/*
 * This program source code file is part of KiCad, a free EDA CAD application.
 *
 * Copyright (C) 2012 Torsten Hueter, torstenhtr <at> gmx.de
 * Copyright (C) 2013-2015 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
 */

#include <wx/wx.h>

#include <view/view.h>
#include <view/wx_view_controls.h>
#include <gal/graphics_abstraction_layer.h>
#include <tool/tool_dispatcher.h>

using namespace KIGFX;

const wxEventType WX_VIEW_CONTROLS::EVT_REFRESH_MOUSE = wxNewEventType();

WX_VIEW_CONTROLS::WX_VIEW_CONTROLS( VIEW* aView, wxScrolledCanvas* aParentPanel ) :
    VIEW_CONTROLS( aView ), m_state( IDLE ), m_parentPanel( aParentPanel ), m_scrollScale( 1.0, 1.0 )
{
    m_parentPanel->Connect( wxEVT_MOTION,
                            wxMouseEventHandler( WX_VIEW_CONTROLS::onMotion ), NULL, this );
#ifdef USE_OSX_MAGNIFY_EVENT
    m_parentPanel->Connect( wxEVT_MAGNIFY,
                            wxMouseEventHandler( WX_VIEW_CONTROLS::onMagnify ), NULL, this );
#endif
    m_parentPanel->Connect( wxEVT_MOUSEWHEEL,
                            wxMouseEventHandler( WX_VIEW_CONTROLS::onWheel ), NULL, this );
    m_parentPanel->Connect( wxEVT_MIDDLE_UP,
                            wxMouseEventHandler( WX_VIEW_CONTROLS::onButton ), NULL, this );
    m_parentPanel->Connect( wxEVT_MIDDLE_DOWN,
                            wxMouseEventHandler( WX_VIEW_CONTROLS::onButton ), NULL, this );
    m_parentPanel->Connect( wxEVT_LEFT_UP,
                            wxMouseEventHandler( WX_VIEW_CONTROLS::onButton ), NULL, this );
    m_parentPanel->Connect( wxEVT_LEFT_DOWN,
                            wxMouseEventHandler( WX_VIEW_CONTROLS::onButton ), NULL, this );
#if defined _WIN32 || defined _WIN64
    m_parentPanel->Connect( wxEVT_ENTER_WINDOW,
                            wxMouseEventHandler( WX_VIEW_CONTROLS::onEnter ), NULL, this );
#endif
    m_parentPanel->Connect( wxEVT_LEAVE_WINDOW,
                            wxMouseEventHandler( WX_VIEW_CONTROLS::onLeave ), NULL, this );
    m_parentPanel->Connect( wxEVT_SCROLLWIN_THUMBTRACK,
                            wxScrollWinEventHandler( WX_VIEW_CONTROLS::onScroll ), NULL, this );

    m_panTimer.SetOwner( this );
    this->Connect( wxEVT_TIMER,
                   wxTimerEventHandler( WX_VIEW_CONTROLS::onTimer ), NULL, this );
}


void WX_VIEW_CONTROLS::onMotion( wxMouseEvent& aEvent )
{
    bool isAutoPanning = false;

    if( m_autoPanEnabled )
        isAutoPanning = handleAutoPanning( aEvent );

    if( !isAutoPanning && aEvent.Dragging() )
    {
        if( m_state == DRAG_PANNING )
        {
            VECTOR2D   d = m_dragStartPoint - VECTOR2D( aEvent.GetX(), aEvent.GetY() );
            VECTOR2D   delta = m_view->ToWorld( d, false );

            m_view->SetCenter( m_lookStartPoint + delta );
            aEvent.StopPropagation();
        }
    }

    aEvent.Skip();
}


void WX_VIEW_CONTROLS::onWheel( wxMouseEvent& aEvent )
{
    const double wheelPanSpeed = 0.001;

    if( aEvent.ControlDown() || aEvent.ShiftDown() )
    {
        // Scrolling
        VECTOR2D scrollVec = m_view->ToWorld( m_view->GetScreenPixelSize(), false ) *
                             ( (double) aEvent.GetWheelRotation() * wheelPanSpeed );
        double   scrollSpeed;

        if( std::abs( scrollVec.x ) > std::abs( scrollVec.y ) )
            scrollSpeed = scrollVec.x;
        else
            scrollSpeed = scrollVec.y;

        VECTOR2D delta( aEvent.ControlDown() ? -scrollSpeed : 0.0,
                        aEvent.ShiftDown() ? -scrollSpeed : 0.0 );

        m_view->SetCenter( m_view->GetCenter() + delta );
    }
    else
    {
        // Zooming
        wxLongLong  timeStamp   = wxGetLocalTimeMillis();
        double      timeDiff    = timeStamp.ToDouble() - m_timeStamp.ToDouble();
        int         rotation    = aEvent.GetWheelRotation();
        double      zoomScale;

#ifdef __APPLE__
        // The following is to support Apple pointer devices (MagicMouse &
        // Macbook touchpad), which send events more frequently, but with smaller
        // wheel rotation.
        //
        // It should not break other platforms, but I prefer to be safe than
        // sorry. If you find a device that behaves in the same way on another
        // platform, feel free to remove #ifdef directives.
        if( timeDiff > 0 && timeDiff < 100 && std::abs( rotation ) < 20 )
        {
            aEvent.Skip();
            return;
        }
#endif

        m_timeStamp = timeStamp;

        // Set scaling speed depending on scroll wheel event interval
        if( timeDiff < 500 && timeDiff > 0 )
        {
            zoomScale = 2.05 - timeDiff / 500;

            if( rotation < 0 )
                zoomScale = 1.0 / zoomScale;
        }
        else
        {
            zoomScale = ( rotation > 0 ) ? 1.05 : 0.95;
        }

        if( IsCursorWarpingEnabled() )
        {
            CenterOnCursor();
            m_view->SetScale( m_view->GetScale() * zoomScale );
        }
        else
        {
            VECTOR2D anchor = m_view->ToWorld( VECTOR2D( aEvent.GetX(), aEvent.GetY() ) );
            m_view->SetScale( m_view->GetScale() * zoomScale, anchor );
        }
    }

    aEvent.Skip();
}


#ifdef USE_OSX_MAGNIFY_EVENT
void WX_VIEW_CONTROLS::onMagnify( wxMouseEvent& aEvent )
{
    // Scale based on the magnification from our underlying magnification event.
    VECTOR2D anchor = m_view->ToWorld( VECTOR2D( aEvent.GetX(), aEvent.GetY() ) );
    m_view->SetScale( m_view->GetScale() * ( aEvent.GetMagnification() + 1.0f ), anchor );

    aEvent.Skip();
}
#endif


void WX_VIEW_CONTROLS::onButton( wxMouseEvent& aEvent )
{
    switch( m_state )
    {
    case IDLE:
    case AUTO_PANNING:
        if( aEvent.MiddleDown() )
        {
            m_dragStartPoint = VECTOR2D( aEvent.GetX(), aEvent.GetY() );
            m_lookStartPoint = m_view->GetCenter();
            m_state = DRAG_PANNING;
        }

        if( aEvent.LeftUp() )
            m_state = IDLE;     // Stop autopanning when user release left mouse button

        break;

    case DRAG_PANNING:
        if( aEvent.MiddleUp() )
            m_state = IDLE;

        break;
    }

    aEvent.Skip();
}


void WX_VIEW_CONTROLS::onEnter( wxMouseEvent& aEvent )
{
    m_parentPanel->SetFocus();
}


void WX_VIEW_CONTROLS::onLeave( wxMouseEvent& aEvent )
{
    if( m_cursorCaptured )
    {
        bool warp = false;
        int x = aEvent.GetX();
        int y = aEvent.GetY();
        wxSize parentSize = m_parentPanel->GetClientSize();

        if( x < 0 )
        {
            x = 0;
            warp = true;
        }
        else if( x >= parentSize.x )
        {
            x = parentSize.x - 1;
            warp = true;
        }

        if( y < 0 )
        {
            y = 0;
            warp = true;
        }
        else if( y >= parentSize.y )
        {
            y = parentSize.y - 1;
            warp = true;
        }

        if( warp )
            m_parentPanel->WarpPointer( x, y );
    }
}


void WX_VIEW_CONTROLS::onTimer( wxTimerEvent& aEvent )
{
    switch( m_state )
    {
    case AUTO_PANNING:
    {
#if wxCHECK_VERSION( 3, 0, 0 )
        if( !m_parentPanel->HasFocus() )
            break;
#endif

        double borderSize = std::min( m_autoPanMargin * m_view->GetScreenPixelSize().x,
                                      m_autoPanMargin * m_view->GetScreenPixelSize().y );

        VECTOR2D dir( m_panDirection );

        if( dir.EuclideanNorm() > borderSize )
            dir = dir.Resize( borderSize );

        dir = m_view->ToWorld( dir, false );
        m_view->SetCenter( m_view->GetCenter() + dir * m_autoPanSpeed );

        // Notify tools that the cursor position has changed in the world coordinates
        wxMouseEvent moveEvent( EVT_REFRESH_MOUSE );

        // Set the modifiers state
#if wxCHECK_VERSION( 3, 0, 0 )
        moveEvent.SetControlDown( wxGetKeyState( WXK_CONTROL ) );
        moveEvent.SetShiftDown( wxGetKeyState( WXK_SHIFT ) );
        moveEvent.SetAltDown( wxGetKeyState( WXK_ALT ) );
#else
        // wx <3.0 do not have accessors, but the fields are exposed
        moveEvent.m_controlDown = wxGetKeyState( WXK_CONTROL );
        moveEvent.m_shiftDown = wxGetKeyState( WXK_SHIFT );
        moveEvent.m_altDown = wxGetKeyState( WXK_ALT );
#endif

        wxPostEvent( m_parentPanel, moveEvent );
    }
    break;

    case IDLE:    // Just remove unnecessary warnings
    case DRAG_PANNING:
        break;
    }
}


void WX_VIEW_CONTROLS::onScroll( wxScrollWinEvent& aEvent )
{
    VECTOR2D center = m_view->GetCenter();
    const BOX2I& boundary = m_view->GetBoundary();

    if( aEvent.GetOrientation() == wxHORIZONTAL )
        center.x = (double) aEvent.GetPosition() * boundary.GetWidth() / m_scrollScale.x + boundary.GetLeft();
    else if( aEvent.GetOrientation() == wxVERTICAL )
        center.y = (double) aEvent.GetPosition() * boundary.GetHeight() / m_scrollScale.y + boundary.GetTop();

    m_view->SetCenter( center );
    m_parentPanel->Refresh();
}


void WX_VIEW_CONTROLS::SetGrabMouse( bool aEnabled )
{
    if( aEnabled && !m_grabMouse )
        m_parentPanel->CaptureMouse();
    else if( !aEnabled && m_grabMouse )
        m_parentPanel->ReleaseMouse();

    VIEW_CONTROLS::SetGrabMouse( aEnabled );
}


VECTOR2I WX_VIEW_CONTROLS::GetMousePosition() const
{
    wxPoint msp = wxGetMousePosition();
    wxPoint winp = m_parentPanel->GetScreenPosition();

    return VECTOR2I( msp.x - winp.x, msp.y - winp.y );
}


VECTOR2D WX_VIEW_CONTROLS::GetCursorPosition() const
{
    if( m_forceCursorPosition )
    {
        return m_forcedPosition;
    }
    else
    {
        VECTOR2D mousePosition = GetMousePosition();

        if( m_snappingEnabled )
            return m_view->GetGAL()->GetGridPoint( m_view->ToWorld( mousePosition ) );
        else
            return m_view->ToWorld( mousePosition );
    }
}


void WX_VIEW_CONTROLS::WarpCursor( const VECTOR2D& aPosition, bool aWorldCoordinates,
                                    bool aWarpView ) const
{
    if( aWorldCoordinates )
    {
        const VECTOR2I& screenSize = m_view->GetGAL()->GetScreenPixelSize();
        BOX2I screen( VECTOR2I( 0, 0 ), screenSize );
        VECTOR2D screenPos = m_view->ToScreen( aPosition );

        if( !screen.Contains( screenPos ) )
        {
            if( aWarpView )
            {
                m_view->SetCenter( aPosition );
                m_parentPanel->WarpPointer( screenSize.x / 2, screenSize.y / 2 );
            }
        }
        else
        {
            m_parentPanel->WarpPointer( screenPos.x, screenPos.y );
        }
    }
    else
    {
        m_parentPanel->WarpPointer( aPosition.x, aPosition.y );
    }
}


void WX_VIEW_CONTROLS::CenterOnCursor() const
{
    const VECTOR2I& screenSize = m_view->GetGAL()->GetScreenPixelSize();
    VECTOR2I screenCenter( screenSize / 2 );

    if( GetMousePosition() != screenCenter )
    {
        m_view->SetCenter( GetCursorPosition() );
        m_parentPanel->WarpPointer( KiROUND( screenSize.x / 2 ), KiROUND( screenSize.y / 2 ) );
    }
}


bool WX_VIEW_CONTROLS::handleAutoPanning( const wxMouseEvent& aEvent )
{
    VECTOR2D p( aEvent.GetX(), aEvent.GetY() );

    // Compute areas where autopanning is active
    double borderStart = std::min( m_autoPanMargin * m_view->GetScreenPixelSize().x,
                                   m_autoPanMargin * m_view->GetScreenPixelSize().y );
    double borderEndX = m_view->GetScreenPixelSize().x - borderStart;
    double borderEndY = m_view->GetScreenPixelSize().y - borderStart;

    if( p.x < borderStart )
        m_panDirection.x = -( borderStart - p.x );
    else if( p.x > borderEndX )
        m_panDirection.x = ( p.x - borderEndX );
    else
        m_panDirection.x = 0;

    if( p.y < borderStart )
        m_panDirection.y = -( borderStart - p.y );
    else if( p.y > borderEndY )
        m_panDirection.y = ( p.y - borderEndY );
    else
        m_panDirection.y = 0;

    bool borderHit = ( m_panDirection.x != 0 || m_panDirection.y != 0 );

    switch( m_state )
    {
    case AUTO_PANNING:
        if( !borderHit )
        {
            m_panTimer.Stop();
            m_state = IDLE;

            return false;
        }

        return true;
        break;

    case IDLE:
        if( borderHit )
        {
            m_state = AUTO_PANNING;
            m_panTimer.Start( (int) ( 1000.0 / 60.0 ) );

            return true;
        }

        return false;
        break;

    case DRAG_PANNING:
        return false;
    }

    wxASSERT_MSG( false, wxT( "This line should never be reached" ) );
    return false;    // Should not be reached, just avoid the compiler warnings..
}


void WX_VIEW_CONTROLS::UpdateScrollbars()
{
    const BOX2D viewport = m_view->GetViewport();
    const BOX2I& boundary = m_view->GetBoundary();

    m_scrollScale.x = 2e3 * boundary.GetWidth() / viewport.GetWidth();
    m_scrollScale.y = 2e3 * boundary.GetHeight() / viewport.GetHeight();

    // Another example of wxWidgets being broken by design: scroll position is determined by the
    // left (or top, if vertical) edge of the slider. Fortunately, slider size seems to be constant
    // (at least for wxGTK 3.0), so we have to add its size to allow user to scroll the workspace
    // till the end.
    m_parentPanel->SetScrollbars( 1, 1,
#ifdef __LINUX__
            m_scrollScale.x + 1623, m_scrollScale.y + 1623,
#else
            m_scrollScale.x, m_scrollScale.y,
#endif
            ( viewport.Centre().x - boundary.GetLeft() ) / boundary.GetWidth() * m_scrollScale.x,
            ( viewport.Centre().y - boundary.GetTop() ) / boundary.GetHeight() * m_scrollScale.y );
}