#include "inventorywindow.hpp"

#include <cmath>
#include <stdexcept>

#include <MyGUI_Button.h>
#include <MyGUI_EditBox.h>
#include <MyGUI_ImageBox.h>
#include <MyGUI_InputManager.h>
#include <MyGUI_RenderManager.h>
#include <MyGUI_Window.h>

#include <osg/Texture2D>

#include <components/misc/strings/algorithm.hpp>

#include <components/myguiplatform/myguitexture.hpp>

#include <components/settings/values.hpp>

#include "../mwbase/environment.hpp"
#include "../mwbase/luamanager.hpp"
#include "../mwbase/mechanicsmanager.hpp"
#include "../mwbase/windowmanager.hpp"
#include "../mwbase/world.hpp"

#include "../mwworld/action.hpp"
#include "../mwworld/class.hpp"
#include "../mwworld/inventorystore.hpp"

#include "../mwmechanics/actorutil.hpp"
#include "../mwmechanics/npcstats.hpp"

#include "countdialog.hpp"
#include "draganddrop.hpp"
#include "inventoryitemmodel.hpp"
#include "itemtransfer.hpp"
#include "itemview.hpp"
#include "settings.hpp"
#include "sortfilteritemmodel.hpp"
#include "tooltips.hpp"
#include "tradeitemmodel.hpp"
#include "tradewindow.hpp"

namespace
{

    bool isRightHandWeapon(const MWWorld::Ptr& item)
    {
        if (item.getClass().getType() != ESM::Weapon::sRecordId)
            return false;
        std::vector<int> equipmentSlots = item.getClass().getEquipmentSlots(item).first;
        return (!equipmentSlots.empty() && equipmentSlots.front() == MWWorld::InventoryStore::Slot_CarriedRight);
    }

}

namespace MWGui
{
    namespace
    {
        WindowSettingValues getModeSettings(GuiMode mode)
        {
            switch (mode)
            {
                case GM_Container:
                    return makeInventoryContainerWindowSettingValues();
                case GM_Companion:
                    return makeInventoryCompanionWindowSettingValues();
                case GM_Barter:
                    return makeInventoryBarterWindowSettingValues();
                default:
                    return makeInventoryWindowSettingValues();
            }
        }
    }

    InventoryWindow::InventoryWindow(DragAndDrop& dragAndDrop, ItemTransfer& itemTransfer, osg::Group* parent,
        Resource::ResourceSystem* resourceSystem)
        : WindowPinnableBase("openmw_inventory_window.layout")
        , mDragAndDrop(&dragAndDrop)
        , mItemTransfer(&itemTransfer)
        , mSelectedItem(-1)
        , mSortModel(nullptr)
        , mTradeModel(nullptr)
        , mGuiMode(GM_Inventory)
        , mLastXSize(0)
        , mLastYSize(0)
        , mPreview(std::make_unique<MWRender::InventoryPreview>(parent, resourceSystem, MWMechanics::getPlayer()))
        , mTrading(false)
        , mUpdateNextFrame(false)
    {
        mPreviewTexture
            = std::make_unique<osgMyGUI::OSGTexture>(mPreview->getTexture(), mPreview->getTextureStateSet());
        mPreview->rebuild();

        mMainWidget->castType<MyGUI::Window>()->eventWindowChangeCoord
            += MyGUI::newDelegate(this, &InventoryWindow::onWindowResize);

        getWidget(mAvatar, "Avatar");
        getWidget(mAvatarImage, "AvatarImage");
        getWidget(mEncumbranceBar, "EncumbranceBar");
        getWidget(mFilterAll, "AllButton");
        getWidget(mFilterWeapon, "WeaponButton");
        getWidget(mFilterApparel, "ApparelButton");
        getWidget(mFilterMagic, "MagicButton");
        getWidget(mFilterMisc, "MiscButton");
        getWidget(mLeftPane, "LeftPane");
        getWidget(mRightPane, "RightPane");
        getWidget(mArmorRating, "ArmorRating");
        getWidget(mFilterEdit, "FilterEdit");

        mAvatarImage->eventMouseButtonClick += MyGUI::newDelegate(this, &InventoryWindow::onAvatarClicked);
        mAvatarImage->setRenderItemTexture(mPreviewTexture.get());
        mAvatarImage->getSubWidgetMain()->_setUVSet(MyGUI::FloatRect(0.f, 0.f, 1.f, 1.f));

        getWidget(mItemView, "ItemView");
        mItemView->eventItemClicked += MyGUI::newDelegate(this, &InventoryWindow::onItemSelected);
        mItemView->eventBackgroundClicked += MyGUI::newDelegate(this, &InventoryWindow::onBackgroundSelected);

        mFilterAll->eventMouseButtonClick += MyGUI::newDelegate(this, &InventoryWindow::onFilterChanged);
        mFilterWeapon->eventMouseButtonClick += MyGUI::newDelegate(this, &InventoryWindow::onFilterChanged);
        mFilterApparel->eventMouseButtonClick += MyGUI::newDelegate(this, &InventoryWindow::onFilterChanged);
        mFilterMagic->eventMouseButtonClick += MyGUI::newDelegate(this, &InventoryWindow::onFilterChanged);
        mFilterMisc->eventMouseButtonClick += MyGUI::newDelegate(this, &InventoryWindow::onFilterChanged);
        mFilterEdit->eventEditTextChange += MyGUI::newDelegate(this, &InventoryWindow::onNameFilterChanged);

        mFilterAll->setStateSelected(true);

        setGuiMode(mGuiMode);

        adjustPanes();
    }

    void InventoryWindow::adjustPanes()
    {
        const float aspect = 0.5; // fixed aspect ratio for the avatar image
        int leftPaneWidth = static_cast<int>((mMainWidget->getSize().height - 44 - mArmorRating->getHeight()) * aspect);
        mLeftPane->setSize(leftPaneWidth, mMainWidget->getSize().height - 44);
        mRightPane->setCoord(mLeftPane->getPosition().left + leftPaneWidth + 4, mRightPane->getPosition().top,
            mMainWidget->getSize().width - 12 - leftPaneWidth - 15, mMainWidget->getSize().height - 44);
    }

    void InventoryWindow::updatePlayer()
    {
        mPtr = MWBase::Environment::get().getWorld()->getPlayerPtr();
        auto tradeModel = std::make_unique<TradeItemModel>(std::make_unique<InventoryItemModel>(mPtr), MWWorld::Ptr());
        mTradeModel = tradeModel.get();

        mPtr.getClass().getInventoryStore(mPtr).setContListener(this);

        if (mSortModel) // reuse existing SortModel when possible to keep previous category/filter settings
            mSortModel->setSourceModel(std::move(tradeModel));
        else
        {
            auto sortModel = std::make_unique<SortFilterItemModel>(std::move(tradeModel));
            mSortModel = sortModel.get();
            mItemView->setModel(std::move(sortModel));
        }

        mSortModel->setNameFilter(mFilterEdit->getCaption());

        mFilterAll->setStateSelected(true);
        mFilterWeapon->setStateSelected(false);
        mFilterApparel->setStateSelected(false);
        mFilterMagic->setStateSelected(false);
        mFilterMisc->setStateSelected(false);

        mPreview->updatePtr(mPtr);
        mPreview->rebuild();
        mPreview->update();

        dirtyPreview();

        updatePreviewSize();

        updateEncumbranceBar();
        mItemView->update();
        notifyContentChanged();
    }

    void InventoryWindow::clear()
    {
        mPtr = MWWorld::Ptr();
        mTradeModel = nullptr;
        mSortModel = nullptr;
        mItemView->setModel(nullptr);
    }

    void InventoryWindow::toggleMaximized()
    {
        const WindowSettingValues settings = getModeSettings(mGuiMode);
        const WindowRectSettingValues& rect = settings.mIsMaximized ? settings.mRegular : settings.mMaximized;

        MyGUI::IntSize viewSize = MyGUI::RenderManager::getInstance().getViewSize();
        const float x = rect.mX * viewSize.width;
        const float y = rect.mY * viewSize.height;
        const float w = rect.mW * viewSize.width;
        const float h = rect.mH * viewSize.height;
        MyGUI::Window* window = mMainWidget->castType<MyGUI::Window>();
        window->setCoord(x, y, w, h);

        settings.mIsMaximized.set(!settings.mIsMaximized);

        adjustPanes();
        updatePreviewSize();
    }

    void InventoryWindow::setGuiMode(GuiMode mode)
    {
        mGuiMode = mode;
        const WindowSettingValues settings = getModeSettings(mGuiMode);
        setPinButtonVisible(mode != GM_Container && mode != GM_Companion && mode != GM_Barter);

        const WindowRectSettingValues& rect = settings.mIsMaximized ? settings.mMaximized : settings.mRegular;

        MyGUI::IntSize viewSize = MyGUI::RenderManager::getInstance().getViewSize();
        MyGUI::IntPoint pos(static_cast<int>(rect.mX * viewSize.width), static_cast<int>(rect.mY * viewSize.height));
        MyGUI::IntSize size(static_cast<int>(rect.mW * viewSize.width), static_cast<int>(rect.mH * viewSize.height));

        bool needUpdate = (size.width != mMainWidget->getWidth() || size.height != mMainWidget->getHeight());

        mMainWidget->setPosition(pos);
        mMainWidget->setSize(size);

        adjustPanes();

        if (needUpdate)
            updatePreviewSize();
    }

    SortFilterItemModel* InventoryWindow::getSortFilterModel()
    {
        return mSortModel;
    }

    TradeItemModel* InventoryWindow::getTradeModel()
    {
        return mTradeModel;
    }

    ItemModel* InventoryWindow::getModel()
    {
        return mTradeModel;
    }

    void InventoryWindow::onBackgroundSelected()
    {
        if (mDragAndDrop->mIsOnDragAndDrop)
            mDragAndDrop->drop(mTradeModel, mItemView);
    }

    void InventoryWindow::onItemSelected(int index)
    {
        onItemSelectedFromSourceModel(mSortModel->mapToSource(index));
    }

    void InventoryWindow::onItemSelectedFromSourceModel(int index)
    {
        if (mDragAndDrop->mIsOnDragAndDrop)
        {
            mDragAndDrop->drop(mTradeModel, mItemView);
            return;
        }

        const ItemStack& item = mTradeModel->getItem(index);
        const ESM::RefId& sound = item.mBase.getClass().getDownSoundId(item.mBase);

        MWWorld::Ptr object = item.mBase;
        int count = item.mCount;
        bool shift = MyGUI::InputManager::getInstance().isShiftPressed();

        if (MyGUI::InputManager::getInstance().isControlPressed())
            count = 1;

        if (mTrading)
        {
            // Can't give conjured items to a merchant
            if (item.mFlags & ItemStack::Flag_Bound)
            {
                MWBase::Environment::get().getWindowManager()->playSound(sound);
                MWBase::Environment::get().getWindowManager()->messageBox("#{sBarterDialog9}");
                return;
            }

            // check if merchant accepts item
            int services = MWBase::Environment::get().getWindowManager()->getTradeWindow()->getMerchantServices();
            if (!object.getClass().canSell(object, services))
            {
                MWBase::Environment::get().getWindowManager()->playSound(sound);
                MWBase::Environment::get().getWindowManager()->messageBox("#{sBarterDialog4}");
                return;
            }
        }

        // If we unequip weapon during attack, it can lead to unexpected behaviour
        if (MWBase::Environment::get().getMechanicsManager()->isAttackingOrSpell(mPtr))
        {
            bool isWeapon = item.mBase.getType() == ESM::Weapon::sRecordId;
            MWWorld::InventoryStore& invStore = mPtr.getClass().getInventoryStore(mPtr);

            if (isWeapon && invStore.isEquipped(item.mBase))
            {
                MWBase::Environment::get().getWindowManager()->messageBox("#{sCantEquipWeapWarning}");
                return;
            }
        }

        if (count > 1 && !shift)
        {
            CountDialog* dialog = MWBase::Environment::get().getWindowManager()->getCountDialog();
            std::string message = mTrading ? "#{sQuanityMenuMessage01}" : "#{sTake}";
            std::string name{ object.getClass().getName(object) };
            name += MWGui::ToolTips::getSoulString(object.getCellRef());
            dialog->openCountDialog(name, message, count);
            dialog->eventOkClicked.clear();

            if (mTrading)
                dialog->eventOkClicked += MyGUI::newDelegate(this, &InventoryWindow::sellItem);
            else if (MyGUI::InputManager::getInstance().isAltPressed())
                dialog->eventOkClicked += MyGUI::newDelegate(this, &InventoryWindow::transferItem);
            else
                dialog->eventOkClicked += MyGUI::newDelegate(this, &InventoryWindow::dragItem);

            mSelectedItem = index;
        }
        else
        {
            mSelectedItem = index;

            if (mTrading)
                sellItem(nullptr, count);
            else if (MyGUI::InputManager::getInstance().isAltPressed())
                transferItem(nullptr, count);
            else
                dragItem(nullptr, count);
        }
    }

    void InventoryWindow::ensureSelectedItemUnequipped(int count)
    {
        const ItemStack& item = mTradeModel->getItem(mSelectedItem);
        if (item.mType == ItemStack::Type_Equipped)
        {
            MWWorld::InventoryStore& invStore = mPtr.getClass().getInventoryStore(mPtr);
            MWWorld::Ptr newStack = *invStore.unequipItemQuantity(item.mBase, count);

            // The unequipped item was re-stacked. We have to update the index
            // since the item pointed does not exist anymore.
            if (item.mBase != newStack)
            {
                updateItemView(); // Unequipping can produce a new stack, not yet in the window...

                // newIndex will store the index of the ItemStack the item was stacked on
                int newIndex = -1;
                for (size_t i = 0; i < mTradeModel->getItemCount(); ++i)
                {
                    if (mTradeModel->getItem(i).mBase == newStack)
                    {
                        newIndex = i;
                        break;
                    }
                }

                if (newIndex == -1)
                    throw std::runtime_error("Can't find restacked item");

                mSelectedItem = newIndex;
            }
        }
    }

    void InventoryWindow::dragItem(MyGUI::Widget* /*sender*/, std::size_t count)
    {
        ensureSelectedItemUnequipped(count);
        mDragAndDrop->startDrag(mSelectedItem, mSortModel, mTradeModel, mItemView, count);
        notifyContentChanged();
    }

    void InventoryWindow::transferItem(MyGUI::Widget* /*sender*/, std::size_t count)
    {
        ensureSelectedItemUnequipped(count);
        mItemTransfer->apply(mTradeModel->getItem(mSelectedItem), count, *mItemView);
        notifyContentChanged();
    }

    void InventoryWindow::sellItem(MyGUI::Widget* /*sender*/, std::size_t count)
    {
        ensureSelectedItemUnequipped(count);
        const ItemStack& item = mTradeModel->getItem(mSelectedItem);
        const ESM::RefId& sound = item.mBase.getClass().getUpSoundId(item.mBase);
        MWBase::Environment::get().getWindowManager()->playSound(sound);

        if (item.mType == ItemStack::Type_Barter)
        {
            // this was an item borrowed to us by the merchant
            mTradeModel->returnItemBorrowedToUs(mSelectedItem, count);
            MWBase::Environment::get().getWindowManager()->getTradeWindow()->returnItem(mSelectedItem, count);
        }
        else
        {
            // borrow item to the merchant
            mTradeModel->borrowItemFromUs(mSelectedItem, count);
            MWBase::Environment::get().getWindowManager()->getTradeWindow()->borrowItem(mSelectedItem, count);
        }

        mItemView->update();
        notifyContentChanged();
    }

    void InventoryWindow::updateItemView()
    {
        MWBase::Environment::get().getWindowManager()->updateSpellWindow();

        mItemView->update();

        dirtyPreview();
    }

    void InventoryWindow::onOpen()
    {
        // Reset the filter focus when opening the window
        MyGUI::Widget* focus = MyGUI::InputManager::getInstance().getKeyFocusWidget();
        if (focus == mFilterEdit)
            MWBase::Environment::get().getWindowManager()->setKeyFocusWidget(nullptr);

        if (!mPtr.isEmpty())
        {
            updateEncumbranceBar();
            mItemView->update();
            notifyContentChanged();
        }
        adjustPanes();

        mItemTransfer->addTarget(*mItemView);
    }

    void InventoryWindow::onClose()
    {
        mItemTransfer->removeTarget(*mItemView);
    }

    void InventoryWindow::onWindowResize(MyGUI::Window* _sender)
    {
        WindowBase::clampWindowCoordinates(_sender);

        adjustPanes();
        const WindowSettingValues settings = getModeSettings(mGuiMode);

        MyGUI::IntSize viewSize = MyGUI::RenderManager::getInstance().getViewSize();

        settings.mRegular.mX.set(_sender->getPosition().left / static_cast<float>(viewSize.width));
        settings.mRegular.mY.set(_sender->getPosition().top / static_cast<float>(viewSize.height));
        settings.mRegular.mW.set(_sender->getSize().width / static_cast<float>(viewSize.width));
        settings.mRegular.mH.set(_sender->getSize().height / static_cast<float>(viewSize.height));
        settings.mIsMaximized.set(false);

        if (mMainWidget->getSize().width != mLastXSize || mMainWidget->getSize().height != mLastYSize)
        {
            mLastXSize = mMainWidget->getSize().width;
            mLastYSize = mMainWidget->getSize().height;

            updatePreviewSize();
            updateArmorRating();
        }
    }

    void InventoryWindow::updateArmorRating()
    {
        if (mPtr.isEmpty())
            return;

        mArmorRating->setCaptionWithReplacing(
            "#{sArmor}: " + MyGUI::utility::toString(static_cast<int>(mPtr.getClass().getArmorRating(mPtr))));
        if (mArmorRating->getTextSize().width > mArmorRating->getSize().width)
            mArmorRating->setCaptionWithReplacing(
                MyGUI::utility::toString(static_cast<int>(mPtr.getClass().getArmorRating(mPtr))));
    }

    void InventoryWindow::updatePreviewSize()
    {
        const MyGUI::IntSize viewport = getPreviewViewportSize();
        mPreview->setViewport(viewport.width, viewport.height);
        mAvatarImage->getSubWidgetMain()->_setUVSet(
            MyGUI::FloatRect(0.f, 0.f, viewport.width / float(mPreview->getTextureWidth()),
                viewport.height / float(mPreview->getTextureHeight())));
    }

    void InventoryWindow::onNameFilterChanged(MyGUI::EditBox* _sender)
    {
        mSortModel->setNameFilter(_sender->getCaption());
        mItemView->update();
    }

    void InventoryWindow::onFilterChanged(MyGUI::Widget* _sender)
    {
        if (_sender == mFilterAll)
            mSortModel->setCategory(SortFilterItemModel::Category_All);
        else if (_sender == mFilterWeapon)
            mSortModel->setCategory(SortFilterItemModel::Category_Weapon);
        else if (_sender == mFilterApparel)
            mSortModel->setCategory(SortFilterItemModel::Category_Apparel);
        else if (_sender == mFilterMagic)
            mSortModel->setCategory(SortFilterItemModel::Category_Magic);
        else if (_sender == mFilterMisc)
            mSortModel->setCategory(SortFilterItemModel::Category_Misc);
        mFilterAll->setStateSelected(false);
        mFilterWeapon->setStateSelected(false);
        mFilterApparel->setStateSelected(false);
        mFilterMagic->setStateSelected(false);
        mFilterMisc->setStateSelected(false);

        mItemView->update();

        _sender->castType<MyGUI::Button>()->setStateSelected(true);
    }

    void InventoryWindow::onPinToggled()
    {
        Settings::windows().mInventoryPin.set(mPinned);

        MWBase::Environment::get().getWindowManager()->setWeaponVisibility(!mPinned);
    }

    void InventoryWindow::onTitleDoubleClicked()
    {
        if (MyGUI::InputManager::getInstance().isShiftPressed())
            toggleMaximized();
        else if (!mPinned)
            MWBase::Environment::get().getWindowManager()->toggleVisible(GW_Inventory);
    }

    void InventoryWindow::useItem(const MWWorld::Ptr& ptr, bool force)
    {
        const ESM::RefId& script = ptr.getClass().getScript(ptr);
        if (!script.empty())
        {
            // Don't try to equip the item if PCSkipEquip is set to 1
            if (ptr.getRefData().getLocals().getIntVar(script, "pcskipequip") == 1)
            {
                ptr.getRefData().getLocals().setVarByInt(script, "onpcequip", 1);
                return;
            }
            ptr.getRefData().getLocals().setVarByInt(script, "onpcequip", 0);
        }

        MWWorld::Ptr player = MWMechanics::getPlayer();
        auto type = ptr.getType();
        bool isWeaponOrArmor = type == ESM::Weapon::sRecordId || type == ESM::Armor::sRecordId;
        bool isBroken = ptr.getClass().hasItemHealth(ptr) && ptr.getCellRef().getCharge() == 0;

        // In vanilla, broken armor or weapons cannot be equipped
        // tools with 0 charges is equippable
        if (isBroken && isWeaponOrArmor)
        {
            MWBase::Environment::get().getWindowManager()->messageBox("#{sInventoryMessage1}");
            return;
        }

        bool canEquip = ptr.getClass().canBeEquipped(ptr, mPtr).first != 0;
        bool shouldSetOnPcEquip = canEquip || force;

        // If the item has a script, set OnPCEquip or PCSkipEquip to 1
        if (!script.empty() && shouldSetOnPcEquip)
        {
            // Ingredients, books and repair hammers must not have OnPCEquip set to 1 here
            bool isBook = type == ESM::Book::sRecordId;
            if (!isBook && type != ESM::Ingredient::sRecordId && type != ESM::Repair::sRecordId)
                ptr.getRefData().getLocals().setVarByInt(script, "onpcequip", 1);
            // Books must have PCSkipEquip set to 1 instead
            else if (isBook)
                ptr.getRefData().getLocals().setVarByInt(script, "pcskipequip", 1);
        }

        std::unique_ptr<MWWorld::Action> action = ptr.getClass().use(ptr, force);
        action->execute(player, !canEquip);

        // Handles partial equipping (final part)
        if (mEquippedStackableCount.has_value())
        {
            // the count to unequip
            int count = ptr.getCellRef().getCount() - mDragAndDrop->mDraggedCount - mEquippedStackableCount.value();
            if (count > 0)
            {
                MWWorld::InventoryStore& invStore = mPtr.getClass().getInventoryStore(mPtr);
                invStore.unequipItemQuantity(ptr, count);
                updateItemView();
            }
            mEquippedStackableCount.reset();
        }

        if (isVisible())
        {
            mItemView->update();

            notifyContentChanged();
        }
        // else: will be updated in open()
    }

    void InventoryWindow::onAvatarClicked(MyGUI::Widget* _sender)
    {
        if (mDragAndDrop->mIsOnDragAndDrop)
        {
            MWWorld::Ptr ptr = mDragAndDrop->mItem.mBase;

            auto [canEquipRes, canEquipMsg] = ptr.getClass().canBeEquipped(ptr, mPtr);
            if (canEquipRes == 0) // cannot equip
            {
                mDragAndDrop->drop(mTradeModel, mItemView); // also plays down sound
                MWBase::Environment::get().getWindowManager()->messageBox(canEquipMsg);
                return;
            }

            mDragAndDrop->finish();

            if (mDragAndDrop->mSourceModel != mTradeModel)
            {
                // Move item to the player's inventory
                ptr = mDragAndDrop->mSourceModel->moveItem(
                    mDragAndDrop->mItem, mDragAndDrop->mDraggedCount, mTradeModel);
            }

            // Handles partial equipping
            mEquippedStackableCount.reset();
            const auto slots = ptr.getClass().getEquipmentSlots(ptr);
            if (!slots.first.empty() && slots.second)
            {
                MWWorld::InventoryStore& invStore = mPtr.getClass().getInventoryStore(mPtr);
                MWWorld::ConstContainerStoreIterator slotIt = invStore.getSlot(slots.first.front());

                // Save the currently equipped count before useItem()
                if (slotIt != invStore.end() && slotIt->getCellRef().getRefId() == ptr.getCellRef().getRefId())
                    mEquippedStackableCount = slotIt->getCellRef().getCount();
                else
                    mEquippedStackableCount = 0;
            }

            MWBase::Environment::get().getLuaManager()->useItem(ptr, MWMechanics::getPlayer(), false);

            // If item is ingredient or potion don't stop drag and drop to simplify action of taking more than one 1
            // item
            if ((ptr.getType() == ESM::Potion::sRecordId || ptr.getType() == ESM::Ingredient::sRecordId)
                && mDragAndDrop->mDraggedCount > 1)
            {
                // Item can be provided from other window for example container.
                // But after DragAndDrop::startDrag item automaticly always gets to player inventory.
                mSelectedItem = getModel()->getIndex(mDragAndDrop->mItem);
                dragItem(nullptr, mDragAndDrop->mDraggedCount - 1);
            }
        }
        else
        {
            MyGUI::IntPoint mousePos
                = MyGUI::InputManager::getInstance().getLastPressedPosition(MyGUI::MouseButton::Left);
            MyGUI::IntPoint relPos = mousePos - mAvatarImage->getAbsolutePosition();

            MWWorld::Ptr itemSelected = getAvatarSelectedItem(relPos.left, relPos.top);
            if (itemSelected.isEmpty())
                return;

            for (size_t i = 0; i < mTradeModel->getItemCount(); ++i)
            {
                if (mTradeModel->getItem(i).mBase == itemSelected)
                {
                    onItemSelectedFromSourceModel(i);
                    return;
                }
            }
            throw std::runtime_error("Can't find clicked item");
        }
    }

    MWWorld::Ptr InventoryWindow::getAvatarSelectedItem(int x, int y)
    {
        const osg::Vec2f viewport_coords = mapPreviewWindowToViewport(x, y);
        int slot = mPreview->getSlotSelected(viewport_coords.x(), viewport_coords.y());

        if (slot == -1)
            return MWWorld::Ptr();

        MWWorld::InventoryStore& invStore = mPtr.getClass().getInventoryStore(mPtr);
        if (invStore.getSlot(slot) != invStore.end())
        {
            MWWorld::Ptr item = *invStore.getSlot(slot);
            if (!item.getClass().showsInInventory(item))
                return MWWorld::Ptr();
            return item;
        }

        return MWWorld::Ptr();
    }

    void InventoryWindow::updateEncumbranceBar()
    {
        MWWorld::Ptr player = MWMechanics::getPlayer();

        float capacity = player.getClass().getCapacity(player);
        float encumbrance = player.getClass().getEncumbrance(player);
        mTradeModel->adjustEncumbrance(encumbrance);
        mEncumbranceBar->setValue(std::ceil(encumbrance), static_cast<int>(capacity));
    }

    void InventoryWindow::onFrame(float dt)
    {
        if (mUpdateNextFrame)
        {
            if (mTrading)
            {
                mTradeModel->updateBorrowed();
                MWBase::Environment::get().getWindowManager()->getTradeWindow()->mTradeModel->updateBorrowed();
                MWBase::Environment::get().getWindowManager()->getTradeWindow()->updateItemView();
                MWBase::Environment::get().getWindowManager()->getTradeWindow()->updateOffer();
            }

            updateEncumbranceBar();
            mDragAndDrop->update();
            mItemView->update();
            notifyContentChanged();
            mUpdateNextFrame = false;
        }
    }

    void InventoryWindow::setTrading(bool trading)
    {
        mTrading = trading;
    }

    void InventoryWindow::dirtyPreview()
    {
        mPreview->update();

        updateArmorRating();
    }

    void InventoryWindow::notifyContentChanged()
    {
        // update the spell window just in case new enchanted items were added to inventory
        MWBase::Environment::get().getWindowManager()->updateSpellWindow();

        MWBase::Environment::get().getMechanicsManager()->updateMagicEffects(MWMechanics::getPlayer());

        dirtyPreview();
    }

    void InventoryWindow::pickUpObject(MWWorld::Ptr object)
    {
        // If the inventory is not yet enabled, don't pick anything up
        if (!MWBase::Environment::get().getWindowManager()->isAllowed(GW_Inventory))
            return;
        // make sure the object is of a type that can be picked up
        auto type = object.getType();
        if ((type != ESM::Apparatus::sRecordId) && (type != ESM::Armor::sRecordId) && (type != ESM::Book::sRecordId)
            && (type != ESM::Clothing::sRecordId) && (type != ESM::Ingredient::sRecordId)
            && (type != ESM::Light::sRecordId) && (type != ESM::Miscellaneous::sRecordId)
            && (type != ESM::Lockpick::sRecordId) && (type != ESM::Probe::sRecordId) && (type != ESM::Repair::sRecordId)
            && (type != ESM::Weapon::sRecordId) && (type != ESM::Potion::sRecordId))
            return;

        // An object that can be picked up must have a tooltip.
        if (!object.getClass().hasToolTip(object))
            return;

        int count = object.getCellRef().getCount();
        if (object.getClass().isGold(object))
            count *= object.getClass().getValue(object);

        MWWorld::Ptr player = MWMechanics::getPlayer();
        MWBase::Environment::get().getWorld()->breakInvisibility(player);

        if (!object.getRefData().activate())
            return;

        // Player must not be paralyzed, knocked down, or dead to pick up an item.
        const MWMechanics::NpcStats& playerStats = player.getClass().getNpcStats(player);
        if (playerStats.isParalyzed() || playerStats.getKnockedDown() || playerStats.isDead())
            return;

        MWBase::Environment::get().getMechanicsManager()->itemTaken(player, object, MWWorld::Ptr(), count);

        // add to player inventory
        // can't use ActionTake here because we need an MWWorld::Ptr to the newly inserted object
        MWWorld::Ptr newObject = *player.getClass().getContainerStore(player).add(object, count);

        // remove from world
        MWBase::Environment::get().getWorld()->deleteObject(object);

        // get ModelIndex to the item
        mTradeModel->update();
        size_t i = 0;
        for (; i < mTradeModel->getItemCount(); ++i)
        {
            if (mTradeModel->getItem(i).mBase == newObject)
                break;
        }
        if (i == mTradeModel->getItemCount())
            throw std::runtime_error("Added item not found");

        if (mDragAndDrop->mIsOnDragAndDrop)
            mDragAndDrop->finish();

        if (MyGUI::InputManager::getInstance().isAltPressed())
        {
            const MWWorld::Ptr item = mTradeModel->getItem(i).mBase;
            MWBase::Environment::get().getWindowManager()->playSound(item.getClass().getDownSoundId(item));
            mItemView->update();
        }
        else
        {
            mDragAndDrop->startDrag(i, mSortModel, mTradeModel, mItemView, count);
        }

        MWBase::Environment::get().getWindowManager()->updateSpellWindow();
    }

    void InventoryWindow::cycle(bool next)
    {
        MWWorld::Ptr player = MWMechanics::getPlayer();

        if (MWBase::Environment::get().getMechanicsManager()->isAttackingOrSpell(player))
            return;

        const MWMechanics::CreatureStats& stats = player.getClass().getCreatureStats(player);
        if (stats.isParalyzed() || stats.getKnockedDown() || stats.isDead() || stats.getHitRecovery())
            return;

        ItemModel::ModelIndex selected = -1;
        // not using mSortFilterModel as we only need sorting, not filtering
        SortFilterItemModel model(std::make_unique<InventoryItemModel>(player));
        model.setSortByType(false);
        model.update();
        if (model.getItemCount() == 0)
            return;

        for (ItemModel::ModelIndex i = 0; i < int(model.getItemCount()); ++i)
        {
            MWWorld::Ptr item = model.getItem(i).mBase;
            if (model.getItem(i).mType & ItemStack::Type_Equipped && isRightHandWeapon(item))
                selected = i;
        }

        int incr = next ? 1 : -1;
        bool found = false;
        ESM::RefId lastId;
        if (selected != -1)
            lastId = model.getItem(selected).mBase.getCellRef().getRefId();
        ItemModel::ModelIndex cycled = selected;
        for (size_t i = 0; i < model.getItemCount(); ++i)
        {
            cycled += incr;
            cycled = (cycled + model.getItemCount()) % model.getItemCount();

            MWWorld::Ptr item = model.getItem(cycled).mBase;

            // skip different stacks of the same item, or we will get stuck as stacking/unstacking them may change their
            // relative ordering
            if (lastId == item.getCellRef().getRefId())
                continue;

            lastId = item.getCellRef().getRefId();

            if (item.getClass().getType() == ESM::Weapon::sRecordId && isRightHandWeapon(item)
                && item.getClass().canBeEquipped(item, player).first)
            {
                found = true;
                break;
            }
        }

        if (!found || selected == cycled)
            return;

        useItem(model.getItem(cycled).mBase);
    }

    void InventoryWindow::rebuildAvatar()
    {
        mPreview->rebuild();
    }

    void InventoryWindow::itemAdded(const MWWorld::ConstPtr& item, int count)
    {
        mUpdateNextFrame = true;
    }

    void InventoryWindow::itemRemoved(const MWWorld::ConstPtr& item, int count)
    {
        mUpdateNextFrame = true;
    }

    MyGUI::IntSize InventoryWindow::getPreviewViewportSize() const
    {
        const MyGUI::IntSize previewWindowSize = mAvatarImage->getSize();
        const float scale = MWBase::Environment::get().getWindowManager()->getScalingFactor();

        return MyGUI::IntSize(std::min<int>(mPreview->getTextureWidth(), previewWindowSize.width * scale),
            std::min<int>(mPreview->getTextureHeight(), previewWindowSize.height * scale));
    }

    osg::Vec2f InventoryWindow::mapPreviewWindowToViewport(int x, int y) const
    {
        const MyGUI::IntSize previewWindowSize = mAvatarImage->getSize();
        const float normalisedX = x / std::max<float>(1.0f, previewWindowSize.width);
        const float normalisedY = y / std::max<float>(1.0f, previewWindowSize.height);

        const MyGUI::IntSize viewport = getPreviewViewportSize();
        return osg::Vec2f(normalisedX * float(viewport.width - 1), (1.0 - normalisedY) * float(viewport.height - 1));
    }
}
