<?php

/**
 * Part of the Joomla Framework Filesystem Package
 *
 * @copyright  Copyright (C) 2005 - 2021 Open Source Matters, Inc. All rights reserved.
 * @license    GNU General Public License version 2 or later; see LICENSE
 */

namespace Joomla\Filesystem\Stream;

use Joomla\Filesystem\Support\StringController;

/**
 * String Stream Wrapper
 *
 * This class allows you to use a PHP string in the same way that you would normally use a regular stream wrapper
 *
 * @since  1.3.0
 */
class StringWrapper
{
    /**
     * The current string
     *
     * @var   string
     * @since  1.3.0
     */
    protected $currentString;

    /**
     * The path
     *
     * @var   string
     * @since  1.3.0
     */
    protected $path;

    /**
     * The mode
     *
     * @var   string
     * @since  1.3.0
     */
    protected $mode;

    /**
     * Enter description here ...
     *
     * @var    string
     * @since  1.3.0
     */
    protected $options;

    /**
     * Enter description here ...
     *
     * @var    string
     * @since  1.3.0
     */
    protected $openedPath;

    /**
     * Current position
     *
     * @var    ?integer
     * @since  1.3.0
     */
    protected $pos;

    /**
     * Length of the string
     *
     * @var    integer
     * @since  1.3.0
     */
    protected $len;

    /**
     * Statistics for a file
     *
     * @var    array
     * @since  1.3.0
     * @link   https://www.php.net/manual/en/function.stat.php
     */
    protected $stat;

    /**
     * Method to open a file or URL.
     *
     * @param   string   $path        The stream path.
     * @param   string   $mode        Not used.
     * @param   integer  $options     Not used.
     * @param   string   $openedPath  Not used.
     *
     * @return  boolean
     *
     * @since   1.3.0
     */
    public function stream_open($path, $mode, $options, &$openedPath)
    {
        $refPath = StringController::getRef(str_replace('string://', '', $path));

        $this->currentString = &$refPath;

        if ($this->currentString) {
            $this->len  = \strlen($this->currentString);
            $this->pos  = 0;
            $this->stat = $this->url_stat($path, 0);

            return true;
        }

        return false;
    }

    /**
     * Method to retrieve information from a file resource
     *
     * @return  array
     *
     * @link    https://www.php.net/manual/en/streamwrapper.stream-stat.php
     * @since   1.3.0
     */
    public function stream_stat()
    {
        return $this->stat;
    }

    /**
     * Method to retrieve information about a file.
     *
     * @param   string   $path   File path or URL to stat
     * @param   integer  $flags  Additional flags set by the streams API
     *
     * @return  array
     *
     * @link    https://www.php.net/manual/en/streamwrapper.url-stat.php
     * @since   1.3.0
     */
    public function url_stat($path, $flags = 0)
    {
        $now     = time();
        $refPath = StringController::getRef(str_replace('string://', '', $path));
        $string  = &$refPath;
        $stat    = [
            'dev'     => 0,
            'ino'     => 0,
            'mode'    => 0,
            'nlink'   => 1,
            'uid'     => 0,
            'gid'     => 0,
            'rdev'    => 0,
            'size'    => \strlen($string),
            'atime'   => $now,
            'mtime'   => $now,
            'ctime'   => $now,
            'blksize' => '512',
            'blocks'  => ceil(\strlen($string) / 512),
        ];

        return $stat;
    }

    /**
     * Method to read a given number of bytes starting at the current position
     * and moving to the end of the string defined by the current position plus the
     * given number.
     *
     * @param   integer  $count  Bytes of data from the current position should be returned.
     *
     * @return  string
     *
     * @link    https://www.php.net/manual/en/streamwrapper.stream-read.php
     * @since   1.3.0
     */
    public function stream_read($count)
    {
        $result = substr($this->currentString, $this->pos ?? 0, $count);
        $this->pos += $count;

        return $result;
    }

    /**
     * Stream write, always returning false.
     *
     * @param   string  $data  The data to write.
     *
     * @return  boolean
     *
     * @since   1.3.0
     * @note    Updating the string is not supported.
     */
    public function stream_write($data)
    {
        // We don't support updating the string.
        return false;
    }

    /**
     * Method to get the current position
     *
     * @return  integer  The position
     *
     * @since   1.3.0
     */
    public function stream_tell()
    {
        return $this->pos;
    }

    /**
     * End of field check
     *
     * @return  boolean  True if at end of field.
     *
     * @since   1.3.0
     */
    public function stream_eof()
    {
        if ($this->pos >= $this->len) {
            return true;
        }

        return false;
    }

    /**
     * Stream offset
     *
     * @param   integer  $offset  The starting offset.
     * @param   integer  $whence  SEEK_SET, SEEK_CUR, SEEK_END
     *
     * @return  boolean  True on success.
     *
     * @since   1.3.0
     */
    public function stream_seek($offset, $whence)
    {
        // $whence: SEEK_SET, SEEK_CUR, SEEK_END
        if ($offset > $this->len) {
            // We can't seek beyond our len.
            return false;
        }

        switch ($whence) {
            case \SEEK_SET:
                $this->pos = $offset;

                break;

            case \SEEK_CUR:
                if (($this->pos + $offset) > $this->len) {
                    return false;
                }

                $this->pos += $offset;

                break;

            case \SEEK_END:
                $this->pos = $this->len - $offset;

                break;
        }

        return true;
    }

    /**
     * Stream flush, always returns true.
     *
     * @return  boolean
     *
     * @since   1.3.0
     * @note    Data storage is not supported
     */
    public function stream_flush()
    {
        // We don't store data.
        return true;
    }
}

// phpcs:disable PSR1.Files.SideEffects
if (!stream_wrapper_register('string', '\\Joomla\\Filesystem\\Stream\\StringWrapper')) {
    die('\\Joomla\\Filesystem\\Stream\\StringWrapper Wrapper Registration Failed');
}
// phpcs:enable PSR1.Files.SideEffects
