<?php

/*

 * Copyright 2011 Johannes M. Schmitt <schmittjoh@gmail.com>

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 *

 * http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

namespace Metadata;

use Metadata\Cache\CacheInterface;

use Metadata\Driver\DriverInterface;

final class MetadataFactory implements MetadataFactoryInterface

{

    private $driver;

    private $cache;

    private $loadedMetadata = array();

    private $loadedClassMetadata = array();

    private $hierarchyMetadataClass;

    private $debug;

    public function __construct(DriverInterface $driver, $hierarchyMetadataClass = 'Metadata\ClassHierarchyMetadata', $debug = false)

    {

        $this->driver = $driver;

        $this->hierarchyMetadataClass = $hierarchyMetadataClass;

        $this->debug = $debug;

    }

    public function setCache(CacheInterface $cache)

    {

        $this->cache = $cache;

    }

    public function getMetadataForClass($className)

    {

        if (isset($this->loadedMetadata[$className])) {

            return $this->loadedMetadata[$className];

        }

        $metadata = new $this->hierarchyMetadataClass;

        foreach ($this->getClassHierarchy($className) as $class) {

            if (isset($this->loadedClassMetadata[$name = $class->getName()])) {

                $metadata->addClassMetadata($this->loadedClassMetadata[$name]);

                continue;

            }

            // check the cache

            if (null !== $this->cache

                && (null !== $classMetadata = $this->cache->loadClassMetadataFromCache($class))) {

                if ($this->debug && !$classMetadata->isFresh()) {

                    $this->cache->evictClassMetadataFromCache($classMetadata->reflection);

                } else {

                    $this->loadedClassMetadata[$name] = $classMetadata;

                    $metadata->addClassMetadata($classMetadata);

                    continue;

                }

            }

            // load from source

            if (null !== $classMetadata = $this->driver->loadMetadataForClass($class)) {

                $this->loadedClassMetadata[$name] = $classMetadata;

                $metadata->addClassMetadata($classMetadata);

                if (null !== $this->cache) {

                    $this->cache->putClassMetadataInCache($classMetadata);

                }

                continue;

            }

        }

        if (!$metadata->classMetadata) {

            return null;

        }

        return $this->loadedMetadata[$className] = $metadata;

    }

    private function getClassHierarchy($class)

    {

        $classes = array();

        $refl = new \ReflectionClass($class);

        do {

            $classes[] = $refl;

        } while (false !== $refl = $refl->getParentClass());

        return array_reverse($classes, false);

    }

}