/*!
	@file
	@author		Albert Semenov
	@date		11/2007
	@module
*/
/*
	This file is part of MyGUI.

	MyGUI is free software: you can redistribute it and/or modify
	it under the terms of the GNU Lesser General Public License as published by
	the Free Software Foundation, either version 3 of the License, or
	(at your option) any later version.

	MyGUI is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU Lesser General Public License for more details.

	You should have received a copy of the GNU Lesser General Public License
	along with MyGUI.  If not, see <http://www.gnu.org/licenses/>.
*/
#include "MyGUI_Precompiled.h"
#include "MyGUI_VScroll.h"
#include "MyGUI_InputManager.h"
#include "MyGUI_Button.h"
#include "MyGUI_ResourceSkin.h"

namespace MyGUI
{

	const int SCROLL_MOUSE_WHEEL = 50; // колличество пикселей для колеса мыши

	VScroll::VScroll() :
		mWidgetStart(nullptr),
		mWidgetEnd(nullptr),
		mWidgetTrack(nullptr),
		mWidgetFirstPart(nullptr),
		mWidgetSecondPart(nullptr),
		mSkinRangeStart(0),
		mSkinRangeEnd(0),
		mScrollRange(0),
		mScrollPosition(0),
		mScrollPage(0),
		mScrollViewPage(0),
		mMinTrackSize(0),
		mMoveToClick(false)
	{
	}

	void VScroll::_initialise(WidgetStyle _style, const IntCoord& _coord, Align _align, ResourceSkin* _info, Widget* _parent, ICroppedRectangle * _croppedParent, IWidgetCreator * _creator, const std::string& _name)
	{
		Base::_initialise(_style, _coord, _align, _info, _parent, _croppedParent, _creator, _name);

		initialiseWidgetSkin(_info);
	}

	VScroll::~VScroll()
	{
		shutdownWidgetSkin();
	}

	void VScroll::baseChangeWidgetSkin(ResourceSkin* _info)
	{
		shutdownWidgetSkin();
		Base::baseChangeWidgetSkin(_info);
		initialiseWidgetSkin(_info);
	}

	void VScroll::initialiseWidgetSkin(ResourceSkin* _info)
	{
		// при нуле, будет игнорировать кнопки
		mScrollPage = 1;
		mScrollViewPage = 1;

		for (VectorWidgetPtr::iterator iter = mWidgetChildSkin.begin(); iter!=mWidgetChildSkin.end(); ++iter)
		{
			if (*(*iter)->_getInternalData<std::string>() == "Start")
			{
				MYGUI_DEBUG_ASSERT( ! mWidgetStart, "widget already assigned");
				mWidgetStart = (*iter)->castType<Button>();
				mWidgetStart->eventMouseButtonPressed = newDelegate(this, &VScroll::notifyMousePressed);
				mWidgetStart->eventMouseWheel = newDelegate(this, &VScroll::notifyMouseWheel);
			}
			else if (*(*iter)->_getInternalData<std::string>() == "End")
			{
				MYGUI_DEBUG_ASSERT( ! mWidgetEnd, "widget already assigned");
				mWidgetEnd = (*iter)->castType<Button>();
				mWidgetEnd->eventMouseButtonPressed = newDelegate(this, &VScroll::notifyMousePressed);
				mWidgetEnd->eventMouseWheel = newDelegate(this, &VScroll::notifyMouseWheel);
			}
			else if (*(*iter)->_getInternalData<std::string>() == "Track")
			{
				MYGUI_DEBUG_ASSERT( ! mWidgetTrack, "widget already assigned");
				mWidgetTrack = (*iter)->castType<Button>();
				mWidgetTrack->eventMouseDrag = newDelegate(this, &VScroll::notifyMouseDrag);
				mWidgetTrack->eventMouseButtonPressed = newDelegate(this, &VScroll::notifyMousePressed);
				mWidgetTrack->eventMouseButtonReleased = newDelegate(this, &VScroll::notifyMouseReleased);
				mWidgetTrack->eventMouseWheel = newDelegate(this, &VScroll::notifyMouseWheel);
				mWidgetTrack->setVisible(false);
			}
			else if (*(*iter)->_getInternalData<std::string>() == "FirstPart")
			{
				MYGUI_DEBUG_ASSERT( ! mWidgetFirstPart, "widget already assigned");
				mWidgetFirstPart = (*iter)->castType<Button>();
				mWidgetFirstPart->eventMouseButtonPressed = newDelegate(this, &VScroll::notifyMousePressed);
				mWidgetFirstPart->eventMouseWheel = newDelegate(this, &VScroll::notifyMouseWheel);
			}
			else if (*(*iter)->_getInternalData<std::string>() == "SecondPart")
			{
				MYGUI_DEBUG_ASSERT( ! mWidgetSecondPart, "widget already assigned");
				mWidgetSecondPart = (*iter)->castType<Button>();
				mWidgetSecondPart->eventMouseButtonPressed = newDelegate(this, &VScroll::notifyMousePressed);
				mWidgetSecondPart->eventMouseWheel = newDelegate(this, &VScroll::notifyMouseWheel);
			}
		}

		// slider don't have buttons
		//MYGUI_ASSERT(nullptr != mWidgetTrack, "Child Button Track not found in skin (Scroll must have Track)");

		// парсим свойства
		const MapString& properties = _info->getProperties();
		MapString::const_iterator iter = properties.find("TrackRangeMargins");
		if (iter != properties.end())
		{
			IntSize range = IntSize::parse(iter->second);
			mSkinRangeStart = range.width;
			mSkinRangeEnd = range.height;
		}
		else
		{
			mSkinRangeStart = 0;
			mSkinRangeEnd = 0;
		}
		iter = properties.find("MinTrackSize");
		if (iter != properties.end()) mMinTrackSize = utility::parseInt(iter->second);
		else mMinTrackSize = 0;

		iter = properties.find("MoveToClick");
		if (iter != properties.end()) mMoveToClick = utility::parseBool(iter->second);
	}

	void VScroll::shutdownWidgetSkin()
	{
		mWidgetStart = nullptr;
		mWidgetEnd = nullptr;
		mWidgetTrack = nullptr;
		mWidgetFirstPart = nullptr;
		mWidgetSecondPart = nullptr;
	}

	void VScroll::updateTrack()
	{
		if (mWidgetTrack == nullptr)
			return;

		_forcePeek(mWidgetTrack);
		// размер диапазана в пикселях
		int pos = getLineSize();

		// скрываем если диапазан маленький или места мало
		if ((mScrollRange < 2) || (pos <= mWidgetTrack->getHeight()))
		{
			mWidgetTrack->setVisible(false);
			if ( nullptr != mWidgetFirstPart ) mWidgetFirstPart->setSize(mWidgetFirstPart->getWidth(), pos/2);
			if ( nullptr != mWidgetSecondPart ) mWidgetSecondPart->setCoord(mWidgetSecondPart->getLeft(), pos/2 + (int)mSkinRangeStart, mWidgetSecondPart->getWidth(), pos - pos/2);
			return;
		}
		// если скрыт то покажем
		if (!mWidgetTrack->isVisible())
		{
			mWidgetTrack->setVisible(true);
		}

		// и обновляем позицию
		pos = (int)(((size_t)(pos-getTrackSize()) * mScrollPosition) / (mScrollRange-1) + mSkinRangeStart);

		mWidgetTrack->setPosition(mWidgetTrack->getLeft(), pos);
		if ( nullptr != mWidgetFirstPart )
		{
			int height = pos + mWidgetTrack->getHeight()/2 - mWidgetFirstPart->getTop();
			mWidgetFirstPart->setSize(mWidgetFirstPart->getWidth(), height);
		}
		if ( nullptr != mWidgetSecondPart )
		{
			int top = pos + mWidgetTrack->getHeight()/2;
			int height = mWidgetSecondPart->getHeight() + mWidgetSecondPart->getTop() - top;
			mWidgetSecondPart->setCoord(mWidgetSecondPart->getLeft(), top, mWidgetSecondPart->getWidth(), height);
		}
	}

	void VScroll::TrackMove(int _left, int _top)
	{
		if (mWidgetTrack == nullptr)
			return;

		const IntPoint& point = InputManager::getInstance().getLastLeftPressed();

		// расчитываем позицию виджета
		int start = mPreActionOffset.top + (_top - point.top);
		if (start < (int)mSkinRangeStart) start = (int)mSkinRangeStart;
		else if (start > (mCoord.height - (int)mSkinRangeEnd - mWidgetTrack->getHeight())) start = (mCoord.height - (int)mSkinRangeEnd - mWidgetTrack->getHeight());
		if (mWidgetTrack->getTop() != start) mWidgetTrack->setPosition(mWidgetTrack->getLeft(), start);

		// расчитываем положение соответствующее позиции
		// плюс пол позиции
		int pos = start - (int)mSkinRangeStart + (getLineSize() - getTrackSize()) / (((int)mScrollRange-1) * 2);
		// высчитываем ближайшее значение и обновляем
		pos = pos * (int)(mScrollRange-1) / (getLineSize() - getTrackSize());

		// проверяем на выходы и изменения
		if (pos < 0) pos = 0;
		else if (pos >= (int)mScrollRange) pos = (int)mScrollRange - 1;
		if (pos == (int)mScrollPosition) return;

		mScrollPosition = pos;
		// отсылаем событие
		eventScrollChangePosition(this, (int)mScrollPosition);
	}

	void VScroll::notifyMousePressed(Widget* _sender, int _left, int _top, MouseButton _id)
	{
		// диспечерезируем нажатие своих детей как свое
		eventMouseButtonPressed(this, _left, _top, _id);

		if (MouseButton::Left != _id) return;

		if (mMoveToClick && mWidgetTrack != _sender)
		{
			mPreActionOffset = InputManager::getInstance().getLastLeftPressed();
			const IntPoint& point = InputManager::getInstance().getMousePositionByLayer() - getAbsolutePosition();

			TrackMove(point.left, point.top);

		}
		else if (_sender == mWidgetStart)
		{
			// минимальное значение
			if (mScrollPosition == 0) return;

			// расчитываем следующее положение
			if (mScrollPosition > mScrollPage) mScrollPosition -= mScrollPage;
			else mScrollPosition = 0;

			// оповещаем
			eventScrollChangePosition(this, (int)mScrollPosition);
			updateTrack();

		}
		else if (_sender == mWidgetEnd)
		{
			// максимальное значение
			if ( (mScrollRange < 2) || (mScrollPosition >= (mScrollRange-1)) ) return;

			// расчитываем следующее положение
			if ((mScrollPosition + mScrollPage) < (mScrollRange-1)) mScrollPosition += mScrollPage;
			else mScrollPosition = mScrollRange - 1;

			// оповещаем
			eventScrollChangePosition(this, (int)mScrollPosition);
			updateTrack();

		}
		else if (_sender == mWidgetFirstPart)
		{
			// минимальное значение
			if (mScrollPosition == 0) return;

			// расчитываем следующее положение
			if (mScrollPosition > mScrollViewPage) mScrollPosition -= mScrollViewPage;
			else mScrollPosition = 0;

			// оповещаем
			eventScrollChangePosition(this, (int)mScrollPosition);
			updateTrack();

		}
		else if (_sender == mWidgetSecondPart)
		{
			// максимальное значение
			if ( (mScrollRange < 2) || (mScrollPosition >= (mScrollRange-1)) ) return;

			// расчитываем следующее положение
			if ((mScrollPosition + mScrollViewPage) < (mScrollRange-1)) mScrollPosition += mScrollViewPage;
			else mScrollPosition = mScrollRange - 1;

			// оповещаем
			eventScrollChangePosition(this, (int)mScrollPosition);
			updateTrack();

		}
		else if (_sender == mWidgetTrack)
		{
			mPreActionOffset.left = _sender->getLeft();
			mPreActionOffset.top = _sender->getTop();
		}
	}

	void VScroll::notifyMouseReleased(Widget* _sender, int _left, int _top, MouseButton _id)
	{
		updateTrack();
	}

	void VScroll::notifyMouseDrag(Widget* _sender, int _left, int _top)
	{
		TrackMove(_left, _top);
	}

	void VScroll::setScrollRange(size_t _range)
	{
		if (_range == mScrollRange) return;
		mScrollRange = _range;
		mScrollPosition = (mScrollPosition < mScrollRange) ? mScrollPosition : 0;
		updateTrack();
	}

	void VScroll::setScrollPosition(size_t _position)
	{
		if (_position == mScrollPosition) return;
		if (_position >= mScrollRange) _position = 0;
		mScrollPosition = _position;
		updateTrack();
	}

	void VScroll::setPosition(const IntPoint& _point)
	{
		Base::setPosition(_point);
	}

	void VScroll::setSize(const IntSize& _size)
	{
		Base::setSize(_size);
		// обновляем трек
		updateTrack();
	}

	void VScroll::setCoord(const IntCoord& _coord)
	{
		Base::setCoord(_coord);
		// обновляем трек
		updateTrack();
	}

	void VScroll::setTrackSize(int _size)
	{
		if (mWidgetTrack != nullptr)
			mWidgetTrack->setSize(mWidgetTrack->getWidth(), ((int)_size < (int)mMinTrackSize)? (int)mMinTrackSize : (int)_size);
		updateTrack();
	}

	int VScroll::getTrackSize()
	{
		return mWidgetTrack == nullptr ? 1 : mWidgetTrack->getHeight();
	}

	int VScroll::getLineSize()
	{
		return mCoord.height - (int)(mSkinRangeStart + mSkinRangeEnd);
	}

	void VScroll::onMouseWheel(int _rel)
	{
		notifyMouseWheel(nullptr, _rel);

		Base::onMouseWheel(_rel);
	}

	void VScroll::notifyMouseWheel(Widget* _sender, int _rel)
	{
		if (mScrollRange < 2) return;

		int offset = mScrollPosition;
		if (_rel < 0) offset += SCROLL_MOUSE_WHEEL;
		else offset -= SCROLL_MOUSE_WHEEL;

		if (offset < 0) offset = 0;
		else if (offset > (int)(mScrollRange - 1)) offset = mScrollRange - 1;

		if ((size_t)offset != mScrollPosition)
		{
			mScrollPosition = offset;
			// оповещаем
			eventScrollChangePosition(this, (int)mScrollPosition);
			updateTrack();
		}
	}

	void VScroll::setProperty(const std::string& _key, const std::string& _value)
	{
		if (_key == "Scroll_Range") setScrollRange(utility::parseValue<size_t>(_value));
		else if (_key == "Scroll_Position") setScrollPosition(utility::parseValue<size_t>(_value));
		else if (_key == "Scroll_Page") setScrollPage(utility::parseValue<size_t>(_value));
		else if (_key == "Scroll_ViewPage") setScrollViewPage(utility::parseValue<size_t>(_value));
		else if (_key == "Scroll_MoveToClick") setMoveToClick(utility::parseValue<bool>(_value));
		else
		{
			Base::setProperty(_key, _value);
			return;
		}
		eventChangeProperty(this, _key, _value);
	}

} // namespace MyGUI