/*
Copyright 2015 Ian Jauslin

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

#include "pdfWindow.h"

// constructor
pdfWindow::pdfWindow(QWidget *parent) :
  QMainWindow(parent)
{
  // set defaults
  fullscreen=0;
  curpage=0;
  totalpages=0;
  verticalOffset=0;
  document=NULL;

  //scene to draw the view
  pdfViewScene=new QGraphicsScene;
  pdfView=new QGraphicsView(pdfViewScene);
}

// set PDF document
void pdfWindow::setDoc(char* file){
  if(document){delete document;}
  doc=file;

  QString filename=file;
  document = Poppler::Document::load(filename);
  if(document){
    // display options
    document->setRenderHint(Poppler::Document::Antialiasing,true);
    document->setRenderHint(Poppler::Document::TextAntialiasing,true);

    curpage=0;
    totalpages=document->numPages();
    this->updatePDF();
  }
}

void pdfWindow::gotoPage(int page){
  if(page<totalpages && page>=0){
    curpage=page;
    this->updatePDF();
  }
}
void pdfWindow::nextPage(){
  if(curpage<totalpages-1){
    curpage++;
    this->updatePDF();
  }
}
void pdfWindow::previousPage(){
  if(curpage>0){
    curpage--;
    this->updatePDF();
  }
}

// toggle fullscreen
void pdfWindow::fullscreenPDF(){
  if(!fullscreen){
    fullscreen=1;
    this->showFullScreen();
  }
  else{
    fullscreen=0;
    this->showNormal();
  }
}

// draw (or redraw) PDF
void pdfWindow::updatePDF(){
  // current page
  Poppler::Page* pdfPage = document->page(curpage);
  if(!pdfPage){
    std::cout << "Error: could not load page " << curpage << '\n';
    return;
  }

  // total size available
  QSize windowsize=this->size();
  // verticalOffset to allow timebar
  QSize viewSize(windowsize.width()+2,windowsize.height()+2-verticalOffset);
  pdfView->setGeometry(-1,-1,viewSize.width(),viewSize.height());
  
  // page size in points (1/72 inch)
  QSize pageSize=pdfPage->pageSize();
  // aspect ratio
  double aspect=double(pageSize.width())/double(pageSize.height());
  // an image to display the page
  QImage image;
  // keep aspect ratop
  if(viewSize.width()<=aspect*viewSize.height()){
    // render PDF page with appropriate resolution (pix/inch)
    image = pdfPage->renderToImage(72*viewSize.width()/pageSize.width(),72*viewSize.width()/aspect/pageSize.height(),0,0,viewSize.width(),viewSize.width()/aspect);
  }
  else{
    // render PDF page with appropriate resolution (pix/inch)
    image = pdfPage->renderToImage(72*viewSize.height()*aspect/pageSize.width(),72*viewSize.height()/pageSize.height(),0,0,viewSize.height()*aspect,viewSize.height());
  }
  delete pdfPage;

  // update scene
  delete pdfViewScene;
  pdfViewScene=new QGraphicsScene;
  pdfView->setScene(pdfViewScene);
  pdfViewScene->setBackgroundBrush(Qt::black);
  // draw image
  pdfViewScene->addPixmap(QPixmap::fromImage(image));
}

// respond to resize
void pdfWindow::resizeEvent(QResizeEvent* event){
  if(document){
    this->updatePDF();
  }
  
  QMainWindow::resizeEvent(event);
}

// destructor
pdfWindow::~pdfWindow(){
  if(document){delete document;}
  delete pdfView;
  delete pdfViewScene;
}