/*
 * 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>
 * @author Maciej Suminski <maciej.suminski@cern.ch>
 *
 * 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 __SELECTION_TOOL_H
#define __SELECTION_TOOL_H

#include <math/vector2d.h>
#include <tool/tool_interactive.h>
#include <tool/context_menu.h>
#include <class_undoredo_container.h>

#include "selection_conditions.h"

class PCB_BASE_FRAME;
class SELECTION_AREA;
class BOARD_ITEM;
class GENERAL_COLLECTOR;

namespace KIGFX
{
class VIEW_GROUP;
}

struct SELECTION
{
    /// Set of selected items
    PICKED_ITEMS_LIST items;

    /// VIEW_GROUP that holds currently selected items
    KIGFX::VIEW_GROUP* group;

    /// Checks if there is anything selected
    bool Empty() const
    {
        return ( items.GetCount() == 0 );
    }

    /// Returns the number of selected parts
    int Size() const
    {
        return items.GetCount();
    }

    /// Alias to make code shorter and clearer
    template <typename T>
    T* Item( unsigned int aIndex ) const
    {
        return static_cast<T*>( items.GetPickedItem( aIndex ) );
    }

private:
    /// Clears both the VIEW_GROUP and set of selected items. Please note that it does not
    /// change properties of selected items (e.g. selection flag).
    void clear();

    friend class SELECTION_TOOL;
};

/**
 * Class SELECTION_TOOL
 *
 * Our sample selection tool: currently supports:
 * - pick single objects (click LMB)
 * - add objects to existing selection (Shift+LMB)
 * - draw selection box (drag LMB)
 * - handles MODULEs properly (i.e. selects either MODULE or its PADs, TEXTs, etc.)
 * - takes into account high-contrast & layer visibility settings
 * - invokes InteractiveEdit tool when user starts to drag selected items
 */
class SELECTION_TOOL : public TOOL_INTERACTIVE
{
public:
    SELECTION_TOOL();
    ~SELECTION_TOOL();

    /// @copydoc TOOL_INTERACTIVE::Reset()
    void Reset( RESET_REASON aReason );

    /**
     * Function Main()
     *
     * The main loop.
     */
    int Main( TOOL_EVENT& aEvent );

    /**
     * Function GetSelection()
     *
     * Returns the set of currently selected items.
     */
    const SELECTION& GetSelection() const
    {
        return m_selection;
    }

    /**
     * Function AddMenuItem()
     *
     * Adds a menu entry to run a TOOL_ACTION on selected items.
     * @param aAction is a menu entry to be added.
     * @param aCondition is a condition that has to be fulfilled to enable the menu entry.
     */
    void AddMenuItem( const TOOL_ACTION& aAction,
                      const SELECTION_CONDITION& aCondition = SELECTION_CONDITIONS::ShowAlways );

    /**
     * Function AddSubMenu()
     *
     * Adds a submenu to the selection tool right-click context menu.
     * @param aMenu is the submenu to be added.
     * @param aLabel is the label of added submenu.
     * @param aCondition is a condition that has to be fulfilled to enable the submenu entry.
     */
    void AddSubMenu( CONTEXT_MENU* aMenu, const wxString& aLabel,
                     const SELECTION_CONDITION& aCondition = SELECTION_CONDITIONS::ShowAlways );

    /**
     * Function EditModules()
     *
     * Toggles edit module mode. When enabled, one may select parts of modules individually
     * (graphics, pads, etc.), so they can be modified.
     * @param aEnabled decides if the mode should be enabled.
     */
    void EditModules( bool aEnabled )
    {
        m_editModules = aEnabled;
    }

    ///> Checks if the user has agreed to modify locked items for the given selection.
    bool CheckLock();

    ///> Select a single item under cursor event handler.
    int CursorSelection( TOOL_EVENT& aEvent );

    ///> Clear current selection event handler.
    int ClearSelection( TOOL_EVENT& aEvent );

    ///> Item selection event handler.
    int SelectItem( TOOL_EVENT& aEvent );

    ///> Item unselection event handler.
    int UnselectItem( TOOL_EVENT& aEvent );

    ///> Event sent after an item is selected.
    const TOOL_EVENT SelectedEvent;

    ///> Event sent after an item is unselected.
    const TOOL_EVENT UnselectedEvent;

    ///> Event sent after selection is cleared.
    const TOOL_EVENT ClearedEvent;

private:
    /**
     * Function selectCursor()
     * Selects an item pointed by the parameter aWhere. If there is more than one item at that
     * place, there is a menu displayed that allows to choose the item.
     *
     * @param aWhere is the place where the item should be selected.
     * @param aAllowDisambiguation decides what to do in case of disambiguation. If true, then
     * a menu is shown, otherise function finishes without selecting anything.
     * @return True if an item was selected, false otherwise.
     */
    bool selectCursor( const VECTOR2I& aWhere, bool aAllowDisambiguation = true );

    /**
     * Function selectMultiple()
     * Handles drawing a selection box that allows to select many items at the same time.
     *
     * @return true if the function was cancelled (i.e. CancelEvent was received).
     */
    bool selectMultiple();

    ///> Find dialog callback.
    void findCallback( BOARD_ITEM* aItem );

    ///> Find an item.
    int find( TOOL_EVENT& aEvent );

    ///> Find an item and start moving.
    int findMove( TOOL_EVENT& aEvent );

    ///> Sets up handlers for various events.
    void setTransitions();

    /**
     * Function ClearSelection()
     * Clears the current selection.
     */
    void clearSelection();

    /**
     * Function disambiguationMenu()
     * Handles the menu that allows to select one of many items in case there is more than one
     * item at the selected point (@see selectCursor()).
     *
     * @param aItems contains list of items that are displayed to the user.
     */
    BOARD_ITEM* disambiguationMenu( GENERAL_COLLECTOR* aItems );

    /**
     * Function pickSmallestComponent()
     * Allows to find the smallest (in terms of bounding box area) item from the list.
     *
     * @param aCollector containes the list of items.
     */
    BOARD_ITEM* pickSmallestComponent( GENERAL_COLLECTOR* aCollector );

    /**
     * Function toggleSelection()
     * Changes selection status of a given item.
     *
     * @param aItem is the item to have selection status changed.
     */
    void toggleSelection( BOARD_ITEM* aItem );

    /**
     * Function selectable()
     * Checks conditions for an item to be selected.
     *
     * @return True if the item fulfills conditions to be selected.
     */
    bool selectable( const BOARD_ITEM* aItem ) const;

    /**
     * Function selectItem()
     * Takes necessary action mark an item as selected.
     *
     * @param aItem is an item to be selected.
     */
    void select( BOARD_ITEM* aItem );

    /**
     * Function unselectItem()
     * Takes necessary action mark an item as unselected.
     *
     * @param aItem is an item to be unselected.
     */
    void unselect( BOARD_ITEM* aItem );

    /**
     * Function unselectVisually()
     * Marks item as selected, but does not add it to the ITEMS_PICKED_LIST.
     * @param aItem is an item to be be marked.
     */
    void selectVisually( BOARD_ITEM* aItem ) const;

    /**
     * Function unselectVisually()
     * Marks item as selected, but does not add it to the ITEMS_PICKED_LIST.
     * @param aItem is an item to be be marked.
     */
    void unselectVisually( BOARD_ITEM* aItem ) const;

    /**
     * Function containsSelected()
     * Checks if the given point is placed within any of selected items' bounding box.
     *
     * @return True if the given point is contained in any of selected items' bouding box.
     */
    bool selectionContains( const VECTOR2I& aPoint ) const;

    /**
     * Function highlightNet()
     * Looks for a BOARD_CONNECTED_ITEM in a given spot, and if one is found - it enables
     * highlight for its net.
     * @param aPoint is the point where an item is expected (world coordinates).
     */
    void highlightNet( const VECTOR2I& aPoint );

    /**
     * Function prefer()
     * Checks if collector's list contains only single entry of asked types. If so, it returns it.
     * @param aCollector is the collector that has a list of items to be queried.
     * @param aTypes is the list of searched/preferred types.
     * @return Pointer to the preferred item, if there is only one entry of given type or NULL
     * if there are more entries or no entries at all.
     */
    BOARD_ITEM* prefer( GENERAL_COLLECTOR& aCollector, const KICAD_T aTypes[] ) const;

    /**
     * Function generateMenu()
     * Creates a copy of context menu that is filtered by menu conditions and displayed to
     * the user.
     */
    void generateMenu();

    /// Pointer to the parent frame.
    PCB_BASE_FRAME* m_frame;

    /// Visual representation of selection box.
    SELECTION_AREA* m_selArea;

    /// Current state of selection.
    SELECTION m_selection;

    /// Flag saying if items should be added to the current selection or rather replace it.
    bool m_additive;

    /// Flag saying if multiple selection mode is active.
    bool m_multiple;

    /// Right click popup menu (master instance).
    CONTEXT_MENU m_menu;

    /// Copy of the context menu that is filtered by menu conditions and displayed to the user.
    CONTEXT_MENU m_menuCopy;

    /// Edit module mode flag.
    bool m_editModules;

    /// Can other tools modify locked items.
    bool m_locked;

    /// Conditions for specific context menu entries.
    std::deque<SELECTION_CONDITION> m_menuConditions;
};

#endif
