<?php
namespace Clue\StreamFilter;
/**
 * @internal
 * @see append()
 * @see prepend()
 */

class CallbackFilter extends \php_user_filter
{
    private $callback;
    private $closed = true;
    private $supportsClose = false;
    /** @return bool */
    #[\ReturnTypeWillChange]
    public function onCreate()
    {
        $this->closed = false;
        if (!\is_callable($this->params)) {
            throw new \InvalidArgumentException('No valid callback parameter given to stream_filter_(append|prepend)');
        }
        $this->callback = $this->params;
        $ref = new \ReflectionFunction($this->callback);
        $this->supportsClose = ($ref->getNumberOfRequiredParameters() === 0);
        return true;
    }
    #[\ReturnTypeWillChange]
    public function onClose()
    {
        $this->closed = true;
        if ($this->supportsClose) {
            $this->supportsClose = false;
            try {
                \call_user_func($this->callback);
            } catch (\Exception $ignored) {
            }
        }
        $this->callback = null;
    }
    #[\ReturnTypeWillChange]
    public function filter($in, $out, &$consumed, $closing)
    {
        $data = '';
        while ($bucket = \stream_bucket_make_writeable($in)) {
            $consumed += $bucket->datalen;
            $data .= $bucket->data;
        }
        if ($this->closed) {
            return \PSFS_FEED_ME;
        }
        if ($data !== '') {
            try {
                $data = \call_user_func($this->callback, $data);
            } catch (\Exception $e) {
                $this->onClose();
                \trigger_error('Error invoking filter: ' . $e->getMessage(), \E_USER_WARNING);
                return \PSFS_ERR_FATAL;
            }
        }
        if ($closing) {
            $this->closed = true;
            if ($this->supportsClose) {
                $this->supportsClose = false;
                try {
                    $data .= \call_user_func($this->callback);
                } catch (\Exception $e) {
                    \trigger_error('Error ending filter: ' . $e->getMessage(), \E_USER_WARNING);
                    return \PSFS_ERR_FATAL;
                }
            }
        }
        if ($data !== '') {
            $bucket = @\stream_bucket_new($this->stream, $data);
            if ($bucket !== false) {
                \stream_bucket_append($out, $bucket);
            }
        }
        return \PSFS_PASS_ON;
    }
}