<?php

/*

 * This file is part of the Assetic package, an OpenSky project.

 *

 * (c) 2010-2011 OpenSky Project Inc

 *

 * For the full copyright and license information, please view the LICENSE

 * file that was distributed with this source code.

 */

namespace Assetic\Factory;

use Assetic\AssetManager;

use Assetic\Factory\Loader\FormulaLoaderInterface;

use Assetic\Factory\Resource\ResourceInterface;

/**

 * A lazy asset manager is a composition of a factory and many formula loaders.

 *

 * @author Kris Wallsmith <kris.wallsmith@gmail.com>

 */

class LazyAssetManager extends AssetManager

{

    private $factory;

    private $loaders;

    private $resources;

    private $formulae;

    private $loaded;

    private $loading;

    /**

     * Constructor.

     *

     * @param AssetFactory $factory The asset factory

     * @param array        $loaders An array of loaders indexed by alias

     */

    public function __construct(AssetFactory $factory, $loaders = array())

    {

        $this->factory = $factory;

        $this->loaders = array();

        $this->resources = array();

        $this->formulae = array();

        $this->loaded = false;

        $this->loading = false;

        foreach ($loaders as $alias => $loader) {

            $this->setLoader($alias, $loader);

        }

    }

    /**

     * Adds a loader to the asset manager.

     *

     * @param string                 $alias  An alias for the loader

     * @param FormulaLoaderInterface $loader A loader

     */

    public function setLoader($alias, FormulaLoaderInterface $loader)

    {

        $this->loaders[$alias] = $loader;

        $this->loaded = false;

    }

    /**

     * Adds a resource to the asset manager.

     *

     * @param ResourceInterface $resource A resource

     * @param string            $loader   The loader alias for this resource

     */

    public function addResource(ResourceInterface $resource, $loader)

    {

        $this->resources[$loader][] = $resource;

        $this->loaded = false;

    }

    /**

     * Returns an array of resources.

     *

     * @return array An array of resources

     */

    public function getResources()

    {

        $resources = array();

        foreach ($this->resources as $r) {

            $resources = array_merge($resources, $r);

        }

        return $resources;

    }

    /**

     * Checks for an asset formula.

     *

     * @param string $name An asset name

     *

     * @return Boolean If there is a formula

     */

    public function hasFormula($name)

    {

        if (!$this->loaded) {

            $this->load();

        }

        return isset($this->formulae[$name]);

    }

    /**

     * Returns an asset's formula.

     *

     * @param string $name An asset name

     *

     * @return array The formula

     *

     * @throws InvalidArgumentException If there is no formula by that name

     */

    public function getFormula($name)

    {

        if (!$this->loaded) {

            $this->load();

        }

        if (!isset($this->formulae[$name])) {

            throw new \InvalidArgumentException(sprintf('There is no "%s" formula.', $name));

        }

        return $this->formulae[$name];

    }

    /**

     * Sets a formula on the asset manager.

     *

     * @param string $name    An asset name

     * @param array  $formula A formula

     */

    public function setFormula($name, array $formula)

    {

        $this->formulae[$name] = $formula;

    }

    /**

     * Loads formulae from resources.

     *

     * @throws LogicException If a resource has been added to an invalid loader

     */

    public function load()

    {

        if ($this->loading) {

            return;

        }

        if ($diff = array_diff(array_keys($this->resources), array_keys($this->loaders))) {

            throw new \LogicException('The following loader(s) are not registered: '.implode(', ', $diff));

        }

        $this->loading = true;

        foreach ($this->resources as $loader => $resources) {

            foreach ($resources as $resource) {

                $this->formulae = array_replace($this->formulae, $this->loaders[$loader]->load($resource));

            }

        }

        $this->loaded = true;

        $this->loading = false;

    }

    public function get($name)

    {

        if (!$this->loaded) {

            $this->load();

        }

        if (!parent::has($name) && isset($this->formulae[$name])) {

            list($inputs, $filters, $options) = $this->formulae[$name];

            $options['name'] = $name;

            parent::set($name, $this->factory->createAsset($inputs, $filters, $options));

        }

        return parent::get($name);

    }

    public function has($name)

    {

        if (!$this->loaded) {

            $this->load();

        }

        return isset($this->formulae[$name]) || parent::has($name);

    }

    public function getNames()

    {

        if (!$this->loaded) {

            $this->load();

        }

        return array_unique(array_merge(parent::getNames(), array_keys($this->formulae)));

    }

    public function isDebug()

    {

        return $this->factory->isDebug();

    }

}