/*
 * KiRouter - a push-and-(sometimes-)shove PCB router
 *
 * Copyright (C) 2013-2014 CERN
 * Copyright (C) 2016-2021 KiCad Developers, see AUTHORS.txt for contributors.
 * 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 3 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, see <http://www.gnu.org/licenses/>.
 */

#include "pns_arc.h"

#include "pns_dragger.h"
#include "pns_shove.h"
#include "pns_router.h"
#include "pns_debug_decorator.h"
#include "pns_walkaround.h"

namespace PNS {

DRAGGER::DRAGGER( ROUTER* aRouter ) :
    DRAG_ALGO( aRouter ),
    m_initialVia( {} ),
    m_draggedVia( {} )
{
    m_world = nullptr;
    m_lastNode = nullptr;
    m_mode = DM_SEGMENT;
    m_draggedSegmentIndex = 0;
    m_dragStatus = false;
    m_currentMode = RM_MarkObstacles;
    m_freeAngleMode = false;
}


DRAGGER::~DRAGGER()
{
}


bool DRAGGER::propagateViaForces( NODE* node, std::set<VIA*>& vias )
{
    VIA* via = *vias.begin();

    VECTOR2I force;
    VECTOR2I lead = m_mouseTrailTracer.GetTrailLeadVector();

    bool solidsOnly = false;// ( m_currentMode != RM_Walkaround );

    if( via->PushoutForce( node, lead, force, solidsOnly, 40 ) )
    {
        via->SetPos( via->Pos() + force );
        return true;
    }

    return false;
}


VVIA* DRAGGER::checkVirtualVia( const VECTOR2D& aP, SEGMENT* aSeg )
{
    int w2 = aSeg->Width() / 2;

    auto distA = ( aP - aSeg->Seg().A ).EuclideanNorm();
    auto distB = ( aP - aSeg->Seg().B ).EuclideanNorm();

    VECTOR2I psnap;

    if( distA <= w2 )
    {
        psnap = aSeg->Seg().A;
    }
    else if( distB <= w2 )
    {
        psnap = aSeg->Seg().B;
    }
    else
    {
        return nullptr;
    }

    JOINT *jt = m_world->FindJoint( psnap, aSeg );

    if ( !jt )
    {
        return nullptr;
    }

    for( auto lnk : jt->LinkList() )
    {
        if( lnk.item->IsVirtual() && lnk.item->OfKind( ITEM::VIA_T ))
        {
            return static_cast<VVIA*>( lnk.item );
        }
    }

    return nullptr;
}


bool DRAGGER::startDragSegment( const VECTOR2D& aP, SEGMENT* aSeg )
{
    int w2 = aSeg->Width() / 2;

    m_draggedLine      = m_world->AssembleLine( aSeg, &m_draggedSegmentIndex );
    m_lastDragSolution = m_draggedLine;

    if( m_shove )
    {
        m_shove->SetInitialLine( m_draggedLine );
    }

    auto distA = ( aP - aSeg->Seg().A ).EuclideanNorm();
    auto distB = ( aP - aSeg->Seg().B ).EuclideanNorm();

    if( distA <= w2 )
    {
        m_mode = DM_CORNER;
    }
    else if( distB <= w2 )
    {
        m_draggedSegmentIndex++;
        m_mode = DM_CORNER;
    }
    else if( m_freeAngleMode )
    {
        if( distB < distA &&
            ( m_draggedSegmentIndex < m_draggedLine.PointCount() - 2 ) &&
            ( !m_draggedLine.CLine().IsPtOnArc( static_cast<size_t>(m_draggedSegmentIndex) + 1 ) ) )
        {
            m_draggedSegmentIndex++;
        }

        m_mode = DM_CORNER;
    }
    else
    {
        m_mode = DM_SEGMENT;
    }

    return true;
}


bool DRAGGER::startDragArc( const VECTOR2D& aP, ARC* aArc )
{
    m_draggedLine = m_world->AssembleLine( aArc, &m_draggedSegmentIndex );
    m_shove->SetInitialLine( m_draggedLine );
    m_mode = DM_ARC;

    return true;
}


bool DRAGGER::startDragVia( VIA* aVia )
{
    m_initialVia = aVia->MakeHandle();
    m_draggedVia = m_initialVia;

    m_mode = DM_VIA;

    return true;
}

const ITEM_SET DRAGGER::findViaFanoutByHandle ( NODE *aNode, const VIA_HANDLE& handle )
{
    ITEM_SET rv;

    JOINT* jt = aNode->FindJoint( handle.pos, handle.layers.Start(), handle.net );

    if( !jt )
        return rv;

    for( ITEM* item : jt->LinkList() )
    {
        if( item->OfKind( ITEM::SEGMENT_T | ITEM::ARC_T ) )
        {
            int segIndex;
            LINKED_ITEM* seg = ( LINKED_ITEM*) item;
            LINE l = aNode->AssembleLine( seg, &segIndex );

            if( segIndex != 0 )
                l.Reverse();

            rv.Add( l );
        }
        else if( item->OfKind( ITEM::VIA_T ) )
        {
            rv.Add( item );
        }
    }

    return rv;
}

bool DRAGGER::Start( const VECTOR2I& aP, ITEM_SET& aPrimitives )
{
    if( aPrimitives.Empty() )
        return false;

    ITEM* startItem = aPrimitives[0];

    m_lastNode = nullptr;
    m_draggedItems.Clear();
    m_currentMode = Settings().Mode();
    m_freeAngleMode = (m_mode & DM_FREE_ANGLE);
    m_lastValidPoint = aP;

    m_mouseTrailTracer.Clear();
    m_mouseTrailTracer.AddTrailPoint( aP );

    if( m_currentMode == RM_Shove  && !m_freeAngleMode )
    {
        m_shove = std::make_unique<SHOVE>( m_world, Router() );
        m_shove->SetLogger( Logger() );
        m_shove->SetDebugDecorator( Dbg() );
    }

    startItem->Unmark( MK_LOCKED );

    PNS_DBG( Dbg(), Message, wxString::Format( "StartDragging: item %p [kind %d]",
                                               startItem, (int) startItem->Kind() ) );

    switch( startItem->Kind() )
    {
    case ITEM::SEGMENT_T:
    {
        SEGMENT* seg = static_cast<SEGMENT*>( startItem );
        VVIA* vvia = checkVirtualVia( aP, seg );

        if( vvia )
        {
            return startDragVia( vvia );
        }
        else
        {
            return startDragSegment( aP, seg );
        }
    }
    case ITEM::VIA_T:
        return startDragVia( static_cast<VIA*>( startItem ) );

    case ITEM::ARC_T:
        return startDragArc( aP, static_cast<ARC*>( startItem ) );

    default:
        return false;
    }
}


void DRAGGER::SetMode( int aMode )
{
    m_mode = aMode;
}


bool DRAGGER::dragMarkObstacles( const VECTOR2I& aP )
{
    // fixme: rewrite using shared_ptr...
    if( m_lastNode )
    {
        delete m_lastNode;
        m_lastNode = nullptr;
    }

    m_lastNode = m_world->Branch();

    switch( m_mode )
    {
    case DM_SEGMENT:
    case DM_CORNER:
    {
        //TODO: Make threshold configurable
        int  thresh = Settings().SmoothDraggedSegments() ? m_draggedLine.Width() / 4 : 0;
        LINE origLine( m_draggedLine );
        LINE dragged( m_draggedLine );
        dragged.SetSnapThreshhold( thresh );
        dragged.ClearLinks();

        if( m_mode == DM_SEGMENT )
            dragged.DragSegment( aP, m_draggedSegmentIndex );
        else
            dragged.DragCorner( aP, m_draggedSegmentIndex, m_freeAngleMode );

        m_lastNode->Remove( origLine );
        m_lastNode->Add( dragged );

        m_draggedItems.Clear();
        m_draggedItems.Add( dragged );

        break;
    }

    case DM_VIA: // fixme...
    {
        dragViaMarkObstacles( m_initialVia, m_lastNode, aP );

        break;
    }
    }

    if( Settings().AllowDRCViolations() )
        m_dragStatus = true;
    else
        m_dragStatus = !m_world->CheckColliding( m_draggedItems );

    return true;
}


bool DRAGGER::dragViaMarkObstacles( const VIA_HANDLE& aHandle, NODE* aNode, const VECTOR2I& aP )
{
    m_draggedItems.Clear();

    ITEM_SET fanout = findViaFanoutByHandle( aNode, aHandle );

    if( fanout.Empty() )
    {
        return true;
    }

    for( ITEM* item : fanout.Items() )
    {
        if( const LINE* l = dyn_cast<const LINE*>( item ) )
        {
            LINE origLine( *l );
            LINE draggedLine( *l );

            draggedLine.DragCorner( aP, origLine.CLine().Find( aHandle.pos ), m_freeAngleMode );
            draggedLine.ClearLinks();

            m_draggedItems.Add( draggedLine );

            m_lastNode->Remove( origLine );
            m_lastNode->Add( draggedLine );
        }
        else if ( VIA *via = dyn_cast<VIA*>( item ) )
        {
            auto nvia = Clone( *via );

            nvia->SetPos( aP );
            m_draggedItems.Add( nvia.get() );

            m_lastNode->Remove( via );
            m_lastNode->Add( std::move( nvia ) );
        }
    }

    return true;
}


bool DRAGGER::dragViaWalkaround( const VIA_HANDLE& aHandle, NODE* aNode, const VECTOR2I& aP )
{
    m_draggedItems.Clear();

    ITEM_SET fanout = findViaFanoutByHandle( aNode, aHandle );

    if( fanout.Empty() )
    {
        return true;
    }

    bool viaPropOk = false;
    VECTOR2I viaTargetPos;

    for( ITEM* item : fanout.Items() )
    {
        if ( VIA *via = dyn_cast<VIA*>( item ) )
        {
            auto draggedVia = Clone( *via );

            draggedVia->SetPos( aP );
            m_draggedItems.Add( draggedVia.get() );

            std::set<VIA*> vias;

            vias.insert( draggedVia.get() );

            bool ok = propagateViaForces( m_lastNode, vias );

            if( ok )
            {
                viaTargetPos = draggedVia->Pos();
                viaPropOk = true;
                m_lastNode->Remove( via );
                m_lastNode->Add( std::move(draggedVia) );
            }
        }
    }

    if( !viaPropOk ) // can't force-propagate the via? bummer...
        return false;

    for( ITEM* item : fanout.Items() )
    {
        if( const LINE* l = dyn_cast<const LINE*>( item ) )
        {
            LINE origLine( *l );
            LINE draggedLine( *l );
            LINE walkLine( *l );

            draggedLine.DragCorner( viaTargetPos, origLine.CLine().Find( aHandle.pos ),
                                    m_freeAngleMode );
            draggedLine.ClearLinks();

            if ( m_world->CheckColliding( &draggedLine ) )
            {
                bool ok = tryWalkaround( m_lastNode, draggedLine, walkLine );

                if( !ok )
                    return false;

                m_lastNode->Remove( origLine );
                optimizeAndUpdateDraggedLine( walkLine, origLine, aP );
            }
            else
            {
                m_draggedItems.Add( draggedLine );

                m_lastNode->Remove( origLine );
                m_lastNode->Add( draggedLine );
            }
        }
    }

    return true;
}


void DRAGGER::optimizeAndUpdateDraggedLine( LINE& aDragged, const LINE& aOrig, const VECTOR2I& aP )
{
    VECTOR2D lockV;
    aDragged.ClearLinks();
    aDragged.Unmark();

    lockV = aDragged.CLine().NearestPoint( aP );

    OPTIMIZER optimizer( m_lastNode );

    int effort = OPTIMIZER::MERGE_SEGMENTS | OPTIMIZER::KEEP_TOPOLOGY | OPTIMIZER::RESTRICT_AREA;

    if( Settings().SmoothDraggedSegments() )
        effort |= OPTIMIZER::MERGE_COLINEAR;

    optimizer.SetEffortLevel( effort );

    OPT_BOX2I affectedArea = aDragged.ChangedArea( &aOrig );
    VECTOR2I anchor( aP );

    if( aDragged.CLine().Find( aP ) < 0 )
    {
        anchor = aDragged.CLine().NearestPoint( aP );
    }

    optimizer.SetPreserveVertex( anchor );

    // People almost never want KiCad to reroute tracks in areas they can't even see, so restrict
    // the area to what is visible even if we are optimizing the "entire" track.
    if( Settings().GetOptimizeEntireDraggedTrack() )
        affectedArea = VisibleViewArea();
    else if( !affectedArea )
        affectedArea = BOX2I( aP ); // No valid area yet? set to minimum to disable optimization

    PNS_DBG( Dbg(), AddPoint, anchor, YELLOW, 100000, "drag-anchor" );
    PNS_DBG( Dbg(), AddBox, *affectedArea, RED, "drag-affected-area" );

    optimizer.SetRestrictArea( *affectedArea );
    optimizer.Optimize( &aDragged );

    OPT_BOX2I optArea = aDragged.ChangedArea( &aOrig );

    if( optArea )
        PNS_DBG( Dbg(), AddBox, *optArea, BLUE, "drag-opt-area" );

    m_lastNode->Add( aDragged );
    m_draggedItems.Clear();
    m_draggedItems.Add( aDragged );
}


bool DRAGGER::tryWalkaround( NODE* aNode, LINE& aOrig, LINE& aWalk )
{
    WALKAROUND walkaround( aNode, Router() );
    bool       ok = false;
    walkaround.SetSolidsOnly( false );
    walkaround.SetDebugDecorator( Dbg() );
    walkaround.SetLogger( Logger() );
    walkaround.SetIterationLimit( Settings().WalkaroundIterationLimit() );

    aWalk = aOrig;

    WALKAROUND::RESULT wr = walkaround.Route( aWalk );


    if( wr.statusCcw == WALKAROUND::DONE && wr.statusCw == WALKAROUND::DONE )
    {
        aWalk = ( wr.lineCw.CLine().Length() < wr.lineCcw.CLine().Length() ? wr.lineCw :
                                                                             wr.lineCcw );
        ok    = true;
    }
    else if( wr.statusCw == WALKAROUND::DONE )
    {
        aWalk = wr.lineCw;
        ok    = true;
    }
    else if( wr.statusCcw == WALKAROUND::DONE )
    {
        aWalk = wr.lineCcw;
        ok    = true;
    }
    return ok;
}


bool DRAGGER::dragWalkaround( const VECTOR2I& aP )
{
    bool ok = false;

    // fixme: rewrite using shared_ptr...
    if( m_lastNode )
    {
        delete m_lastNode;
        m_lastNode = nullptr;
    }

    m_lastNode = m_world->Branch();

    switch( m_mode )
    {
    case DM_SEGMENT:
    case DM_CORNER:
    {
        int thresh = Settings().SmoothDraggedSegments() ? m_draggedLine.Width() / 4 : 0;
        LINE dragged( m_draggedLine );
        LINE draggedWalk( m_draggedLine );
        LINE origLine( m_draggedLine );

        dragged.SetSnapThreshhold( thresh );

        if( m_mode == DM_SEGMENT )
            dragged.DragSegment( aP, m_draggedSegmentIndex );
        else
            dragged.DragCorner( aP, m_draggedSegmentIndex );

        if ( m_world->CheckColliding( &dragged ) )
        {
            ok = tryWalkaround( m_lastNode, dragged, draggedWalk );
        }
        else
        {
            draggedWalk = dragged;
            ok = true;
        }

        if( ok )
        {
            PNS_DBG( Dbg(), AddLine, origLine.CLine(), BLUE, 50000, "drag-orig-line" );
            PNS_DBG( Dbg(), AddLine, draggedWalk.CLine(), CYAN, 75000, "drag-walk" );
            m_lastNode->Remove( origLine );
            optimizeAndUpdateDraggedLine( draggedWalk, origLine, aP );
        }

        break;
    }
    case DM_VIA: // fixme...
    {
        ok = dragViaWalkaround( m_initialVia, m_lastNode, aP );
        break;
    }
    }

    m_dragStatus = ok;

    return true;
}


bool DRAGGER::dragShove( const VECTOR2I& aP )
{
    bool ok = false;

    if( m_lastNode )
    {
        delete m_lastNode;
        m_lastNode = nullptr;
    }

    switch( m_mode )
    {
    case DM_SEGMENT:
    case DM_CORNER:
    {
        //TODO: Make threshold configurable
        int  thresh = Settings().SmoothDraggedSegments() ? m_draggedLine.Width() / 2 : 0;
        LINE dragged( m_draggedLine );
        dragged.SetSnapThreshhold( thresh );

        if( m_mode == DM_SEGMENT )
            dragged.DragSegment( aP, m_draggedSegmentIndex );
        else
            dragged.DragCorner( aP, m_draggedSegmentIndex );

        PNS_DBG( Dbg(), AddLine, dragged.CLine(), BLUE, 5000, "drag-shove-line" );

        SHOVE::SHOVE_STATUS st = m_shove->ShoveLines( dragged );

        if( st == SHOVE::SH_OK )
        {
            ok = true;
        }
        else if( st == SHOVE::SH_HEAD_MODIFIED )
        {
            dragged = m_shove->NewHead();
            ok = true;
        }

        m_lastNode = m_shove->CurrentNode()->Branch();

        if( ok )
        {
            VECTOR2D lockV;
            dragged.ClearLinks();
            dragged.Unmark();
            optimizeAndUpdateDraggedLine( dragged, m_draggedLine, aP );
            m_lastDragSolution = dragged;
        }
        else
        {
            m_lastDragSolution.ClearLinks();
            m_lastNode->Add( m_lastDragSolution );
        }

        break;
    }

    case DM_VIA:
    {
        VIA_HANDLE newVia;

        // corner count limiter intended to avoid excessive optimization produces mediocre results for via shoving.
        // this is a hack that disables it, before I figure out a more reliable solution
        m_shove->DisablePostShoveOptimizations( OPTIMIZER::LIMIT_CORNER_COUNT );
        SHOVE::SHOVE_STATUS st = m_shove->ShoveDraggingVia( m_draggedVia, aP, newVia );

        if( st == SHOVE::SH_OK || st == SHOVE::SH_HEAD_MODIFIED )
            ok = true;

        m_lastNode = m_shove->CurrentNode()->Branch();

        if( newVia.valid )
            m_draggedVia = newVia;

        m_draggedItems.Clear();
        break;
    }
    }

    m_dragStatus = ok;

    return ok;
}


bool DRAGGER::FixRoute()
{
    NODE* node = CurrentNode();

    if( node )
    {
        // If collisions exist, we can fix in shove/smart mode because all tracks to be committed
        // will be in valid positions (even if the current routing solution to the mouse cursor is
        // invalid).  In other modes, we can only commit if "Allow DRC violations" is enabled.
        if( !m_dragStatus )
        {
            Drag( m_lastValidPoint );
            node = CurrentNode();

            if( !node )
                return false;
        }

        if( !m_dragStatus && !Settings().AllowDRCViolations() )
            return false;

        Router()->CommitRouting( node );
        return true;
    }

    return false;
}


bool DRAGGER::Drag( const VECTOR2I& aP )
{
    m_mouseTrailTracer.AddTrailPoint( aP );

    bool ret = false;

    if( m_freeAngleMode )
    {
        ret = dragMarkObstacles( aP );
    }
    else
    {
        switch( m_currentMode )
        {
        case RM_MarkObstacles:   ret = dragMarkObstacles( aP );   break;
        case RM_Shove:           ret = dragShove( aP );           break;
        case RM_Walkaround:      ret = dragWalkaround( aP );      break;
        default:                                                  break;
        }
    }

    if( ret )
        m_lastValidPoint = aP;

    return ret;
}


NODE* DRAGGER::CurrentNode() const
{
   return m_lastNode ? m_lastNode : m_world;
}


const ITEM_SET DRAGGER::Traces()
{
    return m_draggedItems;
}

}