#include "containeritemmodel.hpp"

#include <algorithm>

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

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

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

namespace
{

    bool stacks (const MWWorld::Ptr& left, const MWWorld::Ptr& right)
    {
        if (left == right)
            return true;

        // If one of the items is in an inventory and currently equipped, we need to check stacking both ways to be sure
        if (left.getContainerStore() && right.getContainerStore())
            return left.getContainerStore()->stacks(left, right)
                    && right.getContainerStore()->stacks(left, right);

        if (left.getContainerStore())
            return left.getContainerStore()->stacks(left, right);
        if (right.getContainerStore())
            return right.getContainerStore()->stacks(left, right);

        MWWorld::ContainerStore store;
        return store.stacks(left, right);
    }

}

namespace MWGui
{
ContainerItemModel::ContainerItemModel(const std::vector<MWWorld::Ptr>& itemSources, const std::vector<MWWorld::Ptr>& worldItems)
    : mWorldItems(worldItems)
    , mTrading(true)
{
    assert (!itemSources.empty());
    // Tie resolution lifetimes to the ItemModel
    mItemSources.reserve(itemSources.size());
    for(const MWWorld::Ptr& source : itemSources)
    {
        MWWorld::ContainerStore& store = source.getClass().getContainerStore(source);
        mItemSources.emplace_back(source, store.resolveTemporarily());
    }
}

ContainerItemModel::ContainerItemModel (const MWWorld::Ptr& source) : mTrading(false)
{
    MWWorld::ContainerStore& store = source.getClass().getContainerStore(source);
    mItemSources.emplace_back(source, store.resolveTemporarily());
}

bool ContainerItemModel::allowedToUseItems() const
{
    if (mItemSources.empty())
        return true;

    MWWorld::Ptr ptr = MWMechanics::getPlayer();
    MWWorld::Ptr victim;

    // Check if the player is allowed to use items from opened container
    MWBase::MechanicsManager* mm = MWBase::Environment::get().getMechanicsManager();
    return mm->isAllowedToUse(ptr, mItemSources[0].first, victim);
}

ItemStack ContainerItemModel::getItem (ModelIndex index)
{
    if (index < 0)
        throw std::runtime_error("Invalid index supplied");
    if (mItems.size() <= static_cast<size_t>(index))
        throw std::runtime_error("Item index out of range");
    return mItems[index];
}

size_t ContainerItemModel::getItemCount()
{
    return mItems.size();
}

ItemModel::ModelIndex ContainerItemModel::getIndex (ItemStack item)
{
    size_t i = 0;
    for (ItemStack& itemStack : mItems)
    {
        if (itemStack == item)
            return i;
        ++i;
    }
    return -1;
}

MWWorld::Ptr ContainerItemModel::copyItem (const ItemStack& item, size_t count, bool allowAutoEquip)
{
    auto& source = mItemSources[0];
    MWWorld::ContainerStore& store = source.first.getClass().getContainerStore(source.first);
    if (item.mBase.getContainerStore() == &store)
        throw std::runtime_error("Item to copy needs to be from a different container!");
    return *store.add(item.mBase, count, source.first, allowAutoEquip);
}

void ContainerItemModel::removeItem (const ItemStack& item, size_t count)
{
    int toRemove = count;

    for (auto& source : mItemSources)
    {
        MWWorld::ContainerStore& store = source.first.getClass().getContainerStore(source.first);

        for (MWWorld::ContainerStoreIterator it = store.begin(); it != store.end(); ++it)
        {
            if (stacks(*it, item.mBase))
            {
                int quantity = it->mRef->mData.getCount(false);
                // If this is a restocking quantity, just don't remove it
                if(quantity < 0 && mTrading)
                    toRemove += quantity;
                else
                    toRemove -= store.remove(*it, toRemove, source.first);
                if (toRemove <= 0)
                    return;
            }
        }
    }
    for (MWWorld::Ptr& source : mWorldItems)
    {
        if (stacks(source, item.mBase))
        {
            int refCount = source.getRefData().getCount();
            if (refCount - toRemove <= 0)
                MWBase::Environment::get().getWorld()->deleteObject(source);
            else
                source.getRefData().setCount(std::max(0, refCount - toRemove));
            toRemove -= refCount;
            if (toRemove <= 0)
                return;
        }
    }

    throw std::runtime_error("Not enough items to remove could be found");
}

void ContainerItemModel::update()
{
    mItems.clear();
    for (auto& source : mItemSources)
    {
        MWWorld::ContainerStore& store = source.first.getClass().getContainerStore(source.first);

        for (MWWorld::ContainerStoreIterator it = store.begin(); it != store.end(); ++it)
        {
            if (!(*it).getClass().showsInInventory(*it))
                continue;

            bool found = false;
            for (ItemStack& itemStack : mItems)
            {
                if (stacks(*it, itemStack.mBase))
                {
                    // we already have an item stack of this kind, add to it
                    itemStack.mCount += it->getRefData().getCount();
                    found = true;
                    break;
                }
            }

            if (!found)
            {
                // no stack yet, create one
                ItemStack newItem (*it, this, it->getRefData().getCount());
                mItems.push_back(newItem);
            }
        }
    }
    for (MWWorld::Ptr& source : mWorldItems)
    {
        bool found = false;
        for (ItemStack& itemStack : mItems)
        {
            if (stacks(source, itemStack.mBase))
            {
                // we already have an item stack of this kind, add to it
                itemStack.mCount += source.getRefData().getCount();
                found = true;
                break;
            }
        }

        if (!found)
        {
            // no stack yet, create one
            ItemStack newItem (source, this, source.getRefData().getCount());
            mItems.push_back(newItem);
        }
    }
}
bool ContainerItemModel::onDropItem(const MWWorld::Ptr &item, int count)
{
    if (mItemSources.empty())
        return false;

    MWWorld::Ptr target = mItemSources[0].first;

    if (target.getTypeName() != typeid(ESM::Container).name())
        return true;

    // check container organic flag
    MWWorld::LiveCellRef<ESM::Container>* ref = target.get<ESM::Container>();
    if (ref->mBase->mFlags & ESM::Container::Organic)
    {
        MWBase::Environment::get().getWindowManager()->
            messageBox("#{sContentsMessage2}");
        return false;
    }

    // check that we don't exceed container capacity
    float weight = item.getClass().getWeight(item) * count;
    if (target.getClass().getCapacity(target) < target.getClass().getEncumbrance(target) + weight)
    {
        MWBase::Environment::get().getWindowManager()->messageBox("#{sContentsMessage3}");
        return false;
    }

    return true;
}

bool ContainerItemModel::onTakeItem(const MWWorld::Ptr &item, int count)
{
    if (mItemSources.empty())
        return false;

    MWWorld::Ptr target = mItemSources[0].first;

    // Looting a dead corpse is considered OK
    if (target.getClass().isActor() && target.getClass().getCreatureStats(target).isDead())
        return true;

    MWWorld::Ptr player = MWMechanics::getPlayer();
    MWBase::Environment::get().getMechanicsManager()->itemTaken(player, item, target, count);

    return true;
}

}