/* Copyright (C) 2015 Wildfire Games.
 * This file is part of 0 A.D.
 *
 * 0 A.D. is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 *
 * 0 A.D. 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with 0 A.D.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "precompiled.h"

#include "CGUIScrollBarVertical.h"

#include "GUI.h"

#include "ps/CLogger.h"


CGUIScrollBarVertical::CGUIScrollBarVertical()
{
}

CGUIScrollBarVertical::~CGUIScrollBarVertical()
{
}

void CGUIScrollBarVertical::SetPosFromMousePos(const CPos& mouse)
{
	if (!GetStyle())
		return;

	/**
	 * Calculate the position for the top of the item being scrolled
	 */
	float emptyBackground = m_Length - m_BarSize;
	if (GetStyle()->m_UseEdgeButtons)
		emptyBackground -= GetStyle()->m_Width * 2;
	m_Pos = m_PosWhenPressed + GetMaxPos() * (mouse.y - m_BarPressedAtPos.y) / emptyBackground;
}

void CGUIScrollBarVertical::Draw()
{
	if (!GetStyle())
	{
		LOGWARNING("Attempt to draw scrollbar without a style.");
		return;
	}

	if (GetGUI() && GetMaxPos() != 1)
	{
		CRect outline = GetOuterRect();

		// Draw background
		GetGUI()->DrawSprite(GetStyle()->m_SpriteBackVertical,
							 0,
							 m_Z+0.1f,
							 CRect(outline.left,
								   outline.top+(GetStyle()->m_UseEdgeButtons?GetStyle()->m_Width:0),
								   outline.right,
								   outline.bottom-(GetStyle()->m_UseEdgeButtons?GetStyle()->m_Width:0))
							 );

		if (GetStyle()->m_UseEdgeButtons)
		{
			// Get Appropriate sprites
			const CGUISpriteInstance* button_top;
			const CGUISpriteInstance* button_bottom;

			// figure out what sprite to use for top button
			if (m_ButtonMinusHovered)
			{
				if (m_ButtonMinusPressed)
					button_top = &GUI<>::FallBackSprite(GetStyle()->m_SpriteButtonTopPressed, GetStyle()->m_SpriteButtonTop);
				else
					button_top = &GUI<>::FallBackSprite(GetStyle()->m_SpriteButtonTopOver, GetStyle()->m_SpriteButtonTop);
			}
			else
				button_top = &GetStyle()->m_SpriteButtonTop;

			// figure out what sprite to use for bottom button
			if (m_ButtonPlusHovered)
			{
				if (m_ButtonPlusPressed)
					button_bottom = &GUI<>::FallBackSprite(GetStyle()->m_SpriteButtonBottomPressed, GetStyle()->m_SpriteButtonBottom);
				else
					button_bottom = &GUI<>::FallBackSprite(GetStyle()->m_SpriteButtonBottomOver, GetStyle()->m_SpriteButtonBottom);
			}
			else
				button_bottom = &GetStyle()->m_SpriteButtonBottom;

			// Draw top button
			GetGUI()->DrawSprite(*button_top,
								 0,
								 m_Z+0.2f,
								 CRect(outline.left,
									   outline.top,
									   outline.right,
									   outline.top+GetStyle()->m_Width)
								);

			// Draw bottom button
			GetGUI()->DrawSprite(*button_bottom,
								 0,
								 m_Z+0.2f,
								 CRect(outline.left,
									   outline.bottom-GetStyle()->m_Width,
									   outline.right,
									   outline.bottom)
								);
		}

		// Draw bar
		GetGUI()->DrawSprite(GetStyle()->m_SpriteBarVertical,
							 0,
							 m_Z + 0.2f,
							 GetBarRect());
	}
}

void CGUIScrollBarVertical::HandleMessage(SGUIMessage& Message)
{
	IGUIScrollBar::HandleMessage(Message);
}

CRect CGUIScrollBarVertical::GetBarRect() const
{
	CRect ret;
	if (!GetStyle())
		return ret;

	// Get from where the scroll area begins to where it ends
	float from = m_Y;
	float to = m_Y + m_Length - m_BarSize;

	if (GetStyle()->m_UseEdgeButtons)
	{
		from += GetStyle()->m_Width;
		to -= GetStyle()->m_Width;
	}

	// Setup rectangle
	ret.top = from + (to - from) * (m_Pos / GetMaxPos());
	ret.bottom = ret.top + m_BarSize;
	ret.right = m_X + ((m_RightAligned)?(0.f):(GetStyle()->m_Width));
	ret.left = ret.right - GetStyle()->m_Width;

	return ret;
}

CRect CGUIScrollBarVertical::GetOuterRect() const
{
	CRect ret;
	if (!GetStyle())
		return ret;

	ret.top = m_Y;
	ret.bottom = m_Y+m_Length;
	ret.right = m_X + ((m_RightAligned)?(0):(GetStyle()->m_Width));
	ret.left = ret.right - GetStyle()->m_Width;

	return ret;
}

bool CGUIScrollBarVertical::HoveringButtonMinus(const CPos& mouse)
{
	if (!GetStyle())
		return false;

	float StartX = (m_RightAligned)?(m_X-GetStyle()->m_Width):(m_X);

	return (mouse.x >= StartX &&
			mouse.x <= StartX + GetStyle()->m_Width &&
			mouse.y >= m_Y &&
			mouse.y <= m_Y + GetStyle()->m_Width);
}

bool CGUIScrollBarVertical::HoveringButtonPlus(const CPos& mouse)
{
	if (!GetStyle())
		return false;

	float StartX = (m_RightAligned)?(m_X-GetStyle()->m_Width):(m_X);

	return (mouse.x > StartX &&
			mouse.x < StartX + GetStyle()->m_Width &&
			mouse.y > m_Y + m_Length - GetStyle()->m_Width &&
			mouse.y < m_Y + m_Length);
}