#pragma once

namespace mt
{
	class Path
	{
	public:
		void SetPoints(const List<vec3>& points);
		void SetScale(const List<float>& scale);
		void SetRotation(const List<float>& rotation);

		vec3 GetPoint(float t) const;
		float GetScale(float t) const;
		float GetRotation(float t) const;
		vec3 GetDirection(float t) const;

	private:
		template <typename T> static void GetValues(const List<T>& source, float& t, T& p0, T& p1, T& p2, T& p3)
		{
			auto maxT = source.Count();
			auto p1Index = (int)Math::Min(t * maxT, maxT - 1.0f);
			auto p0Index = (int)Math::Max(p1Index - 1.0f, 0.0f);
			auto p2Index = (int)Math::Min(p1Index + 1.0f, maxT - 1.0f);
			auto p3Index = (int)Math::Min(p2Index + 1.0f, maxT - 1.0f);

			p1 = source[p1Index];
			p2 = p1Index == p2Index ? p1 + (p1 - source[p0Index]) : source[p2Index];
			p0 = p0Index == p1Index ? p1 - (p2 - p1) : source[p0Index];
			p3 = p3Index == p2Index ? p1 + (p2 - p1) : source[p3Index];

			t = (t - (1.0f / maxT * p1Index)) / (1.0f / maxT);
		}

		static float Spline(float p0, float p1, float p2, float p3, float t);
		static vec3 Spline(const vec3& p0, const vec3& p1, const vec3& p2, const vec3& p3, float t);


	private:
		List<vec3> points;
		List<float> rotation;
		List<float> scale;
	};
}