and its AVCodecDescriptor %s "
                        "differ: %s vs %s\n",
                        desc->name, get_type_string(codec->type), get_type_string(desc->type));
            if (desc->props & AV_CODEC_PROP_ENHANCEMENT)
                ERR_EXT("Codec descriptor for codec %s (descriptor name %s) has "
                        "AV_CODEC_PROP_ENHANCEMENT flag set.\n", desc->name);
        }
    }
    return ret;
}
