/*
 * 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>
 *
 * 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
 */

#include <boost/foreach.hpp>
#include <boost/optional.hpp>

#include <class_drawpanel_gal.h>
#include <class_board.h>
#include <class_board_item.h>
#include <class_track.h>
#include <class_module.h>

#include <wxPcbStruct.h>
#include <collectors.h>
#include <view/view_controls.h>
#include <painter.h>

#include <tool/context_menu.h>
#include <tool/tool_event.h>
#include <tool/tool_manager.h>

#include "selection_tool.h"
#include "selection_area.h"
#include "bright_box.h"

using namespace KiGfx;
using boost::optional;

SELECTION_TOOL::SELECTION_TOOL() :
        TOOL_INTERACTIVE( "pcbnew.InteractiveSelection" ), m_multiple( false )
{
    m_selArea = new SELECTION_AREA;
}


SELECTION_TOOL::~SELECTION_TOOL()
{
    if( m_selArea )
        delete m_selArea;
}


void SELECTION_TOOL::Reset()
{
    m_selectedItems.clear();

    // The tool launches upon reception of activate ("pcbnew.InteractiveSelection")
    Go( &SELECTION_TOOL::Main, TOOL_EVENT( TC_Command, TA_ActivateTool, GetName() ) );
}


int SELECTION_TOOL::Main( TOOL_EVENT& aEvent )
{
    bool dragging = false;
    bool allowMultiple = true;
    BOARD* board = getModel<BOARD>( PCB_T );

    if( !board )
        return 0;

    // Main loop: keep receiving events
    while( OPT_TOOL_EVENT evt = Wait() )
    {
        m_additive = evt->Modifier( MD_ModShift );

        if( evt->IsCancel() )
        {
            if( !m_selectedItems.empty() )
                clearSelection();
            else
                break;  // Finish
        }

        // single click? Select single object
        if( evt->IsClick( MB_Left ) )
            selectSingle( evt->Position() );

        // unlock the multiple selection box
        if( evt->IsMouseUp( MB_Left ) )
            allowMultiple = true;

        // drag with LMB? Select multiple objects (or at least draw a selection box) or drag them
        if( evt->IsDrag( MB_Left ) )
        {
            dragging = true;
            getViewControls()->SetAutoPan( true );

            if( m_selectedItems.empty() || m_additive )
            {
                // If nothings has been selected or user wants to select more
                // draw the selection box
                if( allowMultiple )
                    allowMultiple = !selectMultiple();
            }
            else
            {
                bool runTool = false;

                // Check if dragging event started within the currently selected items bounding box
                std::set<BOARD_ITEM*>::iterator it, it_end;
                for( it = m_selectedItems.begin(), it_end = m_selectedItems.end();
                        it != it_end; ++it )
                {
                    BOX2I itemBox = (*it)->ViewBBox();
                    itemBox.Inflate( 500000 );    // Give some margin for gripping an item

                    if( itemBox.Contains( evt->Position() ) )
                    {
                        // Click event occurred within a selected item bounding box
                        // -> user wants to drag selected items
                        runTool = true;
                        break;
                    }
                }

                if( runTool )
                    m_toolMgr->InvokeTool( "pcbnew.InteractiveMove" );
                else
                    clearSelection();
            }
        }
        else if( dragging )
        {
            dragging = false;
            getViewControls()->SetAutoPan( false );
        }
    }

    // Restore the default settings
    getViewControls()->SetAutoPan( false );

    return 0;
}


void SELECTION_TOOL::toggleSelection( BOARD_ITEM* aItem )
{
    if( m_selectedItems.find( aItem ) != m_selectedItems.end() )
    {
        aItem->ClearSelected();
        m_selectedItems.erase( aItem );
    }
    else
    {
        if( !m_additive )
            clearSelection();

        // Prevent selection of invisible items
        if( selectable( aItem ) )
        {
            aItem->SetSelected();
            m_selectedItems.insert( aItem );
        }
    }
}


void SELECTION_TOOL::clearSelection()
{
    BOOST_FOREACH( BOARD_ITEM* item, m_selectedItems )
    {
        item->ClearSelected();
    }

    m_selectedItems.clear();
}


void SELECTION_TOOL::selectSingle( const VECTOR2I& aWhere )
{
    BOARD* pcb = getModel<BOARD>( PCB_T );
    BOARD_ITEM* item;
    GENERAL_COLLECTORS_GUIDE guide = getEditFrame<PCB_EDIT_FRAME>()->GetCollectorsGuide();
    GENERAL_COLLECTOR collector;

    collector.Collect( pcb, GENERAL_COLLECTOR::AllBoardItems,
                       wxPoint( aWhere.x, aWhere.y ), guide );

    switch( collector.GetCount() )
    {
    case 0:
        if( !m_additive )
            clearSelection();
        break;

    case 1:
        toggleSelection( collector[0] );
        break;

    default:
        // Remove modules, they have to be selected by clicking on area that does not
        // contain anything but module footprint and not selectable items
        for( int i = collector.GetCount() - 1; i >= 0 ; --i )
        {
            BOARD_ITEM* boardItem = ( collector )[i];
            if( boardItem->Type() == PCB_MODULE_T || !selectable( boardItem ) )
                collector.Remove( i );
        }

        // Let's see if there is still disambiguation in selection..
        if( collector.GetCount() == 1 )
        {
            toggleSelection( collector[0] );
        }
        else if( collector.GetCount() > 1 )
        {
            item = disambiguationMenu( &collector );
            if( item )
                toggleSelection( item );
        }
        break;
    }
}


BOARD_ITEM* SELECTION_TOOL::pickSmallestComponent( GENERAL_COLLECTOR* aCollector )
{
    int count = aCollector->GetPrimaryCount();     // try to use preferred layer
    if( 0 == count )
        count = aCollector->GetCount();

    for( int i = 0; i < count; ++i )
    {
        if( ( *aCollector )[i]->Type() != PCB_MODULE_T )
            return NULL;
    }

    // All are modules, now find smallest MODULE
    int minDim = 0x7FFFFFFF;
    int minNdx = 0;

    for( int i = 0; i < count; ++i )
    {
        MODULE* module = (MODULE*)( *aCollector )[i];

        int lx = module->GetBoundingBox().GetWidth();
        int ly = module->GetBoundingBox().GetHeight();

        int lmin = std::min( lx, ly );

        if( lmin < minDim )
        {
            minDim = lmin;
            minNdx = i;
        }
    }

    return (*aCollector)[minNdx];
}


bool SELECTION_TOOL::selectMultiple()
{
    OPT_TOOL_EVENT evt;
    VIEW* v = getView();
    bool cancelled = false;
    m_multiple = true;

    // Those 2 lines remove the blink-in-the-random-place effect
    m_selArea->SetOrigin( VECTOR2I( 0, 0 ) );
    m_selArea->SetEnd( VECTOR2I( 0, 0 ) );
    v->Add( m_selArea );

    while( evt = Wait() )
    {
        if( evt->IsCancel() )
        {
            cancelled = true;
            break;
        }

        if( evt->IsDrag( MB_Left ) )
        {
            if( !m_additive )
                clearSelection();

            // Start drawing a selection box
            m_selArea->SetOrigin( evt->DragOrigin() );
            m_selArea->SetEnd( evt->Position() );
            m_selArea->ViewSetVisible( true );
            m_selArea->ViewUpdate( VIEW_ITEM::GEOMETRY );
        }

        if( evt->IsMouseUp( MB_Left ) )
        {
            // End drawing a selection box
            m_selArea->ViewSetVisible( false );

            // Mark items within a box as selected
            std::vector<VIEW::LayerItemPair> selectedItems;
            BOX2I selectionBox = m_selArea->ViewBBox();

            v->Query( selectionBox, selectedItems );
            std::vector<VIEW::LayerItemPair>::iterator it, it_end;
            for( it = selectedItems.begin(), it_end = selectedItems.end(); it != it_end; ++it )
            {
                BOARD_ITEM* item = static_cast<BOARD_ITEM*>( it->first );

                // Add only those items which are visible and fully within the selection box
                if( selectable( item ) && selectionBox.Contains( item->ViewBBox() ) )
                {
                    item->SetSelected();
                    m_selectedItems.insert( item );
                }
            }
            break;
        }
    }

    v->Remove( m_selArea );
    m_multiple = false;

    return cancelled;
}


BOARD_ITEM* SELECTION_TOOL::disambiguationMenu( GENERAL_COLLECTOR* aCollector )
{
    BOARD_ITEM* current = NULL;
    boost::shared_ptr<BRIGHT_BOX> brightBox;

    m_menu.reset( new CONTEXT_MENU() );
    m_menu->SetTitle( _( "Clarify selection" ) );

    int limit = std::min( 10, aCollector->GetCount() );

    for( int i = 0; i < limit; ++i )
    {
        wxString text;
        BOARD_ITEM* item = ( *aCollector )[i];
        text = item->GetSelectMenuText();
        m_menu->Add( text, i );
    }

    SetContextMenu( m_menu.get(), CMENU_NOW );

    while( OPT_TOOL_EVENT evt = Wait() )
    {
        if( evt->Action() == TA_ContextMenuUpdate )
        {
            // User has pointed an item, so show it in a different way
            if( current )
                current->ClearBrightened();

            int id = *evt->GetCommandId();

            if( id >= 0 )
            {
                current = ( *aCollector )[id];
                current->SetBrightened();
            }
            else
                current = NULL;
        }
        else if( evt->Action() == TA_ContextMenuChoice )
        {
            optional<int> id = evt->GetCommandId();

            if( current )
                current->ClearSelected();

            if( id && ( *id >= 0 ) )
            {
                current = ( *aCollector )[*id];
                current->SetSelected();
            }

            break;
        }

        if( current && current->IsBrightened() )
        {
            brightBox.reset( new BRIGHT_BOX( current ) );
            getView()->Add( brightBox.get() );
        }
    }

    getView()->MarkTargetDirty( TARGET_OVERLAY );
    return current;
}


bool SELECTION_TOOL::selectable( const BOARD_ITEM* aItem )
{
    bool highContrast = getView()->GetPainter()->GetSettings()->GetHighContrast();

    if( highContrast )
    {
        bool onActive = false;
        int layers[KiGfx::VIEW::VIEW_MAX_LAYERS], layers_count;

        // Filter out items that do not belong to active layers
        std::set<unsigned int> activeLayers = getView()->GetPainter()->
                                                GetSettings()->GetActiveLayers();
        aItem->ViewGetLayers( layers, layers_count );

        for( int i = 0; i < layers_count; ++i )
        {
            if( activeLayers.count( layers[i] ) > 0 )   // Item is on at least one active layer
            {
                onActive = true;
                break;
            }
        }

        if( !onActive )
            return false;
    }

    BOARD* board = getModel<BOARD>( PCB_T );
    switch( aItem->Type() )
    {
    case PCB_VIA_T:
    {
        // For vias it is enough if only one of layers is visible
        LAYER_NUM top, bottom;
        static_cast<const SEGVIA*>( aItem )->ReturnLayerPair( &top, &bottom );

        return ( board->IsLayerVisible( top ) ||
                 board->IsLayerVisible( bottom ) );
    }
    break;

    case PCB_PAD_T:
    {
        // Pads are not selectable in multiple selection mode
        if( m_multiple )
            return false;

        // Pads are supposed to be on top, bottom or both at the same time (THT)
        if( aItem->IsOnLayer( LAYER_N_FRONT ) && board->IsLayerVisible( LAYER_N_FRONT ) )
            return true;

        if( aItem->IsOnLayer( LAYER_N_BACK ) && board->IsLayerVisible( LAYER_N_BACK ) )
            return true;

        return false;
    }
    break;

    case PCB_MODULE_TEXT_T:
        // Module texts are not selectable in multiple selection mode
        if( m_multiple )
            return false;
        break;

    case PCB_MODULE_EDGE_T:
        // These are not selectable, otherwise silkscreen drawings would be easily destroyed
        return false;
        break;
    }

    // All other items are selected only if the layer on which they exist is visible
    return board->IsLayerVisible( aItem->GetLayer() );
}
