// Copyright (c) 2016-2018 Kiwano - Nomango
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

#include "Transition.h"
#include "Actor.h"
#include "Stage.h"
#include "../base/Window.h"
#include "../base/Logger.h"
#include "../renderer/Renderer.h"

namespace kiwano
{
	//-------------------------------------------------------
	// Transition
	//-------------------------------------------------------

	Transition::Transition(Duration duration)
		: done_(false)
		, duration_(duration)
		, delta_()
		, process_(0)
		, window_size_()
		, out_stage_(nullptr)
		, in_stage_(nullptr)
		, out_layer_()
		, in_layer_()
	{
	}

	Transition::~Transition()
	{
	}

	bool Transition::IsDone()
	{
		return done_;
	}

	void Transition::Init(StagePtr prev, StagePtr next)
	{
		process_ = 0;
		delta_ = Duration{};

		out_stage_ = prev;
		in_stage_ = next;
		window_size_ = Renderer::GetInstance()->GetOutputSize();

		if (in_stage_)
		{
			in_layer_.SetAreaRect(Rect{ Point(), window_size_ });
		}

		if (out_stage_)
		{
			out_layer_.SetAreaRect(Rect{ Point(), window_size_ });
		}
	}

	void Transition::Update(Duration dt)
	{
		if (duration_.IsZero())
		{
			process_ = 1;
		}
		else
		{
			delta_ += dt;
			process_ = std::min(delta_ / duration_, 1.f);
		}

		if (process_ >= 1)
		{
			this->Stop();
		}
	}

	void Transition::Render(RenderTarget* rt)
	{
		if (out_stage_)
		{
			out_stage_->PrepareRender(rt);
			rt->PushClipRect(Rect{ Point{}, window_size_ });
			rt->PushLayer(out_layer_);

			out_stage_->Render(rt);

			rt->PopLayer();
			rt->PopClipRect();
		}

		if (in_stage_)
		{
			in_stage_->PrepareRender(rt);
			rt->PushClipRect(Rect{ Point{}, window_size_ });
			rt->PushLayer(in_layer_);

			in_stage_->Render(rt);

			rt->PopLayer();
			rt->PopClipRect();
		}
	}

	void Transition::Stop()
	{
		done_ = true;
		Reset();
	}

	//-------------------------------------------------------
	// BoxTransition
	//-------------------------------------------------------

	BoxTransition::BoxTransition(Duration duration)
		: Transition(duration)
	{
	}

	void BoxTransition::Init(StagePtr prev, StagePtr next)
	{
		Transition::Init(prev, next);

		in_layer_.SetOpacity(0.f);
	}

	void BoxTransition::Update(Duration dt)
	{
		Transition::Update(dt);

		if (process_ < .5f)
		{
			out_layer_.SetAreaRect(
				Rect(
					window_size_.x * process_,
					window_size_.y * process_,
					window_size_.x * (1 - process_),
					window_size_.y * (1 - process_)
				)
			);
		}
		else
		{
			out_layer_.SetOpacity(0.f);
			in_layer_.SetOpacity(1.f);
			in_layer_.SetAreaRect(
				Rect(
					window_size_.x * (1 - process_),
					window_size_.y * (1 - process_),
					window_size_.x * process_,
					window_size_.y * process_
				)
			);
		}
	}

	//-------------------------------------------------------
	// EmergeTransition
	//-------------------------------------------------------

	EmergeTransition::EmergeTransition(Duration duration)
		: Transition(duration)
	{
	}

	void EmergeTransition::Init(StagePtr prev, StagePtr next)
	{
		Transition::Init(prev, next);

		out_layer_.SetOpacity(1.f);
		in_layer_.SetOpacity(0.f);
	}

	void EmergeTransition::Update(Duration dt)
	{
		Transition::Update(dt);

		out_layer_.SetOpacity(1 - process_);
		in_layer_.SetOpacity(process_);
	}

	//-------------------------------------------------------
	// FadeTransition
	//-------------------------------------------------------

	FadeTransition::FadeTransition(Duration duration)
		: Transition(duration)
	{
	}

	void FadeTransition::Init(StagePtr prev, StagePtr next)
	{
		Transition::Init(prev, next);

		out_layer_.SetOpacity(1.f);
		in_layer_.SetOpacity(0.f);
	}

	void FadeTransition::Update(Duration dt)
	{
		Transition::Update(dt);

		if (process_ < 0.5)
		{
			out_layer_.SetOpacity(1 - process_ * 2);
			in_layer_.SetOpacity(0.f);
		}
		else
		{
			out_layer_.SetOpacity(0.f);
			in_layer_.SetOpacity((process_ - 0.5f) * 2);
		}
	}

	//-------------------------------------------------------
	// MoveTransition
	//-------------------------------------------------------

	MoveTransition::MoveTransition(Duration duration, Type type)
		: Transition(duration)
		, type_(type)
	{
	}

	void MoveTransition::Init(StagePtr prev, StagePtr next)
	{
		Transition::Init(prev, next);

		switch (type_)
		{
		case Type::Up:
			pos_delta_ = Point(0, -window_size_.y);
			start_pos_ = Point(0, window_size_.y);
			break;
		case Type::Down:
			pos_delta_ = Point(0, window_size_.y);
			start_pos_ = Point(0, -window_size_.y);
			break;
		case Type::Left:
			pos_delta_ = Point(-window_size_.x, 0);
			start_pos_ = Point(window_size_.x, 0);
			break;
		case Type::Right:
			pos_delta_ = Point(window_size_.x, 0);
			start_pos_ = Point(-window_size_.x, 0);
			break;
		}

		if (out_stage_)
		{
			out_stage_->SetTransform(Transform{});
		}

		if (in_stage_)
		{
			auto transform = Transform{};
			transform.position = start_pos_;
			in_stage_->SetTransform(transform);
		}
	}

	void MoveTransition::Update(Duration dt)
	{
		Transition::Update(dt);

		if (out_stage_)
		{
			auto transform = Transform{};
			transform.position = pos_delta_ * process_;
			out_stage_->SetTransform(transform);
		}

		if (in_stage_)
		{
			auto transform = Transform{};
			transform.position = start_pos_ + pos_delta_ * process_;
			in_stage_->SetTransform(transform);
		}
	}

	void MoveTransition::Reset()
	{
		if (out_stage_)
		{
			out_stage_->SetTransform(Transform{});
		}

		if (in_stage_)
		{
			in_stage_->SetTransform(Transform{});
		}
	}

	//-------------------------------------------------------
	// RotationTransition
	//-------------------------------------------------------

	RotationTransition::RotationTransition(Duration duration, Float32 rotation)
		: Transition(duration)
		, rotation_(rotation)
	{
	}

	void RotationTransition::Init(StagePtr prev, StagePtr next)
	{
		Transition::Init(prev, next);

		auto transform = Transform{};
		transform.position = Point{ window_size_.x / 2, window_size_.y / 2 };

		if (out_stage_)
		{
			out_stage_->SetTransform(transform);
			out_stage_->SetAnchor(Vec2{ 0.5f, 0.5f });
		}

		if (in_stage_)
		{
			in_stage_->SetTransform(transform);
			in_stage_->SetAnchor(Vec2{ 0.5f, 0.5f });
		}

		in_layer_.SetOpacity(0.f);
	}

	void RotationTransition::Update(Duration dt)
	{
		Transition::Update(dt);

		if (process_ < .5f)
		{
			if (out_stage_)
			{
				auto transform = out_stage_->GetTransform();
				transform.scale = Point{ (.5f - process_) * 2, (.5f - process_) * 2 };
				transform.rotation = rotation_ * (.5f - process_) * 2;
				out_stage_->SetTransform(transform);
			}
		}
		else
		{
			if (in_stage_)
			{
				out_layer_.SetOpacity(0.f);
				in_layer_.SetOpacity(1.f);

				auto transform = in_stage_->GetTransform();
				transform.scale = Point{ (process_ - .5f) * 2, (process_ - .5f) * 2 };
				transform.rotation = rotation_ * (process_ - .5f) * 2;

				in_stage_->SetTransform(transform);
			}
		}
	}

	void RotationTransition::Reset()
	{
		if (out_stage_)
		{
			out_stage_->SetTransform(Transform{});
			out_stage_->SetAnchor(Vec2{ 0.f, 0.f });
		}

		if (in_stage_)
		{
			in_stage_->SetTransform(Transform{});
			in_stage_->SetAnchor(Vec2{ 0.f, 0.f });
		}
	}
}