#pragma once

#include <AK/AKString.h>
#include <AK/Types.h>
#include <AK/WeakPtr.h>
#include <AK/Function.h>

class CObject;

class CEvent {
public:
    enum Type {
        Invalid = 0,
        Quit,
        Timer,
        DeferredDestroy,
        DeferredInvoke,
        ChildAdded,
        ChildRemoved,
    };

    CEvent() { }
    explicit CEvent(unsigned type) : m_type(type) { }
    virtual ~CEvent() { }

    unsigned type() const { return m_type; }

private:
    unsigned m_type { Type::Invalid };
};

class CDeferredInvocationEvent : public CEvent {
    friend class CEventLoop;
public:
    CDeferredInvocationEvent(Function<void(CObject&)> invokee)
        : CEvent(CEvent::Type::DeferredInvoke)
        , m_invokee(move(invokee))
    {
    }

private:
    Function<void(CObject&)> m_invokee;
};

class CTimerEvent final : public CEvent {
public:
    explicit CTimerEvent(int timer_id)
        : CEvent(CEvent::Timer), m_timer_id(timer_id)
    {
    }
    ~CTimerEvent() { }

    int timer_id() const { return m_timer_id; }

private:
    int m_timer_id;
};

class CChildEvent final : public CEvent {
public:
    CChildEvent(Type, CObject& child);
    ~CChildEvent();

    CObject* child() { return m_child.ptr(); }
    const CObject* child() const { return m_child.ptr(); }

private:
    WeakPtr<CObject> m_child;
};