/**
 * @file llfloaterimsessiontab.cpp
 * @brief LLFloaterIMSessionTab class implements the common behavior of LNearbyChatBar
 * @brief and LLFloaterIMSession for hosting both in LLIMContainer
 *
 * $LicenseInfo:firstyear=2012&license=viewerlgpl$
 * Second Life Viewer Source Code
 * Copyright (C) 2012, 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 "llviewerprecompiledheaders.h"

#include "llfloaterimsessiontab.h"

#include "llagent.h"
#include "llagentcamera.h"
#include "llavataractions.h"
#include "llavatariconctrl.h"
#include "llchatentry.h"
#include "llchathistory.h"
#include "llchiclet.h"
#include "llchicletbar.h"
#include "lldraghandle.h"
#include "llemojidictionary.h"
#include "llfloaterreg.h"
#include "llfloateremojipicker.h"
#include "llfloaterimsession.h"
#include "llfloaterimcontainer.h" // to replace separate IM Floaters with multifloater container
#include "llfloaterimnearbychat.h"
#include "llgroupiconctrl.h"
#include "lllayoutstack.h"
#include "llpanelemojicomplete.h"
#include "lltoolbarview.h"

const F32 REFRESH_INTERVAL = 1.0f;
const std::string ICN_GROUP("group_chat_icon");
const std::string ICN_NEARBY("nearby_chat_icon");
const std::string ICN_AVATAR("avatar_icon");

void cb_group_do_nothing()
{
}

LLFloaterIMSessionTab::LLFloaterIMSessionTab(const LLSD& session_id)
:   super(NULL, false, session_id),
    mIsP2PChat(false),
    mExpandCollapseBtn(NULL),
    mTearOffBtn(NULL),
    mCloseBtn(NULL),
    mSessionID(session_id.asUUID()),
    mConversationsRoot(NULL),
    mScroller(NULL),
    mChatHistory(NULL),
    mInputEditor(NULL),
    mInputEditorPad(0),
    mRefreshTimer(new LLTimer()),
    mIsHostAttached(false),
    mHasVisibleBeenInitialized(false),
    mIsParticipantListExpanded(true),
    mChatLayoutPanel(NULL),
    mInputPanels(NULL),
    mChatLayoutPanelHeight(0)
{
    setAutoFocus(false);
    mSession = LLIMModel::getInstance()->findIMSession(mSessionID);

    mCommitCallbackRegistrar.add("IMSession.Menu.Action",
            boost::bind(&LLFloaterIMSessionTab::onIMSessionMenuItemClicked,  this, _2));
    mEnableCallbackRegistrar.add("IMSession.Menu.CompactExpandedModes.CheckItem",
            boost::bind(&LLFloaterIMSessionTab::onIMCompactExpandedMenuItemCheck, this, _2));
    mEnableCallbackRegistrar.add("IMSession.Menu.ShowModes.CheckItem",
            boost::bind(&LLFloaterIMSessionTab::onIMShowModesMenuItemCheck,   this, _2));
    mEnableCallbackRegistrar.add("IMSession.Menu.ShowModes.Enable",
            boost::bind(&LLFloaterIMSessionTab::onIMShowModesMenuItemEnable,  this, _2));

    // Right click menu handling
    mEnableCallbackRegistrar.add("Avatar.CheckItem",  boost::bind(&LLFloaterIMSessionTab::checkContextMenuItem, this, _2));
    mEnableCallbackRegistrar.add("Avatar.EnableItem", boost::bind(&LLFloaterIMSessionTab::enableContextMenuItem, this, _2));
    mCommitCallbackRegistrar.add("Avatar.DoToSelected", boost::bind(&LLFloaterIMSessionTab::doToSelected, this, _2));
    mCommitCallbackRegistrar.add("Group.DoToSelected", boost::bind(&cb_group_do_nothing));

    mMinFloaterHeight = getMinHeight();
}

LLFloaterIMSessionTab::~LLFloaterIMSessionTab()
{
    delete mRefreshTimer;

    LLFloaterIMContainer* im_container = LLFloaterIMContainer::findInstance();
    if (im_container)
    {
        LLParticipantList* session = dynamic_cast<LLParticipantList*>(im_container->getSessionModel(mSessionID));
        if (session)
        {
            for (const conversations_widgets_map::value_type& widget_pair : mConversationsWidgets)
            {
                LLFolderViewItem* widget = widget_pair.second;
                LLFolderViewModelItem* item_vmi = widget->getViewModelItem();
                if (item_vmi && item_vmi->getNumRefs() == 1)
                {
                    // This is the last pointer, remove participant from session
                    // before participant gets deleted on destroyView.
                    session->removeChild(item_vmi);
                }
            }
        }
    }
}

// static
LLFloaterIMSessionTab* LLFloaterIMSessionTab::findConversation(const LLUUID& uuid)
{
    LLFloaterIMSessionTab* conv;

    if (uuid.isNull())
    {
        conv = LLFloaterReg::findTypedInstance<LLFloaterIMSessionTab>("nearby_chat");
    }
    else
    {
        conv = LLFloaterReg::findTypedInstance<LLFloaterIMSessionTab>("impanel", LLSD(uuid));
    }

    return conv;
};

// static
LLFloaterIMSessionTab* LLFloaterIMSessionTab::getConversation(const LLUUID& uuid)
{
    LLFloaterIMSessionTab* conv;

    if (uuid.isNull())
    {
        conv = LLFloaterReg::getTypedInstance<LLFloaterIMSessionTab>("nearby_chat");
    }
    else
    {
        conv = LLFloaterReg::getTypedInstance<LLFloaterIMSessionTab>("impanel", LLSD(uuid));
        conv->setOpenPositioning(LLFloaterEnums::POSITIONING_RELATIVE);
    }

    return conv;

};

// virtual
void LLFloaterIMSessionTab::setVisible(bool visible)
{
    if (visible && !mHasVisibleBeenInitialized)
    {
        mHasVisibleBeenInitialized = true;
        if (!gAgentCamera.cameraMouselook())
        {
            LLFloaterReg::getTypedInstance<LLFloaterIMContainer>("im_container")->setVisible(true);
        }
        LLFloaterIMSessionTab::addToHost(mSessionID);
        LLFloaterIMSessionTab* conversp = LLFloaterIMSessionTab::getConversation(mSessionID);

        if (conversp && conversp->isNearbyChat() && gSavedPerAccountSettings.getBOOL("NearbyChatIsNotCollapsed"))
        {
            onCollapseToLine(this);
        }
        mInputButtonPanel->setVisible(isTornOff());
    }

    super::setVisible(visible);
}

// virtual
void LLFloaterIMSessionTab::setFocus(bool focus)
{
    super::setFocus(focus);

    // Redirect focus to input editor
    if (focus)
    {
        updateMessages();

        if (mInputEditor)
        {
            mInputEditor->setFocus(true);
        }
    }
}

void LLFloaterIMSessionTab::addToHost(const LLUUID& session_id)
{
    if ((session_id.notNull() && !gIMMgr->hasSession(session_id))
            || !LLFloaterIMSessionTab::isChatMultiTab())
    {
        return;
    }

    // Get the floater: this will create the instance if it didn't exist
    LLFloaterIMSessionTab* conversp = LLFloaterIMSessionTab::getConversation(session_id);
    if (conversp)
    {
        LLFloaterIMContainer* floater_container = LLFloaterIMContainer::getInstance();

        // Do not add again existing floaters
        if (floater_container && !conversp->isHostAttached())
        {
            conversp->setHostAttached(true);

            if (!conversp->isNearbyChat()
                    || gSavedPerAccountSettings.getBOOL("NearbyChatIsNotTornOff"))
            {
                floater_container->addFloater(conversp, false, LLTabContainer::RIGHT_OF_CURRENT);
            }
            else
            {
                // setting of the "potential" host for Nearby Chat: this sequence sets
                // LLFloater::mHostHandle = NULL (a current host), but
                // LLFloater::mLastHostHandle = floater_container (a "future" host)
                conversp->setHost(floater_container);
                conversp->setHost(NULL);

                conversp->forceReshape();
            }
            // Added floaters share some state (like sort order) with their host
            conversp->setSortOrder(floater_container->getSortOrder());
        }
    }
}

void LLFloaterIMSessionTab::assignResizeLimits()
{
    bool is_participants_pane_collapsed = mParticipantListPanel->isCollapsed();

    // disable a layoutstack's functionality when participant list panel is collapsed
    mRightPartPanel->setIgnoreReshape(is_participants_pane_collapsed);

    S32 participants_pane_target_width = is_participants_pane_collapsed?
            0 : (mParticipantListPanel->getRect().getWidth() + mParticipantListAndHistoryStack->getPanelSpacing());

    S32 new_min_width = participants_pane_target_width + mRightPartPanel->getExpandedMinDim() + mFloaterExtraWidth;

    setResizeLimits(new_min_width, getMinHeight());

    this->mParticipantListAndHistoryStack->updateLayout();
}

// virtual
bool LLFloaterIMSessionTab::postBuild()
{
    bool result;

    mContentsView = getChild<LLView>("contents_view");
    mBodyStack = getChild<LLLayoutStack>("main_stack");
    mParticipantListAndHistoryStack = getChild<LLLayoutStack>("im_panels");

    mCloseBtn = getChild<LLButton>("close_btn");
    mCloseBtn->setCommitCallback([this](LLUICtrl*, const LLSD&) { onClickClose(this); });

    mExpandCollapseBtn = getChild<LLButton>("expand_collapse_btn");
    mExpandCollapseBtn->setClickedCallback([this](LLUICtrl*, const LLSD&) { onSlide(this); });

    mExpandCollapseLineBtn = getChild<LLButton>("minz_btn");
    mExpandCollapseLineBtn->setClickedCallback([this](LLUICtrl*, const LLSD&) { onCollapseToLine(this); });

    mTearOffBtn = getChild<LLButton>("tear_off_btn");
    mTearOffBtn->setCommitCallback(boost::bind(&LLFloaterIMSessionTab::onTearOffClicked, this));

    mEmojiRecentPanelToggleBtn = getChild<LLButton>("emoji_recent_panel_toggle_btn");
    mEmojiRecentPanelToggleBtn->setClickedCallback([this](LLUICtrl*, const LLSD&) { onEmojiRecentPanelToggleBtnClicked(); });

    mEmojiRecentPanel = getChild<LLLayoutPanel>("emoji_recent_layout_panel");
    mEmojiRecentPanel->setVisible(false);

    mEmojiRecentEmptyText = getChild<LLTextBox>("emoji_recent_empty_text");
    mEmojiRecentEmptyText->setToolTip(mEmojiRecentEmptyText->getText());
    mEmojiRecentEmptyText->setVisible(false);

    mEmojiRecentContainer = getChild<LLPanel>("emoji_recent_container");
    mEmojiRecentContainer->setVisible(false);

    mEmojiRecentIconsCtrl = getChild<LLPanelEmojiComplete>("emoji_recent_icons_ctrl");
    mEmojiRecentIconsCtrl->setFocusReceivedCallback([this](LLFocusableElement*) { onEmojiRecentPanelFocusReceived(); });
    mEmojiRecentIconsCtrl->setFocusLostCallback([this](LLFocusableElement*) { onEmojiRecentPanelFocusLost(); });
    mEmojiRecentIconsCtrl->setCommitCallback([this](LLUICtrl*, const LLSD& value) { onRecentEmojiPicked(value); });

    mEmojiPickerShowBtn = getChild<LLButton>("emoji_picker_show_btn");
    mEmojiPickerShowBtn->setClickedCallback([this](LLUICtrl*, const LLSD&) { onEmojiPickerShowBtnClicked(); });

    mGearBtn = getChild<LLButton>("gear_btn");
    mAddBtn = getChild<LLButton>("add_btn");
    mVoiceButton = getChild<LLButton>("voice_call_btn");

    mParticipantListPanel = getChild<LLLayoutPanel>("speakers_list_panel");
    mRightPartPanel = getChild<LLLayoutPanel>("right_part_holder");

    mToolbarPanel = getChild<LLLayoutPanel>("toolbar_panel");
    mContentPanel = getChild<LLLayoutPanel>("body_panel");
    mInputButtonPanel = getChild<LLLayoutPanel>("input_button_layout_panel");
    mInputButtonPanel->setVisible(false);
    // Add a scroller for the folder (participant) view
    LLRect scroller_view_rect = mParticipantListPanel->getRect();
    scroller_view_rect.translate(-scroller_view_rect.mLeft, -scroller_view_rect.mBottom);
    LLScrollContainer::Params scroller_params(LLUICtrlFactory::getDefaultParams<LLFolderViewScrollContainer>());
    scroller_params.rect(scroller_view_rect);
    mScroller = LLUICtrlFactory::create<LLFolderViewScrollContainer>(scroller_params);
    mScroller->setFollowsAll();

    // Insert that scroller into the panel widgets hierarchy
    mParticipantListPanel->addChild(mScroller);

    mChatHistory = getChild<LLChatHistory>("chat_history");

    mInputEditor = getChild<LLChatEntry>("chat_editor");

    mChatLayoutPanel = getChild<LLLayoutPanel>("chat_layout_panel");
    mInputPanels = getChild<LLLayoutStack>("input_panels");

    mInputEditor->setTextExpandedCallback(boost::bind(&LLFloaterIMSessionTab::reshapeChatLayoutPanel, this));
    mInputEditor->setMouseUpCallback(boost::bind(&LLFloaterIMSessionTab::onInputEditorClicked, this));
    mInputEditor->setCommitOnFocusLost( false );
    mInputEditor->setPassDelete(true);
    mInputEditor->setFont(LLViewerChat::getChatFont());

    mChatLayoutPanelHeight = mChatLayoutPanel->getRect().getHeight();
    mInputEditorPad = mChatLayoutPanelHeight - mInputEditor->getRect().getHeight();

    setOpenPositioning(LLFloaterEnums::POSITIONING_RELATIVE);

    mSaveRect = isNearbyChat()
                    &&  !gSavedPerAccountSettings.getBOOL("NearbyChatIsNotTornOff");
    initRectControl();

    if (isChatMultiTab())
    {
        result = LLFloater::postBuild();
    }
    else
    {
        result = LLDockableFloater::postBuild();
    }

    // Create the root using an ad-hoc base item
    LLConversationItem* base_item = new LLConversationItem(mSessionID, mConversationViewModel);
    LLFolderView::Params p(LLUICtrlFactory::getDefaultParams<LLFolderView>());
    p.rect = LLRect(0, 0, getRect().getWidth(), 0);
    p.parent_panel = mParticipantListPanel;
    p.listener = base_item;
    p.view_model = &mConversationViewModel;
    p.root = NULL;
    p.use_ellipses = true;
    p.options_menu = "menu_conversation.xml";
    p.name = "root";
    mConversationsRoot = LLUICtrlFactory::create<LLFolderView>(p);
    mConversationsRoot->setCallbackRegistrar(&mCommitCallbackRegistrar);
    mConversationsRoot->setEnableRegistrar(&mEnableCallbackRegistrar);
    // Attach that root to the scroller
    mScroller->addChild(mConversationsRoot);
    mConversationsRoot->setScrollContainer(mScroller);
    mConversationsRoot->setFollowsAll();
    mConversationsRoot->addChild(mConversationsRoot->mStatusTextBox);

    setMessagePaneExpanded(true);

    buildConversationViewParticipant();
    refreshConversation();

    // Zero expiry time is set only once to allow initial update.
    mRefreshTimer->setTimerExpirySec(0);
    mRefreshTimer->start();
    initBtns();

    if (mIsParticipantListExpanded != (bool)gSavedSettings.getBOOL("IMShowControlPanel"))
    {
        LLFloaterIMSessionTab::onSlide(this);
    }

    // The resize limits for LLFloaterIMSessionTab should be updated, based on current values of width of conversation and message panels
    mParticipantListPanel->getResizeBar()->setResizeListener(boost::bind(&LLFloaterIMSessionTab::assignResizeLimits, this));
    mFloaterExtraWidth =
            getRect().getWidth()
            - mParticipantListAndHistoryStack->getRect().getWidth()
            - (mParticipantListPanel->isCollapsed()? 0 : LLPANEL_BORDER_WIDTH);

    assignResizeLimits();

    return result;
}

LLParticipantList* LLFloaterIMSessionTab::getParticipantList()
{
    return dynamic_cast<LLParticipantList*>(LLFloaterIMContainer::getInstance()->getSessionModel(mSessionID));
}

// virtual
void LLFloaterIMSessionTab::draw()
{
    if (mRefreshTimer->hasExpired())
    {
        LLParticipantList* item = getParticipantList();
        if (item)
        {
            // Update all model items
            item->update();
            // If the model and view list diverge in count, rebuild
            // Note: this happens sometimes right around init (add participant events fire but get dropped) and is the cause
            // of missing participants, often, the user agent itself. As there will be no other event fired, there's
            // no other choice but get those inconsistencies regularly (and lightly) checked and scrubbed.
            if (item->getChildrenCount() != mConversationsWidgets.size())
            {
                buildConversationViewParticipant();
            }
            refreshConversation();
        }

        // Restart the refresh timer
        mRefreshTimer->setTimerExpirySec(REFRESH_INTERVAL);
    }

    super::draw();
}

void LLFloaterIMSessionTab::enableDisableCallBtn()
{
    if (LLVoiceClient::instanceExists() && mVoiceButton)
    {
        mVoiceButton->setEnabled(
            mSessionID.notNull()
            && mSession
            && mSession->mSessionInitialized
            && LLVoiceClient::getInstance()->voiceEnabled()
            && LLVoiceClient::getInstance()->isVoiceWorking()
            && mSession->mCallBackEnabled);
    }
}

// virtual
void LLFloaterIMSessionTab::onFocusReceived()
{
    setBackgroundOpaque(true);

    if (mSessionID.notNull() && isInVisibleChain())
    {
        LLIMModel::instance().sendNoUnreadMessages(mSessionID);
    }

    super::onFocusReceived();
}

// virtual
void LLFloaterIMSessionTab::onFocusLost()
{
    setBackgroundOpaque(false);
    super::onFocusLost();
}

void LLFloaterIMSessionTab::onInputEditorClicked()
{
    LLFloaterIMContainer* im_box = LLFloaterIMContainer::findInstance();
    if (im_box)
    {
        im_box->flashConversationItemWidget(mSessionID,false);
    }
    gToolBarView->flashCommand(LLCommandId("chat"), false);
}

void LLFloaterIMSessionTab::onEmojiRecentPanelToggleBtnClicked()
{
    bool show = !mEmojiRecentPanel->getVisible();
    if (show)
    {
        initEmojiRecentPanel();
    }

    mEmojiRecentPanel->setVisible(show);
    mInputEditor->setFocus(true);
}

void LLFloaterIMSessionTab::onEmojiPickerShowBtnClicked()
{
    mInputEditor->setFocus(true);
    mInputEditor->showEmojiHelper();
}

void LLFloaterIMSessionTab::initEmojiRecentPanel()
{
    std::list<llwchar>& recentlyUsed = LLFloaterEmojiPicker::getRecentlyUsed();
    if (recentlyUsed.empty())
    {
        mEmojiRecentEmptyText->setVisible(true);
        mEmojiRecentContainer->setVisible(false);
    }
    else
    {
        LLWString emojis;
        for (llwchar emoji : recentlyUsed)
        {
            emojis += emoji;
        }
        mEmojiRecentIconsCtrl->setEmojis(emojis);
        mEmojiRecentEmptyText->setVisible(false);
        mEmojiRecentContainer->setVisible(true);
    }
}

// static
void LLFloaterIMSessionTab::onEmojiRecentPanelFocusReceived()
{
    mEmojiRecentContainer->addBorder();
}

// static
void LLFloaterIMSessionTab::onEmojiRecentPanelFocusLost()
{
    mEmojiRecentContainer->removeBorder();
}

void LLFloaterIMSessionTab::onRecentEmojiPicked(const LLSD& value)
{
    LLSD::String str = value.asString();
    if (str.size())
    {
        LLWString wstr = utf8string_to_wstring(str);
        if (wstr.size())
        {
            llwchar emoji = wstr[0];
            mInputEditor->insertEmoji(emoji);
        }
    }
}

void LLFloaterIMSessionTab::closeFloater(bool app_quitting)
{
    LLFloaterEmojiPicker::saveState();
    super::closeFloater(app_quitting);
}

void LLFloaterIMSessionTab::deleteAllChildren()
{
    super::deleteAllChildren();
    mVoiceButton = NULL;
}

std::string LLFloaterIMSessionTab::appendTime()
{
    std::string timeStr = "[" + LLTrans::getString("TimeHour") + "]:"
                          "[" + LLTrans::getString("TimeMin") + "]:"
                          "[" + LLTrans::getString("TimeSec") + "]";

    LLSD substitution;
    substitution["datetime"] = (S32)time_corrected();
    LLStringUtil::format(timeStr, substitution);

    return timeStr;
}

void LLFloaterIMSessionTab::appendMessage(const LLChat& chat, const LLSD& args)
{
    if (chat.mMuted || !mChatHistory)
        return;

    // Update the participant activity time
    LLFloaterIMContainer* im_box = LLFloaterIMContainer::findInstance();
    if (im_box)
    {
        im_box->setTimeNow(mSessionID, chat.mFromID);
    }

    LLChat& tmp_chat = const_cast<LLChat&>(chat);

    if (tmp_chat.mTimeStr.empty())
        tmp_chat.mTimeStr = appendTime();

    tmp_chat.mFromName = chat.mFromName;

    LLSD chat_args = args;
    chat_args["use_plain_text_chat_history"] =
            gSavedSettings.getBOOL("PlainTextChatHistory");
    chat_args["show_time"] = gSavedSettings.getBOOL("IMShowTime");
    chat_args["show_names_for_p2p_conv"] = !mIsP2PChat ||
            gSavedSettings.getBOOL("IMShowNamesForP2PConv");

    mChatHistory->appendMessage(chat, chat_args);
}

void LLFloaterIMSessionTab::updateUsedEmojis(LLWStringView text)
{
    LLEmojiDictionary* dictionary = LLEmojiDictionary::getInstance();
    llassert_always(dictionary);

    bool emojiSent = false;
    for (const llwchar& c : text)
    {
        if (dictionary->isEmoji(c))
        {
            LLFloaterEmojiPicker::onEmojiUsed(c);
            emojiSent = true;
        }
    }

    if (!emojiSent)
        return;

    LLFloaterEmojiPicker::saveState();

    if (mEmojiRecentPanel->getVisible())
    {
        initEmojiRecentPanel();
    }
}

static LLTrace::BlockTimerStatHandle FTM_BUILD_CONVERSATION_VIEW_PARTICIPANT("Build Conversation View");
void LLFloaterIMSessionTab::buildConversationViewParticipant()
{
    LL_RECORD_BLOCK_TIME(FTM_BUILD_CONVERSATION_VIEW_PARTICIPANT);
    // Clear the widget list since we are rebuilding afresh from the model
    conversations_widgets_map::iterator widget_it = mConversationsWidgets.begin();
    while (widget_it != mConversationsWidgets.end())
    {
        removeConversationViewParticipant(widget_it->first);
        // Iterators are invalidated by erase so we need to pick begin again
        widget_it = mConversationsWidgets.begin();
    }

    // Get the model list
    LLParticipantList* item = getParticipantList();
    if (!item)
    {
        // Nothing to do if the model list is inexistent
        return;
    }

    // Create the participants widgets now
    LLFolderViewModelItemCommon::child_list_t::const_iterator current_participant_model = item->getChildrenBegin();
    LLFolderViewModelItemCommon::child_list_t::const_iterator end_participant_model = item->getChildrenEnd();
    while (current_participant_model != end_participant_model)
    {
        LLConversationItem* participant_model = dynamic_cast<LLConversationItem*>(*current_participant_model);
        if (participant_model)
        {
            addConversationViewParticipant(participant_model);
        }
        current_participant_model++;
    }
}

void LLFloaterIMSessionTab::addConversationViewParticipant(LLConversationItem* participant_model, bool update_view)
{
    if (!participant_model)
    {
        // Nothing to do if the model is inexistent
        return;
    }

    // Check if the model already has an associated view
    LLUUID uuid = participant_model->getUUID();
    LLFolderViewItem* widget = get_ptr_in_map(mConversationsWidgets,uuid);

    // If not already present, create the participant view and attach it to the root, otherwise, just refresh it
    if (widget)
    {
        if (update_view)
        {
            updateConversationViewParticipant(uuid); // overkill?
        }
    }
    else
    {
        LLConversationViewParticipant* participant_view = createConversationViewParticipant(participant_model);
        mConversationsWidgets[uuid] = participant_view;
        participant_view->addToFolder(mConversationsRoot);
        participant_view->addToSession(mSessionID);
        participant_view->setVisible(true);
    }
}

void LLFloaterIMSessionTab::removeConversationViewParticipant(const LLUUID& participant_id)
{
    LLFolderViewItem* widget = get_ptr_in_map(mConversationsWidgets,participant_id);
    if (widget)
    {
        LLFolderViewModelItem* item_vmi = widget->getViewModelItem();
        if (item_vmi && item_vmi->getNumRefs() == 1)
        {
            // This is the last pointer, remove participant from session
            // before participant gets deleted on destroyView.
            //
            // Floater (widget) and participant's view can simultaneously
            // co-own the model, in which case view is responsible for
            // the deletion and floater is free to clear and recreate
            // the list, yet there are cases where only widget owns
            // the pointer so it should do the cleanup.
            // See "add_participant".
            //
            // Todo: If it keeps causing issues turn participants
            // into LLPointers in the session
            LLParticipantList* session = getParticipantList();
            if (session)
            {
                session->removeChild(item_vmi);
            }
        }
        widget->destroyView();
    }
    mConversationsWidgets.erase(participant_id);
}

void LLFloaterIMSessionTab::updateConversationViewParticipant(const LLUUID& participant_id)
{
    LLFolderViewItem* widget = get_ptr_in_map(mConversationsWidgets,participant_id);
    if (widget && widget->getViewModelItem())
    {
        widget->refresh();
    }
}

void LLFloaterIMSessionTab::refreshConversation()
{
    // Note: We collect participants names to change the session name only in the case of ad-hoc conversations
    bool is_ad_hoc = (mSession ? mSession->isAdHocSessionType() : false);
    uuid_vec_t participants_uuids; // uuids vector for building the added participants name string
    // For P2P chat, we still need to update the session name who may have changed (switch display name for instance)
    if (mIsP2PChat && mSession)
    {
        participants_uuids.push_back(mSession->mOtherParticipantID);
    }

    conversations_widgets_map::iterator widget_it = mConversationsWidgets.begin();
    while (widget_it != mConversationsWidgets.end())
    {
        // Add the participant to the list except if it's the agent itself (redundant)
        if (is_ad_hoc && (widget_it->first != gAgentID))
        {
            participants_uuids.push_back(widget_it->first);
        }
        if (widget_it->second->getViewModelItem())
        {
            widget_it->second->refresh();
            widget_it->second->setVisible(true);
        }
        ++widget_it;
    }
    if (is_ad_hoc || mIsP2PChat)
    {
        // Build the session name and update it
        std::string session_name;
        if (participants_uuids.size() != 0)
        {
            LLAvatarActions::buildResidentsString(participants_uuids, session_name);
        }
        else
        {
            session_name = LLIMModel::instance().getName(mSessionID);
        }
        updateSessionName(session_name);
    }

    if (mSessionID.notNull())
    {
        LLParticipantList* participant_list = getParticipantList();
        if (participant_list)
        {
            LLFolderViewModelItemCommon::child_list_t::const_iterator current_participant_model = participant_list->getChildrenBegin();
            LLFolderViewModelItemCommon::child_list_t::const_iterator end_participant_model = participant_list->getChildrenEnd();
            LLIMSpeakerMgr *speaker_mgr = LLIMModel::getInstance()->getSpeakerManager(mSessionID);
            while (current_participant_model != end_participant_model)
            {
                LLConversationItemParticipant* participant_model = dynamic_cast<LLConversationItemParticipant*>(*current_participant_model);
                if (speaker_mgr && participant_model)
                {
                    LLSpeaker *participant_speaker = speaker_mgr->findSpeaker(participant_model->getUUID());
                    LLSpeaker *agent_speaker = speaker_mgr->findSpeaker(gAgentID);
                    if (participant_speaker && agent_speaker)
                    {
                        participant_model->setDisplayModeratorRole(agent_speaker->mIsModerator && participant_speaker->mIsModerator);
                    }
                }
                current_participant_model++;
            }
        }
    }

    mConversationViewModel.requestSortAll();
    if(mConversationsRoot != NULL)
    {
        mConversationsRoot->arrangeAll();
        mConversationsRoot->update();
    }
    updateHeaderAndToolbar();
    refresh();
}

// Copied from LLFloaterIMContainer::createConversationViewParticipant(). Refactor opportunity!
LLConversationViewParticipant* LLFloaterIMSessionTab::createConversationViewParticipant(LLConversationItem* item)
{
    LLRect panel_rect = mParticipantListPanel->getRect();

    LLConversationViewParticipant::Params params;
    params.name = item->getDisplayName();
    params.root = mConversationsRoot;
    params.listener = item;
    params.rect = LLRect (0, 24, panel_rect.getWidth(), 0); // *TODO: use conversation_view_participant.xml itemHeight value in lieu of 24
    params.tool_tip = params.name;
    params.participant_id = item->getUUID();

    return LLUICtrlFactory::create<LLConversationViewParticipant>(params);
}

void LLFloaterIMSessionTab::setSortOrder(const LLConversationSort& order)
{
    mConversationViewModel.setSorter(order);
    mConversationsRoot->arrangeAll();
    refreshConversation();
}

void LLFloaterIMSessionTab::onIMSessionMenuItemClicked(const LLSD& userdata)
{
    std::string item = userdata.asString();

    if (item == "compact_view" || item == "expanded_view")
    {
        gSavedSettings.setBOOL("PlainTextChatHistory", item == "compact_view");
    }
    else
    {
        bool prev_value = gSavedSettings.getBOOL(item);
        gSavedSettings.setBOOL(item, !prev_value);
    }

    LLFloaterIMSessionTab::processChatHistoryStyleUpdate();
}

bool LLFloaterIMSessionTab::onIMCompactExpandedMenuItemCheck(const LLSD& userdata)
{
    std::string item = userdata.asString();
    bool is_plain_text_mode = gSavedSettings.getBOOL("PlainTextChatHistory");

    return is_plain_text_mode? item == "compact_view" : item == "expanded_view";
}


bool LLFloaterIMSessionTab::onIMShowModesMenuItemCheck(const LLSD& userdata)
{
    return gSavedSettings.getBOOL(userdata.asString());
}

// enable/disable states for the "show time" and "show names" items of the show-modes menu
bool LLFloaterIMSessionTab::onIMShowModesMenuItemEnable(const LLSD& userdata)
{
    std::string item = userdata.asString();
    bool plain_text = gSavedSettings.getBOOL("PlainTextChatHistory");
    bool is_not_names = (item != "IMShowNamesForP2PConv");
    return (plain_text && (is_not_names || mIsP2PChat));
}

void LLFloaterIMSessionTab::hideOrShowTitle()
{
    const LLFloater::Params& default_params = LLFloater::getDefaultParams();
    S32 floater_header_size = default_params.header_height;

    LLRect floater_rect = getLocalRect();
    S32 top_border_of_contents = floater_rect.mTop - (isTornOff()? floater_header_size : 0);
    LLRect handle_rect (0, floater_rect.mTop, floater_rect.mRight, top_border_of_contents);
    LLRect contents_rect (0, top_border_of_contents, floater_rect.mRight, floater_rect.mBottom);
    mDragHandle->setShape(handle_rect);
    mDragHandle->setVisible(isTornOff());
    mContentsView->setShape(contents_rect);
}

void LLFloaterIMSessionTab::updateSessionName(const std::string& name)
{
    mInputEditor->setLabel(LLTrans::getString("IM_to_label") + " " + name);
}

void LLFloaterIMSessionTab::updateChatIcon(const LLUUID& id)
{
    if (mSession)
    {
        if (mSession->isP2PSessionType())
        {
            LLAvatarIconCtrl* icon = getChild<LLAvatarIconCtrl>(ICN_AVATAR);
            icon->setVisible(true);
            icon->setValue(id);
        }
        if (mSession->isAdHocSessionType())
        {
            LLGroupIconCtrl* icon = getChild<LLGroupIconCtrl>(ICN_GROUP);
            icon->setVisible(true);
        }
        if (mSession->isGroupSessionType())
        {
            LLGroupIconCtrl* icon = getChild<LLGroupIconCtrl>(ICN_GROUP);
            icon->setVisible(true);
            icon->setValue(id);
        }
    }
    else
    {
        if (mIsNearbyChat)
        {
            LLIconCtrl* icon = getChild<LLIconCtrl>(ICN_NEARBY);
            icon->setVisible(true);
        }
    }

}

void LLFloaterIMSessionTab::hideAllStandardButtons()
{
    for (S32 i = 0; i < BUTTON_COUNT; i++)
    {
        if (mButtons[i])
        {
            // Hide the standard header buttons in a docked IM floater.
            mButtons[i]->setVisible(false);
        }
    }
}

void LLFloaterIMSessionTab::updateHeaderAndToolbar()
{
    // prevent start conversation before its container
    LLFloaterIMContainer::getInstance();

    bool is_not_torn_off = !checkIfTornOff();
    if (is_not_torn_off)
    {
        hideAllStandardButtons();
    }

    hideOrShowTitle();

    // Participant list should be visible only in torn off floaters.
    bool is_participant_list_visible =
            !is_not_torn_off
            && mIsParticipantListExpanded
            && !mIsP2PChat;

    mParticipantListAndHistoryStack->collapsePanel(mParticipantListPanel, !is_participant_list_visible);
    mParticipantListPanel->setVisible(is_participant_list_visible);

    // Display collapse image (<<) if the floater is hosted
    // or if it is torn off but has an open control panel.
    bool is_expanded = is_not_torn_off || is_participant_list_visible;

    mExpandCollapseBtn->setImageOverlay(getString(is_expanded ? "collapse_icon" : "expand_icon"));
    mExpandCollapseBtn->setToolTip(
            is_not_torn_off?
                getString("expcol_button_not_tearoff_tooltip") :
                (is_expanded?
                    getString("expcol_button_tearoff_and_expanded_tooltip") :
                    getString("expcol_button_tearoff_and_collapsed_tooltip")));

    // toggle floater's drag handle and title visibility
    if (mDragHandle)
    {
        mDragHandle->setTitleVisible(!is_not_torn_off);
    }

    // The button (>>) should be disabled for torn off P2P conversations.
    mExpandCollapseBtn->setEnabled(is_not_torn_off || !mIsP2PChat);

    mTearOffBtn->setImageOverlay(getString(is_not_torn_off? "tear_off_icon" : "return_icon"));
    mTearOffBtn->setToolTip(getString(is_not_torn_off? "tooltip_to_separate_window" : "tooltip_to_main_window"));


    mCloseBtn->setVisible(is_not_torn_off && !mIsNearbyChat);

    enableDisableCallBtn();
}

void LLFloaterIMSessionTab::forceReshape()
{
    LLRect floater_rect = getRect();
    reshape(llmax(floater_rect.getWidth(), this->getMinWidth()),
            llmax(floater_rect.getHeight(), this->getMinHeight()),
            true);
}


void LLFloaterIMSessionTab::reshapeChatLayoutPanel()
{
    mChatLayoutPanel->reshape(mChatLayoutPanel->getRect().getWidth(), mInputEditor->getRect().getHeight() + mInputEditorPad, false);
}

// static
void LLFloaterIMSessionTab::processChatHistoryStyleUpdate(bool clean_messages/* = false*/)
{
    LLFloaterReg::const_instance_list_t& inst_list = LLFloaterReg::getFloaterList("impanel");
    for (LLFloaterReg::const_instance_list_t::const_iterator iter = inst_list.begin();
            iter != inst_list.end(); ++iter)
    {
        LLFloaterIMSession* floater = dynamic_cast<LLFloaterIMSession*>(*iter);
        if (floater)
        {
            floater->reloadMessages(clean_messages);
        }
    }

    LLFloaterIMNearbyChat* nearby_chat = LLFloaterReg::findTypedInstance<LLFloaterIMNearbyChat>("nearby_chat");
    if (nearby_chat)
    {
             nearby_chat->reloadMessages(clean_messages);
    }
}

// static
void LLFloaterIMSessionTab::reloadEmptyFloaters()
{
    LLFloaterReg::const_instance_list_t& inst_list = LLFloaterReg::getFloaterList("impanel");
    for (LLFloaterReg::const_instance_list_t::const_iterator iter = inst_list.begin();
        iter != inst_list.end(); ++iter)
    {
        LLFloaterIMSession* floater = dynamic_cast<LLFloaterIMSession*>(*iter);
        if (floater && floater->getLastChatMessageIndex() == -1)
        {
            floater->reloadMessages(true);
        }
    }

    LLFloaterIMNearbyChat* nearby_chat = LLFloaterReg::findTypedInstance<LLFloaterIMNearbyChat>("nearby_chat");
    if (nearby_chat && nearby_chat->getMessageArchiveLength() == 0)
    {
        nearby_chat->reloadMessages(true);
    }
}

void LLFloaterIMSessionTab::updateCallBtnState(bool callIsActive)
{
    mVoiceButton->setImageOverlay(callIsActive? getString("call_btn_stop") : getString("call_btn_start"));
    mVoiceButton->setToolTip(callIsActive? getString("end_call_button_tooltip") : getString("start_call_button_tooltip"));

    enableDisableCallBtn();
}

void LLFloaterIMSessionTab::onSlide(LLFloaterIMSessionTab* self)
{
    LLFloaterIMContainer* host_floater = dynamic_cast<LLFloaterIMContainer*>(self->getHost());
    bool should_be_expanded = false;
    if (host_floater)
    {
        // Hide the messages pane if a floater is hosted in the Conversations
        host_floater->collapseMessagesPane(true);
    }
    else ///< floater is torn off
    {
        if (!self->mIsP2PChat)
        {
            // The state must toggle the collapsed state of the panel
            should_be_expanded = self->mParticipantListPanel->isCollapsed();

            // Update the expand/collapse flag of the participant list panel and save it
            gSavedSettings.setBOOL("IMShowControlPanel", should_be_expanded);
            self->mIsParticipantListExpanded = should_be_expanded;

            // Refresh for immediate feedback
            self->refreshConversation();
        }
    }

    self->assignResizeLimits();
    if (should_be_expanded)
    {
        self->forceReshape();
    }
}

void LLFloaterIMSessionTab::onCollapseToLine(LLFloaterIMSessionTab* self)
{
    LLFloaterIMContainer* host_floater = dynamic_cast<LLFloaterIMContainer*>(self->getHost());
    if (!host_floater)
    {
        bool expand = self->isMessagePaneExpanded();
        self->mExpandCollapseLineBtn->setImageOverlay(self->getString(expand ? "collapseline_icon" : "expandline_icon"));
        self->mContentPanel->setVisible(!expand);
        self->mToolbarPanel->setVisible(!expand);
        self->mInputEditor->enableSingleLineMode(expand);
        self->reshapeFloater(expand);
        self->setMessagePaneExpanded(!expand);
    }
}

void LLFloaterIMSessionTab::reshapeFloater(bool collapse)
{
    LLRect floater_rect = getRect();

    if(collapse)
    {
        mFloaterHeight = floater_rect.getHeight();
        S32 height = mContentPanel->getRect().getHeight() + mToolbarPanel->getRect().getHeight()
            + mChatLayoutPanel->getRect().getHeight() - mChatLayoutPanelHeight + 2;
        floater_rect.mTop -= height;

        setResizeLimits(getMinWidth(), floater_rect.getHeight());
    }
    else
    {
        floater_rect.mTop = floater_rect.mBottom + mFloaterHeight;
        setResizeLimits(getMinWidth(), mMinFloaterHeight);
    }

    enableResizeCtrls(true, true, !collapse);

    saveCollapsedState();
    setShape(floater_rect, true);
    mBodyStack->updateLayout();
}

void LLFloaterIMSessionTab::restoreFloater()
{
    if(!isMessagePaneExpanded())
    {
        if(isMinimized())
        {
            setMinimized(false);
        }
        mContentPanel->setVisible(true);
        mToolbarPanel->setVisible(true);
        LLRect floater_rect = getRect();
        floater_rect.mTop = floater_rect.mBottom + mFloaterHeight;
        setShape(floater_rect, true);
        mBodyStack->updateLayout();
        mExpandCollapseLineBtn->setImageOverlay(getString("expandline_icon"));
        setResizeLimits(getMinWidth(), mMinFloaterHeight);
        setMessagePaneExpanded(true);
        saveCollapsedState();
        mInputEditor->enableSingleLineMode(false);
        enableResizeCtrls(true, true, true);
    }
}

/*virtual*/
void LLFloaterIMSessionTab::onOpen(const LLSD& key)
{
    if (!checkIfTornOff())
    {
        LLFloaterIMContainer* host_floater = dynamic_cast<LLFloaterIMContainer*>(getHost());
        // Show the messages pane when opening a floater hosted in the Conversations
        host_floater->collapseMessagesPane(false);
    }

    mInputButtonPanel->setVisible(isTornOff());

    setFocus(true);
}


void LLFloaterIMSessionTab::onTearOffClicked()
{
    restoreFloater();
    setFollows(isTornOff()? FOLLOWS_ALL : FOLLOWS_NONE);
    mSaveRect = isTornOff();
    initRectControl();
    LLFloater::onClickTearOff(this);
    LLFloaterIMContainer* container = LLFloaterReg::findTypedInstance<LLFloaterIMContainer>("im_container");

    if (isTornOff())
    {
        container->selectAdjacentConversation(false);
        forceReshape();
    }
    //Upon re-docking the torn off floater, select the corresponding conversation line item
    else
    {
        container->selectConversation(mSessionID);

    }
    mInputButtonPanel->setVisible(isTornOff());

    refreshConversation();
    updateGearBtn();
}

void LLFloaterIMSessionTab::updateGearBtn()
{
    bool prevVisibility = mGearBtn->getVisible();
    mGearBtn->setVisible(checkIfTornOff() && mIsP2PChat);


    // Move buttons if Gear button changed visibility
    if(prevVisibility != mGearBtn->getVisible())
    {
        LLRect gear_btn_rect =  mGearBtn->getRect();
        LLRect add_btn_rect = mAddBtn->getRect();
        LLRect call_btn_rect = mVoiceButton->getRect();
        S32 gap_width = call_btn_rect.mLeft - add_btn_rect.mRight;
        S32 right_shift = gear_btn_rect.getWidth() + gap_width;
        if(mGearBtn->getVisible())
        {
            // Move buttons to the right to give space for Gear button
            add_btn_rect.translate(right_shift,0);
            call_btn_rect.translate(right_shift,0);
        }
        else
        {
            add_btn_rect.translate(-right_shift,0);
            call_btn_rect.translate(-right_shift,0);
        }
        mAddBtn->setRect(add_btn_rect);
        mVoiceButton->setRect(call_btn_rect);
    }
}

void LLFloaterIMSessionTab::initBtns()
{
    LLRect gear_btn_rect =  mGearBtn->getRect();
    LLRect add_btn_rect = mAddBtn->getRect();
    LLRect call_btn_rect = mVoiceButton->getRect();
    S32 gap_width = call_btn_rect.mLeft - add_btn_rect.mRight;
    S32 right_shift = gear_btn_rect.getWidth() + gap_width;

    add_btn_rect.translate(-right_shift,0);
    call_btn_rect.translate(-right_shift,0);

    mAddBtn->setRect(add_btn_rect);
    mVoiceButton->setRect(call_btn_rect);
}

// static
bool LLFloaterIMSessionTab::isChatMultiTab()
{
    // Restart is required in order to change chat window type.
    return true;
}

bool LLFloaterIMSessionTab::checkIfTornOff()
{
    bool isTorn = !getHost();

    if (isTorn != isTornOff())
    {
        setTornOff(isTorn);
        refreshConversation();
    }

    return isTorn;
}

void LLFloaterIMSessionTab::doToSelected(const LLSD& userdata)
{
    // Get the list of selected items in the tab
    std::string command = userdata.asString();
    uuid_vec_t selected_uuids;
    getSelectedUUIDs(selected_uuids);

    // Perform the command (IM, profile, etc...) on the list using the general conversation container method
    LLFloaterIMContainer* floater_container = LLFloaterIMContainer::getInstance();
    // Note: By construction, those can only be participants so we can call doToParticipants() directly
    floater_container->doToParticipants(command, selected_uuids);
}

bool LLFloaterIMSessionTab::enableContextMenuItem(const LLSD& userdata)
{
    // Get the list of selected items in the tab
    std::string command = userdata.asString();
    uuid_vec_t selected_uuids;
    getSelectedUUIDs(selected_uuids);

    // Perform the item enable test on the list using the general conversation container method
    LLFloaterIMContainer* floater_container = LLFloaterIMContainer::getInstance();
    return floater_container->enableContextMenuItem(command, selected_uuids);
}

bool LLFloaterIMSessionTab::checkContextMenuItem(const LLSD& userdata)
{
    // Get the list of selected items in the tab
    std::string command = userdata.asString();
    uuid_vec_t selected_uuids;
    getSelectedUUIDs(selected_uuids);

    // Perform the item check on the list using the general conversation container method
    LLFloaterIMContainer* floater_container = LLFloaterIMContainer::getInstance();
    return floater_container->checkContextMenuItem(command, selected_uuids);
}

void LLFloaterIMSessionTab::getSelectedUUIDs(uuid_vec_t& selected_uuids)
{
    const std::set<LLFolderViewItem*> selected_items = mConversationsRoot->getSelectionList();

    std::set<LLFolderViewItem*>::const_iterator it = selected_items.begin();
    const std::set<LLFolderViewItem*>::const_iterator it_end = selected_items.end();

    for (; it != it_end; ++it)
    {
        LLConversationItem* conversation_item = static_cast<LLConversationItem *>((*it)->getViewModelItem());
        if (conversation_item)
        {
            selected_uuids.push_back(conversation_item->getUUID());
        }
    }
}

LLConversationItem* LLFloaterIMSessionTab::getCurSelectedViewModelItem()
{
    LLConversationItem *conversationItem = NULL;

    if(mConversationsRoot &&
        mConversationsRoot->getCurSelectedItem() &&
        mConversationsRoot->getCurSelectedItem()->getViewModelItem())
    {
        conversationItem = static_cast<LLConversationItem *>(mConversationsRoot->getCurSelectedItem()->getViewModelItem()) ;
    }

    return conversationItem;
}

void LLFloaterIMSessionTab::saveCollapsedState()
{
    LLFloaterIMSessionTab* conversp = LLFloaterIMSessionTab::getConversation(mSessionID);
    if(conversp->isNearbyChat())
    {
        gSavedPerAccountSettings.setBOOL("NearbyChatIsNotCollapsed", isMessagePaneExpanded());
    }
}

LLView* LLFloaterIMSessionTab::getChatHistory()
{
    return mChatHistory;
}

bool LLFloaterIMSessionTab::handleKeyHere(KEY key, MASK mask )
{
    bool handled = false;

    if(mask == MASK_ALT)
    {
        LLFloaterIMContainer* floater_container = LLFloaterIMContainer::getInstance();
        if (KEY_RETURN == key && !isTornOff())
        {
            floater_container->expandConversation();
            handled = true;
        }
        if ((KEY_UP == key) || (KEY_LEFT == key))
        {
            floater_container->selectNextorPreviousConversation(false);
            handled = true;
        }
        if ((KEY_DOWN == key ) || (KEY_RIGHT == key))
        {
            floater_container->selectNextorPreviousConversation(true);
            handled = true;
        }
    }
    return handled;
}