/*
 * Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#pragma once

#include <AK/FlyString.h>
#include <AK/Function.h>
#include <AK/Noncopyable.h>
#include <AK/Vector.h>
#include <LibJS/Forward.h>
#include <LibWeb/Forward.h>

namespace Web::DOM {

class EventTarget {
    AK_MAKE_NONCOPYABLE(EventTarget);
    AK_MAKE_NONMOVABLE(EventTarget);

public:
    virtual ~EventTarget();

    void ref() { ref_event_target(); }
    void unref() { unref_event_target(); }

    void add_event_listener(const FlyString& event_name, NonnullRefPtr<EventListener>);
    void remove_event_listener(const FlyString& event_name, NonnullRefPtr<EventListener>);

    void remove_from_event_listener_list(NonnullRefPtr<EventListener>);

    virtual bool dispatch_event(NonnullRefPtr<Event>) = 0;
    virtual Bindings::EventTargetWrapper* create_wrapper(JS::GlobalObject&) = 0;
    Bindings::ScriptExecutionContext* script_execution_context() { return m_script_execution_context; }

    virtual EventTarget* get_parent(const Event&) { return nullptr; }

    struct EventListenerRegistration {
        FlyString event_name;
        NonnullRefPtr<EventListener> listener;
    };

    const Vector<EventListenerRegistration>& listeners() const { return m_listeners; }

    virtual bool is_node() const { return false; }
    virtual bool is_window() const { return false; }

    Function<void(const Event&)> activation_behaviour;

    // NOTE: These only exist for checkbox and radio input elements.
    Function<void()> legacy_pre_activation_behaviour;
    Function<void()> legacy_cancelled_activation_behaviour;

protected:
    explicit EventTarget(Bindings::ScriptExecutionContext&);

    virtual void ref_event_target() = 0;
    virtual void unref_event_target() = 0;

private:
    // FIXME: This should not be a raw pointer.
    Bindings::ScriptExecutionContext* m_script_execution_context { nullptr };

    Vector<EventListenerRegistration> m_listeners;
};

}