<?php
/**
 * @package dompdf
 * @link    http://dompdf.github.com/
 * @author  Benj Carson <benjcarson@digitaljunkies.ca>
 * @author  Helmut Tischer <htischer@weihenstephan.org>
 * @author  Fabien Ménager <fabien.menager@gmail.com>
 * @license http://www.gnu.org/copyleft/lesser.html GNU Lesser General Public License
 */

/**
 * Base renderer class
 *
 * @access private
 * @package dompdf
 */
abstract class Abstract_Renderer {

  /**
   * Rendering backend
   *
   * @var Canvas
   */
  protected $_canvas;

  /**
   * Current dompdf instance
   *
   * @var DOMPDF
   */
  protected $_dompdf;
  
  /**
   * Class constructor
   *
   * @param DOMPDF $dompdf The current dompdf instance
   */
  function __construct(DOMPDF $dompdf) {
    $this->_dompdf = $dompdf;
    $this->_canvas = $dompdf->get_canvas();
  }
  
  /**
   * Render a frame.
   *
   * Specialized in child classes
   *
   * @param Frame $frame The frame to render
   */
  abstract function render(Frame $frame);

  //........................................................................

  /**
   * Render a background image over a rectangular area
   *
   * @param string $url      The background image to load
   * @param float  $x        The left edge of the rectangular area
   * @param float  $y        The top edge of the rectangular area
   * @param float  $width    The width of the rectangular area
   * @param float  $height   The height of the rectangular area
   * @param Style  $style    The associated Style object
   *
   * @throws Exception
   */
  protected function _background_image($url, $x, $y, $width, $height, $style) {
    if ( !function_exists("imagecreatetruecolor") ) {
      throw new Exception("The PHP GD extension is required, but is not installed.");
    }

    $sheet = $style->get_stylesheet();

    // Skip degenerate cases
    if ( $width == 0 || $height == 0 ) {
      return;
    }
    
    $box_width = $width;
    $box_height = $height;

    //debugpng
    if (DEBUGPNG) print '[_background_image '.$url.']';

    list($img, $type, /*$msg*/) = Image_Cache::resolve_url(
      $url,
      $sheet->get_protocol(),
      $sheet->get_host(),
      $sheet->get_base_path(),
      $this->_dompdf
    );

    // Bail if the image is no good
    if ( Image_Cache::is_broken($img) ) {
      return;
    }

    //Try to optimize away reading and composing of same background multiple times
    //Postponing read with imagecreatefrom   ...()
    //final composition parameters and name not known yet
    //Therefore read dimension directly from file, instead of creating gd object first.
    //$img_w = imagesx($src); $img_h = imagesy($src);

    list($img_w, $img_h) = dompdf_getimagesize($img, $this->_dompdf->get_http_context());
    if (!isset($img_w) || $img_w == 0 || !isset($img_h) || $img_h == 0) {
      return;
    }

    $repeat = $style->background_repeat;
    $dpi = $this->_dompdf->get_option("dpi");

    //Increase background resolution and dependent box size according to image resolution to be placed in
    //Then image can be copied in without resize
    $bg_width = round((float)($width * $dpi) / 72);
    $bg_height = round((float)($height * $dpi) / 72);

    //Need %bg_x, $bg_y as background pos, where img starts, converted to pixel

    list($bg_x, $bg_y) = $style->background_position;

    if ( is_percent($bg_x) ) {
      // The point $bg_x % from the left edge of the image is placed
      // $bg_x % from the left edge of the background rectangle
      $p = ((float)$bg_x)/100.0;
      $x1 = $p * $img_w;
      $x2 = $p * $bg_width;

      $bg_x = $x2 - $x1;
    }
    else {
      $bg_x = (float)($style->length_in_pt($bg_x)*$dpi) / 72;
    }
    
    $bg_x = round($bg_x + $style->length_in_pt($style->border_left_width)*$dpi / 72);

    if ( is_percent($bg_y) ) {
      // The point $bg_y % from the left edge of the image is placed
      // $bg_y % from the left edge of the background rectangle
      $p = ((float)$bg_y)/100.0;
      $y1 = $p * $img_h;
      $y2 = $p * $bg_height;

      $bg_y = $y2 - $y1;
    }
    else {
      $bg_y = (float)($style->length_in_pt($bg_y)*$dpi) / 72;
    }
    
    $bg_y = round($bg_y + $style->length_in_pt($style->border_top_width)*$dpi / 72);

    //clip background to the image area on partial repeat. Nothing to do if img off area
    //On repeat, normalize start position to the tile at immediate left/top or 0/0 of area
    //On no repeat with positive offset: move size/start to have offset==0
    //Handle x/y Dimensions separately

    if ( $repeat !== "repeat" && $repeat !== "repeat-x" ) {
      //No repeat x
      if ($bg_x < 0) {
        $bg_width = $img_w + $bg_x;
      }
      else {
        $x += ($bg_x * 72)/$dpi;
        $bg_width = $bg_width - $bg_x;
        if ($bg_width > $img_w) {
          $bg_width = $img_w;
        }
        $bg_x = 0;
      }
      
      if ($bg_width <= 0) {
        return;
      }
      
      $width = (float)($bg_width * 72)/$dpi;
    }
    else {
      //repeat x
      if ($bg_x < 0) {
        $bg_x = - ((-$bg_x) % $img_w);
      }
      else {
        $bg_x = $bg_x % $img_w;
        if ($bg_x > 0) {
          $bg_x -= $img_w;
        }
      }
    }

    if ( $repeat !== "repeat" && $repeat !== "repeat-y" ) {
      //no repeat y
      if ($bg_y < 0) {
        $bg_height = $img_h + $bg_y;
      }
      else {
        $y += ($bg_y * 72)/$dpi;
        $bg_height = $bg_height - $bg_y;
        if ($bg_height > $img_h) {
          $bg_height = $img_h;
        }
        $bg_y = 0;
      }
      if ($bg_height <= 0) {
        return;
      }
      $height = (float)($bg_height * 72)/$dpi;
    }
    else {
      //repeat y
      if ($bg_y < 0) {
        $bg_y = - ((-$bg_y) % $img_h);
      }
      else {
        $bg_y = $bg_y % $img_h;
        if ($bg_y > 0) {
          $bg_y -= $img_h;
        }
      }
    }

    //Optimization, if repeat has no effect
    if ( $repeat === "repeat" && $bg_y <= 0 && $img_h+$bg_y >= $bg_height ) {
      $repeat = "repeat-x";
    }
    
    if ( $repeat === "repeat" && $bg_x <= 0 && $img_w+$bg_x >= $bg_width ) {
      $repeat = "repeat-y";
    }
    
    if ( ($repeat === "repeat-x" && $bg_x <= 0 && $img_w+$bg_x >= $bg_width) ||
         ($repeat === "repeat-y" && $bg_y <= 0 && $img_h+$bg_y >= $bg_height) ) {
      $repeat = "no-repeat";
    }

    //Use filename as indicator only
    //different names for different variants to have different copies in the pdf
    //This is not dependent of background color of box! .'_'.(is_array($bg_color) ? $bg_color["hex"] : $bg_color)
    //Note: Here, bg_* are the start values, not end values after going through the tile loops!

    $filedummy = $img;
    
    $is_png = false;
    $filedummy .= '_'.$bg_width.'_'.$bg_height.'_'.$bg_x.'_'.$bg_y.'_'.$repeat;

    //Optimization to avoid multiple times rendering the same image.
    //If check functions are existing and identical image already cached,
    //then skip creation of duplicate, because it is not needed by addImagePng
    if ( $this->_canvas instanceof CPDF_Adapter &&
         $this->_canvas->get_cpdf()->image_iscached($filedummy) ) {
      $bg = null;
    }
    
    else {
  
      // Create a new image to fit over the background rectangle
      $bg = imagecreatetruecolor($bg_width, $bg_height);
      
      switch (strtolower($type)) {
        case IMAGETYPE_PNG:
          $is_png = true;
          imagesavealpha($bg, true);
          imagealphablending($bg, false);
          $src = imagecreatefrompng($img);
          break;
    
        case IMAGETYPE_JPEG:
          $src = imagecreatefromjpeg($img);
          break;
    
        case IMAGETYPE_GIF:
          $src = imagecreatefromgif($img);
          break;
          
        case IMAGETYPE_BMP:
          $src = imagecreatefrombmp($img);
          break;
    
        default:
          return; // Unsupported image type
      }
  
      if ( $src == null ) {
        return;
      }
  
      //Background color if box is not relevant here
      //Non transparent image: box clipped to real size. Background non relevant.
      //Transparent image: The image controls the transparency and lets shine through whatever background.
      //However on transparent image preset the composed image with the transparency color,
      //to keep the transparency when copying over the non transparent parts of the tiles.
      $ti = imagecolortransparent($src);
      
      if ( $ti >= 0 ) {
        $tc = imagecolorsforindex($src, $ti);
        $ti = imagecolorallocate($bg, $tc['red'], $tc['green'], $tc['blue']);
        imagefill($bg, 0, 0, $ti);
        imagecolortransparent($bg, $ti);
      }
  
      //This has only an effect for the non repeatable dimension.
      //compute start of src and dest coordinates of the single copy
      if ( $bg_x < 0 ) {
        $dst_x = 0;
        $src_x = -$bg_x;
      }
      else {
        $src_x = 0;
        $dst_x = $bg_x;
      }
  
      if ( $bg_y < 0 ) {
        $dst_y = 0;
        $src_y = -$bg_y;
      }
      else {
        $src_y = 0;
        $dst_y = $bg_y;
      }
  
      //For historical reasons exchange meanings of variables:
      //start_* will be the start values, while bg_* will be the temporary start values in the loops
      $start_x = $bg_x;
      $start_y = $bg_y;
  
      // Copy regions from the source image to the background
      if ( $repeat === "no-repeat" ) {
  
        // Simply place the image on the background
        imagecopy($bg, $src, $dst_x, $dst_y, $src_x, $src_y, $img_w, $img_h);
  
      }
      else if ( $repeat === "repeat-x" ) {
  
        for ( $bg_x = $start_x; $bg_x < $bg_width; $bg_x += $img_w ) {
          if ( $bg_x < 0 ) {
            $dst_x = 0;
            $src_x = -$bg_x;
            $w = $img_w + $bg_x;
          }
          else {
            $dst_x = $bg_x;
            $src_x = 0;
            $w = $img_w;
          }
          imagecopy($bg, $src, $dst_x, $dst_y, $src_x, $src_y, $w, $img_h);
        }
  
      }
      else if ( $repeat === "repeat-y" ) {
  
        for ( $bg_y = $start_y; $bg_y < $bg_height; $bg_y += $img_h ) {
          if ( $bg_y < 0 ) {
            $dst_y = 0;
            $src_y = -$bg_y;
            $h = $img_h + $bg_y;
          }
          else {
            $dst_y = $bg_y;
            $src_y = 0;
            $h = $img_h;
          }
          imagecopy($bg, $src, $dst_x, $dst_y, $src_x, $src_y, $img_w, $h);
  
        }
  
      }
      else if ( $repeat === "repeat" ) {
  
        for ( $bg_y = $start_y; $bg_y < $bg_height; $bg_y += $img_h ) {
          for ( $bg_x = $start_x; $bg_x < $bg_width; $bg_x += $img_w ) {
  
            if ( $bg_x < 0 ) {
              $dst_x = 0;
              $src_x = -$bg_x;
              $w = $img_w + $bg_x;
            }
            else {
              $dst_x = $bg_x;
              $src_x = 0;
              $w = $img_w;
            }
  
            if ( $bg_y < 0 ) {
              $dst_y = 0;
              $src_y = -$bg_y;
              $h = $img_h + $bg_y;
            }
            else {
              $dst_y = $bg_y;
              $src_y = 0;
              $h = $img_h;
            }
            imagecopy($bg, $src, $dst_x, $dst_y, $src_x, $src_y, $w, $h);
          }
        }
      }
      
      else {
        print 'Unknown repeat!';
      }
      
      imagedestroy($src);

    } /* End optimize away creation of duplicates */

    $this->_canvas->clipping_rectangle($x, $y, $box_width, $box_height);
    
    //img: image url string
    //img_w, img_h: original image size in px
    //width, height: box size in pt
    //bg_width, bg_height: box size in px
    //x, y: left/top edge of box on page in pt
    //start_x, start_y: placement of image relative to pattern
    //$repeat: repeat mode
    //$bg: GD object of result image
    //$src: GD object of original image
    //When using cpdf and optimization to direct png creation from gd object is available,
    //don't create temp file, but place gd object directly into the pdf
    if ( !$is_png && $this->_canvas instanceof CPDF_Adapter ) {
      // Note: CPDF_Adapter image converts y position
      $this->_canvas->get_cpdf()->addImagePng($filedummy, $x, $this->_canvas->get_height() - $y - $height, $width, $height, $bg);
    } 
    
    else {
      $tmp_dir = $this->_dompdf->get_option("temp_dir");
      $tmp_name = tempnam($tmp_dir, "bg_dompdf_img_");
      @unlink($tmp_name);
      $tmp_file = "$tmp_name.png";
      
      //debugpng
      if (DEBUGPNG) print '[_background_image '.$tmp_file.']';

      imagepng($bg, $tmp_file);
      $this->_canvas->image($tmp_file, $x, $y, $width, $height);
      imagedestroy($bg);

      //debugpng
      if (DEBUGPNG) print '[_background_image unlink '.$tmp_file.']';

      if (!DEBUGKEEPTEMP) {
        unlink($tmp_file);
      }
    }
    
    $this->_canvas->clipping_end();
  }
  
  protected function _get_dash_pattern($style, $width) {
    $pattern = array();
    
    switch ($style) {
      default:
      /*case "solid":
      case "double":
      case "groove":
      case "inset":
      case "outset":
      case "ridge":*/
      case "none": break;
      
      case "dotted": 
        if ( $width <= 1 )
          $pattern = array($width, $width*2);
        else
          $pattern = array($width);
      break;
      
      case "dashed": 
        $pattern = array(3 * $width);
      break;
    }
    
    return $pattern;
  }

  protected function _border_none($x, $y, $length, $color, $widths, $side, $corner_style = "bevel", $r1 = 0, $r2 = 0) {
    return;
  }
  
  protected function _border_hidden($x, $y, $length, $color, $widths, $side, $corner_style = "bevel", $r1 = 0, $r2 = 0) {
    return;
  }
  
  // Border rendering functions

  protected function _border_dotted($x, $y, $length, $color, $widths, $side, $corner_style = "bevel", $r1 = 0, $r2 = 0) {
    $this->_border_line($x, $y, $length, $color, $widths, $side, $corner_style, "dotted", $r1, $r2);
  }


  protected function _border_dashed($x, $y, $length, $color, $widths, $side, $corner_style = "bevel", $r1 = 0, $r2 = 0) {
    $this->_border_line($x, $y, $length, $color, $widths, $side, $corner_style, "dashed", $r1, $r2);
  }


  protected function _border_solid($x, $y, $length, $color, $widths, $side, $corner_style = "bevel", $r1 = 0, $r2 = 0) {
    // TODO: Solve rendering where one corner is beveled (radius == 0), one corner isn't.
    if ( $corner_style !== "bevel" || $r1 > 0 || $r2 > 0 ) {
      // do it the simple way
      $this->_border_line($x, $y, $length, $color, $widths, $side, $corner_style, "solid", $r1, $r2);
      return;
    }

    list($top, $right, $bottom, $left) = $widths;

    // All this polygon business is for beveled corners...
    switch ($side) {
      case "top":
        $points = array($x, $y,
                        $x + $length, $y,
                        $x + $length - $right, $y + $top,
                        $x + $left, $y + $top);
        $this->_canvas->polygon($points, $color, null, null, true);
        break;
  
      case "bottom":
        $points = array($x, $y,
                        $x + $length, $y,
                        $x + $length - $right, $y - $bottom,
                        $x + $left, $y - $bottom);
        $this->_canvas->polygon($points, $color, null, null, true);
        break;
  
      case "left":
        $points = array($x, $y,
                        $x, $y + $length,
                        $x + $left, $y + $length - $bottom,
                        $x + $left, $y + $top);
        $this->_canvas->polygon($points, $color, null, null, true);
        break;
  
      case "right":
        $points = array($x, $y,
                        $x, $y + $length,
                        $x - $right, $y + $length - $bottom,
                        $x - $right, $y + $top);
        $this->_canvas->polygon($points, $color, null, null, true);
        break;
  
      default:
        return;
    }
  }

  protected function _apply_ratio($side, $ratio, $top, $right, $bottom, $left, &$x, &$y, &$length, &$r1, &$r2) {
    switch ($side) {

    case "top":
      $r1 -= $left * $ratio;
      $r2 -= $right * $ratio;
      $x += $left * $ratio;
      $y += $top * $ratio;
      $length -= $left * $ratio + $right * $ratio;
      break;

    case "bottom":
      $r1 -= $right * $ratio;
      $r2 -= $left * $ratio;
      $x += $left * $ratio;
      $y -= $bottom * $ratio;
      $length -= $left * $ratio + $right * $ratio;
      break;

    case "left":
      $r1 -= $top * $ratio;
      $r2 -= $bottom * $ratio;
      $x += $left * $ratio;
      $y += $top * $ratio;
      $length -= $top * $ratio + $bottom * $ratio;
      break;

    case "right":
      $r1 -= $bottom * $ratio;
      $r2 -= $top * $ratio;
      $x -= $right * $ratio;
      $y += $top * $ratio;
      $length -= $top * $ratio + $bottom * $ratio;
      break;

    default:
      return;

    }
  }

  protected function _border_double($x, $y, $length, $color, $widths, $side, $corner_style = "bevel", $r1 = 0, $r2 = 0) {
    list($top, $right, $bottom, $left) = $widths;

    $third_widths = array($top / 3, $right / 3, $bottom / 3, $left / 3);

    // draw the outer border
    $this->_border_solid($x, $y, $length, $color, $third_widths, $side, $corner_style, $r1, $r2);

    $this->_apply_ratio($side, 2/3, $top, $right, $bottom, $left, $x, $y, $length, $r1, $r2);

    $this->_border_solid($x, $y, $length, $color, $third_widths, $side, $corner_style, $r1, $r2);
  }

  protected function _border_groove($x, $y, $length, $color, $widths, $side, $corner_style = "bevel", $r1 = 0, $r2 = 0) {
    list($top, $right, $bottom, $left) = $widths;

    $half_widths = array($top / 2, $right / 2, $bottom / 2, $left / 2);

    $this->_border_inset($x, $y, $length, $color, $half_widths, $side, $corner_style, $r1, $r2);
    
    $this->_apply_ratio($side, 0.5, $top, $right, $bottom, $left, $x, $y, $length, $r1, $r2);

    $this->_border_outset($x, $y, $length, $color, $half_widths, $side, $corner_style, $r1, $r2);

  }

  protected function _border_ridge($x, $y, $length, $color, $widths, $side, $corner_style = "bevel", $r1 = 0, $r2 = 0) {
    list($top, $right, $bottom, $left) = $widths;

    $half_widths = array($top / 2, $right / 2, $bottom / 2, $left / 2);

    $this->_border_outset($x, $y, $length, $color, $half_widths, $side, $corner_style, $r1, $r2);
    
    $this->_apply_ratio($side, 0.5, $top, $right, $bottom, $left, $x, $y, $length, $r1, $r2);

    $this->_border_inset($x, $y, $length, $color, $half_widths, $side, $corner_style, $r1, $r2);

  }

  protected function _tint($c) {
    if ( !is_numeric($c) )
      return $c;

    return min(1, $c + 0.16);
  }

  protected function _shade($c) {
    if ( !is_numeric($c) )
      return $c;

    return max(0, $c - 0.33);
  }

  protected function _border_inset($x, $y, $length, $color, $widths, $side, $corner_style = "bevel", $r1 = 0, $r2 = 0) {
    switch ($side) {
      case "top":
      case "left":
        $shade = array_map(array($this, "_shade"), $color);
        $this->_border_solid($x, $y, $length, $shade, $widths, $side, $corner_style, $r1, $r2);
        break;
  
      case "bottom":
      case "right":
        $tint = array_map(array($this, "_tint"), $color);
        $this->_border_solid($x, $y, $length, $tint, $widths, $side, $corner_style, $r1, $r2);
        break;
  
      default:
        return;
    }
  }

  protected function _border_outset($x, $y, $length, $color, $widths, $side, $corner_style = "bevel", $r1 = 0, $r2 = 0) {
    switch ($side) {
      case "top":
      case "left":
        $tint = array_map(array($this, "_tint"), $color);
        $this->_border_solid($x, $y, $length, $tint, $widths, $side, $corner_style, $r1, $r2);
        break;
  
      case "bottom":
      case "right":
        $shade = array_map(array($this, "_shade"), $color);
        $this->_border_solid($x, $y, $length, $shade, $widths, $side, $corner_style, $r1, $r2);
        break;
  
      default:
        return;
    }
  }
  // Draws a solid, dotted, or dashed line, observing the border radius
  protected function _border_line($x, $y, $length, $color, $widths, $side, $corner_style = "bevel", $pattern_name, $r1 = 0, $r2 = 0) {
    list($top, $right, $bottom, $left) = $widths;
    
    $width = $$side;
    $pattern = $this->_get_dash_pattern($pattern_name, $width);

    $half_width = $width/2;
    $r1 -= $half_width;
    $r2 -= $half_width;
    $adjust = $r1/80;
    $length -= $width; 
    
    switch ($side) {
      case "top":
        $x += $half_width; 
        $y += $half_width;
  
        if ( $r1 > 0 ) {
          $this->_canvas->arc($x + $r1, $y + $r1, $r1, $r1, 90-$adjust, 135+$adjust, $color, $width, $pattern);
        }
  
        $this->_canvas->line($x + $r1, $y, $x + $length - $r2, $y, $color, $width, $pattern);
  
        if ( $r2 > 0 ) {
          $this->_canvas->arc($x + $length - $r2, $y + $r2, $r2, $r2, 45-$adjust, 90+$adjust, $color, $width, $pattern);
        }
        break;
        
      case "bottom":
        $x += $half_width; 
        $y -= $half_width;
        
        if ( $r1 > 0 ) {
          $this->_canvas->arc($x + $r1, $y - $r1, $r1, $r1, 225-$adjust, 270+$adjust, $color, $width, $pattern);
        }
        
        $this->_canvas->line($x + $r1, $y, $x + $length - $r2, $y, $color, $width, $pattern);
        
        if ( $r2 > 0 ) {
          $this->_canvas->arc($x + $length - $r2, $y - $r2, $r2, $r2, 270-$adjust, 315+$adjust, $color, $width, $pattern);
        }
        break;
        
      case "left":
        $y += $half_width; 
        $x += $half_width;
        
        if ( $r1 > 0 ) {
          $this->_canvas->arc($x + $r1, $y + $r1, $r1, $r1, 135-$adjust, 180+$adjust, $color, $width, $pattern);
        }
        
        $this->_canvas->line($x, $y + $r1, $x, $y + $length - $r2, $color, $width, $pattern);
        
        if ( $r2 > 0 ) {
          $this->_canvas->arc($x + $r2, $y + $length - $r2, $r2, $r2, 180-$adjust, 225+$adjust, $color, $width, $pattern);
        }
        break;
        
      case "right":
        $y += $half_width; 
        $x -= $half_width;
        
        if ( $r1 > 0 ) {
          $this->_canvas->arc($x - $r1, $y + $r1, $r1, $r1, 0-$adjust, 45+$adjust, $color, $width, $pattern);
        }
        
        $this->_canvas->line($x, $y + $r1, $x, $y + $length - $r2, $color, $width, $pattern);
        
        if ( $r2 > 0 ) {
          $this->_canvas->arc($x - $r2, $y + $length - $r2, $r2, $r2, 315-$adjust, 360+$adjust, $color, $width, $pattern);
        }
        break;
    }
  }

  protected function _set_opacity($opacity) {
    if ( is_numeric($opacity) && $opacity <= 1.0 && $opacity >= 0.0 ) {
      $this->_canvas->set_opacity( $opacity );
    }
  }

  protected function _debug_layout($box, $color = "red", $style = array()) {
    $this->_canvas->rectangle($box[0], $box[1], $box[2], $box[3], CSS_Color::parse($color), 0.1, $style);
  }
}
