/*
 * 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/.
 */

#include "TextDrawable.hpp"
#include "Scene/Geometry.hpp"
#include "Scene/Material.hpp"
#include "Scene/Vertex.hpp"
#include "Scene/UniformBuffer.hpp"
#include "Scene/FontAtlasGenerator.hpp"
#include "Base/Logger.hpp"
#include "utf8.h"
#include "fmt/core.h"

namespace OpenVulkano::Scene
{
	using namespace msdfgen;
	using namespace msdf_atlas;

	TextDrawable::~TextDrawable()
	{ 
		delete m_mesh;
		delete m_material;
	}

	void TextDrawable::GenerateText(const std::string& text, const Math::Vector3f& pos) 
	{
		if (!m_fontAtlasGenerator)
		{
			Logger::RENDER->error("Can't draw text. FontAtlasGenerator is nullptr");
			return;
		}
		if (m_mesh)
		{
			delete m_mesh;
			m_mesh = nullptr;
		}
		if (m_material)
		{
			delete m_material;
			m_material = nullptr;
		}
		if (text.empty())
		{
			return;
		}
		std::map<unicode_t, GlyphInfo>& symbols = m_fontAtlasGenerator->GetAtlasInfo();
		if (symbols.empty())
		{
			throw std::runtime_error("Glyphs are not loaded");
		}

		m_mesh = new Geometry();
		m_material = new Material();
		m_mesh->freeAfterUpload = false;
		m_mesh->Init(text.size() * 4, text.size() * 6);

		struct Bbox
		{
			double l = 0, r = 0, t = 0, b = 0;
		};

		double cursorX = pos.x;
		auto begin = text.begin();
		auto end = text.end();
		for (size_t i = 0; begin != end; i++)
		{
			unicode_t c = utf8::next(begin, end);
			if (symbols.find(c) != symbols.end())
			{
				Bbox glyphBaselineBbox, glyphAtlasBbox;
				uint32_t vIdx = i * 4;
				uint32_t indices[] = { 1 + vIdx, 2 + vIdx, 3 + vIdx, 1 + vIdx, 3 + vIdx, 0 + vIdx };
				GlyphInfo& info = symbols.at(c);
				info.geometry.getQuadPlaneBounds(glyphBaselineBbox.l, glyphBaselineBbox.b, glyphBaselineBbox.r,
				                                 glyphBaselineBbox.t);
				info.geometry.getQuadAtlasBounds(glyphAtlasBbox.l, glyphAtlasBbox.b, glyphAtlasBbox.r,
				                                 glyphAtlasBbox.t);
				double bearingX = info.glyphBox.bounds.l;
				double bearingY = info.glyphBox.bounds.t;
				double w = glyphBaselineBbox.r - glyphBaselineBbox.l;
				double h = glyphBaselineBbox.t - glyphBaselineBbox.b;
				double l = glyphAtlasBbox.l;
				double r = glyphAtlasBbox.r;
				double t = glyphAtlasBbox.t;
				double b = glyphAtlasBbox.b;
				double ax = cursorX + bearingX;
				double ay = pos.y - (h - bearingY);

				const Texture& atlasTex = m_fontAtlasGenerator->GetAtlas();
				m_material->texture = const_cast<Texture*>(&atlasTex);

				m_mesh->vertices[vIdx].position.x = ax;
				m_mesh->vertices[vIdx].position.y = ay;
				m_mesh->vertices[vIdx].position.z = 1;
				m_mesh->vertices[vIdx].textureCoordinates.x = l / atlasTex.resolution.x;
				m_mesh->vertices[vIdx].textureCoordinates.y = b / atlasTex.resolution.y;

				m_mesh->vertices[vIdx + 1].position.x = ax + w;
				m_mesh->vertices[vIdx + 1].position.y = ay;
				m_mesh->vertices[vIdx + 1].position.z = 1;
				m_mesh->vertices[vIdx + 1].textureCoordinates.x = r / atlasTex.resolution.x;
				m_mesh->vertices[vIdx + 1].textureCoordinates.y = b / atlasTex.resolution.y;

				m_mesh->vertices[vIdx + 2].position.x = ax + w;
				m_mesh->vertices[vIdx + 2].position.y = ay + h;
				m_mesh->vertices[vIdx + 2].position.z = 1;
				m_mesh->vertices[vIdx + 2].textureCoordinates.x = r / atlasTex.resolution.x;
				m_mesh->vertices[vIdx + 2].textureCoordinates.y = t / atlasTex.resolution.y;

				m_mesh->vertices[vIdx + 3].position.x = ax;
				m_mesh->vertices[vIdx + 3].position.y = ay + h;
				m_mesh->vertices[vIdx + 3].position.z = 1;
				m_mesh->vertices[vIdx + 3].textureCoordinates.x = l / atlasTex.resolution.x;
				m_mesh->vertices[vIdx + 3].textureCoordinates.y = t / atlasTex.resolution.y;

				m_mesh->SetIndices(indices, 6, 6 * i);
				// TODO: change to lower value(or ideally remove completely) to avoid overlapping and make less space between symbols
				// when setting for depth comparison operator will be available( <= )
				cursorX += info.glyphBox.advance + 0.08;
			}
			else
			{
				// throw ? replace with ? character (if available) ?
				Logger::RENDER->error(fmt::format("Could not find glyph for character {}", c));
			}
		}
	}
}