//===========================================
//  Lumina-DE source code
//  Copyright (c) 2015, Ken Moore
//  Available under the 3-clause BSD license
//  See the LICENSE file for full details
//===========================================
#include "LDesktopPluginSpace.h"
#include "LSession.h"
#include "desktop-plugins/NewDP.h"

#include <LuminaXDG.h>
#include <QDesktopWidget>

#define DEBUG 0

// ===================
//      PUBLIC
// ===================
LDesktopPluginSpace::LDesktopPluginSpace() : QWidget(){
  this->setObjectName("LuminaDesktopPluginSpace");
  //this->setAttribute(Qt::WA_TranslucentBackground);
  //this->setAttribute(Qt::WA_NoSystemBackground);
  this->setAutoFillBackground(false);
  this->setStyleSheet("QWidget#LuminaDesktopPluginSpace{ border: none; background: transparent; }"); 
  this->setWindowFlags(Qt::WindowStaysOnBottomHint | Qt::CustomizeWindowHint | Qt::FramelessWindowHint);
  this->setAcceptDrops(true);
  this->setContextMenuPolicy(Qt::NoContextMenu);
  this->setMouseTracking(true);
  TopToBottom = true;
  GRIDSIZE = 100.0; //default value if not set
  plugsettings = LSession::handle()->DesktopPluginSettings();
  LSession::handle()->XCB->SetAsDesktop(this->winId());
  //this->setWindowOpacity(0.0);
}

LDesktopPluginSpace::~LDesktopPluginSpace(){
  
}

void LDesktopPluginSpace::LoadItems(QStringList plugs, QStringList files){
  if(DEBUG){ qDebug() << "Loading Desktop Items:" << plugs << files << "Area:" << this->size() << GRIDSIZE; }
  bool changes = false;
  if(plugs != plugins){ plugins = plugs; changes = true; }
  if(files != deskitems){ deskitems = files; changes = true; }
  if(changes){ QTimer::singleShot(0,this, SLOT(reloadPlugins())); }
  this->show();
}

void LDesktopPluginSpace::SetIconSize(int size){
  if(DEBUG){ qDebug() << "Set Desktop Icon Size:" << size; }
  //QSize newsize = calculateItemSize(size);
  int oldsize = GRIDSIZE;
  GRIDSIZE = size; //turn the int into a float;
  //itemSize = QSize(1,1); //save this for all the later icons which are generated (grid size)
  UpdateGeom(oldsize);
  //Now re-set the item icon size
  //reloadPlugins(true);
}

void LDesktopPluginSpace::cleanup(){
  //Perform any final cleanup actions here
  for(int i=0; i<ITEMS.length(); i++){
    ITEMS.takeAt(i)->deleteLater();
    i--;
  }
  plugins.clear();
  deskitems.clear();
  this->hide();
}

void LDesktopPluginSpace::setBackground(QPixmap pix){
  wallpaper = pix;
  this->repaint();
}

void LDesktopPluginSpace::setDesktopArea(QRect area){
  //qDebug() << "Setting Desktop Plugin Area:" << area;
  desktopRect = area;
  
}

// ===================
//      PUBLIC SLOTS
// ===================
void LDesktopPluginSpace::UpdateGeom(int oldgrid){
  if(DEBUG){ qDebug() << "Updated Desktop Geom:" << desktopRect.size() << GRIDSIZE << desktopRect.size()/GRIDSIZE; }
  //Go through and check the locations/sizes of all items (particularly the ones on the bottom/right edges)
  //bool reload = false;
  for(int i=0; i<ITEMS.length(); i++){
    QRect grid = ITEMS[i]->gridGeometry(); //geomToGrid(ITEMS[i]->geometry(), oldgrid);
    if(DEBUG){ qDebug() << " - Check Plugin:" << ITEMS[i]->whatsThis() << grid; }
    if( !ValidGrid(grid) ){
      //This plugin is too far out of the screen - find new location for it
      if(DEBUG){ qDebug() << " -- Out of bounds - Find a new spot"; }
      grid = findOpenSpot(grid, ITEMS[i]->whatsThis(), true); //Reverse lookup spot
    }
    if(!ValidGrid(grid)){
      qDebug() << "No Place for plugin:" << ITEMS[i]->whatsThis();
      qDebug() << " - Removing it for now...";
      ITEMS.takeAt(i)->deleteLater();
      i--;
    }else{
      //NOTE: We are not doing the ValidGeometry() checks because we are only resizing existing plugin with pre-set & valid grid positions
      ITEMS[i]->setGridGeometry(grid); //save the new grid position for later
      MovePlugin(ITEMS[i], gridToGeom(grid)); //convert to pixels before saving/sizing (desktop canvas might have moved)
    }
  }
  //if(reload){ QTimer::singleShot(0,this, SLOT(reloadPlugins())); }
}

// ===================
//          PRIVATE
// ===================
void LDesktopPluginSpace::addDesktopItem(QString filepath){
  addDesktopPlugin("applauncher::"+filepath+"---dlink"+QString::number(LSession::handle()->desktop()->screenNumber(this)) );
}

void LDesktopPluginSpace::addDesktopPlugin(QString plugID){
  //This is used for generic plugins (QWidget-based)
  if(DEBUG){ qDebug() << "Adding Desktop Plugin:" << plugID; }
  LDPlugin *plug = NewDP::createPlugin(plugID, this);
    if(plug==0){ return; } //invalid plugin
    //plug->setAttribute(Qt::WA_TranslucentBackground);
    plug->setWhatsThis(plugID);
  //Now get the saved geometry for the plugin
  QRect geom = plug->gridGeometry(); //grid coordinates
  if(geom.isNull()){
    geom = plug->loadPluginGeometry(); //in pixel coords
    if(!geom.isNull()){ geom = geomToGrid(geom); } //convert to grid coordinates
  }
  //Now determine the position to put it
  if(geom.isNull()){
    //No previous location - need to calculate initial geom
    QSize sz = plug->defaultPluginSize(); //in grid coordinates
    geom.setSize(sz);
    //if an applauncher - add from top-left, otherwise add in from bottom-right
    if(plugID.startsWith("applauncher")){ geom = findOpenSpot(geom.width(), geom.height() ); }
    else{ geom = findOpenSpot(geom.width(), geom.height(), RoundUp(this->height()/GRIDSIZE), RoundUp(this->width()/GRIDSIZE), true); }
  }else if(!ValidGeometry(plugID, gridToGeom(geom)) ){
    //Find a new location for the plugin (saved location is invalid)
    geom = findOpenSpot(geom.width(), geom.height(), geom.y(), geom.x(), false); //try to get it within the same general area first
  }
  if(geom.x() < 0 || geom.y() < 0){
    qDebug() << "No available space for desktop plugin:" << plugID << " - IGNORING";
    delete plug;
  }else{
    if(DEBUG){ qDebug() <<  " - New Plugin Geometry (grid):" << geom; }
    //Now place the item in the proper spot/size
    plug->setGridGeometry(geom); //save for later
    MovePlugin(plug, gridToGeom(geom));
    //plug->setGeometry( gridToGeom(geom) );
    plug->show();
    if(DEBUG){ qDebug() << " - New Plugin Geometry (px):" << plug->geometry(); }
    ITEMS << plug;
    connect(plug, SIGNAL(StartMoving(QString)), this, SLOT(StartItemMove(QString)) );
    connect(plug, SIGNAL(StartResizing(QString)), this, SLOT(StartItemResize(QString)) );
    connect(plug, SIGNAL(RemovePlugin(QString)), this, SLOT(RemoveItem(QString)) );
    connect(plug, SIGNAL(IncreaseIconSize()), this, SIGNAL(IncreaseIcons()) );
    connect(plug, SIGNAL(DecreaseIconSize()), this, SIGNAL(DecreaseIcons()) );
    connect(plug, SIGNAL(CloseDesktopMenu()), this, SIGNAL(HideDesktopMenu()) );
  }
}

QRect LDesktopPluginSpace::findOpenSpot(int gridwidth, int gridheight, int startRow, int startCol, bool reversed, QString plugID){
  //Note about the return QPoint: x() is the column number, y() is the row number
  QPoint pt(0,0);
  //qDebug() << "FIND OPEN SPOT:" << gridwidth << gridheight << startRow << startCol << reversed;
  int row = startRow; int col = startCol;
  if(row<0){ row = 0; } //just in case - since this can be recursively called
  if(col<0){ col = 0; } //just in case - since this can be recursively called
  bool found = false;
  int rowCount, colCount;
  rowCount = RoundUp(desktopRect.height()/GRIDSIZE);
  colCount = RoundUp(desktopRect.width()/GRIDSIZE);
  if( (row+gridheight)>rowCount){ row = rowCount-gridheight; startRow = row; }
  if( (col+gridwidth)>colCount){ col = colCount-gridwidth; startCol = col; }
  QRect geom = gridToGeom( QRect(startCol, startRow, gridwidth, gridheight) );
  //qDebug() << "Find Open Space:" <<geom << QRect(startCol, startRow, gridwidth, gridheight);
  if(DEBUG){ qDebug() << "Search for plugin space:" << rowCount << colCount << gridheight << gridwidth << this->size(); }
  if(TopToBottom && reversed && (startRow>0 || startCol>0) ){
    //Arrange Top->Bottom (work backwards)
    //qDebug() << "Search backwards for space:" << rowCount << colCount << startRow << startCol << gridheight << gridwidth;
    while(col>=0 && !found){
      while(row>=0 && !found){
        bool ok = true;
        geom.moveTo(  gridToPos(QPoint(col,row)) ); //col*GRIDSIZE+desktopRect.x(), row*GRIDSIZE+desktopRect.y());
	//qDebug() << " - Check Geom:" << geom << col << row;
        //Check all the existing items to ensure no overlap
        for(int i=0; i<ITEMS.length() && ok; i++){
	  if(ITEMS[i]->whatsThis()==plugID){ continue; } //same plugin - this is not a conflict
          if(geom.intersects(ITEMS[i]->geometry())){
            //Collision - move the next searchable row/column index
	    ok = false;
	    //qDebug() << "Collision:" << col << row;
	    row = ((ITEMS[i]->geometry().y()-GRIDSIZE/2)/GRIDSIZE) -gridheight; //use top edge for next search (minus item height)
	    //qDebug() << " - new row:" << row;
	  }
        }
        if(ok){ pt = QPoint(col,row); found = true; } //found an open spot
      }
      if(!found){ col--; row=rowCount-gridheight; } //go to the previous column
    }
  }else if(TopToBottom){
    //Arrange Top->Bottom
    while(col<(colCount-gridwidth) && !found){
      while(row<(rowCount-gridheight) && !found){
        bool ok = true;
        geom.moveTo( gridToPos(QPoint(col,row)) ); //col*GRIDSIZE+desktopRect.x(), row*GRIDSIZE+desktopRect.y());
	//qDebug() << " - Check Geom:" << geom << col << row;
        //Check all the existing items to ensure no overlap
        for(int i=0; i<ITEMS.length() && ok; i++){
	  if(ITEMS[i]->whatsThis()==plugID){ continue; } //same plugin - this is not a conflict
          if(geom.intersects(ITEMS[i]->geometry())){
            //Collision - move the next searchable row/column index
	    ok = false;
	    row = posToGrid(ITEMS[i]->geometry().bottomLeft()).y(); //use bottom edge for next search
	  }
        }
        if(ok){ pt = QPoint(col,row); found = true; } //found an open spot
        //else{ row++; }
      }
      if(!found){ col++; row=0; } //go to the next column
    }	    
  }else if(reversed && (startRow>0 || startCol>0) ){
    //Arrange Left->Right (work backwards)
    while(row>=0 && !found){
      while(col>=0 && !found){
        bool ok = true;
        geom.moveTo( gridToPos(QPoint(col,row)) ); //col*GRIDSIZE, row*GRIDSIZE);
        //Check all the existing items to ensure no overlap
        for(int i=0; i<ITEMS.length() && ok; i++){
	  if(ITEMS[i]->whatsThis()==plugID){ continue; } //same plugin - this is not a conflict
          if(geom.intersects(ITEMS[i]->geometry())){
            //Collision - move the next searchable row/column index
	    ok = false;
	    col = (ITEMS[i]->geometry().x()-GRIDSIZE/2)/GRIDSIZE - gridwidth; // Fill according to row/column
	  }
        }
        if(ok){ pt = QPoint(col,row); found = true; } //found an open spot
        //else{ col++; }
      }
      if(!found){ row--; col=colCount-gridwidth;} //go to the previous row
    }	  
  }else{
    //Arrange Left->Right
    while(row<(rowCount-gridheight) && !found){
      while(col<(colCount-gridwidth) && !found){
        bool ok = true;
        geom.moveTo( gridToPos(QPoint(col,row)) ); //col*GRIDSIZE, row*GRIDSIZE);
        //Check all the existing items to ensure no overlap
        for(int i=0; i<ITEMS.length() && ok; i++){
	  if(ITEMS[i]->whatsThis()==plugID){ continue; } //same plugin - this is not a conflict
          if(geom.intersects(ITEMS[i]->geometry())){
            //Collision - move the next searchable row/column index
	    ok = false;
	    col = posToGrid(ITEMS[i]->geometry().topRight()).x(); // Fill according to row/column
	  }
        }
        if(ok){ pt = QPoint(col,row); found = true; } //found an open spot
        //else{ col++; }
      }
      if(!found){ row++; col=0;} //go to the next row
    }
  }
  if(!found){
    //qDebug() << "Could not find a spot:" << startRow << startCol << gridheight << gridwidth;
    if( (startRow!=0 || startCol!=0) && !reversed){
      //Did not check the entire screen yet - gradually work it's way back to the top/left corner
      //qDebug() << " - Start backwards search";
      return findOpenSpot(gridwidth, gridheight,startRow,startCol, true); //reverse the scan
    }else if(gridwidth>1 && gridheight>1){
      //Decrease the size of the item by 1x1 grid points and try again
      //qDebug() << " - Out of space: Decrease item size and try again...";
      return findOpenSpot(gridwidth-1, gridheight-1, 0, 0);
    }else{
      //qDebug() << " - Could not find an open spot for a desktop plugin:" << gridwidth << gridheight << startRow << startCol;
      return QRect(-1,-1,-1,-1);
    }
  }else{
    return QRect(pt,QSize(gridwidth,gridheight));
  }
}

QRect LDesktopPluginSpace::findOpenSpot(QRect grid, QString plugID, bool recursive){ //Reverse lookup spotc{
  //This is just an overloaded simplification for checking currently existing plugins
  return findOpenSpot(grid.width(), grid.height(), grid.y(), grid.x(), recursive, plugID);
}

// ===================
//     PRIVATE SLOTS
// ===================
void LDesktopPluginSpace::reloadPlugins(bool ForceIconUpdate ){
  //Remove any plugins as necessary
  QStringList plugs = plugins;
  QStringList items = deskitems;
  for(int i=0; i<ITEMS.length(); i++){
    
    if( ITEMS[i]->whatsThis().startsWith("applauncher") && ForceIconUpdate){ 
	//Change the size of the existing plugin - preserving the location if possible
	/*QRect geom = ITEMS[i]->loadPluginGeometry(); //pixel coords
	if(!geom.isNull()){
	  geom = geomToGrid(geom); //convert to grid coords
	  geom.setSize(itemSize); //Reset back to default size (does not change location)
	  ITEMS[i]->savePluginGeometry( gridToGeom(geom)); //save it back in pixel coords
	}*/
	//Now remove the plugin for the moment - run it through the re-creation routine below
	ITEMS.takeAt(i)->deleteLater();  
	i--;
    }
    else if(plugs.contains(ITEMS[i]->whatsThis())){ plugs.removeAll(ITEMS[i]->whatsThis()); }
    else if(items.contains(ITEMS[i]->whatsThis().section("---",0,0).section("::",1,50))){ items.removeAll(ITEMS[i]->whatsThis().section("---",0,0).section("::",1,50)); }
    else{ ITEMS[i]->removeSettings(true); ITEMS.takeAt(i)->deleteLater();  i--; } //this is considered a permanent removal (cleans settings)
  }
  
  //Now create any new items
  //First load the plugins (almost always have fixed locations)
  for(int i=0; i<plugs.length(); i++){
    addDesktopPlugin(plugs[i]);
  }
  //Now load the desktop shortcuts (fill in the gaps as needed)
  for(int i=0; i<items.length(); i++){
    addDesktopItem(items[i]);
  }
}


//=================
//      PROTECTED
//=================
void LDesktopPluginSpace::paintEvent(QPaintEvent*ev){
  if(!wallpaper.isNull()){
    QPainter painter(this);
    //painter.setBrush(wallpaper);
    //painter.drawRect(ev->rect().adjusted(-1,-1,2,2));
    painter.drawPixmap(ev->rect(), wallpaper, ev->rect() );
  }else{
    QWidget::paintEvent(ev);
  }
}