/*
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at https://mozilla.org/MPL/2.0/.
 */

#pragma once

#include "IFontAtlasGenerator.hpp"
#include "Math/AABB.hpp"
#include <ft2build.h>
#include FT_FREETYPE_H
#include <variant>
#include <set>

namespace OpenVulkano::Scene
{
	class FontAtlasGeneratorBase : public IFontAtlasGenerator
	{
		struct LibDeleter
		{
			void operator()(FT_Library lib)
			{ 
				FT_Done_FreeType(lib);
			}
		};

		struct FaceDeleter
		{
			void operator()(FT_Face face)
			{ 
				FT_Done_Face(face);
			}
		};

	public:
		using FT_LIB_REC = std::unique_ptr<FT_LibraryRec_, LibDeleter>;
		using FT_FACE_REC = std::unique_ptr<FT_FaceRec_, FaceDeleter>;
		
		FontAtlasGeneratorBase(int channelsCount) : m_channelsCount(channelsCount) {}
		void SaveAtlasMetadataInfo(const std::string& outputFile, bool packIntoSingleFile = true) const override;
		std::shared_ptr<AtlasData> GetAtlasData() const { return m_atlasData; }
		int GetAtlasChannelsCount() const { return m_channelsCount; }

		static std::set<uint32_t> LoadAllGlyphs(const std::variant<std::string, Array<char>>& data);

	protected:
		void SavePng(const std::string& output) const;
		void SetupAtlasData(Math::Vector2ui textureResolution, double lineHeight, FontAtlasType::Type atlasType);
		void SetGlyphData(GlyphInfo& info, Math::Vector2d bearing, Math::Vector2d size, const Math::AABB& aabb, double advance);
		static std::pair<FT_LIB_REC, FT_FACE_REC> InitFreetype(const std::variant<std::string, Array<char>>& source);
	protected:
		int m_channelsCount;
		std::shared_ptr<AtlasData> m_atlasData;
	};
}