#include "Sprite.hpp"

#include "Image.hpp"
#include "RapidJsonHelper.hpp"

#include <rapidjson/document.h>
#include <memory>

using namespace std::literals;

bool Sprite::IsValid() const {
	return mAtlas != nullptr;
}

bool IresSpriteFiles::IsValid() const {
	return !spriteFiles.empty();
}

Sprite* IresSpriteFiles::CreateInstance() const {
	if (IsValid()) {
		return nullptr;
	}

	std::vector<Texture::AtlasSource> sources;
	sources.resize(spriteFiles.size());
	for (auto& file : spriteFiles) {
	}

	Texture::AtlasOutput atlasOut;
	Texture::AtlasInput atlasIn{
		.sources = sources,
		.packingMode = Texture::PM_KeepSquare,
	};
	atlasIn.sources = sources;
	auto atlas = std::make_unique<Texture>();
	if (atlas->InitAtlas(atlasIn, &atlasOut) != Texture::EC_Success) {
		return nullptr;
	}

	auto sprite = std::make_unique<Sprite>();
	sprite->mAtlas.Attach(atlas.release());
	sprite->mBoundingBox = atlasOut.elements[0].subregionSize;
	sprite->mFrames.reserve(atlasOut.elements.size());
	for (auto& elm : atlasOut.elements) {
		// Validate bounding box
		if (sprite->mBoundingBox != elm.subregionSize) {
			return nullptr;
		}

		// Copy frame subregion
		sprite->mFrames.push_back(elm.subregion);
	}
	return sprite.release();
}

Sprite* IresSpriteFiles::GetInstance() {
	if (mInstance == nullptr) {
		mInstance.Attach(CreateInstance());
	}
	return mInstance.Get();
}

void IresSpriteFiles::InvalidateInstance() {
	mInstance.Attach(nullptr);
}

void IresSpriteFiles::Write(rapidjson::Value& value, rapidjson::Document& root) const {
	value.AddMember("Sprites", rapidjson::WriteVectorPrimitives(root, spriteFiles.begin(), spriteFiles.end()), root.GetAllocator());
}

void IresSpriteFiles::Read(const rapidjson::Value& value) {
	auto rvFileList = rapidjson::GetProperty(value, rapidjson::kArrayType, "Sprites"sv);
	if (!rvFileList) return;
	spriteFiles.clear();
	rapidjson::ReadVectorPrimitives<decltype(spriteFiles)>(*rvFileList, spriteFiles);
}

bool IresSpritesheet::IsValid() const {
	return !spritesheetFile.empty() &&
		sheetWSplit != 0 &&
		sheetHSplit != 0;
}

void IresSpritesheet::ResplitSpritesheet(Sprite* sprite, int wSplit, int hSplit) {
	auto atlas = sprite->GetAtlas();
	auto size = atlas->GetInfo().size;
	int frameWidth = size.x / wSplit;
	int frameHeight = size.y / hSplit;

	sprite->mBoundingBox = { frameWidth, frameHeight };
	sprite->mFrames.clear();
	sprite->mFrames.reserve(wSplit * hSplit);

	// Width and height in UV coordinates for each frame
	float deltaU = 1.0f / wSplit;
	float deltaV = 1.0f / hSplit;
	for (int y = 0; y < hSplit; ++y) {
		for (int x = 0; x < wSplit; ++x) {
			auto& subregion = sprite->mFrames.emplace_back();
			// Top left
			subregion.u0 = deltaU * x;
			subregion.v0 = deltaV * y;
			// Bottom right
			subregion.u1 = subregion.u0 + deltaU;
			subregion.u1 = subregion.v0 + deltaV;
		}
	}
}

Sprite* IresSpritesheet::CreateInstance() const {
	if (!IsValid()) {
		return nullptr;
	}

	auto atlas = std::make_unique<Texture>();
	if (!atlas->InitFromFile(spritesheetFile.c_str())) {
		return nullptr;
	}

	auto sprite = std::make_unique<Sprite>();
	sprite->mAtlas.Attach(atlas.release());
	ResplitSpritesheet(sprite.get(), sheetWSplit, sheetHSplit);
	return sprite.release();
}

Sprite* IresSpritesheet::GetInstance() {
	if (mInstance == nullptr) {
		mInstance.Attach(CreateInstance());
	}
	return mInstance.Get();
}

void IresSpritesheet::InvalidateInstance() {
	mInstance.Attach(nullptr);
}

void IresSpritesheet::Write(rapidjson::Value& value, rapidjson::Document& root) const {
	value.AddMember("SpriteSheet", spritesheetFile, root.GetAllocator());
	value.AddMember("WSplit", sheetWSplit, root.GetAllocator());
	value.AddMember("HSplit", sheetHSplit, root.GetAllocator());
}

void IresSpritesheet::Read(const rapidjson::Value& value) {
	BRUSSEL_JSON_GET(value, "SpriteSheet", std::string, spritesheetFile, return );
	BRUSSEL_JSON_GET(value, "WSplit", int, sheetWSplit, return );
	BRUSSEL_JSON_GET(value, "HSplit", int, sheetHSplit, return );
}

SpriteMesh::SpriteMesh(Sprite* sprite)
	: mSprite(sprite) {
}

void SpriteMesh::SetFrame(int frame) {
	// TODO
}

void SpriteMesh::PlayFrame() {
	// TODO
}

void SpriteMesh::SetPlaybackSpeed(int speed) {
	// TODO
}