#include "draganddrop.hpp"

#include <MyGUI_ControllerManager.h>
#include <MyGUI_Gui.h>

#include "../mwbase/environment.hpp"
#include "../mwbase/windowmanager.hpp"

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

#include "controllers.hpp"
#include "inventorywindow.hpp"
#include "itemview.hpp"
#include "sortfilteritemmodel.hpp"

namespace MWGui
{

    DragAndDrop::DragAndDrop()
        : mIsOnDragAndDrop(false)
        , mDraggedWidget(nullptr)
        , mSourceModel(nullptr)
        , mSourceView(nullptr)
        , mSourceSortModel(nullptr)
        , mDraggedCount(0)
    {
    }

    void DragAndDrop::startDrag(
        int index, SortFilterItemModel* sortModel, ItemModel* sourceModel, ItemView* sourceView, std::size_t count)
    {
        mItem = sourceModel->getItem(index);
        mDraggedCount = count;
        mSourceModel = sourceModel;
        mSourceView = sourceView;
        mSourceSortModel = sortModel;

        // If picking up an item that isn't from the player's inventory, the item gets added to player inventory backend
        // immediately, even though it's still floating beneath the mouse cursor. A bit counterintuitive,
        // but this is how it works in vanilla, and not doing so would break quests (BM_beasts for instance).
        ItemModel* playerModel = MWBase::Environment::get().getWindowManager()->getInventoryWindow()->getModel();
        if (mSourceModel != playerModel)
        {
            MWWorld::Ptr item = mSourceModel->moveItem(mItem, mDraggedCount, playerModel);

            playerModel->update();

            ItemModel::ModelIndex newIndex = -1;
            for (size_t i = 0; i < playerModel->getItemCount(); ++i)
            {
                if (playerModel->getItem(i).mBase == item)
                {
                    newIndex = i;
                    break;
                }
            }
            mItem = playerModel->getItem(newIndex);
            mSourceModel = playerModel;

            SortFilterItemModel* playerFilterModel
                = MWBase::Environment::get().getWindowManager()->getInventoryWindow()->getSortFilterModel();
            mSourceSortModel = playerFilterModel;
        }

        const ESM::RefId& sound = mItem.mBase.getClass().getUpSoundId(mItem.mBase);
        MWBase::Environment::get().getWindowManager()->playSound(sound);

        if (mSourceSortModel)
        {
            mSourceSortModel->clearDragItems();
            mSourceSortModel->addDragItem(mItem.mBase, count);
        }

        mDraggedWidget = MyGUI::Gui::getInstance().createWidget<ItemWidget>(
            "MW_ItemIcon", 0, 0, 42, 42, MyGUI::Align::Default, "DragAndDrop");

        Controllers::ControllerFollowMouse* controller
            = MyGUI::ControllerManager::getInstance()
                  .createItem(Controllers::ControllerFollowMouse::getClassTypeName())
                  ->castType<Controllers::ControllerFollowMouse>();
        MyGUI::ControllerManager::getInstance().addItem(mDraggedWidget, controller);

        mDraggedWidget->setItem(mItem.mBase);
        mDraggedWidget->setNeedMouseFocus(false);
        mDraggedWidget->setCount(count);

        MWBase::Environment::get().getWindowManager()->setDragDrop(true);

        mIsOnDragAndDrop = true;

        // Update item view after completing drag-and-drop setup
        mSourceView->update();
    }

    void DragAndDrop::drop(ItemModel* targetModel, ItemView* targetView)
    {
        const ESM::RefId& sound = mItem.mBase.getClass().getDownSoundId(mItem.mBase);
        MWBase::Environment::get().getWindowManager()->playSound(sound);

        // We can't drop a conjured item to the ground; the target container should always be the source container
        if (mItem.mFlags & ItemStack::Flag_Bound && targetModel != mSourceModel)
        {
            MWBase::Environment::get().getWindowManager()->messageBox("#{sBarterDialog12}");
            return;
        }

        // If item is dropped where it was taken from, we don't need to do anything -
        // otherwise, do the transfer
        if (targetModel != mSourceModel)
        {
            mSourceModel->moveItem(mItem, mDraggedCount, targetModel);
        }

        mSourceModel->update();

        finish();
        if (targetView)
            targetView->update();

        MWBase::Environment::get().getWindowManager()->getInventoryWindow()->updateItemView();

        // We need to update the view since an other item could be auto-equipped.
        mSourceView->update();
    }

    void DragAndDrop::update()
    {
        if (!mIsOnDragAndDrop)
            return;

        const unsigned count = mItem.mBase.getCellRef().getAbsCount();
        if (count >= mDraggedCount)
            return;

        mItem.mCount = count;
        mDraggedCount = count;
        mDraggedWidget->setCount(mDraggedCount);
        mSourceSortModel->clearDragItems();
        mSourceSortModel->addDragItem(mItem.mBase, mDraggedCount);
    }

    void DragAndDrop::onFrame()
    {
        if (mIsOnDragAndDrop && mItem.mBase.getCellRef().getCount() == 0)
            finish();
    }

    void DragAndDrop::finish()
    {
        mIsOnDragAndDrop = false;
        mSourceSortModel->clearDragItems();
        // since mSourceView doesn't get updated in drag()
        MWBase::Environment::get().getWindowManager()->getInventoryWindow()->updateItemView();

        if (mDraggedWidget)
        {
            MyGUI::Gui::getInstance().destroyWidget(mDraggedWidget);
            mDraggedWidget = nullptr;
        }

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

}
