<?php

final class PHUIImageMaskView extends AphrontTagView {

  private $image;
  private $withMask;

  private $displayWidth;
  private $displayHeight;

  private $centerX;
  private $centerY;
  private $maskH;
  private $maskW;

  public function setImage($image) {
    $this->image = $image;
    return $this;
  }

  public function setDisplayWidth($width) {
    $this->displayWidth = $width;
    return $this;
  }

  public function setDisplayHeight($height) {
    $this->displayHeight = $height;
    return $this;
  }

  public function centerViewOnPoint($x, $y, $h, $w) {
    $this->centerX = $x;
    $this->centerY = $y;
    $this->maskH = $h;
    $this->maskW = $w;
    return $this;
  }

  public function withMask($mask) {
    $this->withMask = $mask;
    return $this;
  }

  protected function getTagName() {
    return 'div';
  }

  protected function getTagAttributes() {
    require_celerity_resource('phui-image-mask-css');

    $classes = array();
    $classes[] = 'phui-image-mask';

    $styles = array();
    $styles[] = 'height: '.$this->displayHeight.'px;';
    $styles[] = 'width: '.$this->displayWidth.'px;';

    return array(
        'class' => implode(' ', $classes),
        'styles' => implode(' ', $styles),
      );

  }

  protected function getTagContent() {

    /* Center it in the middle of the selected area */
    $center_x = round($this->centerX + ($this->maskW / 2));
    $center_y = round($this->centerY + ($this->maskH / 2));
    $center_x = round($center_x - ($this->displayWidth / 2));
    $center_y = round($center_y - ($this->displayHeight / 2));

    $center_x = -$center_x;
    $center_y = -$center_y;

    $classes = array();
    $classes[] = 'phui-image-mask-image';

    $styles = array();
    $styles[] = 'height: '.$this->displayHeight.'px;';
    $styles[] = 'width: '.$this->displayWidth.'px;';
    $styles[] = 'background-image: url('.$this->image.');';
    $styles[] = 'background-position: '.$center_x.'px '.$center_y.'px;';

    $mask = null;
    if ($this->withMask) {
    /*  The mask is a 300px border around a transparent box.
        so we do the math here to position the box correctly. */
      $border = 300;
      $left = round((($this->displayWidth - $this->maskW) / 2) - $border);
      $top = round((($this->displayHeight - $this->maskH) / 2) - $border);

      $mstyles = array();
      $mstyles[] = 'left: '.$left.'px;';
      $mstyles[] = 'top: '.$top.'px;';
      $mstyles[] = 'height: '.$this->maskH.'px;';
      $mstyles[] = 'width: '.$this->maskW.'px;';

      $mask = phutil_tag(
        'span',
        array(
          'class' => 'phui-image-mask-mask',
          'style' => implode(' ', $mstyles),
        ),
        null);
    }

    return phutil_tag(
      'div',
      array(
        'class' => implode(' ', $classes),
        'style' => implode(' ', $styles),
      ),
      $mask);
  }
}