/*
 * Copyright (c) 2015 John R. Bradley <jrb@turrettech.com>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include "ff-util.h"

#include <libavcodec/avcodec.h>
#include <libavdevice/avdevice.h>
#include <libavformat/avformat.h>
#include <libavutil/log.h>

#include <stdbool.h>

struct ff_format_desc {
	const char *name;
	const char *long_name;
	const char *mime_type;
	const char *extensions;
	enum AVCodecID audio_codec;
	enum AVCodecID video_codec;
	const struct AVCodecTag * const *codec_tags;
	const struct ff_format_desc *next;
};

struct ff_codec_desc {
	const char *name;
	const char *long_name;
	int id;
	bool alias;
	const char *base_name;
	enum ff_codec_type type;
	const struct ff_codec_desc *next;
};

void ff_init()
{
	av_register_all();
	avdevice_register_all();
	avcodec_register_all();
	avformat_network_init();
}

const char *ff_codec_name_from_id(int codec_id)
{
	AVCodec *codec = avcodec_find_encoder(codec_id);
	if (codec != NULL)
		return codec->name;
	else
		return NULL;
}

static bool get_codecs(const AVCodecDescriptor*** descs, unsigned int *size)
{
	const AVCodecDescriptor *desc = NULL;
	const AVCodecDescriptor **codecs;
	unsigned int codec_count = 0;
	unsigned int i = 0;

	while ((desc = avcodec_descriptor_next(desc)))
		codec_count++;

	codecs = av_calloc(codec_count, sizeof(AVCodecDescriptor *));

	if (codecs == NULL) {
		av_log(NULL, AV_LOG_ERROR, "unable to allocate sorted codec "
				"array with size %d", codec_count);
		return false;
	}

	while ((desc = avcodec_descriptor_next(desc)))
		codecs[i++] = desc;

	*size = codec_count;
	*descs = codecs;
	return true;
}

static const AVCodec *next_codec_for_id(enum AVCodecID id, const AVCodec *prev)
{
    while ((prev = av_codec_next(prev))) {
        if (prev->id == id && av_codec_is_encoder(prev))
            return prev;
    }

    return NULL;
}

static void add_codec_to_list(const struct ff_format_desc *format_desc,
		struct ff_codec_desc **first, struct ff_codec_desc **current,
		enum AVCodecID id, const AVCodec *codec)
{
	if (codec == NULL)
		codec = avcodec_find_encoder(id);

	// No codec, or invalid id
	if (codec == NULL)
		return;

	// Not an encoding codec
	if (!av_codec_is_encoder(codec))
		return;

	// Format doesn't support this codec
	unsigned int tag = av_codec_get_tag(format_desc->codec_tags,
			codec->id);
	if (tag == 0)
		return;

	struct ff_codec_desc *d = av_mallocz(sizeof(struct ff_codec_desc));

	d->name = codec->name;
	d->long_name = codec->long_name;
	d->id = codec->id;
	AVCodec *base_codec = avcodec_find_encoder(codec->id);
	if (strcmp(base_codec->name, codec->name) != 0) {
		d->alias = true;
		d->base_name = base_codec->name;
	}

	switch (codec->type) {
	case AVMEDIA_TYPE_AUDIO:
		d->type = FF_CODEC_AUDIO;
		break;
	case AVMEDIA_TYPE_VIDEO:
		d->type = FF_CODEC_VIDEO;
		break;
	default:
		d->type = FF_CODEC_UNKNOWN;
	}

	if (*current != NULL)
		(*current)->next = d;
	else
		*first = d;

	*current = d;
}

static void get_codecs_for_id(const struct ff_format_desc *format_desc,
		struct ff_codec_desc **first, struct ff_codec_desc **current,
		enum AVCodecID id)
{
	const AVCodec *codec = NULL;
	while ((codec = next_codec_for_id(id, codec)))
		add_codec_to_list(format_desc, first, current, codec->id,
				codec);
}

const struct ff_codec_desc *ff_codec_supported(
		const struct ff_format_desc *format_desc)
{
	const AVCodecDescriptor **codecs;
	unsigned int size;
	unsigned int i;
	struct ff_codec_desc *current = NULL;
	struct ff_codec_desc *first = NULL;

	if (!get_codecs(&codecs, &size))
		return NULL;

	for(i = 0; i < size; i++) {
		const AVCodecDescriptor *codec = codecs[i];
		get_codecs_for_id(format_desc, &first, &current, codec->id);
	}

	av_free((void *)codecs);

	return first;
}

const char *ff_codec_desc_name(const struct ff_codec_desc *codec_desc)
{
	if (codec_desc != NULL)
		return codec_desc->name;
	else
		return NULL;
}

const char *ff_codec_desc_long_name(const struct ff_codec_desc *codec_desc)
{
	if (codec_desc != NULL)
		return codec_desc->long_name;
	else
		return NULL;
}

bool ff_codec_desc_is_alias(const struct ff_codec_desc *codec_desc)
{
	if (codec_desc != NULL)
		return codec_desc->alias;
	else
		return false;
}

const char *ff_codec_desc_base_name(const struct ff_codec_desc *codec_desc)
{
	if (codec_desc != NULL)
		return codec_desc->base_name;
	else
		return NULL;
}

enum ff_codec_type ff_codec_desc_type(const struct ff_codec_desc *codec_desc)
{
	if (codec_desc != NULL)
		return codec_desc->type;
	else
		return FF_CODEC_UNKNOWN;
}

const struct ff_codec_desc *ff_codec_desc_next(
		const struct ff_codec_desc *codec_desc)
{
	if (codec_desc != NULL)
		return codec_desc->next;
	else
		return NULL;
}

int ff_codec_desc_id(const struct ff_codec_desc *codec_desc)
{
	if (codec_desc != NULL)
		return codec_desc->id;
	else
		return AV_CODEC_ID_NONE;
}

void ff_codec_desc_free(const struct ff_codec_desc *codec_desc)
{
	const struct ff_codec_desc *desc = codec_desc;
	while(desc != NULL) {
		const struct ff_codec_desc *next = desc->next;
		av_free((void *)desc);
		desc = next;
	}
}

static inline bool is_output_device(const AVClass *avclass)
{
	if (!avclass)
		return 0;

#if LIBAVUTIL_VERSION_INT >= AV_VERSION_INT(52, 66, 101)
	switch (avclass->category) {
	case AV_CLASS_CATEGORY_DEVICE_VIDEO_OUTPUT:
	case AV_CLASS_CATEGORY_DEVICE_AUDIO_OUTPUT:
	case AV_CLASS_CATEGORY_DEVICE_OUTPUT:
		return true;
	default:
		return false;
	}
#else
	return (avclass->category == AV_CLASS_CATEGORY_OUTPUT);
#endif
}

const struct ff_format_desc *ff_format_supported()
{
	AVOutputFormat *output_format = NULL;
	struct ff_format_desc *desc = NULL;
	struct ff_format_desc *current = NULL;

	while ((output_format = av_oformat_next(output_format))) {
		struct ff_format_desc *d;
		if (is_output_device(output_format->priv_class))
			continue;

		d = av_mallocz(sizeof(struct ff_format_desc));

		d->audio_codec = output_format->audio_codec;
		d->video_codec = output_format->video_codec;
		d->name = output_format->name;
		d->long_name = output_format->long_name;
		d->mime_type = output_format->mime_type;
		d->extensions = output_format->extensions;
		d->codec_tags = output_format->codec_tag;

		if (current != NULL) {
			current->next = d;
			current = d;
		} else {
			desc = current = d;
		}
	}

	return desc;
}

const char *ff_format_desc_name(const struct ff_format_desc *format_desc)
{
	if (format_desc != NULL)
		return format_desc->name;
	else
		return NULL;
}

const char *ff_format_desc_long_name(const struct ff_format_desc *format_desc)
{
	if (format_desc != NULL)
		return format_desc->long_name;
	else
		return NULL;
}

const char *ff_format_desc_mime_type(const struct ff_format_desc *format_desc)
{
	if (format_desc != NULL)
		return format_desc->mime_type;
	else
		return NULL;
}

const char *ff_format_desc_extensions(const struct ff_format_desc *format_desc)
{
	if (format_desc != NULL)
		return format_desc->extensions;
	else
		return NULL;
}

bool ff_format_desc_has_audio(const struct ff_format_desc *format_desc)
{
	if (format_desc != NULL)
		return format_desc->audio_codec != AV_CODEC_ID_NONE;
	else
		return false;
}

bool ff_format_desc_has_video(const struct ff_format_desc *format_desc)
{
	if (format_desc != NULL)
		return format_desc->video_codec != AV_CODEC_ID_NONE;
	else
		return false;
}

int ff_format_desc_audio(const struct ff_format_desc *format_desc)
{
	if (format_desc != NULL)
		return format_desc->audio_codec;
	else
		return false;
}

int ff_format_desc_video(const struct ff_format_desc *format_desc)
{
	if (format_desc != NULL)
		return format_desc->video_codec;
	else
		return false;
}

const struct ff_format_desc *ff_format_desc_next(
		const struct ff_format_desc *format_desc)
{
	if (format_desc != NULL)
		return format_desc->next;
	else
		return NULL;
}

static const char *get_encoder_name(const struct ff_format_desc *format_desc,
		enum AVCodecID codec_id)
{
	AVCodec *codec = avcodec_find_encoder(codec_id);
	if (codec == NULL && codec_id == AV_CODEC_ID_NONE)
		return NULL;
	else if (codec == NULL)
		return format_desc->name;
	else
		return codec->name;
}

const char *ff_format_desc_get_default_name(
		const struct ff_format_desc *format_desc,
		enum ff_codec_type codec_type)
{
	switch (codec_type)
	{
		case FF_CODEC_AUDIO:
			return get_encoder_name(format_desc,
					format_desc->audio_codec);
		case FF_CODEC_VIDEO:
			return get_encoder_name(format_desc,
					format_desc->video_codec);
		default:
			return NULL;
	}
}

void ff_format_desc_free(const struct ff_format_desc *format_desc)
{
	const struct ff_format_desc *desc = format_desc;
	while(desc != NULL) {
		const struct ff_format_desc *next = desc->next;
		av_free((void *)desc);
		desc = next;
	}
}