/*      _______   __   __   __   ______   __   __   _______   __   __
 *     / _____/\ / /\ / /\ / /\ / ____/\ / /\ / /\ / ___  /\ /  |\/ /\
 *    / /\____\// / // / // / // /\___\// /_// / // /\_/ / // , |/ / /
 *   / / /__   / / // / // / // / /    / ___  / // ___  / // /| ' / /
 *  / /_// /\ / /_// / // / // /_/_   / / // / // /\_/ / // / |  / /
 * /______/ //______/ //_/ //_____/\ /_/ //_/ //_/ //_/ //_/ /|_/ /
 * \______\/ \______\/ \_\/ \_____\/ \_\/ \_\/ \_\/ \_\/ \_\/ \_\/
 *
 * Copyright (c) 2004, 2005, 2006, 2007 Olof Naessén and Per Larsson
 *
 *                                                         Js_./
 * Per Larsson a.k.a finalman                          _RqZ{a<^_aa
 * Olof Naessén a.k.a jansem/yakslem                _asww7!uY`>  )\a//
 *                                                 _Qhm`] _f "'c  1!5m
 * Visit: http://guichan.darkbits.org             )Qk<P ` _: :+' .'  "{[
 *                                               .)j(] .d_/ '-(  P .   S
 * License: (BSD)                                <Td/Z <fP"5(\"??"\a.  .L
 * Redistribution and use in source and          _dV>ws?a-?'      ._/L  #'
 * binary forms, with or without                 )4d[#7r, .   '     )d`)[
 * modification, are permitted provided         _Q-5'5W..j/?'   -?!\)cam'
 * that the following conditions are met:       j<<WP+k/);.        _W=j f
 * 1. Redistributions of source code must       .$%w\/]Q  . ."'  .  mj$
 *    retain the above copyright notice,        ]E.pYY(Q]>.   a     J@\
 *    this list of conditions and the           j(]1u<sE"L,. .   ./^ ]{a
 *    following disclaimer.                     4'_uomm\.  )L);-4     (3=
 * 2. Redistributions in binary form must        )_]X{Z('a_"a7'<a"a,  ]"[
 *    reproduce the above copyright notice,       #}<]m7`Za??4,P-"'7. ).m
 *    this list of conditions and the            ]d2e)Q(<Q(  ?94   b-  LQ/
 *    following disclaimer in the                <B!</]C)d_, '(<' .f. =C+m
 *    documentation and/or other materials      .Z!=J ]e []('-4f _ ) -.)m]'
 *    provided with the distribution.          .w[5]' _[ /.)_-"+?   _/ <W"
 * 3. Neither the name of Guichan nor the      :$we` _! + _/ .        j?
 *    names of its contributors may be used     =3)= _f  (_yQmWW$#(    "
 *    to endorse or promote products derived     -   W,  sQQQQmZQ#Wwa]..
 *    from this software without specific        (js, \[QQW$QWW#?!V"".
 *    prior written permission.                    ]y:.<\..          .
 *                                                 -]n w/ '         [.
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT       )/ )/           !
 * HOLDERS AND CONTRIBUTORS "AS IS" AND ANY         <  (; sac    ,    '
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 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF            c <   r
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 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE          5%  )P'-3L
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR        _bQf` y`..)a
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 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES               _Pa,)!f/<[]/  ?"
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT      _2-..:. .r+_,.. .
 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,     ?a.<%"'  " -'.a_ _,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION)                     ^
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
 * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * For comments regarding functions please see the header file.
 */

#include "guisan/focushandler.hpp"

#include "guisan/focuslistener.hpp"
#include "guisan/exception.hpp"
#include "guisan/widget.hpp"

namespace gcn
{
	FocusHandler::FocusHandler()
		: mFocusedWidget(nullptr),
		  mModalFocusedWidget(nullptr),
		  mModalMouseInputFocusedWidget(nullptr),
		  mDraggedWidget(nullptr),
		  mLastWidgetWithMouse(nullptr),
		  mLastWidgetWithModalFocus(nullptr),
		  mLastWidgetWithModalMouseInputFocus(nullptr),
		  mLastWidgetPressed(nullptr)
	{
	}

	void FocusHandler::requestFocus(Widget* widget)
	{
		if (widget == nullptr
			|| widget == mFocusedWidget)
		{
			return;
		}

		auto toBeFocusedIndex = -1;
		for (unsigned int i = 0; i < mWidgets.size(); ++i)
		{
			if (mWidgets[i] == widget)
			{
				toBeFocusedIndex = i;
				break;
			}
		}

		if (toBeFocusedIndex < 0)
		{
			throw GCN_EXCEPTION("Trying to focus a none existing widget.");
		}

		auto* oldFocused = mFocusedWidget;

		if (oldFocused != widget)
		{
			mFocusedWidget = mWidgets.at(toBeFocusedIndex);

			if (oldFocused != nullptr)
			{
				const Event focusEvent(oldFocused);
				distributeFocusLostEvent(focusEvent);
			}

			const Event focusEvent(mWidgets.at(toBeFocusedIndex));
			distributeFocusGainedEvent(focusEvent);
		}
	}

	void FocusHandler::requestModalFocus(Widget* widget)
	{
		if (mModalFocusedWidget != nullptr && mModalFocusedWidget != widget)
		{
			throw GCN_EXCEPTION("Another widget already has modal focus.");
		}

		mModalFocusedWidget = widget;

		if (mFocusedWidget != nullptr && !mFocusedWidget->hasModalFocus())
		{
			focusNone();
		}
	}

	void FocusHandler::requestModalMouseInputFocus(Widget* widget)
	{
		if (mModalMouseInputFocusedWidget != nullptr
			&& mModalMouseInputFocusedWidget != widget)
		{
			throw GCN_EXCEPTION("Another widget already has modal input focus.");
		}

		mModalMouseInputFocusedWidget = widget;
	}

	void FocusHandler::releaseModalFocus(Widget* widget)
	{
		if (mModalFocusedWidget == widget)
		{
			mModalFocusedWidget = nullptr;
		}
	}

	void FocusHandler::releaseModalMouseInputFocus(Widget* widget)
	{
		if (mModalMouseInputFocusedWidget == widget)
		{
			mModalMouseInputFocusedWidget = nullptr;
		}
	}

	Widget* FocusHandler::getFocused() const
	{
		return mFocusedWidget;
	}

	Widget* FocusHandler::getModalFocused() const
	{
		return mModalFocusedWidget;
	}

	Widget* FocusHandler::getModalMouseInputFocused() const
	{
		return mModalMouseInputFocusedWidget;
	}

	void FocusHandler::focusNext()
	{
		int i;
		auto focusedWidget = -1;
		for (i = 0; i < static_cast<int>(mWidgets.size()); ++i)
		{
			if (mWidgets[i] == mFocusedWidget)
			{
				focusedWidget = i;
			}
		}
		const auto focused = focusedWidget;

		// i is a counter that ensures that the following loop
		// won't get stuck in an infinite loop
		i = static_cast<int>(mWidgets.size());
		do
		{
			++focusedWidget;

			if (i == 0)
			{
				focusedWidget = -1;
				break;
			}

			--i;

			if (focusedWidget >= static_cast<int>(mWidgets.size()))
			{
				focusedWidget = 0;
			}

			if (focusedWidget == focused)
			{
				return;
			}
		}
		while (!mWidgets.at(focusedWidget)->isFocusable());

		if (focusedWidget >= 0)
		{
			mFocusedWidget = mWidgets.at(focusedWidget);

			const Event focusEvent(mFocusedWidget);
			distributeFocusGainedEvent(focusEvent);
		}

		if (focused >= 0)
		{
			const Event focusEvent(mWidgets.at(focused));
			distributeFocusLostEvent(focusEvent);
		}
	}

	void FocusHandler::focusPrevious()
	{
		if (mWidgets.empty())
		{
			mFocusedWidget = nullptr;
			return;
		}

		int i;
		auto focusedWidget = -1;
		for (i = 0; i < static_cast<int>(mWidgets.size()); ++i)
		{
			if (mWidgets[i] == mFocusedWidget)
			{
				focusedWidget = i;
			}
		}
		const auto focused = focusedWidget;

		// i is a counter that ensures that the following loop
		// won't get stuck in an infinite loop
		i = static_cast<int>(mWidgets.size());
		do
		{
			--focusedWidget;

			if (i == 0)
			{
				focusedWidget = -1;
				break;
			}

			--i;

			if (focusedWidget <= 0)
			{
				focusedWidget = mWidgets.size() - 1;
			}

			if (focusedWidget == focused)
			{
				return;
			}
		}
		while (!mWidgets.at(focusedWidget)->isFocusable());

		if (focusedWidget >= 0)
		{
			mFocusedWidget = mWidgets.at(focusedWidget);
			const Event focusEvent(mFocusedWidget);
			distributeFocusGainedEvent(focusEvent);
		}

		if (focused >= 0)
		{
			const Event focusEvent(mWidgets.at(focused));
			distributeFocusLostEvent(focusEvent);
		}
	}

	bool FocusHandler::isFocused(const Widget* widget) const
	{
		return mFocusedWidget == widget;
	}

	void FocusHandler::add(Widget* widget)
	{
		mWidgets.push_back(widget);
	}

	void FocusHandler::remove(Widget* widget)
	{
		if (isFocused(widget))
		{
			mFocusedWidget = nullptr;
		}

		for (auto iter = mWidgets.begin(); iter != mWidgets.end(); ++iter)
		{
			if (*iter == widget)
			{
				mWidgets.erase(iter);
				break;
			}
		}

		if (mDraggedWidget == widget)
		{
			mDraggedWidget = nullptr;
			return;
		}

		if (mLastWidgetWithMouse == widget)
		{
			mLastWidgetWithMouse = nullptr;
			return;
		}

		if (mLastWidgetWithModalFocus == widget)
		{
			mLastWidgetWithModalFocus = nullptr;
			return;
		}

		if (mLastWidgetWithModalMouseInputFocus == widget)
		{
			mLastWidgetWithModalMouseInputFocus = nullptr;
			return;
		}

		if (mLastWidgetPressed == widget)
		{
			mLastWidgetPressed = nullptr;
		}
	}

	void FocusHandler::focusNone()
	{
		if (mFocusedWidget != nullptr)
		{
			auto* const focused = mFocusedWidget;
			mFocusedWidget = nullptr;

			const Event focusEvent(focused);
			distributeFocusLostEvent(focusEvent);
		}
	}

	void FocusHandler::tabNext()
	{
		if (mFocusedWidget != nullptr)
		{
			if (!mFocusedWidget->isTabOutEnabled())
			{
				return;
			}
		}

		if (mWidgets.empty())
		{
			mFocusedWidget = nullptr;
			return;
		}

		int i;
		auto focusedWidget = -1;
		for (i = 0; i < static_cast<int>(mWidgets.size()); ++i)
		{
			if (mWidgets[i] == mFocusedWidget)
			{
				focusedWidget = i;
			}
		}
		const auto focused = focusedWidget;
		auto done = false;

		// i is a counter that ensures that the following loop
		// won't get stuck in an infinite loop
		i = static_cast<int>(mWidgets.size());
		do
		{
			++focusedWidget;

			if (i == 0)
			{
				focusedWidget = -1;
				break;
			}

			--i;

			if (focusedWidget >= static_cast<int>(mWidgets.size()))
			{
				focusedWidget = 0;
			}

			if (focusedWidget == focused)
			{
				return;
			}

			if (mWidgets.at(focusedWidget)->isFocusable() &&
				mWidgets.at(focusedWidget)->isTabInEnabled() &&
				(mModalFocusedWidget == nullptr ||
					mWidgets.at(focusedWidget)->hasModalFocus()))
			{
				done = true;
			}
		}
		while (!done);

		if (focusedWidget >= 0)
		{
			mFocusedWidget = mWidgets.at(focusedWidget);
			const Event focusEvent(mFocusedWidget);
			distributeFocusGainedEvent(focusEvent);
		}

		if (focused >= 0)
		{
			const Event focusEvent(mWidgets.at(focused));
			distributeFocusLostEvent(focusEvent);
		}
	}

	void FocusHandler::tabPrevious()
	{
		if (mFocusedWidget != nullptr)
		{
			if (!mFocusedWidget->isTabOutEnabled())
			{
				return;
			}
		}

		if (mWidgets.empty())
		{
			mFocusedWidget = nullptr;
			return;
		}

		int i;
		auto focusedWidget = -1;
		for (i = 0; i < static_cast<int>(mWidgets.size()); ++i)
		{
			if (mWidgets[i] == mFocusedWidget)
			{
				focusedWidget = i;
			}
		}
		const auto focused = focusedWidget;
		auto done = false;

		// i is a counter that ensures that the following loop
		// won't get stuck in an infinite loop
		i = static_cast<int>(mWidgets.size());
		do
		{
			--focusedWidget;

			if (i == 0)
			{
				focusedWidget = -1;
				break;
			}

			--i;

			if (focusedWidget <= 0)
			{
				focusedWidget = mWidgets.size() - 1;
			}

			if (focusedWidget == focused)
			{
				return;
			}

			if (mWidgets.at(focusedWidget)->isFocusable() &&
				mWidgets.at(focusedWidget)->isTabInEnabled() &&
				(mModalFocusedWidget == nullptr ||
					mWidgets.at(focusedWidget)->hasModalFocus()))
			{
				done = true;
			}
		}
		while (!done);

		if (focusedWidget >= 0)
		{
			mFocusedWidget = mWidgets.at(focusedWidget);
			const Event focusEvent(mFocusedWidget);
			distributeFocusGainedEvent(focusEvent);
		}

		if (focused >= 0)
		{
			const Event focusEvent(mWidgets.at(focused));
			distributeFocusLostEvent(focusEvent);
		}
	}

	void FocusHandler::distributeFocusLostEvent(const Event& focusEvent)
	{
		auto* sourceWidget = focusEvent.getSource();

		auto focusListeners = sourceWidget->_getFocusListeners();

		// Send the event to all focus listeners of the widget.
		for (auto& focusListener : focusListeners)
		{
			focusListener->focusLost(focusEvent);
		}
	}

	void FocusHandler::distributeFocusGainedEvent(const Event& focusEvent)
	{
		auto sourceWidget = focusEvent.getSource();

		auto focusListeners = sourceWidget->_getFocusListeners();

		// Send the event to all focus listeners of the widget.
		for (auto& focusListener : focusListeners)
		{
			focusListener->focusGained(focusEvent);
		}
	}

	Widget* FocusHandler::getDraggedWidget()
	{
		return mDraggedWidget;
	}

	void FocusHandler::setDraggedWidget(Widget* draggedWidget)
	{
		mDraggedWidget = draggedWidget;
	}

	Widget* FocusHandler::getLastWidgetWithMouse()
	{
		return mLastWidgetWithMouse;
	}

	void FocusHandler::setLastWidgetWithMouse(Widget* lastWidgetWithMouse)
	{
		mLastWidgetWithMouse = lastWidgetWithMouse;
	}

	Widget* FocusHandler::getLastWidgetWithModalFocus()
	{
		return mLastWidgetWithModalFocus;
	}

	void FocusHandler::setLastWidgetWithModalFocus(Widget* lastWidgetWithModalFocus)
	{
		mLastWidgetWithModalFocus = lastWidgetWithModalFocus;
	}

	Widget* FocusHandler::getLastWidgetWithModalMouseInputFocus()
	{
		return mLastWidgetWithModalMouseInputFocus;
	}

	void FocusHandler::setLastWidgetWithModalMouseInputFocus(Widget* lastWidgetWithModalMouseInputFocus)
	{
		mLastWidgetWithModalMouseInputFocus = lastWidgetWithModalMouseInputFocus;
	}

	Widget* FocusHandler::getLastWidgetPressed()
	{
		return mLastWidgetPressed;
	}

	void FocusHandler::setLastWidgetPressed(Widget* lastWidgetPressed)
	{
		mLastWidgetPressed = lastWidgetPressed;
	}
}