/**
* @file llemojihelper.h
* @brief Header file for LLEmojiHelper
*
* $LicenseInfo:firstyear=2014&license=viewerlgpl$
* Second Life Viewer Source Code
* Copyright (C) 2014, Linden Research, Inc.
*
* This library 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;
* version 2.1 of the License only.
*
* This library 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 this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
*
* Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
* $/LicenseInfo$
*/

#include "linden_common.h"

#include "llemojidictionary.h"
#include "llemojihelper.h"
#include "llfloater.h"
#include "llfloaterreg.h"
#include "lluictrl.h"

// ============================================================================
// Constants
//

constexpr char DEFAULT_EMOJI_HELPER_FLOATER[] = "emoji_complete";
constexpr S32 HELPER_FLOATER_OFFSET_X = 20;
constexpr S32 HELPER_FLOATER_OFFSET_Y = 0;

// ============================================================================
// LLEmojiHelper
//

std::string LLEmojiHelper::getToolTip(llwchar ch) const
{
	return LLEmojiDictionary::instance().getNameFromEmoji(ch);
}

bool LLEmojiHelper::isActive(const LLUICtrl* ctrl_p) const
{
	return mHostHandle.get() == ctrl_p;
}

// static
bool LLEmojiHelper::isCursorInEmojiCode(const LLWString& wtext, S32 cursorPos, S32* pShortCodePos)
{
	// If the cursor is currently on a colon start the check one character further back
	S32 shortCodePos = (cursorPos == 0 || L':' != wtext[cursorPos - 1]) ? cursorPos : cursorPos - 1;

	auto isPartOfShortcode = [](llwchar ch) {
		switch (ch)
		{
			case L'-':
			case L'_':
			case L'+':
				return true;
			default:
				return LLStringOps::isAlnum(ch);
		}
	};
	while (shortCodePos > 1 && isPartOfShortcode(wtext[shortCodePos - 1]))
	{
		shortCodePos--;
	}

	bool isShortCode = (L':' == wtext[shortCodePos - 1]) && (cursorPos - shortCodePos >= 2);
	if (pShortCodePos)
		*pShortCodePos = (isShortCode) ? shortCodePos - 1 : -1;
	return isShortCode;
}

void LLEmojiHelper::showHelper(LLUICtrl* hostctrl_p, S32 local_x, S32 local_y, const std::string& short_code, std::function<void(llwchar)> cb)
{
	// Commit immediately if the user already typed a full shortcode
	if (const auto* emojiDescrp = LLEmojiDictionary::instance().getDescriptorFromShortCode(short_code))
	{
		cb(emojiDescrp->Character);
		hideHelper();
		return;
	}

	if (mHelperHandle.isDead())
	{
		LLFloater* pHelperFloater = LLFloaterReg::getInstance(DEFAULT_EMOJI_HELPER_FLOATER);
		mHelperHandle = pHelperFloater->getHandle();
		mHelperCommitConn = pHelperFloater->setCommitCallback(std::bind([&](const LLSD& sdValue) { onCommitEmoji(utf8str_to_wstring(sdValue.asStringRef())[0]); }, std::placeholders::_2));
	}
	setHostCtrl(hostctrl_p);
	mEmojiCommitCb = cb;

	S32 floater_x, floater_y;
	if (!hostctrl_p->localPointToOtherView(local_x, local_y, &floater_x, &floater_y, gFloaterView))
	{
		LL_ERRS() << "Cannot show emoji helper for non-floater controls." << LL_ENDL;
		return;
	}

	LLFloater* pHelperFloater = mHelperHandle.get();
	LLRect rct = pHelperFloater->getRect();
	rct.setLeftTopAndSize(floater_x - HELPER_FLOATER_OFFSET_X, floater_y - HELPER_FLOATER_OFFSET_Y + rct.getHeight(), rct.getWidth(), rct.getHeight());
	pHelperFloater->setRect(rct);
	pHelperFloater->openFloater(LLSD().with("hint", short_code));
}

void LLEmojiHelper::hideHelper(const LLUICtrl* ctrl_p)
{
	if (ctrl_p && !isActive(ctrl_p))
	{
		return;
	}

	setHostCtrl(nullptr);
}

bool LLEmojiHelper::handleKey(const LLUICtrl* ctrl_p, KEY key, MASK mask)
{
	if (mHelperHandle.isDead() || !isActive(ctrl_p))
	{
		return false;
	}

	return mHelperHandle.get()->handleKey(key, mask, true);
}

void LLEmojiHelper::onCommitEmoji(llwchar emoji)
{
	if (!mHostHandle.isDead() && mEmojiCommitCb)
	{
		mEmojiCommitCb(emoji);
	}
}

void LLEmojiHelper::setHostCtrl(LLUICtrl* hostctrl_p)
{
	const LLUICtrl* pCurHostCtrl = mHostHandle.get();
	if (pCurHostCtrl != hostctrl_p)
	{
		mHostCtrlFocusLostConn.disconnect();
		mHostHandle.markDead();
		mEmojiCommitCb = {};

		if (!mHelperHandle.isDead())
		{
			mHelperHandle.get()->closeFloater();
		}

		if (hostctrl_p)
		{
			mHostHandle = hostctrl_p->getHandle();
			mHostCtrlFocusLostConn = hostctrl_p->setFocusLostCallback(std::bind([&]() { hideHelper(getHostCtrl()); }));
		}
	}
}