/******************************************************************************
    Copyright (C) 2014 by Hugh Bailey <obs.jim@gmail.com>

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 2 of the License, or
    (at your option) any later version.

    This program 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 General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
******************************************************************************/

#include <stdio.h>
#include <util/dstr.h>
#include <util/darray.h>
#include <util/platform.h>
#include <obs-module.h>

#ifndef _STDINT_H_INCLUDED
#define _STDINT_H_INCLUDED
#endif

#include <x264.h>

#define do_log(level, format, ...) \
	blog(level, "[x264 encoder: '%s'] " format, \
			obs_encoder_get_name(obsx264->encoder), ##__VA_ARGS__)

#define warn(format, ...)  do_log(LOG_WARNING, format, ##__VA_ARGS__)
#define info(format, ...)  do_log(LOG_INFO,    format, ##__VA_ARGS__)
#define debug(format, ...) do_log(LOG_DEBUG,   format, ##__VA_ARGS__)

/* ------------------------------------------------------------------------- */

struct obs_x264 {
	obs_encoder_t          *encoder;

	x264_param_t           params;
	x264_t                 *context;

	DARRAY(uint8_t)        packet_data;

	uint8_t                *extra_data;
	uint8_t                *sei;

	size_t                 extra_data_size;
	size_t                 sei_size;

	os_performance_token_t *performance_token;
};

/* ------------------------------------------------------------------------- */

static const char *obs_x264_getname(void *unused)
{
	UNUSED_PARAMETER(unused);
	return "x264";
}

static void obs_x264_stop(void *data);

static void clear_data(struct obs_x264 *obsx264)
{
	if (obsx264->context) {
		x264_encoder_close(obsx264->context);
		bfree(obsx264->sei);
		bfree(obsx264->extra_data);

		obsx264->context    = NULL;
		obsx264->sei        = NULL;
		obsx264->extra_data = NULL;
	}
}

static void obs_x264_destroy(void *data)
{
	struct obs_x264 *obsx264 = data;

	if (obsx264) {
		os_end_high_performance(obsx264->performance_token);
		clear_data(obsx264);
		da_free(obsx264->packet_data);
		bfree(obsx264);
	}
}

static void obs_x264_defaults(obs_data_t *settings)
{
	obs_data_set_default_int   (settings, "bitrate",     2500);
	obs_data_set_default_bool  (settings, "use_bufsize", false);
	obs_data_set_default_int   (settings, "buffer_size", 2500);
	obs_data_set_default_int   (settings, "keyint_sec",  0);
	obs_data_set_default_int   (settings, "crf",         23);
	obs_data_set_default_bool  (settings, "vfr",         false);
	obs_data_set_default_string(settings, "rate_control","CBR");

	obs_data_set_default_string(settings, "preset",      "veryfast");
	obs_data_set_default_string(settings, "profile",     "");
	obs_data_set_default_string(settings, "tune",        "");
	obs_data_set_default_string(settings, "x264opts",    "");
}

static inline void add_strings(obs_property_t *list, const char *const *strings)
{
	while (*strings) {
		obs_property_list_add_string(list, *strings, *strings);
		strings++;
	}
}

#define TEXT_RATE_CONTROL obs_module_text("RateControl")
#define TEXT_BITRATE    obs_module_text("Bitrate")
#define TEXT_CUSTOM_BUF obs_module_text("CustomBufsize")
#define TEXT_BUF_SIZE   obs_module_text("BufferSize")
#define TEXT_VFR        obs_module_text("VFR")
#define TEXT_CRF        obs_module_text("CRF")
#define TEXT_KEYINT_SEC obs_module_text("KeyframeIntervalSec")
#define TEXT_PRESET     obs_module_text("CPUPreset")
#define TEXT_PROFILE    obs_module_text("Profile")
#define TEXT_TUNE       obs_module_text("Tune")
#define TEXT_NONE       obs_module_text("None")
#define TEXT_X264_OPTS  obs_module_text("EncoderOptions")

static bool use_bufsize_modified(obs_properties_t *ppts, obs_property_t *p,
		obs_data_t *settings)
{
	bool use_bufsize = obs_data_get_bool(settings, "use_bufsize");
	const char *rc = obs_data_get_string(settings, "rate_control");
	bool rc_crf = astrcmpi(rc, "CRF") == 0;

	p = obs_properties_get(ppts, "buffer_size");
	obs_property_set_visible(p, use_bufsize && !rc_crf);
	return true;
}

static bool rate_control_modified(obs_properties_t *ppts, obs_property_t *p,
		obs_data_t *settings)
{
	const char *rc = obs_data_get_string(settings, "rate_control");
	bool use_bufsize = obs_data_get_bool(settings, "use_bufsize");
	bool abr = astrcmpi(rc, "CBR") == 0 || astrcmpi(rc, "ABR") == 0;
	bool rc_crf = astrcmpi(rc, "CRF") == 0;

	p = obs_properties_get(ppts, "crf");
	obs_property_set_visible(p, !abr);

	p = obs_properties_get(ppts, "bitrate");
	obs_property_set_visible(p, !rc_crf);
	p = obs_properties_get(ppts, "use_bufsize");
	obs_property_set_visible(p, !rc_crf);
	p = obs_properties_get(ppts, "buffer_size");
	obs_property_set_visible(p, !rc_crf && use_bufsize);
	return true;
}

static obs_properties_t *obs_x264_props(void *unused)
{
	UNUSED_PARAMETER(unused);

	obs_properties_t *props = obs_properties_create();
	obs_property_t *list;
	obs_property_t *p;

	list = obs_properties_add_list(props, "rate_control", TEXT_RATE_CONTROL,
			OBS_COMBO_TYPE_LIST, OBS_COMBO_FORMAT_STRING);
	obs_property_list_add_string(list, "CBR", "CBR");
	obs_property_list_add_string(list, "ABR", "ABR");
	obs_property_list_add_string(list, "VBR", "VBR");
	obs_property_list_add_string(list, "CRF", "CRF");

	obs_property_set_modified_callback(list, rate_control_modified);

	obs_properties_add_int(props, "bitrate", TEXT_BITRATE, 50, 10000000, 1);

	p = obs_properties_add_bool(props, "use_bufsize", TEXT_CUSTOM_BUF);
	obs_property_set_modified_callback(p, use_bufsize_modified);
	obs_properties_add_int(props, "buffer_size", TEXT_BUF_SIZE, 0,
			10000000, 1);

	obs_properties_add_int(props, "crf", TEXT_CRF, 0, 51, 1);

	obs_properties_add_int(props, "keyint_sec", TEXT_KEYINT_SEC, 0, 20, 1);

	list = obs_properties_add_list(props, "preset", TEXT_PRESET,
			OBS_COMBO_TYPE_LIST, OBS_COMBO_FORMAT_STRING);
	add_strings(list, x264_preset_names);

	list = obs_properties_add_list(props, "profile", TEXT_PROFILE,
			OBS_COMBO_TYPE_LIST, OBS_COMBO_FORMAT_STRING);
	obs_property_list_add_string(list, TEXT_NONE, "");
	obs_property_list_add_string(list, "baseline", "baseline");
	obs_property_list_add_string(list, "main", "main");
	obs_property_list_add_string(list, "high", "high");

	list = obs_properties_add_list(props, "tune", TEXT_TUNE,
			OBS_COMBO_TYPE_LIST, OBS_COMBO_FORMAT_STRING);
	obs_property_list_add_string(list, TEXT_NONE, "");
	add_strings(list, x264_tune_names);

	obs_properties_add_bool(props, "vfr", TEXT_VFR);

	obs_properties_add_text(props, "x264opts", TEXT_X264_OPTS,
			OBS_TEXT_DEFAULT);

	return props;
}

static bool getparam(const char *param, char **name, const char **value)
{
	const char *assign;

	if (!param || !*param || (*param == '='))
		return false;

	assign = strchr(param, '=');
	if (!assign || !*assign || !*(assign+1))
		return false;

	*name  = bstrdup_n(param, assign-param);
	*value = assign+1;
	return true;
}

static const char *validate(struct obs_x264 *obsx264,
		const char *val, const char *name,
		const char *const *list)
{
	if (!val || !*val)
		return val;

	while (*list) {
		if (strcmp(val, *list) == 0)
			return val;

		list++;
	}

	warn("Invalid %s: %s", name, val);
	return NULL;
}

static void override_base_param(struct obs_x264 *obsx264, const char *param,
		char **preset, char **profile, char **tune)
{
	char       *name;
	const char *val;

	if (getparam(param, &name, &val)) {
		if (astrcmpi(name, "preset") == 0) {
			const char *valid_name = validate(obsx264, val,
					"preset", x264_preset_names);
			if (valid_name) {
				bfree(*preset);
				*preset = bstrdup(val);
			}

		} else if (astrcmpi(name, "profile") == 0) {
			const char *valid_name = validate(obsx264, val,
					"profile", x264_profile_names);
			if (valid_name) {
				bfree(*profile);
				*profile = bstrdup(val);
			}

		} else if (astrcmpi(name, "tune") == 0) {
			const char *valid_name = validate(obsx264, val,
					"tune", x264_tune_names);
			if (valid_name) {
				bfree(*tune);
				*tune = bstrdup(val);
			}
		}

		bfree(name);
	}
}

static inline void override_base_params(struct obs_x264 *obsx264, char **params,
		char **preset, char **profile, char **tune)
{
	while (*params)
		override_base_param(obsx264, *(params++),
				preset, profile, tune);
}

#define OPENCL_ALIAS "opencl_is_experimental_and_potentially_unstable"

static inline void set_param(struct obs_x264 *obsx264, const char *param)
{
	char       *name;
	const char *val;

	if (getparam(param, &name, &val)) {
		if (strcmp(name, "preset")    != 0 &&
		    strcmp(name, "profile")   != 0 &&
		    strcmp(name, "tune")      != 0 &&
		    strcmp(name, "fps")       != 0 &&
		    strcmp(name, "force-cfr") != 0 &&
		    strcmp(name, "width")     != 0 &&
		    strcmp(name, "height")    != 0 &&
		    strcmp(name, "opencl")    != 0) {
			if (strcmp(name, OPENCL_ALIAS) == 0)
				strcpy(name, "opencl");
			if (x264_param_parse(&obsx264->params, name, val) != 0)
				warn("x264 param: %s failed", param);
		}

		bfree(name);
	}
}

static inline void apply_x264_profile(struct obs_x264 *obsx264,
		const char *profile)
{
	if (!obsx264->context && profile && *profile) {
		int ret = x264_param_apply_profile(&obsx264->params, profile);
		if (ret != 0)
			warn("Failed to set x264 profile '%s'", profile);
	}
}

static inline const char *validate_preset(struct obs_x264 *obsx264,
		const char *preset)
{
	const char *new_preset = validate(obsx264, preset, "preset",
			x264_preset_names);
	return new_preset ? new_preset : "veryfast";
}

static bool reset_x264_params(struct obs_x264 *obsx264,
		const char *preset, const char *tune)
{
	int ret = x264_param_default_preset(&obsx264->params,
			validate_preset(obsx264, preset),
			validate(obsx264, tune, "tune", x264_tune_names));
	return ret == 0;
}

static void log_x264(void *param, int level, const char *format, va_list args)
{
	struct obs_x264 *obsx264 = param;
	char str[1024];

	vsnprintf(str, 1024, format, args);
	info("%s", str);

	UNUSED_PARAMETER(level);
}

static inline const char *get_x264_colorspace_name(enum video_colorspace cs)
{
	switch (cs) {
	case VIDEO_CS_DEFAULT:
	case VIDEO_CS_601:
		return "undef";
	case VIDEO_CS_709:;
	}

	return "bt709";
}

static inline int get_x264_cs_val(enum video_colorspace cs,
		const char *const names[])
{
	const char *name = get_x264_colorspace_name(cs);
	int idx = 0;
	do {
		if (strcmp(names[idx], name) == 0)
			return idx;
	} while (!!names[++idx]);

	return 0;
}

static void obs_x264_video_info(void *data, struct video_scale_info *info);

enum rate_control {
	RATE_CONTROL_CBR,
	RATE_CONTROL_VBR,
	RATE_CONTROL_ABR,
	RATE_CONTROL_CRF
};

static void update_params(struct obs_x264 *obsx264, obs_data_t *settings,
		char **params)
{
	video_t *video = obs_encoder_video(obsx264->encoder);
	const struct video_output_info *voi = video_output_get_info(video);
	struct video_scale_info info;

	info.format = voi->format;
	info.colorspace = voi->colorspace;
	info.range = voi->range;

	obs_x264_video_info(obsx264, &info);

	const char *rate_control = obs_data_get_string(settings, "rate_control");

	int bitrate      = (int)obs_data_get_int(settings, "bitrate");
	int buffer_size  = (int)obs_data_get_int(settings, "buffer_size");
	int keyint_sec   = (int)obs_data_get_int(settings, "keyint_sec");
	int crf          = (int)obs_data_get_int(settings, "crf");
	int width        = (int)obs_encoder_get_width(obsx264->encoder);
	int height       = (int)obs_encoder_get_height(obsx264->encoder);
	bool use_bufsize = obs_data_get_bool(settings, "use_bufsize");
	bool vfr         = obs_data_get_bool(settings, "vfr");
	bool cbr_override= obs_data_get_bool(settings, "cbr");
	enum rate_control rc;

	/* XXX: "cbr" setting has been deprecated */
	if (cbr_override) {
		warn("\"cbr\" setting has been deprecated for all encoders!  "
		     "Please set \"rate_control\" to \"CBR\" instead.  "
		     "Forcing CBR mode.  "
		     "(Note to all: this is why you shouldn't use strings for "
		     "common settings)");
		rate_control = "CBR";
	}

	if (astrcmpi(rate_control, "ABR") == 0) {
		rc = RATE_CONTROL_ABR;
		crf = 0;

	} else if (astrcmpi(rate_control, "VBR") == 0) {
		rc = RATE_CONTROL_VBR;

	} else if (astrcmpi(rate_control, "CRF") == 0) {
		rc = RATE_CONTROL_CRF;
		bitrate = 0;
		buffer_size = 0;

	} else { /* CBR */
		rc = RATE_CONTROL_CBR;
		crf = 0;
	}

	if (keyint_sec)
		obsx264->params.i_keyint_max =
			keyint_sec * voi->fps_num / voi->fps_den;

	if (!use_bufsize)
		buffer_size = bitrate;

	obsx264->params.b_vfr_input          = vfr;
	obsx264->params.rc.i_vbv_max_bitrate = bitrate;
	obsx264->params.rc.i_vbv_buffer_size = buffer_size;
	obsx264->params.rc.i_bitrate         = bitrate;
	obsx264->params.i_width              = width;
	obsx264->params.i_height             = height;
	obsx264->params.i_fps_num            = voi->fps_num;
	obsx264->params.i_fps_den            = voi->fps_den;
	obsx264->params.pf_log               = log_x264;
	obsx264->params.p_log_private        = obsx264;
	obsx264->params.i_log_level          = X264_LOG_WARNING;

	obsx264->params.vui.i_transfer =
		get_x264_cs_val(info.colorspace, x264_transfer_names);
	obsx264->params.vui.i_colmatrix =
		get_x264_cs_val(info.colorspace, x264_colmatrix_names);
	obsx264->params.vui.i_colorprim =
		get_x264_cs_val(info.colorspace, x264_colorprim_names);
	obsx264->params.vui.b_fullrange =
		info.range == VIDEO_RANGE_FULL;

	/* use the new filler method for CBR to allow real-time adjusting of
	 * the bitrate */
	if (rc == RATE_CONTROL_CBR || rc == RATE_CONTROL_ABR) {
		obsx264->params.rc.i_rc_method   = X264_RC_ABR;

		if (rc == RATE_CONTROL_CBR) {
#if X264_BUILD >= 139
			obsx264->params.rc.b_filler = true;
#else
			obsx264->params.i_nal_hrd = X264_NAL_HRD_CBR;
#endif
		}
	} else {
		obsx264->params.rc.i_rc_method   = X264_RC_CRF;
	}

	obsx264->params.rc.f_rf_constant = (float)crf;

	if (info.format == VIDEO_FORMAT_NV12)
		obsx264->params.i_csp = X264_CSP_NV12;
	else if (info.format == VIDEO_FORMAT_I420)
		obsx264->params.i_csp = X264_CSP_I420;
	else if (info.format == VIDEO_FORMAT_I444)
		obsx264->params.i_csp = X264_CSP_I444;
	else
		obsx264->params.i_csp = X264_CSP_NV12;

	while (*params)
		set_param(obsx264, *(params++));

	info("settings:\n"
	     "\trate_control: %s\n"
	     "\tbitrate:      %d\n"
	     "\tbuffer size:  %d\n"
	     "\tcrf:          %d\n"
	     "\tfps_num:      %d\n"
	     "\tfps_den:      %d\n"
	     "\twidth:        %d\n"
	     "\theight:       %d\n"
	     "\tkeyint:       %d\n"
	     "\tvfr:          %s\n",
	     rate_control,
	     obsx264->params.rc.i_vbv_max_bitrate,
	     obsx264->params.rc.i_vbv_buffer_size,
	     (int)obsx264->params.rc.f_rf_constant,
	     voi->fps_num, voi->fps_den,
	     width, height,
	     obsx264->params.i_keyint_max,
	     vfr ? "on" : "off");
}

static bool update_settings(struct obs_x264 *obsx264, obs_data_t *settings)
{
	char *preset     = bstrdup(obs_data_get_string(settings, "preset"));
	char *profile    = bstrdup(obs_data_get_string(settings, "profile"));
	char *tune       = bstrdup(obs_data_get_string(settings, "tune"));
	const char *opts = obs_data_get_string(settings, "x264opts");

	char **paramlist;
	bool success = true;

	paramlist = strlist_split(opts, ' ', false);

	blog(LOG_INFO, "---------------------------------");

	if (!obsx264->context) {
		override_base_params(obsx264, paramlist,
				&preset, &profile, &tune);

		if (preset  && *preset)  info("preset: %s",  preset);
		if (profile && *profile) info("profile: %s", profile);
		if (tune    && *tune)    info("tune: %s",    tune);

		success = reset_x264_params(obsx264, preset, tune);
	}

	if (success) {
		update_params(obsx264, settings, paramlist);
		if (opts && *opts)
			info("custom settings: %s", opts);

		if (!obsx264->context)
			apply_x264_profile(obsx264, profile);
	}

	obsx264->params.b_repeat_headers = false;

	strlist_free(paramlist);
	bfree(preset);
	bfree(profile);
	bfree(tune);

	return success;
}

static bool obs_x264_update(void *data, obs_data_t *settings)
{
	struct obs_x264 *obsx264 = data;
	bool success = update_settings(obsx264, settings);
	int ret;

	if (success) {
		ret = x264_encoder_reconfig(obsx264->context, &obsx264->params);
		if (ret != 0)
			warn("Failed to reconfigure: %d", ret);
		return ret == 0;
	}

	return false;
}

static void load_headers(struct obs_x264 *obsx264)
{
	x264_nal_t      *nals;
	int             nal_count;
	DARRAY(uint8_t) header;
	DARRAY(uint8_t) sei;

	da_init(header);
	da_init(sei);

	x264_encoder_headers(obsx264->context, &nals, &nal_count);

	for (int i = 0; i < nal_count; i++) {
		x264_nal_t *nal = nals+i;

		if (nal->i_type == NAL_SEI)
			da_push_back_array(sei, nal->p_payload, nal->i_payload);
		else
			da_push_back_array(header, nal->p_payload,
					nal->i_payload);
	}

	obsx264->extra_data      = header.array;
	obsx264->extra_data_size = header.num;
	obsx264->sei             = sei.array;
	obsx264->sei_size        = sei.num;
}

static void *obs_x264_create(obs_data_t *settings, obs_encoder_t *encoder)
{
	struct obs_x264 *obsx264 = bzalloc(sizeof(struct obs_x264));
	obsx264->encoder = encoder;

	if (update_settings(obsx264, settings)) {
		obsx264->context = x264_encoder_open(&obsx264->params);

		if (obsx264->context == NULL)
			warn("x264 failed to load");
		else
			load_headers(obsx264);
	} else {
		warn("bad settings specified");
	}

	if (!obsx264->context) {
		bfree(obsx264);
		return NULL;
	}

	obsx264->performance_token =
		os_request_high_performance("x264 encoding");

	return obsx264;
}

static void parse_packet(struct obs_x264 *obsx264,
		struct encoder_packet *packet, x264_nal_t *nals,
		int nal_count, x264_picture_t *pic_out)
{
	if (!nal_count) return;

	da_resize(obsx264->packet_data, 0);

	for (int i = 0; i < nal_count; i++) {
		x264_nal_t *nal = nals+i;
		da_push_back_array(obsx264->packet_data, nal->p_payload,
				nal->i_payload);
	}

	packet->data          = obsx264->packet_data.array;
	packet->size          = obsx264->packet_data.num;
	packet->type          = OBS_ENCODER_VIDEO;
	packet->pts           = pic_out->i_pts;
	packet->dts           = pic_out->i_dts;
	packet->keyframe      = pic_out->b_keyframe != 0;
}

static inline void init_pic_data(struct obs_x264 *obsx264, x264_picture_t *pic,
		struct encoder_frame *frame)
{
	x264_picture_init(pic);

	pic->i_pts = frame->pts;
	pic->img.i_csp = obsx264->params.i_csp;

	if (obsx264->params.i_csp == X264_CSP_NV12)
		pic->img.i_plane = 2;
	else if (obsx264->params.i_csp == X264_CSP_I420)
		pic->img.i_plane = 3;
	else if (obsx264->params.i_csp == X264_CSP_I444)
		pic->img.i_plane = 3;

	for (int i = 0; i < pic->img.i_plane; i++) {
		pic->img.i_stride[i] = (int)frame->linesize[i];
		pic->img.plane[i]    = frame->data[i];
	}
}

static bool obs_x264_encode(void *data, struct encoder_frame *frame,
		struct encoder_packet *packet, bool *received_packet)
{
	struct obs_x264 *obsx264 = data;
	x264_nal_t      *nals;
	int             nal_count;
	int             ret;
	x264_picture_t  pic, pic_out;

	if (!frame || !packet || !received_packet)
		return false;

	if (frame)
		init_pic_data(obsx264, &pic, frame);

	ret = x264_encoder_encode(obsx264->context, &nals, &nal_count,
			(frame ? &pic : NULL), &pic_out);
	if (ret < 0) {
		warn("encode failed");
		return false;
	}

	*received_packet = (nal_count != 0);
	parse_packet(obsx264, packet, nals, nal_count, &pic_out);

	return true;
}

static bool obs_x264_extra_data(void *data, uint8_t **extra_data, size_t *size)
{
	struct obs_x264 *obsx264 = data;

	if (!obsx264->context)
		return false;

	*extra_data = obsx264->extra_data;
	*size       = obsx264->extra_data_size;
	return true;
}

static bool obs_x264_sei(void *data, uint8_t **sei, size_t *size)
{
	struct obs_x264 *obsx264 = data;

	if (!obsx264->context)
		return false;

	*sei  = obsx264->sei;
	*size = obsx264->sei_size;
	return true;
}

static inline bool valid_format(enum video_format format)
{
	return format == VIDEO_FORMAT_I420 ||
	       format == VIDEO_FORMAT_NV12 ||
	       format == VIDEO_FORMAT_I444;
}

static void obs_x264_video_info(void *data, struct video_scale_info *info)
{
	struct obs_x264 *obsx264 = data;
	enum video_format pref_format;

	pref_format = obs_encoder_get_preferred_video_format(obsx264->encoder);

	if (!valid_format(pref_format)) {
		pref_format = valid_format(info->format) ?
			info->format : VIDEO_FORMAT_NV12;
	}

	info->format = pref_format;
}

struct obs_encoder_info obs_x264_encoder = {
	.id             = "obs_x264",
	.type           = OBS_ENCODER_VIDEO,
	.codec          = "h264",
	.get_name       = obs_x264_getname,
	.create         = obs_x264_create,
	.destroy        = obs_x264_destroy,
	.encode         = obs_x264_encode,
	.update         = obs_x264_update,
	.get_properties = obs_x264_props,
	.get_defaults   = obs_x264_defaults,
	.get_extra_data = obs_x264_extra_data,
	.get_sei_data   = obs_x264_sei,
	.get_video_info = obs_x264_video_info
};