/**
 * server/src/core/property.hpp
 *
 * This file is part of the traintastic source code.
 *
 * Copyright (C) 2019-2020 Reinder Feenstra
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

#ifndef TRAINTASTIC_SERVER_CORE_PROPERTY_HPP
#define TRAINTASTIC_SERVER_CORE_PROPERTY_HPP

#include "abstractproperty.hpp"
#include "valuetypetraits.hpp"
#include "to.hpp"
#include <functional>
#include <traintastic/enum/enum.hpp>

template<typename T>
class Property : public AbstractProperty
{
  public:
    using OnChanged = std::function<void(const T& value)>;
    using OnSet = std::function<bool(T& value)>;

  protected:
    T m_value;
    OnChanged m_onChanged;
    OnSet m_onSet;

    /*void loadValue(const nlohmann::json& value) final
    {
      m_value = to<T>(value);
    }*/

  public:
    Property(Object* object, const std::string& name, const T& value, PropertyFlags flags) :
      AbstractProperty(*object, name, value_type<T>::value, flags),
      m_value{value}
    {
      //static_assert(property_type<T>::value != PropertyType::Invalid);
    }

    Property(Object* object, const std::string& name, const T& value, PropertyFlags flags, OnChanged onChanged) :
      Property(object, name, value, flags)
    {
      m_onChanged = std::move(onChanged);
    }

    Property(Object* object, const std::string& name, const T& value, PropertyFlags flags, OnChanged onChanged, OnSet onSet) :
      Property(object, name, value, flags, onChanged)
    {
      m_onSet = std::move(onSet);
    }

    Property(Object* object, const std::string& name, const T& value, PropertyFlags flags, nullptr_t, OnSet onSet) :
      Property(object, name, value, flags)
    {
      m_onSet = std::move(onSet);
    }

    const T& value() const
    {
      return m_value;
    }

    void setValue(T value)
    {
      assert(isWriteable());
      if(m_value == value)
        return;
      else if(!isWriteable())
        throw not_writable_error();
      else if(!m_onSet || m_onSet(value))
      {
        m_value = value;
        if(m_onChanged)
          m_onChanged(m_value);
        changed();
      }
      else
        throw invalid_value_error();
    }

    void setValueInternal(T value)
    {
      if(m_value != value)
      {
        m_value = value;
        changed();
      }
    }

    operator const T&() const
    {
      return m_value;
    }

    Property<T>& operator =(const T& value) // REMOVE !!!!!!
    {
      setValue(value);
      return *this;
    }

    std::string_view enumName() const final
    {
      if constexpr(std::is_enum_v<T> && !is_set_v<T>)
        return EnumName<T>::value;

      assert(false);
      return "";
    }

    std::string_view setName() const final
    {
      if constexpr(is_set_v<T>)
        return set_name_v<T>;

      assert(false);
      return "";
    }

    bool toBool() const final
    {
      return to<bool>(m_value);
    }

    int64_t toInt64() const final
    {
      return to<int64_t>(m_value);
    }

    double toDouble() const final
    {
      return to<double>(m_value);
    }

    std::string toString() const final
    {
      return to<std::string>(m_value);
    }

    ObjectPtr toObject() const final
    {
      throw conversion_error();
    }

    nlohmann::json toJSON() const final
    {
      return m_value;
    }

    void fromBool(bool value) final
    {
      setValue(to<T>(value));
    }

    void fromInt64(int64_t value) final
    {
      setValue(to<T>(value));
    }

    void fromDouble(double value) final
    {
      setValue(to<T>(value));
    }

    void fromString(const std::string& value) final
    {
      setValue(to<T>(value));
    }

    void fromObject(const ObjectPtr& value) final
    {
      throw conversion_error();
    }

    void load(const nlohmann::json& value) final
    {
      m_value = to<T>(value);
    /*
      switch(value.type())
      {
        case nlohmann::json::value_t::boolean:
          fromBool(value);
          break;

        case nlohmann::json::value_t::number_integer:
        case nlohmann::json::value_t::number_unsigned:
          fromInt64(value);
          break;

        case nlohmann::json::value_t::number_float:
          fromDouble(value);
          break;

        case nlohmann::json::value_t::string:
          fromString(value);
          break;

        default:
          throw std::runtime_error("unsupported JSON type");
      }
      */
    }

    void load(const ObjectPtr& value) final
    {
      throw conversion_error();
    }

};

#endif