<?php 
 
/* 
 * This file is part of the Symfony package. 
 * 
 * (c) Fabien Potencier <[email protected]> 
 * 
 * For the full copyright and license information, please view the LICENSE 
 * file that was distributed with this source code. 
 */ 
 
namespace Symfony\Component\Config\Resource; 
 
/** 
 * ClassExistenceResource represents a class existence. 
 * Freshness is only evaluated against resource existence. 
 * 
 * The resource must be a fully-qualified class name. 
 * 
 * @author Fabien Potencier <[email protected]> 
 * 
 * @final 
 */ 
class ClassExistenceResource implements SelfCheckingResourceInterface 
{ 
    private $resource; 
    private $exists; 
 
    private static $autoloadLevel = 0; 
    private static $autoloadedClass; 
    private static $existsCache = []; 
 
    /** 
     * @param string    $resource The fully-qualified class name 
     * @param bool|null $exists   Boolean when the existence check has already been done 
     */ 
    public function __construct(string $resource, ?bool $exists = null) 
    { 
        $this->resource = $resource; 
        if (null !== $exists) { 
            $this->exists = [$exists, null]; 
        } 
    } 
 
    public function __toString(): string 
    { 
        return $this->resource; 
    } 
 
    public function getResource(): string 
    { 
        return $this->resource; 
    } 
 
    /** 
     * {@inheritdoc} 
     * 
     * @throws \ReflectionException when a parent class/interface/trait is not found 
     */ 
    public function isFresh(int $timestamp): bool 
    { 
        $loaded = class_exists($this->resource, false) || interface_exists($this->resource, false) || trait_exists($this->resource, false); 
 
        if (null !== $exists = &self::$existsCache[$this->resource]) { 
            if ($loaded) { 
                $exists = [true, null]; 
            } elseif (0 >= $timestamp && !$exists[0] && null !== $exists[1]) { 
                throw new \ReflectionException($exists[1]); 
            } 
        } elseif ([false, null] === $exists = [$loaded, null]) { 
            if (!self::$autoloadLevel++) { 
                spl_autoload_register(__CLASS__.'::throwOnRequiredClass'); 
            } 
            $autoloadedClass = self::$autoloadedClass; 
            self::$autoloadedClass = ltrim($this->resource, '\\'); 
 
            try { 
                $exists[0] = class_exists($this->resource) || interface_exists($this->resource, false) || trait_exists($this->resource, false); 
            } catch (\Exception $e) { 
                $exists[1] = $e->getMessage(); 
 
                try { 
                    self::throwOnRequiredClass($this->resource, $e); 
                } catch (\ReflectionException $e) { 
                    if (0 >= $timestamp) { 
                        throw $e; 
                    } 
                } 
            } catch (\Throwable $e) { 
                $exists[1] = $e->getMessage(); 
 
                throw $e; 
            } finally { 
                self::$autoloadedClass = $autoloadedClass; 
                if (!--self::$autoloadLevel) { 
                    spl_autoload_unregister(__CLASS__.'::throwOnRequiredClass'); 
                } 
            } 
        } 
 
        if (null === $this->exists) { 
            $this->exists = $exists; 
        } 
 
        return $this->exists[0] xor !$exists[0]; 
    } 
 
    /** 
     * @internal 
     */ 
    public function __sleep(): array 
    { 
        if (null === $this->exists) { 
            $this->isFresh(0); 
        } 
 
        return ['resource', 'exists']; 
    } 
 
    /** 
     * @internal 
     */ 
    public function __wakeup() 
    { 
        if (\is_bool($this->exists)) { 
            $this->exists = [$this->exists, null]; 
        } 
    } 
 
    /** 
     * Throws a reflection exception when the passed class does not exist but is required. 
     * 
     * A class is considered "not required" when it's loaded as part of a "class_exists" or similar check. 
     * 
     * This function can be used as an autoload function to throw a reflection 
     * exception if the class was not found by previous autoload functions. 
     * 
     * A previous exception can be passed. In this case, the class is considered as being 
     * required totally, so if it doesn't exist, a reflection exception is always thrown. 
     * If it exists, the previous exception is rethrown. 
     * 
     * @throws \ReflectionException 
     * 
     * @internal 
     */ 
    public static function throwOnRequiredClass(string $class, ?\Exception $previous = null) 
    { 
        // If the passed class is the resource being checked, we shouldn't throw. 
        if (null === $previous && self::$autoloadedClass === $class) { 
            return; 
        } 
 
        if (class_exists($class, false) || interface_exists($class, false) || trait_exists($class, false)) { 
            if (null !== $previous) { 
                throw $previous; 
            } 
 
            return; 
        } 
 
        if ($previous instanceof \ReflectionException) { 
            throw $previous; 
        } 
 
        $message = sprintf('Class "%s" not found.', $class); 
 
        if (self::$autoloadedClass !== $class) { 
            $message = substr_replace($message, sprintf(' while loading "%s"', self::$autoloadedClass), -1, 0); 
        } 
 
        if (null !== $previous) { 
            $message = $previous->getMessage(); 
        } 
 
        $e = new \ReflectionException($message, 0, $previous); 
 
        if (null !== $previous) { 
            throw $e; 
        } 
 
        $trace = debug_backtrace(); 
        $autoloadFrame = [ 
            'function' => 'spl_autoload_call', 
            'args' => [$class], 
        ]; 
 
        if (\PHP_VERSION_ID >= 80000 && isset($trace[1])) { 
            $callerFrame = $trace[1]; 
            $i = 2; 
        } elseif (false !== $i = array_search($autoloadFrame, $trace, true)) { 
            $callerFrame = $trace[++$i]; 
        } else { 
            throw $e; 
        } 
 
        if (isset($callerFrame['function']) && !isset($callerFrame['class'])) { 
            switch ($callerFrame['function']) { 
                case 'get_class_methods': 
                case 'get_class_vars': 
                case 'get_parent_class': 
                case 'is_a': 
                case 'is_subclass_of': 
                case 'class_exists': 
                case 'class_implements': 
                case 'class_parents': 
                case 'trait_exists': 
                case 'defined': 
                case 'interface_exists': 
                case 'method_exists': 
                case 'property_exists': 
                case 'is_callable': 
                    return; 
            } 
 
            $props = [ 
                'file' => $callerFrame['file'] ?? null, 
                'line' => $callerFrame['line'] ?? null, 
                'trace' => \array_slice($trace, 1 + $i), 
            ]; 
 
            foreach ($props as $p => $v) { 
                if (null !== $v) { 
                    $r = new \ReflectionProperty(\Exception::class, $p); 
                    $r->setAccessible(true); 
                    $r->setValue($e, $v); 
                } 
            } 
        } 
 
        throw $e; 
    } 
}