/*
 * Modern effects for a modern Streamer
 * Copyright (C) 2017 Michael Fabian Dirks
 *
 * 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, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
*/

#include "filter-displacement.hpp"
#include <sys/stat.h>
#include "strings.hpp"

// Initializer & Finalizer
static filter::Displacement* filterDisplacementInstance;
INITIALIZER(FilterDisplacementInit)
{
	initializerFunctions.push_back([] { filterDisplacementInstance = new filter::Displacement(); });
	finalizerFunctions.push_back([] { delete filterDisplacementInstance; });
}

filter::Displacement::Displacement()
{
	memset(&sourceInfo, 0, sizeof(obs_source_info));
	sourceInfo.id             = "obs-stream-effects-filter-displacement";
	sourceInfo.type           = OBS_SOURCE_TYPE_FILTER;
	sourceInfo.output_flags   = OBS_SOURCE_VIDEO;
	sourceInfo.get_name       = get_name;
	sourceInfo.get_defaults   = get_defaults;
	sourceInfo.get_properties = get_properties;

	sourceInfo.create       = create;
	sourceInfo.destroy      = destroy;
	sourceInfo.update       = update;
	sourceInfo.activate     = activate;
	sourceInfo.deactivate   = deactivate;
	sourceInfo.show         = show;
	sourceInfo.hide         = hide;
	sourceInfo.video_tick   = video_tick;
	sourceInfo.video_render = video_render;

	obs_register_source(&sourceInfo);
}

filter::Displacement::~Displacement() {}

const char* filter::Displacement::get_name(void*)
{
	return P_TRANSLATE(S_FILTER_DISPLACEMENT);
}

void* filter::Displacement::create(obs_data_t* data, obs_source_t* source)
{
	return new Instance(data, source);
}

void filter::Displacement::destroy(void* ptr)
{
	delete reinterpret_cast<Instance*>(ptr);
}

uint32_t filter::Displacement::get_width(void* ptr)
{
	return reinterpret_cast<Instance*>(ptr)->get_width();
}

uint32_t filter::Displacement::get_height(void* ptr)
{
	return reinterpret_cast<Instance*>(ptr)->get_height();
}

void filter::Displacement::get_defaults(obs_data_t* data)
{
	char* disp = obs_module_file("filter-displacement/neutral.png");
	obs_data_set_default_string(data, S_FILTER_DISPLACEMENT_FILE, disp);
	obs_data_set_default_double(data, S_FILTER_DISPLACEMENT_RATIO, 0);
	obs_data_set_default_double(data, S_FILTER_DISPLACEMENT_SCALE, 0);
	bfree(disp);
}

obs_properties_t* filter::Displacement::get_properties(void* ptr)
{
	obs_properties_t* pr = obs_properties_create();

	std::string path = "";
	if (ptr)
		path = reinterpret_cast<Instance*>(ptr)->get_file();

	obs_properties_add_path(pr, S_FILTER_DISPLACEMENT_FILE, P_TRANSLATE(S_FILTER_DISPLACEMENT_FILE),
							obs_path_type::OBS_PATH_FILE, P_TRANSLATE(S_FILTER_DISPLACEMENT_FILE_TYPES), path.c_str());
	obs_properties_add_float_slider(pr, S_FILTER_DISPLACEMENT_RATIO, P_TRANSLATE(S_FILTER_DISPLACEMENT_RATIO), 0, 1,
									0.01);
	obs_properties_add_float_slider(pr, S_FILTER_DISPLACEMENT_SCALE, P_TRANSLATE(S_FILTER_DISPLACEMENT_SCALE), -1000,
									1000, 0.01);
	return pr;
}

void filter::Displacement::update(void* ptr, obs_data_t* data)
{
	reinterpret_cast<Instance*>(ptr)->update(data);
}

void filter::Displacement::activate(void* ptr)
{
	reinterpret_cast<Instance*>(ptr)->activate();
}

void filter::Displacement::deactivate(void* ptr)
{
	reinterpret_cast<Instance*>(ptr)->deactivate();
}

void filter::Displacement::show(void* ptr)
{
	reinterpret_cast<Instance*>(ptr)->show();
}

void filter::Displacement::hide(void* ptr)
{
	reinterpret_cast<Instance*>(ptr)->hide();
}

void filter::Displacement::video_tick(void* ptr, float time)
{
	reinterpret_cast<Instance*>(ptr)->video_tick(time);
}

void filter::Displacement::video_render(void* ptr, gs_effect_t* effect)
{
	reinterpret_cast<Instance*>(ptr)->video_render(effect);
}

filter::Displacement::Instance::Instance(obs_data_t* data, obs_source_t* context)
{
	this->dispmap.texture      = nullptr;
	this->dispmap.createTime   = 0;
	this->dispmap.modifiedTime = 0;
	this->dispmap.size         = 0;
	this->timer                = 0;
	this->context              = context;

	obs_enter_graphics();
	char* effectFile   = obs_module_file("effects/displace.effect");
	char* errorMessage = nullptr;
	this->customEffect = gs_effect_create_from_file(effectFile, &errorMessage);
	bfree(effectFile);
	if (errorMessage != nullptr) {
		P_LOG_ERROR("%s", errorMessage);
		bfree(errorMessage);
	}
	obs_leave_graphics();

	update(data);
}

filter::Displacement::Instance::~Instance()
{
	obs_enter_graphics();
	gs_effect_destroy(customEffect);
	gs_texture_destroy(dispmap.texture);
	obs_leave_graphics();
}

void filter::Displacement::Instance::update(obs_data_t* data)
{
	updateDisplacementMap(obs_data_get_string(data, S_FILTER_DISPLACEMENT_FILE));

	distance = float_t(obs_data_get_double(data, S_FILTER_DISPLACEMENT_RATIO));
	vec2_set(&displacementScale, float_t(obs_data_get_double(data, S_FILTER_DISPLACEMENT_SCALE)),
			 float_t(obs_data_get_double(data, S_FILTER_DISPLACEMENT_SCALE)));
}

uint32_t filter::Displacement::Instance::get_width()
{
	return 0;
}

uint32_t filter::Displacement::Instance::get_height()
{
	return 0;
}

void filter::Displacement::Instance::activate() {}

void filter::Displacement::Instance::deactivate() {}

void filter::Displacement::Instance::show() {}

void filter::Displacement::Instance::hide() {}

void filter::Displacement::Instance::video_tick(float time)
{
	timer += time;
	if (timer >= 1.0) {
		timer -= 1.0;
		updateDisplacementMap(dispmap.file);
	}
}

float interp(float a, float b, float v)
{
	return (a * (1.0f - v)) + (b * v);
}

void filter::Displacement::Instance::video_render(gs_effect_t*)
{
	obs_source_t* parent = obs_filter_get_parent(context);
	obs_source_t* target = obs_filter_get_target(context);
	uint32_t      baseW = obs_source_get_base_width(target), baseH = obs_source_get_base_height(target);

	// Skip rendering if our target, parent or context is not valid.
	if (!target || !parent || !context || !dispmap.texture || !baseW || !baseH) {
		obs_source_skip_video_filter(context);
		return;
	}

	if (!obs_source_process_filter_begin(context, GS_RGBA, OBS_ALLOW_DIRECT_RENDERING))
		return;

	gs_eparam_t* param;

	vec2 texelScale;
	vec2_set(&texelScale, interp((1.0f / baseW), 1.0f, distance), interp((1.0f / baseH), 1.0f, distance));
	param = gs_effect_get_param_by_name(customEffect, "texelScale");
	if (param)
		gs_effect_set_vec2(param, &texelScale);
	else
		P_LOG_ERROR("Failed to set texel scale param.");

	param = gs_effect_get_param_by_name(customEffect, "displacementScale");
	if (param)
		gs_effect_set_vec2(param, &displacementScale);
	else
		P_LOG_ERROR("Failed to set displacement scale param.");

	param = gs_effect_get_param_by_name(customEffect, "displacementMap");
	if (param)
		gs_effect_set_texture(param, dispmap.texture);
	else
		P_LOG_ERROR("Failed to set texture param.");

	obs_source_process_filter_end(context, customEffect, baseW, baseH);
}

std::string filter::Displacement::Instance::get_file()
{
	return dispmap.file;
}

void filter::Displacement::Instance::updateDisplacementMap(std::string file)
{
	bool shouldUpdateTexture = false;

	// Different File
	if (file != dispmap.file) {
		dispmap.file        = file;
		shouldUpdateTexture = true;
	} else { // Different Timestamps
		struct stat stats;
		if (os_stat(dispmap.file.c_str(), &stats) != 0) {
			shouldUpdateTexture = shouldUpdateTexture || (dispmap.createTime != stats.st_ctime)
								  || (dispmap.modifiedTime != stats.st_mtime);
			dispmap.createTime   = stats.st_ctime;
			dispmap.modifiedTime = stats.st_mtime;
		}
	}

	if (shouldUpdateTexture) {
		obs_enter_graphics();
		if (dispmap.texture) {
			gs_texture_destroy(dispmap.texture);
			dispmap.texture = nullptr;
		}
		if (os_file_exists(file.c_str()))
			dispmap.texture = gs_texture_create_from_file(dispmap.file.c_str());
		obs_leave_graphics();
	}
}