#include "SigmaView.h"
#include "ItemCurveArc.h"
#include "ItemCurveEdit.h"
#include "ItemSelect.h"
#include "clipper2/clipper.h"

enum class BooleanOp
{
	Difference = 0,
	Intersect = 1,
	Union = 2,
	Xor = 3,
};

/**
 * 多边形处理类
 */
class PolygonCombiner
{
public:
	/**
	 * 差集
	 * 
	 * \param first		第一条闭合曲线
	 * \param second	第二条闭合曲线
	 * \return	返回合并后的曲线
	 */
	static std::vector<std::unique_ptr<CCurveEx>> Difference(const std::vector<CCurveEx*>& first, const std::vector<CCurveEx*>& second)
	{
		return Execute(first, second, BooleanOp::Difference);
	}

	/**
	 * 交集
	 * 
	 * \param first		第一条闭合曲线
	 * \param second	第二条闭合曲线
	 * \return	返回合并后的曲线
	 */
	static std::vector<std::unique_ptr<CCurveEx>> Intersect(const std::vector<CCurveEx*>& first, const std::vector<CCurveEx*>& second)
	{
		return Execute(first, second, BooleanOp::Intersect);
	}

	/**
	 * 并集
	 * 
	 * \param first		第一条闭合曲线
	 * \param second	第二条闭合曲线
	 * \return	返回合并后的曲线
	 */
	static std::vector<std::unique_ptr<CCurveEx>> Union(const std::vector<CCurveEx*>& first, const std::vector<CCurveEx*>& second)
	{
		return Execute(first, second, BooleanOp::Union);
	}

	/**
	 * 异或
	 * 
	 * \param first		第一条闭合曲线
	 * \param second	第二条闭合曲线
	 * \return	返回合并后的曲线
	 */
	static std::vector<std::unique_ptr<CCurveEx>> Xor(const std::vector<CCurveEx*>& first, const std::vector<CCurveEx*>& second)
	{
		return Execute(first, second, BooleanOp::Xor);
	}

	static Clipper2Lib::PathD CurveToPathD(const CCurveEx* curve)
	{
		Clipper2Lib::PathD path;
		path.reserve(curve->num);

		for (int i = 0; i < curve->num; i++)
		{
			path.push_back({ curve->x[i], curve->y[i] });
		}

		return path;
	}

	static Clipper2Lib::PathsD CurvesToPathsD(const std::vector<CCurveEx*>& curves)
	{
		Clipper2Lib::PathsD path;
		path.reserve(curves.size());

		for (auto* pCurve : curves)
		{
			if (pCurve == nullptr)
			{
				continue;
			}

			path.emplace_back(CurveToPathD(pCurve));
		}

		return path;
	}

	static std::unique_ptr<CCurveEx> PathDToCurve(const Clipper2Lib::PathD& path)
	{
		auto pCurve = std::make_unique<CCurveEx>();
		pCurve->Create(path.size() + 1);

		size_t i = 0;
		for (; i < path.size(); i++)
		{
			pCurve->x[i] = path[i].x;
			pCurve->y[i] = path[i].y;
		}

		pCurve->x[i] = path[0].x;
		pCurve->y[i] = path[0].y;

		return pCurve;
	}

	static std::vector<std::unique_ptr<CCurveEx>> Execute(const std::vector<CCurveEx*>& first, const std::vector<CCurveEx*>& second, BooleanOp op)
	{
		auto firstPaths = CurvesToPathsD(first);
		auto secondPaths = CurvesToPathsD(second);

		auto solution = Clipper2Lib::PathsD();
		switch (op)
		{
		case BooleanOp::Difference:
			 solution = Clipper2Lib::Difference(firstPaths, secondPaths, Clipper2Lib::FillRule::NonZero);
			break;
		case BooleanOp::Intersect:
			 solution = Clipper2Lib::Intersect(firstPaths, secondPaths, Clipper2Lib::FillRule::NonZero);
			break;
		case BooleanOp::Union:
			 solution = Clipper2Lib::Union(firstPaths, secondPaths, Clipper2Lib::FillRule::NonZero);
			break;
		case BooleanOp::Xor:
			 solution = Clipper2Lib::Xor(firstPaths, secondPaths, Clipper2Lib::FillRule::NonZero);
			break;
		default:
			break;
		}

		if (solution.empty())
		{
			return {};
		}

		std::vector<std::unique_ptr<CCurveEx>> result;
		for (auto& path : solution)
		{
			result.push_back(PathDToCurve(path));
		}

		return result;
	}
};