Yiisoft\Di\Container

Complexity

Total Complexity

86

Size/Duplication

Total Lines	508
Duplicated Lines	0 %

Test Coverage

Coverage

86.84%

Importance

Changes	14
Bugs	2	Features	0

21 Methods

Rating	Name	Duplication	Size	Complexity
A	has()	0	8	2
A	__construct()	0	11	1
A	get()	0	17	6
A	addProviderDefinitions()	0	4	1
A	setTags()	0	5	4
A	set()	0	20	5
A	addProviders()	0	20	6
A	validateTags()	0	5	3
A	setDefaultDefinitions()	0	3	1
B	buildProvider()	0	27	7
D	isResolvable()	0	82	23
A	setResetter()	0	3	1
A	build()	0	25	4
A	validateMeta()	0	10	3
A	isTagAlias()	0	3	1
A	buildInternal()	0	10	2
A	setMultiple()	0	7	4
A	validateDefinition()	0	16	5
A	getTaggedServices()	0	11	3
A	getVariableType()	0	7	2
A	buildPrimitive()	0	11	2

<?php

declare(strict_types=1);

namespace Yiisoft\Di;

use Closure;
use Psr\Container\ContainerInterface;
use ReflectionClass;
use ReflectionException;
use ReflectionNamedType;
use ReflectionUnionType;
use Yiisoft\Di\Contracts\ServiceProviderInterface;
use Yiisoft\Factory\Definition\ArrayDefinition;
use Yiisoft\Factory\Definition\DefinitionValidator;
use Yiisoft\Factory\Exception\CircularReferenceException;
use Yiisoft\Factory\Exception\InvalidConfigException;
use Yiisoft\Factory\Exception\NotFoundException;
use Yiisoft\Factory\Exception\NotInstantiableException;

use function array_key_exists;
use function array_keys;
use function class_exists;
use function get_class;
use function implode;
use function in_array;
use function is_array;
use function is_object;
use function is_string;

/**
 * Container implements a [dependency injection](http://en.wikipedia.org/wiki/Dependency_injection) container.
 */
final class Container implements ContainerInterface
{
    private const META_TAGS = 'tags';
    private const META_RESET = 'reset';
    private const ALLOWED_META = [self::META_TAGS, self::META_RESET];

    /**
     * @var array object definitions indexed by their types
     */
    private array $definitions = [];
    /**
     * @var array used to collect ids instantiated during build
     * to detect circular references
     */
    private array $building = [];

    /**
     * @var bool $validate Validate definitions when set
     */
    private bool $validate;

    /**
     * @var object[]
     */
    private array $instances = [];

    private array $tags;

    private array $resetters = [];
    /** @psalm-suppress PropertyNotSetInConstructor */
    private DependencyResolver $dependencyResolver;

    /**
     * Container constructor.
     *
     * @param array $definitions Definitions to put into container.
     * @param array $providers Service providers to get definitions from.
     * lookup to when resolving dependencies. If provided the current container
     * is no longer queried for dependencies.
     *
     * @throws InvalidConfigException
     *
     * @psalm-suppress PropertyNotSetInConstructor
     */
    public function __construct(
        array $definitions = [],
        array $providers = [],
        array $tags = [],
        bool $validate = true
    ) {
        $this->tags = $tags;
        $this->validate = $validate;
        $this->setDefaultDefinitions();
        $this->setMultiple($definitions);
        $this->addProviders($providers);
    }

    /**
     * Returns a value indicating whether the container has the definition of the specified name.
     *
     * @param string $id class name, interface name or alias name
     *
     * @return bool whether the container is able to provide instance of class specified.
     *
     * @see set()
     */
    public function has($id): bool
    {
        if ($this->isTagAlias($id)) {
            $tag = substr($id, 4);
            return isset($this->tags[$tag]);
        }

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

    /**
    * @param string $id class name, interface name or alias name
    */
    private function isResolvable($id): bool
    {
        if (isset($this->definitions[$id]) || $id === StateResetter::class) {
            return true;
        }

        if (!class_exists($id) || isset($this->building[$id])) {
            return false;
        }

        try {
            $reflectionClass = new ReflectionClass($id);
        } catch (ReflectionException $e) {
            return false;
        }

        if (!$reflectionClass->isInstantiable()) {
            return false;
        }

        $constructor = $reflectionClass->getConstructor();

        if ($constructor === null) {
            return true;
        }

        $isResolvable = true;
        $this->building[$id] = 1;

        foreach ($constructor->getParameters() as $parameter) {
            $type = $parameter->getType();

            if ($parameter->isVariadic() || $parameter->isOptional()) {
                break;
            }

            if ($type === null || $type->isBuiltin()) {
                $isResolvable = false;
                break;
            }

            // PHP 8 union type is used as type hint
            /** @psalm-suppress UndefinedClass, TypeDoesNotContainType */
            if ($type instanceof ReflectionUnionType) {
                $isUnionTypeResolvable = false;
                /** @var ReflectionNamedType $unionType */
                foreach ($type->getTypes() as $unionType) {
                    if (!$unionType->isBuiltin()) {
                        $typeName = $unionType->getName();
                        $isUnionTypeResolvable = $this->isResolvable($typeName);
                    }
                }

                if (!$isUnionTypeResolvable) {
                    $isResolvable = false;
                    break;
                }
            }

            /** @var ReflectionNamedType|null $type */
            // Our parameter has a class type hint
            if ($type !== null && !$type->isBuiltin()) {
                $typeName = $type->getName();

                if ($typeName === 'self') {
                    $isResolvable = true;
                    break;
                }

                if ($typeName === 'self' || !$this->isResolvable($typeName)) {
                    $isResolvable = false;
                    break;
                }
            }
        }

        if ($isResolvable) {
            $this->definitions[$id] = $id;
        }
        unset($this->building[$id]);

        return $isResolvable;
    }

    /**
     * Returns an instance by either interface name or alias.
     *
     * Same instance of the class will be returned each time this method is called.
     *
     * @param string $id The interface or an alias name that was previously registered.
     *
     * @throws CircularReferenceException
     * @throws InvalidConfigException
     * @throws NotFoundException
     * @throws NotInstantiableException
     *
     * @return mixed|object An instance of the requested interface.
     *
     * @psalm-template T
     * @psalm-param string|class-string<T> $id
     * @psalm-return ($id is class-string ? T : mixed)
     */
    public function get($id)
    {
        if ($id === StateResetter::class && !isset($this->definitions[$id])) {
            $resetters = [];
            foreach ($this->resetters as $serviceId => $callback) {
                if (isset($this->instances[$serviceId])) {
                    $resetters[] = $callback->bindTo($this->instances[$serviceId], get_class($this->instances[$serviceId]));
                }
            }
            return new StateResetter($resetters, $this);
        }

        if (!array_key_exists($id, $this->instances)) {
            $this->instances[$id] = $this->build($id);
        }

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

    /**
     * Sets a definition to the container. Definition may be defined multiple ways.
     *
     * @param string $id
     * @param mixed $definition
     *
     * @throws InvalidConfigException
     *
     * @see `DefinitionNormalizer::normalize()`
     */
    protected function set(string $id, $definition): void
    {
        [$definition, $meta] = DefinitionParser::parse($definition);
        if ($this->validate) {
            $this->validateDefinition($definition, $id);
            $this->validateMeta($meta);
        }

        if (isset($meta[self::META_TAGS])) {
            if ($this->validate) {
                $this->validateTags($meta[self::META_TAGS]);
            }
            $this->setTags($id, $meta[self::META_TAGS]);
        }
        if (isset($meta[self::META_RESET])) {
            $this->setResetter($id, $meta[self::META_RESET]);
        }

        unset($this->instances[$id]);
        $this->definitions[$id] = $definition;
    }

    /**
     * Sets multiple definitions at once.
     *
     * @param array $config definitions indexed by their ids
     *
     * @throws InvalidConfigException
     */
    protected function setMultiple(array $config): void
    {
        foreach ($config as $id => $definition) {
            if ($this->validate && !is_string($id)) {
                throw new InvalidConfigException(sprintf('Key must be a string. %s given.', $this->getVariableType($id)));
            }
            $this->set($id, $definition);
        }
    }

    private function setDefaultDefinitions(): void
    {
        $this->set(ContainerInterface::class, $this);
    }

    /**
     * @param mixed $definition
     *
     * @throws InvalidConfigException
     */
    private function validateDefinition($definition, ?string $id = null): void
    {
        if (is_array($definition) && isset($definition[DefinitionParser::IS_PREPARED_ARRAY_DEFINITION_DATA])) {
            [$class, $constructorArguments, $methodsAndProperties] = $definition;
            $definition = array_merge(
                $class === null ? [] : [ArrayDefinition::CLASS_NAME => $class],
                [ArrayDefinition::CONSTRUCTOR => $constructorArguments],
                $methodsAndProperties,
            );
        }

        if ($definition instanceof ExtensibleService) {
            throw new InvalidConfigException('Invalid definition. ExtensibleService is only allowed in provider extensions.');
        }

        DefinitionValidator::validate($definition, $id);
    }

    /**
     * @throws InvalidConfigException
     */
    private function validateMeta(array $meta): void
    {
        foreach ($meta as $key => $_value) {
            if (!in_array($key, self::ALLOWED_META, true)) {
                throw new InvalidConfigException(
                    sprintf(
                        'Invalid definition: metadata "%s" is not allowed. Did you mean "%s()" or "$%s"?',
                        $key,
                        $key,
                        $key,
                    )
                );
            }
        }
    }

    private function validateTags(array $tags): void
    {
        foreach ($tags as $tag) {
            if (!is_string($tag)) {
                throw new InvalidConfigException('Invalid tag. Expected a string, got ' . var_export($tag, true) . '.');
            }
        }
    }

    private function setTags(string $id, array $tags): void
    {
        foreach ($tags as $tag) {
            if (!isset($this->tags[$tag]) || !in_array($id, $this->tags[$tag], true)) {
                $this->tags[$tag][] = $id;
            }
        }
    }

    private function setResetter(string $id, Closure $resetter): void
    {
        $this->resetters[$id] = $resetter;
    }

    /**
     * Creates new instance by either interface name or alias.
     *
     * @param string $id The interface or an alias name that was previously registered.
     *
     * @throws CircularReferenceException
     * @throws InvalidConfigException
     * @throws NotFoundException
     *
     * @return mixed|object New built instance of the specified class.
     *
     * @internal
     */
    private function build(string $id)
    {
        if ($this->isTagAlias($id)) {
            return $this->getTaggedServices($id);
        }

        if (isset($this->building[$id])) {
            if ($id === ContainerInterface::class) {
                return $this;
            }
            throw new CircularReferenceException(sprintf(
                'Circular reference to "%s" detected while building: %s.',
                $id,
                implode(',', array_keys($this->building))
            ));
        }

        $this->building[$id] = 1;
        try {
            $object = $this->buildInternal($id);
        } finally {
            unset($this->building[$id]);
        }

        return $object;
    }

    private function isTagAlias(string $id): bool
    {
        return strpos($id, 'tag@') === 0;
    }

    private function getTaggedServices(string $tagAlias): array
    {
        $tag = substr($tagAlias, 4);
        $services = [];
        if (isset($this->tags[$tag])) {
            foreach ($this->tags[$tag] as $service) {
                $services[] = $this->get($service);
            }
        }

        return $services;
    }

    /**
     * @param string $id
     *
     * @throws InvalidConfigException
     * @throws NotFoundException
     *
     * @return mixed|object
     */
    private function buildInternal(string $id)
    {
        if (!isset($this->definitions[$id])) {
            return $this->buildPrimitive($id);
        }
        $definition = DefinitionNormalizer::normalize($this->definitions[$id], $id);
        /** @psalm-suppress RedundantPropertyInitializationCheck */
        $this->dependencyResolver ??= new DependencyResolver($this->get(ContainerInterface::class));

        return $definition->resolve($this->dependencyResolver);
    }

    /**
     * @param string $class
     *
     * @throws InvalidConfigException
     * @throws NotFoundException
     *
     * @return mixed|object
     */
    private function buildPrimitive(string $class)
    {
        if (class_exists($class)) {
            $definition = ArrayDefinition::fromPreparedData($class);
            /** @psalm-suppress RedundantPropertyInitializationCheck */
            $this->dependencyResolver ??= new DependencyResolver($this->get(ContainerInterface::class));

            return $definition->resolve($this->dependencyResolver);
        }

        throw new NotFoundException($class);
    }

    private function addProviders(array $providers): void
    {
        $extensions = [];
        foreach ($providers as $provider) {
            $providerInstance = $this->buildProvider($provider);
            $extensions[] = $providerInstance->getExtensions();
            $this->addProviderDefinitions($providerInstance);
        }

        foreach ($extensions as $providerExtensions) {
            foreach ($providerExtensions as $id => $extension) {
                if (!isset($this->definitions[$id])) {
                    throw new InvalidConfigException("Extended service \"$id\" doesn't exist.");
                }

                if (!$this->definitions[$id] instanceof ExtensibleService) {
                    $this->definitions[$id] = new ExtensibleService($this->definitions[$id]);
                }

                $this->definitions[$id]->addExtension($extension);
            }
        }
    }

    /**
     * Adds service provider definitions to the container.
     *
     * @param object $provider
     *
     * @throws InvalidConfigException
     * @throws NotInstantiableException
     *
     * @see ServiceProviderInterface
     */
    private function addProviderDefinitions($provider): void
    {
        $definitions = $provider->getDefinitions();
        $this->setMultiple($definitions);
    }

    /**
     * Builds service provider by definition.
     *
     * @param mixed $provider Class name or instance of provider.
     *
     * @throws InvalidConfigException If provider argument is not valid.
     *
     * @return ServiceProviderInterface Instance of service provider.
     *
     * @psalm-suppress MoreSpecificReturnType
     */
    private function buildProvider($provider): ServiceProviderInterface
    {
        if ($this->validate && !(is_string($provider) || is_object($provider) && $provider instanceof ServiceProviderInterface)) {
            throw new InvalidConfigException(
                sprintf(
                    'Service provider should be a class name or an instance of %s. %s given.',
                    ServiceProviderInterface::class,
                    $this->getVariableType($provider)
                )
            );
        }

        $providerInstance = is_object($provider) ? $provider : new $provider();
        if (!$providerInstance instanceof ServiceProviderInterface) {
            throw new InvalidConfigException(
                sprintf(
                    'Service provider should be an instance of %s. %s given.',
                    ServiceProviderInterface::class,
                    $this->getVariableType($providerInstance)
                )
            );
        }

        /**
         * @psalm-suppress LessSpecificReturnStatement
         */
        return $providerInstance;
    }

    /**
     * @param mixed $variable
     */
    private function getVariableType($variable): string
    {
        if (is_object($variable)) {
            return get_class($variable);
        }

        return gettype($variable);
    }
}