// Copyright (c) 2007, Rodrigo Braz Monteiro
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
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//     this list of conditions and the following disclaimer.
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// Aegisub Project http://www.aegisub.org/

/// @file subtitles_provider_csri.cpp
/// @brief Wrapper for CSRI-based subtitle renderers
/// @ingroup subtitle_rendering
///

#ifdef WITH_CSRI
#include "subtitles_provider_csri.h"

#include "include/aegisub/subtitles_provider.h"
#include "subtitle_format_ass.h"
#include "video_frame.h"

#include <mutex>

#ifdef WIN32
#define CSRIAPI
#endif

#include <csri/csri.h>

namespace {
// CSRI renderers are not required to be thread safe (and VSFilter very much
// is not)
std::mutex csri_mutex;

struct closer {
	void operator()(csri_inst *inst) { if (inst) csri_close(inst); }
};

class CSRISubtitlesProvider final : public SubtitlesProvider {
	std::unique_ptr<csri_inst, closer> instance;
	csri_rend *renderer = nullptr;

	void LoadSubtitles(const char *data, size_t len) override {
		std::lock_guard<std::mutex> lock(csri_mutex);
		instance.reset(csri_open_mem(renderer, data, len, nullptr));
	}

public:
	CSRISubtitlesProvider(std::string subType);

	void DrawSubtitles(VideoFrame &dst, double time) override;
};

CSRISubtitlesProvider::CSRISubtitlesProvider(std::string type) {
	std::lock_guard<std::mutex> lock(csri_mutex);
	for (csri_rend *cur = csri_renderer_default(); cur; cur = csri_renderer_next(cur)) {
		if (type == csri_renderer_info(cur)->name) {
			renderer = cur;
			break;
		}
	}

	if (!renderer)
		throw agi::InternalError("CSRI renderer vanished between initial list and creation?");
}

void CSRISubtitlesProvider::DrawSubtitles(VideoFrame &dst, double time) {
	if (!instance) return;

	csri_frame frame;
	if (dst.flipped) {
		frame.planes[0] = dst.data.data() + (dst.height-1) * dst.width * 4;
		frame.strides[0] = -(signed)dst.width * 4;
	}
	else {
		frame.planes[0] = dst.data.data();
		frame.strides[0] = dst.width * 4;
	}
	frame.pixfmt = CSRI_F_BGR_;

	csri_fmt format = { frame.pixfmt, static_cast<unsigned>(dst.width), static_cast<unsigned>(dst.height) };

	std::lock_guard<std::mutex> lock(csri_mutex);
	if (!csri_request_fmt(instance.get(), &format))
		// Add 1e-9 to guard against floating point imprecision errors on int -> float -> *1000 -> int round trips
		csri_render(instance.get(), &frame, time + 1e-9);
}
}

namespace csri {
std::vector<std::string> List() {
	std::vector<std::string> final;
	for (csri_rend *cur = csri_renderer_default(); cur; cur = csri_renderer_next(cur)) {
		std::string name(csri_renderer_info(cur)->name);
		if (name.find("aegisub") != name.npos)
			final.insert(final.begin(), name);
		else
			final.push_back(name);
	}
	return final;
}

std::unique_ptr<SubtitlesProvider> Create(std::string const& name, agi::BackgroundRunner *) {
	return std::make_unique<CSRISubtitlesProvider>(name);
}
}
#endif // WITH_CSRI
