<?php 
/**
 * Pie Chart Helper
 *
 * @version 1.0
 * @author Aeron Glemann <http://www.electricprism.com/aeron>
 * @license MIT Style License
 */

class PieChartHelper extends Helper {
	var $helpers = array('Html');
	
	var $total = 0;
	
	var $data = null;
	
	var $path = '';
	
	var $eq_pie = null;

	/**
	 * Create eq_pie class instance
	 *
	 * @param array $data Data for pie chart
	 * @return bool Successful
	 */

	function create($data = array()) {
		if (empty($data)) {
			return false;
        }

		foreach($data as $eq_data) {
			$this->total += $eq_data[1];   
		}

		if ($this->total == 0) {
			return false;  
        }

		$this->data = $data;  

		$this->path = WWW_ROOT.'img'.DS.'eq_pie';

		if (!is_dir($this->path)) {			
			mkdir($this->path, 0777);  
			
			if (!is_dir($this->path)) {  
				debug("Error, Unable to create folder at $this->path (check permissions).");
				return false;			
			}
		}    

		vendor('class_eq_pie');

		$this->eq_pie = new eq_pie;  

		return true;   
	}


	/**
	 * Draw a pie chart
	 *
	 * @param int $width Width of pie chart graphic in pixels
	 * @param int $height Height of pie chart graphic in pixels (controls perspective, does not include $shadow)
	 * @param int $shadow How "tall" the pie chart is
	 * @param string $backgroundColor Background color as hexidecimal
	 * @param bool $legend Draw legend too?
	 * @return string HTML image
	 */

	function draw($width = 100, $height = 100, $shadow = 10, $backgroundColor = '#ffffff', $legend = 1) {
		$hash = md5($this->_implode_r(array($this->data, $width, $height, $shadow, $backgroundColor, $legend)));

		$alt = array();

		foreach($this->data as $eq_data) {
			$alt[] = $eq_data[0].' '.number_format($eq_data[1] / $this->total * 100, 1).'%';
		}

		$alt = join(', ', $alt);    

		$filename = $this->path.DS.$hash.'.png';

		if (is_readable($filename)) {
			list($w, $h) = getimagesize($filename); 

			return $this->Html->image(('eq_pie'.DS.$hash.'.png'), array('alt' => $alt, 'width' => $w, 'height' => $h));
		}

		$this->eq_pie->MakePie($filename, $width, $height, $shadow, $backgroundColor, $this->data, $legend); 

		list($w, $h) = getimagesize($filename); 

		return $this->Html->image(('eq_pie'.DS.$hash.'.png'), array('width' => $w, 'height' => $h));
	}


	/**
	 * Create an HTML legend
	 *
	 * @param string $class Name of CSS class to apply to legend div
	 * @return string HTML div and unordered list 
	 */

	function legend($class = 'legend') {
		$out = array();
		$out[] = "<div class='$class'>";
		$out[] = "<ul>";

		foreach($this->data as $eq_data) {
			$hash = md5($eq_data[2]);

			$filename = $this->path.DS.$hash.'.png';

			if (!is_readable($filename)) {				        
				$img = @imagecreatetruecolor(1, 1);
				$r = hexdec(substr($eq_data[2],1,2));
				$g = hexdec(substr($eq_data[2],3,2));
				$b = hexdec(substr($eq_data[2],5,2));   			  

				imagefill($img, 0, 0, imagecolorallocate($img, $r, $g, $b));

				imagepng($img, $filename);
				imagedestroy($img);
			}

			$image = $this->Html->image(('eq_pie'.DS.$hash.'.png'), array('alt' => $eq_data[2]));

			$out[] = sprintf("<li>$image %s</li>", $eq_data[0].' <span>'.number_format($eq_data[1] / $this->total * 100, 1).'%</span>'); 
		}

		$out[] = "</ul>";
		$out[] = "</div>";

		return join("\n", $out);
	}


	/**
	 * Convenience function to merge multi-dimensional array as string
	 *
	 * @param array $pieces Multi-dimensional array to merge
	 * @return string Merged array
	 */

	function _implode_r($pieces) {
		$out = "";

		foreach ($pieces as $piece) {
			if (is_array($piece)) $out .= $this->_implode_r($piece);
			else $out .= $piece;
		}

		return $out;
	} 
}
?>