/*
 * This program source code file is part of KiCad, a free EDA CAD application.
 *
 * Copyright (C) 2013 CERN
 * @author Tomasz Wlostowski <tomasz.wlostowski@cern.ch>
 * Copyright (C) 2016 KiCad Developers, see AUTHORS.txt for contributors.
 *
 * 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, you may find one here:
 * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
 * or you may search the http://www.gnu.org website for the version 2 license,
 * or you may write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */

#ifndef __TOOL_BASE_H
#define __TOOL_BASE_H

#include <cassert>
#include <base_struct.h>    // for KICAD_T

#include <tool/tool_event.h>
#include <tool/tool_settings.h>

#include <functional>

class EDA_ITEM;
class TOOL_MANAGER;

namespace KIGFX
{
class VIEW;
class VIEW_CONTROLS;
};

enum TOOL_TYPE
{
    ///> Tool that interacts with the user
    INTERACTIVE = 0x01,

    ///> Tool that runs in the background without any user intervention
    BATCH       = 0x02
};

/// Unique identifier for tools
typedef int TOOL_ID;

using TOOL_STATE_FUNC = std::function<int(const TOOL_EVENT&)>;


/**
 * Class TOOL_BASE
 *
 * Base abstract interface for all kinds of tools.
 */

class TOOL_BASE
{
public:
    TOOL_BASE( TOOL_TYPE aType, TOOL_ID aId, const std::string& aName = std::string( "" ) ) :
        m_type( aType ),
        m_toolId( aId ),
        m_toolName( aName ),
        m_toolMgr( NULL ) {};

    virtual ~TOOL_BASE() {};

    ///> Determines the reason of reset for a tool
    enum RESET_REASON
    {
        RUN,                ///< Tool is invoked after being inactive
        MODEL_RELOAD,       ///< Model changes (required full reload)
        GAL_SWITCH          ///< Rendering engine changes
    };

    /**
     * Function Init()
     * Init() is called once upon a registration of the tool.
     *
     * @return True if the initialization went fine, false - otherwise.
     */
    virtual bool Init()
    {
        return true;
    }

    /**
     * Function Reset()
     * Brings the tool to a known, initial state. If the tool claimed anything from
     * the model or the view, it must release it when its reset.
     * @param aReason contains information about the reason of tool reset.
     */
    virtual void Reset( RESET_REASON aReason ) = 0;

    /**
     * Function GetType()
     * Returns the type of the tool.
     * @return The type of the tool.
     */
    TOOL_TYPE GetType() const
    {
        return m_type;
    }

    /**
     * Function GetId()
     * Returns the unique identifier of the tool. The identifier is set by an instance of
     * TOOL_MANAGER.
     * @return Identifier of the tool.
     */
    TOOL_ID GetId() const
    {
        return m_toolId;
    }

    /**
     * Function GetName()
     * Returns the name of the tool. Tool names are expected to obey the format:
     * application.ToolName (eg. pcbnew.InteractiveSelection).
     * @return The name of the tool.
     */
    const std::string& GetName() const
    {
        return m_toolName;
    }

    /**
     * Function GetManager()
     * Returns the instance of TOOL_MANAGER that takes care of the tool.
     * @return Instance of the TOOL_MANAGER. If there is no TOOL_MANAGER associated, it returns
     * NULL.
     */
    TOOL_MANAGER* GetManager() const
    {
        return m_toolMgr;
    }

    /**
     * Function SetTransitions()
     * This method is meant to be overridden in order to specify handlers for events. It is called
     * every time tool is reset or finished.
     */
    virtual void SetTransitions() {};

    TOOL_SETTINGS& GetSettings();

protected:
    friend class TOOL_MANAGER;
    friend class TOOL_SETTINGS;

    /**
     * Function attachManager()
     *
     * Sets the TOOL_MANAGER the tool will belong to.
     * Called by TOOL_MANAGER::RegisterTool()
     */
    void attachManager( TOOL_MANAGER* aManager );

    /**
     * Function getView()
     *
     * Returns the instance of VIEW object used in the application. It allows tools to draw.
     * @return The instance of VIEW.
     */
    KIGFX::VIEW* getView() const;

    /**
     * Function getViewControls()
     *
     * Returns the instance of VIEW_CONTROLS object used in the application. It allows tools to
     * read & modify user input and its settings (eg. show cursor, enable snapping to grid, etc.)
     * @return The instance of VIEW_CONTROLS.
     */
    KIGFX::VIEW_CONTROLS* getViewControls() const;

    /**
     * Function getEditFrame()
     *
     * Returns the application window object, casted to requested user type.
     */
    template <typename T>
    T* getEditFrame() const
    {
        return static_cast<T*>( getEditFrameInt() );
    }

    /**
     * Function getModel()
     *
     * Returns the model object if it matches the requested type.
     */
    template <typename T>
    T* getModel() const
    {
        EDA_ITEM* m = getModelInt();

        return static_cast<T*>( m );
    }

    ///> Stores the type of the tool.
    TOOL_TYPE m_type;

    ///> Unique identifier for the tool, assigned by a TOOL_MANAGER instance.
    TOOL_ID m_toolId;

    ///> Name of the tool. Names are expected to obey the format application.ToolName
    ///> (eg. pcbnew.InteractiveSelection).
    std::string m_toolName;
    TOOL_MANAGER* m_toolMgr;
    TOOL_SETTINGS m_toolSettings;

private:
    // hide the implementation to avoid spreading half of
    // kicad and wxWidgets headers to the tools that may not need them at all!
    EDA_ITEM* getModelInt() const;
    wxWindow* getEditFrameInt() const;
};

#endif