#include "KRect.h"

#include "KCircle.h"
#include "Utils.h"

namespace KapitanGame {

	float KRect::GetWidth() const {
		return Width;
	}

	float KRect::GetHeight() const {
		return Height;
	}

	KVector2D KRect::GetSeparationVector(const float left, const float right, const float top, const float bottom) {
		const auto x = left < right ? -left : right;
		const auto y = top < bottom ? -top : bottom;
		auto vX = x;
		auto vY = y;
		if (fabs(x) < fabs(y))
			vY = 0;
		if (fabs(x) > fabs(y))
			vX = 0;
		return { vX, vY };
	}

	KVector2D KRect::GetSeparationVector(const KCircle* other) const {
		const float l = GetLeft();
		const float r = GetRight();
		const float t = GetTop();
		const float b = GetBottom();
		const auto f = KVector2D(Utils::Clamp(other->GetParent()->GetPosition().X, l, r),
			Utils::Clamp(other->GetParent()->GetPosition().Y, t, b));

		if (other->GetParent()->GetPosition() == f) {
			const auto left = other->GetParent()->GetPosition().X - l + other->GetRadius();
			const auto right = r - other->GetParent()->GetPosition().X + other->GetRadius();
			const auto top = other->GetParent()->GetPosition().Y - t + other->GetRadius();
			const auto bottom = b - other->GetParent()->GetPosition().Y + other->GetRadius();
			return GetSeparationVector(left, right, top, bottom) * -1.f;
		}
		return (other->GetParent()->GetPosition() - f) / (other->GetParent()->GetPosition() - f).Length() * (other->GetRadius() - (other->GetParent()->GetPosition() - f).Length()) * 1.f;
	}

	KVector2D KRect::GetSeparationVector(const KRect* other) const {
		const auto left = GetRight() - other->GetLeft();
		const auto right = other->GetRight() - GetLeft();
		const auto top = GetBottom() - other->GetTop();
		const auto bottom = other->GetBottom() - GetTop();

		return GetSeparationVector(left, right, top, bottom);
	}

	bool KRect::IsCollision(const KCircle* other) const {
		const auto f = KVector2D(Utils::Clamp(other->GetParent()->GetPosition().X, GetLeft(), GetRight()),
			Utils::Clamp(other->GetParent()->GetPosition().Y, GetTop(), GetBottom()));

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

	float KRect::GetLeft() const
	{
		return GetParent()->GetPosition().X - Width / 2;
	}

	float KRect::GetRight() const
	{
		return GetParent()->GetPosition().X + Width / 2;
	}

	float KRect::GetBottom() const
	{
		return GetParent()->GetPosition().Y + Height / 2;
	}

	float KRect::GetTop() const
	{
		return GetParent()->GetPosition().Y - Height / 2;
	}

	bool KRect::IsCollision(const KRect* other) const {
		return GetRight() >= other->GetLeft()
			&& other->GetRight() >= GetLeft()
			&& GetBottom() >= other->GetTop()
			&& other->GetBottom() >= GetTop();
	}

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

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

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

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

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

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

	KVector2D KRect::GetSeparationVector(const SDL_FRect& map) const
	{
		KVector2D separationVector{ 0.f,0.f };
		if (GetParent()->GetPosition().X - map.x - GetWidth() / 2 < 0)
		{
			separationVector.X += -(GetParent()->GetPosition().X - map.x - GetWidth() / 2);
		}
		if (GetParent()->GetPosition().X + GetWidth() / 2 - (map.x + map.w) > 0)
		{
			separationVector.X += -(GetParent()->GetPosition().X - (map.x + map.w) + GetWidth() / 2);
		}
		if (GetParent()->GetPosition().Y - GetHeight() / 2 - map.y < 0) {
			separationVector.Y += -(GetParent()->GetPosition().Y - map.y - GetHeight() / 2);
		}
		if (GetParent()->GetPosition().Y + GetHeight() / 2 - (map.y + map.h) > 0) {
			separationVector.Y += -(GetParent()->GetPosition().Y - (map.y + map.h) + GetHeight() / 2);
		}
		return separationVector;
	}
}