/*
 * Copyright 2018 Google, Inc.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met: redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer;
 * 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;
 * neither the name of the copyright holders nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * 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
 * OWNER 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.
 *
 * Authors: Gabe Black
 */

#ifndef __SYSTEMC_CORE_SENSITIVITY_HH__
#define __SYSTEMC_CORE_SENSITIVITY_HH__

#include <set>
#include <vector>

#include "sim/eventq.hh"
#include "systemc/core/sched_event.hh"
#include "systemc/ext/core/sc_module.hh"

namespace sc_core
{

class sc_event;
class sc_event_and_list;
class sc_event_or_list;
class sc_event_finder;
class sc_export_base;
class sc_interface;
class sc_port_base;

} // namespace sc_core

namespace sc_gem5
{

class Process;
class Event;

/*
 * Common sensitivity interface.
 */

class Sensitivity
{
  protected:
    Process *process;

    Sensitivity(Process *p) : process(p) {}
    virtual ~Sensitivity() {}

    virtual void addToEvent(const ::sc_core::sc_event *e) = 0;
    virtual void delFromEvent(const ::sc_core::sc_event *e) = 0;

    virtual bool
    notifyWork(Event *e)
    {
        satisfy();
        return true;
    }

  public:
    virtual void finalize() = 0;
    virtual void clear() = 0;

    void satisfy();
    bool notify(Event *e);

    virtual bool dynamic() = 0;
};


/*
 * Dynamic vs. static sensitivity.
 */

class DynamicSensitivity : virtual public Sensitivity
{
  protected:
    DynamicSensitivity(Process *p) : Sensitivity(p) {}

    void addToEvent(const ::sc_core::sc_event *e) override;
    void delFromEvent(const ::sc_core::sc_event *e) override;

  public:
    bool dynamic() override { return true; }
};

typedef std::vector<DynamicSensitivity *> DynamicSensitivities;


class StaticSensitivity : virtual public Sensitivity
{
  protected:
    StaticSensitivity(Process *p) : Sensitivity(p) {}

    void addToEvent(const ::sc_core::sc_event *e) override;
    void delFromEvent(const ::sc_core::sc_event *e) override;

  public:
    bool dynamic() override { return false; }
};

typedef std::vector<StaticSensitivity *> StaticSensitivities;


/*
 * Sensitivity to events, which can be static or dynamic.
 */

class SensitivityEvent : virtual public Sensitivity
{
  protected:
    const ::sc_core::sc_event *event;

    SensitivityEvent(Process *p, const ::sc_core::sc_event *e=nullptr) :
        Sensitivity(p), event(e)
    {}

  public:
    void finalize() override { addToEvent(event); }
    void clear() override { delFromEvent(event); }
};


/*
 * Static sensitivities.
 */

class StaticSensitivityEvent :
    public StaticSensitivity, public SensitivityEvent
{
  public:
    StaticSensitivityEvent(Process *p, const sc_core::sc_event *e) :
        Sensitivity(p), StaticSensitivity(p), SensitivityEvent(p, e)
    {}
};

class StaticSensitivityInterface :
    public StaticSensitivity, public SensitivityEvent
{
  private:
    const sc_core::sc_interface *interface;

  public:
    StaticSensitivityInterface(Process *p, const sc_core::sc_interface *i) :
        Sensitivity(p), StaticSensitivity(p), SensitivityEvent(p), interface(i)
    {}

    void finalize() override;
};

class StaticSensitivityPort : public StaticSensitivity
{
  private:
    const ::sc_core::sc_port_base *port;
    std::set<const ::sc_core::sc_event *> events;

  public:
    StaticSensitivityPort(Process *p, const sc_core::sc_port_base *pb) :
        Sensitivity(p), StaticSensitivity(p), port(pb)
    {}

    void finalize() override;

    void
    clear() override
    {
        for (auto event: events)
            delFromEvent(event);
    }
};

class StaticSensitivityExport :
    public StaticSensitivity, public SensitivityEvent
{
  private:
    const sc_core::sc_export_base *exp;

  public:
    StaticSensitivityExport(Process *p, const sc_core::sc_export_base *exp) :
        Sensitivity(p), StaticSensitivity(p), SensitivityEvent(p), exp(exp)
    {}

    void finalize() override;
};

class StaticSensitivityFinder : public StaticSensitivity
{
  private:
    const ::sc_core::sc_event_finder *finder;
    std::set<const ::sc_core::sc_event *> events;

  public:
    StaticSensitivityFinder(Process *p, const sc_core::sc_event_finder *f) :
        Sensitivity(p), StaticSensitivity(p), finder(f)
    {}

    void finalize() override;

    void
    clear() override
    {
        for (auto event: events)
            delFromEvent(event);
    }
};


/*
 * Dynamic sensitivities.
 */

class DynamicSensitivityEvent :
    public DynamicSensitivity, public SensitivityEvent
{
  public:
    DynamicSensitivityEvent(Process *p, const sc_core::sc_event *e) :
        Sensitivity(p), DynamicSensitivity(p), SensitivityEvent(p, e)
    {}
};

class DynamicSensitivityEventOrList : public DynamicSensitivity
{
  private:
    std::set<const ::sc_core::sc_event *> events;

  protected:
    bool notifyWork(Event *e) override;

  public:
    DynamicSensitivityEventOrList(
            Process *p, const sc_core::sc_event_or_list *eol);

    void finalize() override;
    void clear() override;
};

//XXX This sensitivity can't be reused. To reset it, it has to be deleted and
//recreated. That works for dynamic sensitivities, but not for static.
//Fortunately processes can't be statically sensitive to sc_event_and_lists.
class DynamicSensitivityEventAndList : public DynamicSensitivity
{
  private:
    std::set<const ::sc_core::sc_event *> events;

  protected:
    bool notifyWork(Event *e) override;

  public:
    DynamicSensitivityEventAndList(
            Process *p, const sc_core::sc_event_and_list *eal);

    void finalize() override;
    void clear() override;
};

} // namespace sc_gem5

#endif  //__SYSTEMC_CORE_SENSITIVITY_HH__