<?php declare(strict_types=1);
/*
 * This file is part of PHPUnit.
 *
 * (c) Sebastian Bergmann <sebastian@phpunit.de>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */
namespace PHPUnit\Framework;

use const PHP_VERSION_ID;
use function array_keys;
use function get_class;
use function spl_object_hash;
use PHPUnit\Util\Filter;
use Throwable;
use WeakReference;

/**
 * Wraps Exceptions thrown by code under test.
 *
 * Re-instantiates Exceptions thrown by user-space code to retain their original
 * class names, properties, and stack traces (but without arguments).
 *
 * Unlike PHPUnit\Framework\Exception, the complete stack of previous Exceptions
 * is processed.
 *
 * @internal This class is not covered by the backward compatibility promise for PHPUnit
 */
final class ExceptionWrapper extends Exception
{
    /**
     * @var string
     */
    protected $className;

    /**
     * @var null|ExceptionWrapper
     */
    protected $previous;

    /**
     * @var null|WeakReference<Throwable>
     */
    private $originalException;

    public function __construct(Throwable $t)
    {
        // PDOException::getCode() is a string.
        // @see https://php.net/manual/en/class.pdoexception.php#95812
        parent::__construct($t->getMessage(), (int) $t->getCode());

        $this->setOriginalException($t);
    }

    public function __toString(): string
    {
        $string = TestFailure::exceptionToString($this);

        if ($trace = Filter::getFilteredStacktrace($this)) {
            $string .= "\n" . $trace;
        }

        if ($this->previous) {
            $string .= "\nCaused by\n" . $this->previous;
        }

        return $string;
    }

    public function getClassName(): string
    {
        return $this->className;
    }

    public function getPreviousWrapped(): ?self
    {
        return $this->previous;
    }

    public function setClassName(string $className): void
    {
        $this->className = $className;
    }

    public function setOriginalException(Throwable $t): void
    {
        $this->originalException($t);

        $this->className = get_class($t);
        $this->file      = $t->getFile();
        $this->line      = $t->getLine();

        $this->serializableTrace = $t->getTrace();

        foreach (array_keys($this->serializableTrace) as $key) {
            unset($this->serializableTrace[$key]['args']);
        }

        if ($t->getPrevious()) {
            $this->previous = new self($t->getPrevious());
        }
    }

    public function getOriginalException(): ?Throwable
    {
        return $this->originalException();
    }

    /**
     * Method to contain static originalException to exclude it from stacktrace to prevent the stacktrace contents,
     * which can be quite big, from being garbage-collected, thus blocking memory until shutdown.
     *
     * Approach works both for var_dump() and var_export() and print_r().
     */
    private function originalException(?Throwable $exceptionToStore = null): ?Throwable
    {
        // drop once PHP 7.3 support is removed
        if (PHP_VERSION_ID < 70400) {
            static $originalExceptions;

            $instanceId = spl_object_hash($this);

            if ($exceptionToStore) {
                $originalExceptions[$instanceId] = $exceptionToStore;
            }

            return $originalExceptions[$instanceId] ?? null;
        }

        if ($exceptionToStore) {
            $this->originalException = WeakReference::create($exceptionToStore);
        }

        return $this->originalException !== null ? $this->originalException->get() : null;
    }
}
