<?php
/**
 * SVG Base Element abstract class. Shapes and Groups inherit from this class.
 *
 * @author     Nicolas Perriault <nperriault@gmail.com>
 * @package    cleversvg
 * @subpackage elements
 */
class csBaseElement
{

  protected
    $dom_document  = null,
    $attributes    = array(),
    $styles        = array(),
    $transforms    = array(),
    $xml_node_name = 'unknown';

  /**
   * Manage object cloning
   *
   */
  public function __clone()
  {
    $this->deteleAttribute('id');
  }

  /**
   * Adds a transformation to current shape
   *
   * @param  string  $type    Transform type (matrix, translate, etc...)
   * @param  array   $params  Parameters of transformation
   * @link   http://www.w3.org/TR/SVG11/coords.html#TransformAttribute
   */
  protected function addTransform($type, $params=array())
  {
    static $types = array('matrix',
                          'translate',
                          'scale',
                          'rotate',
                          'skewX',
                          'skewY');
    if (!in_array($type, $types))
    {
      throw new csException(sprintf('"%s" is not a valid transform type',
                                       $type));
    }
    $this->transforms[$type] = $params;
  }

  /**
   * Computes DOMXML Node
   *
   * @param  boolean  $embedded  Is SVG element embedded ?
   * @return DOMElement
   */
  protected function compile($embedded=false)
  {
    $dom = $this->getDomDocument();
    $element_node = $dom->createElement($this->getElementName($embedded));

    // Attributes
    foreach ($this->attributes as $attr_name => $attr_value)
    {
      if (!is_null($attr_value))
      {
        switch ($attr_name)
        {
          case 'style':
            $styles = array();
            if (is_array($attr_value))
            {
              foreach ($attr_value as $style_name => $style_value)
              {
                $styles[] = sprintf('%s: %s', $style_name, (string)$style_value);
              }
            }
            if (count($styles) > 0)
            {
              $element_node->setAttribute('style', implode('; ', $styles));
            }
          break;
          default:
            $element_node->setAttribute($attr_name, $attr_value);
          break;
        }
      }
    }

    // Transformations, if any
    if (count($this->transforms) > 0)
    {
      $transforms = array();
      foreach ($this->transforms as $transform_name => $transform_params)
      {
        $transforms[] = sprintf('%s(%s)',
                                $transform_name,
                                implode(',', $transform_params));

      }
      $element_node->setAttribute('transform', implode(' ', $transforms));
    }

    return $element_node;
  }

  /**
   * Gets the current depth
   *
   * @return mixed (int depth or NULL)
   */
  public function getDepth()
  {
    if (array_key_exists('style', $this->attributes) &&
        array_key_exists('z-index', $this->attributes['style']))
    {
      return (int) $this->attributes['style']['z-index'];
    }
    else
    {
      return null;
    }
  }

  /**
   * Returns a DOM DOcument
   *
   * @return DOMDocument
   */
  public function getDomDocument()
  {
    if (is_null($this->dom_document))
    {
      $this->dom_document = new DOMDocument('1.0', 'UTF-8');
    }
    return $this->dom_document;
  }

  /**
   * Gets the node name of current SVG element
   *
   * @param  boolean  $embedded
   * @return string
   */
  public function getElementName($embedded = false)
  {
    if ($embedded === true)
    {
      $node_name = 'svg:'.$this->xml_node_name;
    }
    else
    {
      $node_name = $this->xml_node_name;
    }
    return $node_name;
  }

  /**
   * Specifies a transformation in the form of a transformation matrix of
   * six values
   *
   * @param  int  $a
   * @param  int  $b
   * @param  int  $c
   * @param  int  $d
   * @param  int  $e
   * @param  int  $f
   */
  public function matrix($a, $b, $c, $d, $e, $f)
  {
    $this->addTransform('matrix', array($a, $b, $c, $d, $e, $f));
  }

  /**
   * Rotates shape
   *
   * @param  int  $angle
   * @param  int  $cx
   * @param  int  $cy
   */
  public function rotate($angle, $cx=0, $cy=0)
  {
    $this->addTransform('rotate', array($angle, $cx, $cy));
  }

  /**
   * Scales shape
   *
   * @param  int  $xscale
   * @param  int  $yscale
   */
  public function scale($xscale, $yscale=null)
  {
    $params = array($xscale);
    if ($yscale)
    {
      $params[] = $yscale;
    }
    $this->addTransform('scale', $params);
  }

  /**
   * Specifies a skew transformation along the x-axis
   *
   * @param  int  $angle
   */
  public function skewX($angle)
  {
    $this->addTransform('skewX', array($angle));
  }

  /**
   * Specifies a skew transformation along the y-axis
   *
   * @param  int  $angle
   */
  public function skewY($angle)
  {
    $this->addTransform('skewY', array($angle));
  }

  /**
   * Translates shape
   *
   * @param  int  $tx
   * @param  int  $ty
   */
  public function translate($tx, $ty=null)
  {
    $params = array($tx);
    if ($ty)
    {
      $params[] = $ty;
    }
    $this->addTransform('translate', $params);
  }

  /**
   * Deletes an attribute
   *
   */
  protected function deteleAttribute($name)
  {
    if (array_key_exists($name, $this->attributes))
    {
      unset($this->attributes[$name]);
    }
  }

  /**
   * Sets an attribute for current element
   *
   * @param  string  $name
   * @param  mixed   $value
   * @param  string  $default  Default value
   */
  protected function setAttribute($name, $value, $default=null)
  {
    if (!is_null($default) && is_null($value))
    {
      $value = $default;
    }
    if (!is_null($value))
    {
      $this->attributes[strtolower($name)] = $value;
    }
  }

  /**
   * Sets the depth of object
   *
   * @param  int  $depth
   */
  public function setDepth($depth)
  {
    if (is_null($depth))
    {
      unset($this->attributes['style']['z-index']);
    }
    elseif (is_int($depth))
    {
      $this->attributes['style']['z-index'] = (string) $depth;
    }
  }

  /**
   * Gets the DOM id of current element tag
   *
   * @return mixed (string id or NULL)
   */
  public function getId()
  {
    if (isset($this->attributes['id']))
    {
      return $this->attributes['id'];
    }
    else
    {
      return null;
    }
  }

  /**
   * Sets the DOM id of current element tag
   *
   * @param  string  $id
   */
  public function setId($id)
  {
    if (is_string($id) && trim($id) != '')
    {
      $this->setAttribute('id', $id);
    }
  }

  /**
   * Sets a SVG style via an associative array
   *
   * @param  array  $style
   */
  public function setStyle($style)
  {
    // Styles properties bellow should be treated as attributes and not
    // in a style attribute (FF 1.5 compat)
    $convert_styles = array('stroke', 'stroke-width', 'fill');
    foreach ($style as $style_name => $style_value)
    {
      if (in_array($style_name, $convert_styles))
      {
        $this->setAttribute($style_name, $style_value);
        unset($style[$style_name]);
      }
    }
    if (count($style) > 0)
    {
      $this->setAttribute('style', $style);
    }
  }

}