/**
 * @file llhints.cpp
 * @brief Hint popups for displaying context sensitive help in a UI overlay
 *
 * $LicenseInfo:firstyear=2000&license=viewergpl$
 *
 * Copyright (c) 2000-2009, Linden Research, Inc.
 *
 * Second Life Viewer Source Code
 * The source code in this file ("Source Code") is provided by Linden Lab
 * to you under the terms of the GNU General Public License, version 2.0
 * ("GPL"), unless you have obtained a separate licensing agreement
 * ("Other License"), formally executed by you and Linden Lab.  Terms of
 * the GPL can be found in doc/GPL-license.txt in this distribution, or
 * online at http://secondlifegrid.net/programs/open_source/licensing/gplv2
 *
 * There are special exceptions to the terms and conditions of the GPL as
 * it is applied to this Source Code. View the full text of the exception
 * in the file doc/FLOSS-exception.txt in this software distribution, or
 * online at
 * http://secondlifegrid.net/programs/open_source/licensing/flossexception
 *
 * By copying, modifying or distributing this software, you acknowledge
 * that you have read and understood your obligations described above,
 * and agree to abide by those obligations.
 *
 * ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO
 * WARRANTIES, EXPRESS, IMPLIED OR OTHERWISE, REGARDING ITS ACCURACY,
 * COMPLETENESS OR PERFORMANCE.
 * $/LicenseInfo$
 */


#include "llviewerprecompiledheaders.h" // must be first include

#include "llhints.h"

#include "llbutton.h"
#include "lltextbox.h"
#include "llviewerwindow.h"
#include "llsdparam.h"

class LLHintPopup : public LLPanel
{
public:

	typedef enum e_popup_direction
	{
		LEFT,
		TOP,
		RIGHT,
		BOTTOM
	} EPopupDirection;

	struct PopupDirections : public LLInitParam::TypeValuesHelper<LLHintPopup::EPopupDirection, PopupDirections>
	{
		static void declareValues()
		{
			declare("left", LLHintPopup::LEFT);
			declare("right", LLHintPopup::RIGHT);
			declare("top", LLHintPopup::TOP);
			declare("bottom", LLHintPopup::BOTTOM);
		}
	};

	struct TargetParams : public LLInitParam::Block<TargetParams>
	{
		Mandatory<std::string>	target;
		Mandatory<EPopupDirection, PopupDirections> direction;

		TargetParams()
		:	target("target"),
			direction("direction")
		{}
	};

	struct Params : public LLInitParam::Block<Params, LLPanel::Params>
	{
		Mandatory<LLNotificationPtr>	notification;
		Optional<TargetParams>			target_params;
		Optional<S32>					distance;
		Optional<LLUIImage*>			left_arrow,
										up_arrow,
										right_arrow,
										down_arrow;	
		Optional<S32>					left_arrow_offset,
										up_arrow_offset,
										right_arrow_offset,
										down_arrow_offset;
		Optional<F32>					fade_in_time,
										fade_out_time;

		Params()
		:	distance("distance"),
			left_arrow("left_arrow"),
			up_arrow("up_arrow"),
			right_arrow("right_arrow"),
			down_arrow("down_arrow"),
			left_arrow_offset("left_arrow_offset"),
			up_arrow_offset("up_arrow_offset"),
			right_arrow_offset("right_arrow_offset"),
			down_arrow_offset("down_arrow_offset"),
			fade_in_time("fade_in_time"),
			fade_out_time("fade_out_time")
		{}
	};

	LLHintPopup(const Params&);

	/*virtual*/ BOOL postBuild();

	void onClickClose() { hide(); LLNotifications::instance().cancel(mNotification); }
	void draw();
	void hide() { if(!mHidden) {mHidden = true; mFadeTimer.reset();} }

private:
	LLNotificationPtr	mNotification;
	std::string			mTarget;
	EPopupDirection		mDirection;
	S32					mDistance;
	LLUIImagePtr		mArrowLeft,
						mArrowUp,
						mArrowRight,
						mArrowDown;
	S32					mArrowLeftOffset,
						mArrowUpOffset,
						mArrowRightOffset,
						mArrowDownOffset;
	LLFrameTimer		mFadeTimer;
	F32					mFadeInTime,
						mFadeOutTime;
	bool				mHidden;
};

static LLDefaultChildRegistry::Register<LLHintPopup> r("hint_popup");


LLHintPopup::LLHintPopup(const LLHintPopup::Params& p)
:	mNotification(p.notification),
	mDirection(p.target_params.direction),
	mDistance(p.distance),
	mTarget(p.target_params.target),
	mArrowLeft(p.left_arrow),
	mArrowUp(p.up_arrow),
	mArrowRight(p.right_arrow),
	mArrowDown(p.down_arrow),
	mArrowLeftOffset(p.left_arrow_offset),
	mArrowUpOffset(p.up_arrow_offset),
	mArrowRightOffset(p.right_arrow_offset),
	mArrowDownOffset(p.down_arrow_offset),
	mHidden(false),
	mFadeInTime(p.fade_in_time),
	mFadeOutTime(p.fade_out_time),
	LLPanel(p)
{
	buildPanel(this, "panel_hint.xml", NULL, p);
}

BOOL LLHintPopup::postBuild()
{
	LLTextBox& hint_text = getChildRef<LLTextBox>("hint_text");
	hint_text.setText(mNotification->getMessage());
	
	getChild<LLButton>("close")->setClickedCallback(boost::bind(&LLHintPopup::onClickClose, this));
	getChild<LLTextBox>("hint_title")->setText(mNotification->getLabel());

	LLRect text_bounds = hint_text.getTextBoundingRect();
	S32 delta_height = text_bounds.getHeight() - hint_text.getRect().getHeight();
	reshape(getRect().getWidth(), getRect().getHeight() + delta_height);
	return TRUE;
}

void LLHintPopup::draw()
{
	F32 alpha = 1.f;
	if (mHidden)
	{
		alpha = clamp_rescale(mFadeTimer.getElapsedTimeF32(), 0.f, mFadeOutTime, 1.f, 0.f);
		if (alpha == 0.f)
		{
			die();
			return;
		}
	}
	else
	{
		alpha = clamp_rescale(mFadeTimer.getElapsedTimeF32(), 0.f, mFadeInTime, 0.f, 1.f);
	}
	
	{	LLViewDrawContext context(alpha); 

		if (mTarget.empty())
		{
			// just draw contents, no arrow, in default position
			LLPanel::draw();
		}
		else 
		{
			LLView* targetp = LLHints::getHintTarget(mTarget).get();
			if (!targetp)
			{
				// target widget is no longer valid, go away
				die();
			}
			else if (!targetp->isInVisibleChain()) 
			{
				// if target is invisible, don't draw, but keep alive in case widget comes back
			}
			else
			{
				LLRect target_rect;
				targetp->localRectToOtherView(targetp->getLocalRect(), &target_rect, getParent());

				LLRect my_local_rect = getLocalRect();
				LLRect my_rect;
				LLRect arrow_rect;
				LLUIImagePtr arrow_imagep;

				switch(mDirection)
				{
				case LEFT:
					my_rect.setCenterAndSize(	target_rect.mLeft - (my_local_rect.getWidth() / 2 + mDistance), 
												target_rect.getCenterY(), 
												my_local_rect.getWidth(), 
												my_local_rect.getHeight());
					if (mArrowRight)
					{
						arrow_rect.setCenterAndSize(my_local_rect.mRight + mArrowRight->getWidth() / 2 + mArrowRightOffset,
													my_local_rect.getCenterY(),
													mArrowRight->getWidth(), 
													mArrowRight->getHeight());
						arrow_imagep = mArrowRight;
					}
					break;
				case TOP:
					my_rect.setCenterAndSize(	target_rect.getCenterX(), 
												target_rect.mTop + (my_local_rect.getHeight() / 2 + mDistance), 
												my_local_rect.getWidth(), 
												my_local_rect.getHeight());
					if (mArrowDown)
					{
						arrow_rect.setCenterAndSize(my_local_rect.getCenterX(),
													my_local_rect.mBottom - mArrowDown->getHeight() / 2 + mArrowDownOffset,
													mArrowDown->getWidth(), 
													mArrowDown->getHeight());
						arrow_imagep = mArrowDown;
					}
					break;
				case RIGHT:
					my_rect.setCenterAndSize(	target_rect.mRight + (my_local_rect.getWidth() / 2 + mDistance), 
												target_rect.getCenterY(),
												my_local_rect.getWidth(), 
												my_local_rect.getHeight());
					if (mArrowLeft)
					{
						arrow_rect.setCenterAndSize(my_local_rect.mLeft - mArrowLeft->getWidth() / 2 + mArrowLeftOffset,
													my_local_rect.getCenterY(),
													mArrowLeft->getWidth(), 
													mArrowLeft->getHeight());
						arrow_imagep = mArrowLeft;
					}
					break;
				case BOTTOM:
					my_rect.setCenterAndSize(	target_rect.getCenterX(), 
												target_rect.mBottom - (my_local_rect.getHeight() / 2 + mDistance),
												my_local_rect.getWidth(), 
												my_local_rect.getHeight());
					if (mArrowUp)
					{
						arrow_rect.setCenterAndSize(my_local_rect.getCenterX(),
													my_local_rect.mTop + mArrowUp->getHeight() / 2 + mArrowUpOffset,
													mArrowUp->getWidth(), 
													mArrowUp->getHeight());
						arrow_imagep = mArrowUp;
					}
					break;
				}
				setShape(my_rect);
				LLPanel::draw();

				if (arrow_imagep) arrow_imagep->draw(arrow_rect, LLColor4(1.f, 1.f, 1.f, alpha));
			}
		}
	}
}


LLRegistry<std::string, LLHandle<LLView> > LLHints::sTargetRegistry;
std::map<LLNotificationPtr, class LLHintPopup*> LLHints::sHints;

//static
void LLHints::show(LLNotificationPtr hint)
{
	LLHintPopup::Params p(LLUICtrlFactory::getDefaultParams<LLHintPopup>());

	LLParamSDParser::instance().readSD(hint->getPayload(), p);
	p.notification = hint;

	if (p.validateBlock())
	{
		LLHintPopup* popup = new LLHintPopup(p);

		sHints[hint] = popup;

		LLView* hint_holder = gViewerWindow->getHintHolder();
		if (hint_holder)
		{
			hint_holder->addChild(popup);
			popup->centerWithin(hint_holder->getLocalRect());
		}
	}
}

void LLHints::hide(LLNotificationPtr hint)
{
	hint_map_t::iterator found_it = sHints.find(hint);
	if (found_it != sHints.end())
	{
		found_it->second->hide();
		sHints.erase(found_it);
	}
}

//static
void LLHints::registerHintTarget(const std::string& name, LLHandle<LLView> target)
{
	sTargetRegistry.defaultRegistrar().replace(name, target);
}

//static 
LLHandle<LLView> LLHints::getHintTarget(const std::string& name)
{
	LLHandle<LLView>* handlep = sTargetRegistry.getValue(name);
	if (handlep) 
	{
		return *handlep;
	}
	else
	{
		return LLHandle<LLView>();
	}
}