#pragma once

#include <QStandardItemModel>
#include <QTimer>
#include <boost/noncopyable.hpp>
#include <pajlada/signals/signal.hpp>
#include <vector>

#include "debug/AssertInGuiThread.hpp"

namespace chatterino {

template <typename TVectorItem>
struct SignalVectorItemArgs {
    const TVectorItem &item;
    int index;
    void *caller;
};

template <typename TVectorItem>
class ReadOnlySignalVector : boost::noncopyable
{
public:
    ReadOnlySignalVector()
    {
        QObject::connect(&this->itemsChangedTimer_, &QTimer::timeout,
                         [this] { this->delayedItemsChanged.invoke(); });
        this->itemsChangedTimer_.setInterval(100);
        this->itemsChangedTimer_.setSingleShot(true);
    }
    virtual ~ReadOnlySignalVector() = default;

    pajlada::Signals::Signal<SignalVectorItemArgs<TVectorItem>> itemInserted;
    pajlada::Signals::Signal<SignalVectorItemArgs<TVectorItem>> itemRemoved;
    pajlada::Signals::NoArgSignal delayedItemsChanged;

    const std::vector<TVectorItem> &getVector() const
    {
        assertInGuiThread();

        return this->vector_;
    }

    void invokeDelayedItemsChanged()
    {
        assertInGuiThread();

        if (!this->itemsChangedTimer_.isActive())
        {
            this->itemsChangedTimer_.start();
        }
    }

    virtual bool isSorted() const = 0;

protected:
    std::vector<TVectorItem> vector_;
    QTimer itemsChangedTimer_;
};

template <typename TVectorItem>
class BaseSignalVector : public ReadOnlySignalVector<TVectorItem>
{
public:
    // returns the actual index of the inserted item
    virtual int insertItem(const TVectorItem &item, int proposedIndex = -1,
                           void *caller = nullptr) = 0;

    void removeItem(int index, void *caller = nullptr)
    {
        assertInGuiThread();
        assert(index >= 0 && index < this->vector_.size());

        TVectorItem item = this->vector_[index];
        this->vector_.erase(this->vector_.begin() + index);
        SignalVectorItemArgs<TVectorItem> args{item, index, caller};
        this->itemRemoved.invoke(args);

        this->invokeDelayedItemsChanged();
    }

    int appendItem(const TVectorItem &item, void *caller = nullptr)
    {
        return this->insertItem(item, -1, caller);
    }
};

template <typename TVectorItem>
class UnsortedSignalVector : public BaseSignalVector<TVectorItem>
{
public:
    virtual int insertItem(const TVectorItem &item, int index = -1,
                           void *caller = nullptr) override
    {
        assertInGuiThread();
        if (index == -1)
        {
            index = this->vector_.size();
        }
        else
        {
            assert(index >= 0 && index <= this->vector_.size());
        }

        this->vector_.insert(this->vector_.begin() + index, item);

        SignalVectorItemArgs<TVectorItem> args{item, index, caller};
        this->itemInserted.invoke(args);
        this->invokeDelayedItemsChanged();
        return index;
    }

    virtual bool isSorted() const override
    {
        return false;
    }
};

template <typename TVectorItem, typename Compare>
class SortedSignalVector : public BaseSignalVector<TVectorItem>
{
public:
    virtual int insertItem(const TVectorItem &item, int = -1,
                           void *caller = nullptr) override
    {
        assertInGuiThread();

        auto it = std::lower_bound(this->vector_.begin(), this->vector_.end(),
                                   item, Compare{});
        int index = it - this->vector_.begin();
        this->vector_.insert(it, item);

        SignalVectorItemArgs<TVectorItem> args{item, index, caller};
        this->itemInserted.invoke(args);
        this->invokeDelayedItemsChanged();
        return index;
    }

    virtual bool isSorted() const override
    {
        return true;
    }
};

}  // namespace chatterino