<?php

namespace Symfony\Component\DependencyInjection;

use Symfony\Component\DependencyInjection\Extension\ExtensionInterface;
use Symfony\Component\DependencyInjection\Resource\ResourceInterface;
use Symfony\Component\DependencyInjection\Resource\FileResource;

/*
 * This file is part of the Symfony framework.
 *
 * (c) Fabien Potencier <fabien.potencier@symfony-project.com>
 *
 * This source file is subject to the MIT license that is bundled
 * with this source code in the file LICENSE.
 */

/**
 * ContainerBuilder is a DI container that provides an API to easily describe services.
 *
 * @author     Fabien Potencier <fabien.potencier@symfony-project.com>
 */
class ContainerBuilder extends Container implements TaggedContainerInterface
{
    static protected $extensions = array();

    protected $definitions      = array();
    protected $aliases          = array();
    protected $loading          = array();
    protected $resources        = array();
    protected $extensionConfigs = array();

    /**
     * Registers an extension.
     *
     * @param ExtensionInterface $extension An extension instance
     */
    static public function registerExtension(ExtensionInterface $extension)
    {
        static::$extensions[$extension->getAlias()] = static::$extensions[$extension->getNamespace()] = $extension;
    }

    /**
     * Returns an extension by alias or namespace.
     *
     * @param string $name An alias or a namespace
     *
     * @return ExtensionInterface An extension instance
     */
    static public function getExtension($name)
    {
        if (!isset(static::$extensions[$name])) {
            throw new \LogicException(sprintf('Container extension "%s" is not registered', $name));
        }

        return static::$extensions[$name];
    }

    static public function hasExtension($name)
    {
        return isset(static::$extensions[$name]);
    }

    /**
     * Returns an array of resources loaded to build this configuration.
     *
     * @return ResourceInterface[] An array of resources
     */
    public function getResources()
    {
        return array_unique($this->resources);
    }

    /**
     * Adds a resource for this configuration.
     *
     * @param ResourceInterface $resource A resource instance
     *
     * @return ContainerBuilder The current instance
     */
    public function addResource(ResourceInterface $resource)
    {
        $this->resources[] = $resource;

        return $this;
    }

    /**
     * Adds the object class hierarchy as resources.
     *
     * @param object $object An object instance
     */
    public function addObjectResource($object)
    {
        $parent = new \ReflectionObject($object);
        $this->addResource(new FileResource($parent->getFileName()));
        while ($parent = $parent->getParentClass()) {
            $this->addResource(new FileResource($parent->getFileName()));
        }
    }

    /**
     * Loads the configuration for an extension.
     *
     * @param string $extension The extension alias or namespace
     * @param string $tag       The extension tag to load (without the namespace - namespace.tag)
     * @param array  $values    An array of values that customizes the extension
     *
     * @return ContainerBuilder The current instance
     */
    public function loadFromExtension($extension, $tag, array $values = array())
    {
        if (true === $this->isFrozen()) {
            throw new \LogicException('Cannot load from an extension on a frozen container.');
        }

        $namespace = $this->getExtension($extension)->getAlias();

        if (!isset($this->extensionConfigs[$namespace.':'.$tag])) {
            $this->extensionConfigs[$namespace.':'.$tag] = array();
        }

        $this->extensionConfigs[$namespace.':'.$tag][] = $values;

        return $this;
    }

    /**
     * Sets a service.
     *
     * @param string $id      The service identifier
     * @param object $service The service instance
     */
    public function set($id, $service)
    {
        unset($this->definitions[$id]);
        unset($this->aliases[$id]);

        parent::set($id, $service);
    }

    /**
     * Removes a service.
     *
     * @param string $id The service identifier
     */
    public function remove($id)
    {
        unset($this->definitions[$id]);
    }

    /**
     * Returns true if the given service is defined.
     *
     * @param  string  $id      The service identifier
     *
     * @return Boolean true if the service is defined, false otherwise
     */
    public function has($id)
    {
        return isset($this->definitions[$id]) || isset($this->aliases[$id]) || parent::has($id);
    }

    /**
     * Gets a service.
     *
     * @param  string $id              The service identifier
     * @param  int    $invalidBehavior The behavior when the service does not exist
     *
     * @return object The associated service
     *
     * @throws \InvalidArgumentException if the service is not defined
     * @throws \LogicException if the service has a circular reference to itself
     *
     * @see Reference
     */
    public function get($id, $invalidBehavior = ContainerInterface::EXCEPTION_ON_INVALID_REFERENCE)
    {
        try {
            return parent::get($id, ContainerInterface::EXCEPTION_ON_INVALID_REFERENCE);
        } catch (\InvalidArgumentException $e) {
            if (isset($this->loading[$id])) {
                throw new \LogicException(sprintf('The service "%s" has a circular reference to itself.', $id), 0, $e);
            }

            if (!$this->hasDefinition($id) && isset($this->aliases[$id])) {
                return $this->get($this->aliases[$id]);
            }

            try {
                $definition = $this->getDefinition($id);
            } catch (\InvalidArgumentException $e) {
                if (ContainerInterface::EXCEPTION_ON_INVALID_REFERENCE !== $invalidBehavior) {
                    return null;
                }

                throw $e;
            }

            $this->loading[$id] = true;

            $service = $this->createService($definition, $id);

            unset($this->loading[$id]);

            return $service;
        }
    }

    /**
     * Merges a ContainerBuilder with the current ContainerBuilder configuration.
     *
     * Service definitions overrides the current defined ones.
     *
     * But for parameters, they are overridden by the current ones. It allows
     * the parameters passed to the container constructor to have precedence
     * over the loaded ones.
     *
     * $container = new ContainerBuilder(array('foo' => 'bar'));
     * $loader = new LoaderXXX($container);
     * $loader->load('resource_name');
     * $container->register('foo', new stdClass());
     *
     * In the above example, even if the loaded resource defines a foo
     * parameter, the value will still be 'bar' as defined in the ContainerBuilder
     * constructor.
     */
    public function merge(ContainerBuilder $container)
    {
        if (true === $this->isFrozen()) {
            throw new \LogicException('Cannot merge on a frozen container.');
        }

        $this->addDefinitions($container->getDefinitions());
        $this->addAliases($container->getAliases());
        $this->parameterBag->add($container->getParameterBag()->all());

        foreach ($container->getResources() as $resource) {
            $this->addResource($resource);
        }

        foreach ($container->getExtensionConfigs() as $name => $configs) {
            if (isset($this->extensionConfigs[$name])) {
                $this->extensionConfigs[$name] = array_merge($this->extensionConfigs[$name], $configs);
            } else {
                $this->extensionConfigs[$name] = $configs;
            }
        }
    }

    /**
     * Returns the containers for the registered extensions.
     *
     * @return ExtensionInterface[] An array of extension containers
     */
    public function getExtensionConfigs()
    {
        return $this->extensionConfigs;
    }

    /**
     * Freezes the container.
     *
     * This method does four things:
     *
     *  * The extension configurations are merged;
     *  * Parameter values are resolved;
     *  * The parameter bag is freezed;
     *  * Extension loading is disabled.
     */
    public function freeze()
    {
        $parameters = $this->parameterBag->all();
        $definitions = $this->definitions;
        $aliases = $this->aliases;

        foreach ($this->extensionConfigs as $name => $configs) {
            list($namespace, $tag) = explode(':', $name);

            $extension = $this->getExtension($namespace);

            $container = new self($this->parameterBag);
            $container->addObjectResource($extension);
            foreach ($configs as $config) {
                $extension->load($tag, $config, $container);
            }

            $this->merge($container);
        }
        $this->extensionConfigs = array();

        $this->addDefinitions($definitions);
        $this->addAliases($aliases);
        $this->parameterBag->add($parameters);

        parent::freeze();
    }

    /**
     * Gets all service ids.
     *
     * @return array An array of all defined service ids
     */
    public function getServiceIds()
    {
        return array_unique(array_merge(array_keys($this->getDefinitions()), array_keys($this->aliases), parent::getServiceIds()));
    }

    /**
     * Adds the service aliases.
     *
     * @param array $aliases An array of aliases
     */
    public function addAliases(array $aliases)
    {
        foreach ($aliases as $alias => $id) {
            $this->setAlias($alias, $id);
        }
    }

    /**
     * Sets the service aliases.
     *
     * @param array $definitions An array of service definitions
     */
    public function setAliases(array $aliases)
    {
        $this->aliases = array();
        $this->addAliases($aliases);
    }

    /**
     * Sets an alias for an existing service.
     *
     * @param string $alias The alias to create
     * @param string $id    The service to alias
     */
    public function setAlias($alias, $id)
    {
        unset($this->definitions[$alias]);

        $this->aliases[$alias] = $id;
    }

    /**
     * Removes an alias.
     *
     * @param string $alias The alias to remove
     */
    public function removeAlias($alias)
    {
        unset($this->aliases[$alias]);
    }

    /**
     * Returns true if an alias exists under the given identifier.
     *
     * @param  string  $id The service identifier
     *
     * @return Boolean true if the alias exists, false otherwise
     */
    public function hasAlias($id)
    {
        return array_key_exists($id, $this->aliases);
    }

    /**
     * Gets all defined aliases.
     *
     * @return array An array of aliases
     */
    public function getAliases()
    {
        return $this->aliases;
    }

    /**
     * Gets an alias.
     *
     * @param  string  $id The service identifier
     *
     * @return string The aliased service identifier
     *
     * @throws \InvalidArgumentException if the alias does not exist
     */
    public function getAlias($id)
    {
        if (!$this->hasAlias($id)) {
            throw new \InvalidArgumentException(sprintf('The service alias "%s" does not exist.', $id));
        }

        return $this->aliases[$id];
    }

    /**
     * Registers a service definition.
     *
     * This methods allows for simple registration of service definition
     * with a fluid interface.
     *
     * @param  string $id    The service identifier
     * @param  string $class The service class
     *
     * @return Definition A Definition instance
     */
    public function register($id, $class = null)
    {
        return $this->setDefinition($id, new Definition($class));
    }

    /**
     * Adds the service definitions.
     *
     * @param Definition[] $definitions An array of service definitions
     */
    public function addDefinitions(array $definitions)
    {
        foreach ($definitions as $id => $definition) {
            $this->setDefinition($id, $definition);
        }
    }

    /**
     * Sets the service definitions.
     *
     * @param array $definitions An array of service definitions
     */
    public function setDefinitions(array $definitions)
    {
        $this->definitions = array();
        $this->addDefinitions($definitions);
    }

    /**
     * Gets all service definitions.
     *
     * @return array An array of Definition instances
     */
    public function getDefinitions()
    {
        return $this->definitions;
    }

    /**
     * Sets a service definition.
     *
     * @param  string     $id         The service identifier
     * @param  Definition $definition A Definition instance
     */
    public function setDefinition($id, Definition $definition)
    {
        unset($this->aliases[$id]);

        return $this->definitions[$id] = $definition;
    }

    /**
     * Returns true if a service definition exists under the given identifier.
     *
     * @param  string  $id The service identifier
     *
     * @return Boolean true if the service definition exists, false otherwise
     */
    public function hasDefinition($id)
    {
        return array_key_exists($id, $this->definitions);
    }

    /**
     * Gets a service definition.
     *
     * @param  string  $id The service identifier
     *
     * @return Definition A Definition instance
     *
     * @throws \InvalidArgumentException if the service definition does not exist
     */
    public function getDefinition($id)
    {
        if (!$this->hasDefinition($id)) {
            throw new \InvalidArgumentException(sprintf('The service definition "%s" does not exist.', $id));
        }

        return $this->definitions[$id];
    }

    /**
     * Gets a service definition by id or alias.
     *
     * The method "unaliases" recursively to return a Definition instance.
     *
     * @param  string  $id The service identifier or alias
     *
     * @return Definition A Definition instance
     *
     * @throws \InvalidArgumentException if the service definition does not exist
     */
    public function findDefinition($id)
    {
        if ($this->hasAlias($id)) {
            return $this->findDefinition($this->getAlias($id));
        }

        return $this->getDefinition($id);
    }

    /**
     * Creates a service for a service definition.
     *
     * @param  Definition $definition A service definition instance
     * @param  string     $id         The service identifier
     *
     * @return object              The service described by the service definition
     *
     * @throws \InvalidArgumentException When configure callable is not callable
     */
    protected function createService(Definition $definition, $id)
    {
        if (null !== $definition->getFile()) {
            require_once $this->getParameterBag()->resolveValue($definition->getFile());
        }

        $arguments = $this->resolveServices($this->getParameterBag()->resolveValue($definition->getArguments()));

        if (null !== $definition->getFactoryMethod()) {
            if (null !== $definition->getFactoryService()) {
                $factory = $this->get($this->getParameterBag()->resolveValue($definition->getFactoryService()));
            } else {
                $factory = $this->getParameterBag()->resolveValue($definition->getClass());
            }

            $service = call_user_func_array(array($factory, $definition->getFactoryMethod()), $arguments);
        } else {
            $r = new \ReflectionClass($this->getParameterBag()->resolveValue($definition->getClass()));

            $service = null === $r->getConstructor() ? $r->newInstance() : $r->newInstanceArgs($arguments);
        }

        if ($definition->isShared()) {
            $this->services[$id] = $service;
        }

        foreach ($definition->getMethodCalls() as $call) {
            $services = self::getServiceConditionals($call[1]);

            $ok = true;
            foreach ($services as $s) {
                if (!$this->has($s)) {
                    $ok = false;
                    break;
                }
            }

            if ($ok) {
                call_user_func_array(array($service, $call[0]), $this->resolveServices($this->getParameterBag()->resolveValue($call[1])));
            }
        }

        if ($callable = $definition->getConfigurator()) {
            if (is_array($callable) && is_object($callable[0]) && $callable[0] instanceof Reference) {
                $callable[0] = $this->get((string) $callable[0]);
            } elseif (is_array($callable)) {
                $callable[0] = $this->getParameterBag()->resolveValue($callable[0]);
            }

            if (!is_callable($callable)) {
                throw new \InvalidArgumentException(sprintf('The configure callable for class "%s" is not a callable.', get_class($service)));
            }

            call_user_func($callable, $service);
        }

        return $service;
    }

    /**
     * Replaces service references by the real service instance.
     *
     * @param  mixed $value A value
     *
     * @return mixed The same value with all service references replaced by the real service instances
     */
    public function resolveServices($value)
    {
        if (is_array($value)) {
            foreach ($value as &$v) {
                $v = $this->resolveServices($v);
            }
        } else if (is_object($value) && $value instanceof Reference) {
            $value = $this->get((string) $value, $value->getInvalidBehavior());
        }

        return $value;
    }

    /**
     * Returns service ids for a given tag.
     *
     * @param string $name The tag name
     *
     * @return array An array of tags
     */
    public function findTaggedServiceIds($name)
    {
        $tags = array();
        foreach ($this->getDefinitions() as $id => $definition) {
            if ($definition->getTag($name)) {
                $tags[$id] = $definition->getTag($name);
            }
        }

        return $tags;
    }

    static public function getServiceConditionals($value)
    {
        $services = array();

        if (is_array($value)) {
            foreach ($value as $v) {
                $services = array_unique(array_merge($services, self::getServiceConditionals($v)));
            }
        } elseif (is_object($value) && $value instanceof Reference && $value->getInvalidBehavior() === ContainerInterface::IGNORE_ON_INVALID_REFERENCE) {
            $services[] = (string) $value;
        }

        return $services;
    }
}