#include "KCircle.h"

#include <SDL_rect.h>
#include <stdexcept>

#include "KRect.h"
#include "Utils.h"

namespace KapitanGame {

	bool KCircle::IsCollision(const KCircle* other) const {
		return (GetParent()->GetPosition() - other->GetParent()->GetPosition()).Length() < Radius + other->Radius;
	}

	bool KCircle::IsCollision(const KCollider* other) const
	{
		if (const auto circle = dynamic_cast<const KCircle*>(other); circle != nullptr)
			return IsCollision(circle);


		if (const auto rect = dynamic_cast<const KRect*>(other); rect != nullptr)
			return IsCollision(rect);

		throw std::runtime_error("unsupported shape");
	}

	KVector2D KCircle::GetSeparationVector(const KCollider* other) const
	{
		if (const auto circle = dynamic_cast<const KCircle*>(other); circle != nullptr)
			return GetSeparationVector(circle);

		if (const auto rect = dynamic_cast<const KRect*>(other); rect != nullptr)
			return GetSeparationVector(rect);

		throw std::runtime_error("unsupported shape");
	}

	bool KCircle::IsCollision(const KRect* other) const {
		const auto f = KVector2D(Utils::Clamp(GetParent()->GetPosition().X, other->GetParent()->GetPosition().X - other->GetWidth() / 2, other->GetParent()->GetPosition().X + other->GetWidth() / 2),
			Utils::Clamp(GetParent()->GetPosition().Y, other->GetParent()->GetPosition().Y - other->GetHeight() / 2, other->GetParent()->GetPosition().Y + other->GetHeight() / 2));

		return (GetParent()->GetPosition() - f).Length() < Radius;
	}

	KVector2D KCircle::GetSeparationVector(const KCircle* other) const {
		const KVector2D centerDiff = GetParent()->GetPosition() - other->GetParent()->GetPosition();
		const float centerDiffLength = centerDiff.Length();
		return centerDiff / centerDiffLength * (Radius + other->Radius - centerDiffLength);
	}

	KVector2D KCircle::GetSeparationVector(const KRect* other) const {
		const float l = other->GetParent()->GetPosition().X - other->GetWidth() / 2;
		const float r = other->GetParent()->GetPosition().X + other->GetWidth() / 2;
		const float t = other->GetParent()->GetPosition().Y - other->GetHeight() / 2;
		const float b = other->GetParent()->GetPosition().Y + other->GetHeight() / 2;
		const auto f = KVector2D(Utils::Clamp(GetParent()->GetPosition().X, l, r),
			Utils::Clamp(GetParent()->GetPosition().Y, t, b));

		if (GetParent()->GetPosition() == f) {
			const auto left = GetParent()->GetPosition().X - l + Radius;
			const auto right = r - GetParent()->GetPosition().X + Radius;
			const auto top = GetParent()->GetPosition().Y - t + Radius;
			const auto bottom = b - GetParent()->GetPosition().Y + Radius;
			return KRect::GetSeparationVector(left, right, top, bottom);
		}
		return (GetParent()->GetPosition() - f) / (GetParent()->GetPosition() - f).Length() * (Radius - (GetParent()->GetPosition() - f).Length());
	}

	KVector2D KCircle::GetSeparationVector(const SDL_FRect& map) const {
		KVector2D separationVector{ 0.f,0.f };
		if (GetParent()->GetPosition().X - map.x - Radius < 0)
		{
			separationVector.X += -(GetParent()->GetPosition().X - map.x - Radius);
		}
		if (GetParent()->GetPosition().X + Radius - (map.x + map.w) > 0)
		{
			separationVector.X += -(GetParent()->GetPosition().X - (map.x+map.w) + Radius);
		}
		if (GetParent()->GetPosition().Y - Radius - map.y < 0) {
			separationVector.Y += -(GetParent()->GetPosition().Y - map.y - Radius);
		}
		if (GetParent()->GetPosition().Y + Radius - (map.y + map.h) > 0) {
			separationVector.Y += -(GetParent()->GetPosition().Y - (map.y + map.h) + Radius);
		}
		return separationVector;
	}

	float KCircle::GetWidth() const
	{
		return Radius * 2;
	}

	float KCircle::GetHeight() const
	{
		return Radius * 2;
	}

	KCircle::KCircle(KSolid* parent, const float radius): KCollider(parent),
	                                                       Radius(radius)
	{
	}

	float KCircle::GetRadius() const {
		return Radius;
	}

}