class ExtensionSet

final class ExtensionSet {
    private $extensions;
    private $initialized = false;
    private $runtimeInitialized = false;
    private $staging;
    private $parsers;
    private $visitors;
    
    /** @var array<string, TwigFilter> */
    private $filters;
    
    /** @var array<string, TwigFilter> */
    private $dynamicFilters;
    
    /** @var array<string, TwigTest> */
    private $tests;
    
    /** @var array<string, TwigTest> */
    private $dynamicTests;
    
    /** @var array<string, TwigFunction> */
    private $functions;
    
    /** @var array<string, TwigFunction> */
    private $dynamicFunctions;
    
    /** @var array<string, array{precedence: int, class: class-string<AbstractExpression>}> */
    private $unaryOperators;
    
    /** @var array<string, array{precedence: int, class?: class-string<AbstractExpression>, associativity: ExpressionParser::OPERATOR_*}> */
    private $binaryOperators;
    
    /** @var array<string, mixed>|null */
    private $globals;
    private $functionCallbacks = [];
    private $filterCallbacks = [];
    private $parserCallbacks = [];
    private $lastModified = 0;
    public function __construct() {
        $this->staging = new StagingExtension();
    }
    public function initRuntime() {
        $this->runtimeInitialized = true;
    }
    public function hasExtension(string $class) : bool {
        return isset($this->extensions[ltrim($class, '\\')]);
    }
    public function getExtension(string $class) : ExtensionInterface {
        $class = ltrim($class, '\\');
        if (!isset($this->extensions[$class])) {
            throw new RuntimeError(\sprintf('The "%s" extension is not enabled.', $class));
        }
        return $this->extensions[$class];
    }
    
    /**
     * @param ExtensionInterface[] $extensions
     */
    public function setExtensions(array $extensions) : void {
        foreach ($extensions as $extension) {
            $this->addExtension($extension);
        }
    }
    
    /**
     * @return ExtensionInterface[]
     */
    public function getExtensions() : array {
        return $this->extensions;
    }
    public function getSignature() : string {
        return json_encode(array_keys($this->extensions));
    }
    public function isInitialized() : bool {
        return $this->initialized || $this->runtimeInitialized;
    }
    public function getLastModified() : int {
        if (0 !== $this->lastModified) {
            return $this->lastModified;
        }
        foreach ($this->extensions as $extension) {
            $r = new \ReflectionObject($extension);
            if (is_file($r->getFileName()) && ($extensionTime = filemtime($r->getFileName())) > $this->lastModified) {
                $this->lastModified = $extensionTime;
            }
        }
        return $this->lastModified;
    }
    public function addExtension(ExtensionInterface $extension) : void {
        $class = \get_class($extension);
        if ($this->initialized) {
            throw new \LogicException(\sprintf('Unable to register extension "%s" as extensions have already been initialized.', $class));
        }
        if (isset($this->extensions[$class])) {
            throw new \LogicException(\sprintf('Unable to register extension "%s" as it is already registered.', $class));
        }
        $this->extensions[$class] = $extension;
    }
    public function addFunction(TwigFunction $function) : void {
        if ($this->initialized) {
            throw new \LogicException(\sprintf('Unable to add function "%s" as extensions have already been initialized.', $function->getName()));
        }
        $this->staging
            ->addFunction($function);
    }
    
    /**
     * @return TwigFunction[]
     */
    public function getFunctions() : array {
        if (!$this->initialized) {
            $this->initExtensions();
        }
        return $this->functions;
    }
    public function getFunction(string $name) : ?TwigFunction {
        if (!$this->initialized) {
            $this->initExtensions();
        }
        if (isset($this->functions[$name])) {
            return $this->functions[$name];
        }
        foreach ($this->dynamicFunctions as $pattern => $function) {
            if (preg_match($pattern, $name, $matches)) {
                array_shift($matches);
                return $function->withDynamicArguments($name, $function->getName(), $matches);
            }
        }
        foreach ($this->functionCallbacks as $callback) {
            if (false !== ($function = $callback($name))) {
                return $function;
            }
        }
        return null;
    }
    public function registerUndefinedFunctionCallback(callable $callable) : void {
        $this->functionCallbacks[] = $callable;
    }
    public function addFilter(TwigFilter $filter) : void {
        if ($this->initialized) {
            throw new \LogicException(\sprintf('Unable to add filter "%s" as extensions have already been initialized.', $filter->getName()));
        }
        $this->staging
            ->addFilter($filter);
    }
    
    /**
     * @return TwigFilter[]
     */
    public function getFilters() : array {
        if (!$this->initialized) {
            $this->initExtensions();
        }
        return $this->filters;
    }
    public function getFilter(string $name) : ?TwigFilter {
        if (!$this->initialized) {
            $this->initExtensions();
        }
        if (isset($this->filters[$name])) {
            return $this->filters[$name];
        }
        foreach ($this->dynamicFilters as $pattern => $filter) {
            if (preg_match($pattern, $name, $matches)) {
                array_shift($matches);
                return $filter->withDynamicArguments($name, $filter->getName(), $matches);
            }
        }
        foreach ($this->filterCallbacks as $callback) {
            if (false !== ($filter = $callback($name))) {
                return $filter;
            }
        }
        return null;
    }
    public function registerUndefinedFilterCallback(callable $callable) : void {
        $this->filterCallbacks[] = $callable;
    }
    public function addNodeVisitor(NodeVisitorInterface $visitor) : void {
        if ($this->initialized) {
            throw new \LogicException('Unable to add a node visitor as extensions have already been initialized.');
        }
        $this->staging
            ->addNodeVisitor($visitor);
    }
    
    /**
     * @return NodeVisitorInterface[]
     */
    public function getNodeVisitors() : array {
        if (!$this->initialized) {
            $this->initExtensions();
        }
        return $this->visitors;
    }
    public function addTokenParser(TokenParserInterface $parser) : void {
        if ($this->initialized) {
            throw new \LogicException('Unable to add a token parser as extensions have already been initialized.');
        }
        $this->staging
            ->addTokenParser($parser);
    }
    
    /**
     * @return TokenParserInterface[]
     */
    public function getTokenParsers() : array {
        if (!$this->initialized) {
            $this->initExtensions();
        }
        return $this->parsers;
    }
    public function getTokenParser(string $name) : ?TokenParserInterface {
        if (!$this->initialized) {
            $this->initExtensions();
        }
        if (isset($this->parsers[$name])) {
            return $this->parsers[$name];
        }
        foreach ($this->parserCallbacks as $callback) {
            if (false !== ($parser = $callback($name))) {
                return $parser;
            }
        }
        return null;
    }
    public function registerUndefinedTokenParserCallback(callable $callable) : void {
        $this->parserCallbacks[] = $callable;
    }
    
    /**
     * @return array<string, mixed>
     */
    public function getGlobals() : array {
        if (null !== $this->globals) {
            return $this->globals;
        }
        $globals = [];
        foreach ($this->extensions as $extension) {
            if (!$extension instanceof GlobalsInterface) {
                continue;
            }
            $globals = array_merge($globals, $extension->getGlobals());
        }
        if ($this->initialized) {
            $this->globals = $globals;
        }
        return $globals;
    }
    public function resetGlobals() : void {
        $this->globals = null;
    }
    public function addTest(TwigTest $test) : void {
        if ($this->initialized) {
            throw new \LogicException(\sprintf('Unable to add test "%s" as extensions have already been initialized.', $test->getName()));
        }
        $this->staging
            ->addTest($test);
    }
    
    /**
     * @return TwigTest[]
     */
    public function getTests() : array {
        if (!$this->initialized) {
            $this->initExtensions();
        }
        return $this->tests;
    }
    public function getTest(string $name) : ?TwigTest {
        if (!$this->initialized) {
            $this->initExtensions();
        }
        if (isset($this->tests[$name])) {
            return $this->tests[$name];
        }
        foreach ($this->dynamicTests as $pattern => $test) {
            if (preg_match($pattern, $name, $matches)) {
                array_shift($matches);
                return $test->withDynamicArguments($name, $test->getName(), $matches);
            }
        }
        return null;
    }
    
    /**
     * @return array<string, array{precedence: int, class: class-string<AbstractExpression>}>
     */
    public function getUnaryOperators() : array {
        if (!$this->initialized) {
            $this->initExtensions();
        }
        return $this->unaryOperators;
    }
    
    /**
     * @return array<string, array{precedence: int, class?: class-string<AbstractExpression>, associativity: ExpressionParser::OPERATOR_*}>
     */
    public function getBinaryOperators() : array {
        if (!$this->initialized) {
            $this->initExtensions();
        }
        return $this->binaryOperators;
    }
    private function initExtensions() : void {
        $this->parsers = [];
        $this->filters = [];
        $this->functions = [];
        $this->tests = [];
        $this->dynamicFilters = [];
        $this->dynamicFunctions = [];
        $this->dynamicTests = [];
        $this->visitors = [];
        $this->unaryOperators = [];
        $this->binaryOperators = [];
        foreach ($this->extensions as $extension) {
            $this->initExtension($extension);
        }
        $this->initExtension($this->staging);
        // Done at the end only, so that an exception during initialization does not mark the environment as initialized when catching the exception
        $this->initialized = true;
    }
    private function initExtension(ExtensionInterface $extension) : void {
        // filters
        foreach ($extension->getFilters() as $filter) {
            $this->filters[$name = $filter->getName()] = $filter;
            if (str_contains($name, '*')) {
                $this->dynamicFilters['#^' . str_replace('\\*', '(.*?)', preg_quote($name, '#')) . '$#'] = $filter;
            }
        }
        // functions
        foreach ($extension->getFunctions() as $function) {
            $this->functions[$name = $function->getName()] = $function;
            if (str_contains($name, '*')) {
                $this->dynamicFunctions['#^' . str_replace('\\*', '(.*?)', preg_quote($name, '#')) . '$#'] = $function;
            }
        }
        // tests
        foreach ($extension->getTests() as $test) {
            $this->tests[$name = $test->getName()] = $test;
            if (str_contains($name, '*')) {
                $this->dynamicTests['#^' . str_replace('\\*', '(.*?)', preg_quote($name, '#')) . '$#'] = $test;
            }
        }
        // token parsers
        foreach ($extension->getTokenParsers() as $parser) {
            if (!$parser instanceof TokenParserInterface) {
                throw new \LogicException('getTokenParsers() must return an array of \\Twig\\TokenParser\\TokenParserInterface.');
            }
            $this->parsers[$parser->getTag()] = $parser;
        }
        // node visitors
        foreach ($extension->getNodeVisitors() as $visitor) {
            $this->visitors[] = $visitor;
        }
        // operators
        if ($operators = $extension->getOperators()) {
            if (!\is_array($operators)) {
                throw new \InvalidArgumentException(\sprintf('"%s::getOperators()" must return an array with operators, got "%s".', \get_class($extension), get_debug_type($operators) . (\is_resource($operators) ? '' : '#' . $operators)));
            }
            if (2 !== \count($operators)) {
                throw new \InvalidArgumentException(\sprintf('"%s::getOperators()" must return an array of 2 elements, got %d.', \get_class($extension), \count($operators)));
            }
            $this->unaryOperators = array_merge($this->unaryOperators, $operators[0]);
            $this->binaryOperators = array_merge($this->binaryOperators, $operators[1]);
        }
    }

}