<?php
/**
 * Zend Framework (http://framework.zend.com/)
 *
 * @link      http://github.com/zendframework/zf2 for the canonical source repository
 * @copyright Copyright (c) 2005-2013 Zend Technologies USA Inc. (http://www.zend.com)
 * @license   http://framework.zend.com/license/new-bsd New BSD License
 */

namespace Zend\Code\Annotation\Parser;

use Doctrine\Common\Annotations\AnnotationRegistry;
use Doctrine\Common\Annotations\DocParser;
use Traversable;
use Zend\Code\Exception;
use Zend\EventManager\EventInterface;

/**
 * A parser for docblock annotations that utilizes the annotation parser from
 * Doctrine\Common.
 *
 * Consumes Doctrine\Common\Annotations\DocParser, and responds to events from
 * AnnotationManager. If the annotation examined is in the list of classes we
 * are interested in, the raw annotation is passed to the DocParser in order to
 * retrieve the annotation object instance. Otherwise, it is skipped.
 */
class DoctrineAnnotationParser implements ParserInterface
{
    /**
     * @var array Annotation classes we support on this iteration
     */
    protected $allowedAnnotations = array();

    /**
     * @var DocParser
     */
    protected $docParser;

    public function __construct()
    {
        // Hack to ensure an attempt to autoload an annotation class is made
        AnnotationRegistry::registerLoader(function ($class) {
            return (bool) class_exists($class);
        });
    }

    /**
     * Set the DocParser instance
     *
     * @param  DocParser $docParser
     * @return DoctrineAnnotationParser
     */
    public function setDocParser(DocParser $docParser)
    {
        $this->docParser = $docParser;
        return $this;
    }

    /**
     * Retrieve the DocParser instance
     *
     * If none is registered, lazy-loads a new instance.
     *
     * @return DocParser
     */
    public function getDocParser()
    {
        if (!$this->docParser instanceof DocParser) {
            $this->setDocParser(new DocParser());
        }

        return $this->docParser;
    }

    /**
     * Handle annotation creation
     *
     * @param  EventInterface $e
     * @return false|\stdClass
     */
    public function onCreateAnnotation(EventInterface $e)
    {
        $annotationClass = $e->getParam('class', false);
        if (!$annotationClass) {
            return false;
        }

        if (!isset($this->allowedAnnotations[$annotationClass])) {
            return false;
        }

        $annotationString = $e->getParam('raw', false);
        if (!$annotationString) {
            return false;
        }

        // Annotation classes provided by the AnnotationScanner are already
        // resolved to fully-qualified class names. Adding the global namespace
        // prefix allows the Doctrine annotation parser to locate the annotation
        // class correctly.
        $annotationString = preg_replace('/^(@)/', '$1\\', $annotationString);

        $parser      = $this->getDocParser();
        $annotations = $parser->parse($annotationString);
        if (empty($annotations)) {
            return false;
        }

        $annotation = array_shift($annotations);
        if (!is_object($annotation)) {
            return false;
        }

        return $annotation;
    }

    /**
     * Specify an allowed annotation class
     *
     * @param  string $annotation
     * @return DoctrineAnnotationParser
     */
    public function registerAnnotation($annotation)
    {
        $this->allowedAnnotations[$annotation] = true;
        return $this;
    }

    /**
     * Set many allowed annotations at once
     *
     * @param  array|Traversable $annotations Array or traversable object of
     *         annotation class names
     * @throws Exception\InvalidArgumentException
     * @return DoctrineAnnotationParser
     */
    public function registerAnnotations($annotations)
    {
        if (!is_array($annotations) && !$annotations instanceof Traversable) {
            throw new Exception\InvalidArgumentException(sprintf(
                '%s: expects an array or Traversable; received "%s"',
                __METHOD__,
                (is_object($annotations) ? get_class($annotations) : gettype($annotations))
            ));
        }

        foreach ($annotations as $annotation) {
            $this->allowedAnnotations[$annotation] = true;
        }

        return $this;
    }
}
