<?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;

/**
 * Generic Buffer stream handler
 *
 * This class provides a generic buffer stream.  It can be used to store/retrieve/manipulate
 * string buffers with the standard PHP filesystem I/O methods.
 *
 * @since  1.0
 */
class Buffer
{
    /**
     * Stream position
     *
     * @var    integer
     * @since  1.0
     */
    public $position = 0;

    /**
     * Buffer name
     *
     * @var    string
     * @since  1.0
     */
    public $name;

    /**
     * Buffer hash
     *
     * @var    array
     * @since  1.0
     */
    public $buffers = [];

    /**
     * Function to open file or url
     *
     * @param   string   $path        The URL that was passed
     * @param   string   $mode        Mode used to open the file @see fopen
     * @param   integer  $options     Flags used by the API, may be STREAM_USE_PATH and STREAM_REPORT_ERRORS
     * @param   string   $openedPath  Full path of the resource. Used with STREAN_USE_PATH option
     *
     * @return  boolean
     *
     * @since   1.0
     * @see     streamWrapper::stream_open
     */
    public function stream_open($path, $mode, $options, &$openedPath)
    {
        $url                        = parse_url($path);
        $this->name                 = $url['host'];
        $this->buffers[$this->name] = null;
        $this->position             = 0;

        return true;
    }

    /**
     * Read stream
     *
     * @param   integer  $count  How many bytes of data from the current position should be returned.
     *
     * @return  mixed    The data from the stream up to the specified number of bytes (all data if
     *                   the total number of bytes in the stream is less than $count. Null if
     *                   the stream is empty.
     *
     * @see     streamWrapper::stream_read
     * @since   1.0
     */
    public function stream_read($count)
    {
        $ret = substr($this->buffers[$this->name], $this->position, $count);
        $this->position += \strlen($ret);

        return $ret;
    }

    /**
     * Write stream
     *
     * @param   string  $data  The data to write to the stream.
     *
     * @return  integer
     *
     * @see     streamWrapper::stream_write
     * @since   1.0
     */
    public function stream_write($data)
    {
        $left                       = substr($this->buffers[$this->name], 0, $this->position);
        $right                      = substr($this->buffers[$this->name], $this->position + \strlen($data));
        $this->buffers[$this->name] = $left . $data . $right;
        $this->position += \strlen($data);

        return \strlen($data);
    }

    /**
     * Function to get the current position of the stream
     *
     * @return  integer
     *
     * @see     streamWrapper::stream_tell
     * @since   1.0
     */
    public function stream_tell()
    {
        return $this->position;
    }

    /**
     * Function to test for end of file pointer
     *
     * @return  boolean  True if the pointer is at the end of the stream
     *
     * @see     streamWrapper::stream_eof
     * @since   1.0
     */
    public function stream_eof()
    {
        return $this->position >= \strlen($this->buffers[$this->name]);
    }

    /**
     * The read write position updates in response to $offset and $whence
     *
     * @param   integer  $offset  The offset in bytes
     * @param   integer  $whence  Position the offset is added to
     *                            Options are SEEK_SET, SEEK_CUR, and SEEK_END
     *
     * @return  boolean  True if updated
     *
     * @see     streamWrapper::stream_seek
     * @since   1.0
     */
    public function stream_seek($offset, $whence)
    {
        switch ($whence) {
            case \SEEK_SET:
                if ($offset < \strlen($this->buffers[$this->name]) && $offset >= 0) {
                    $this->position = $offset;

                    return true;
                }

                return false;

            case \SEEK_CUR:
                if ($offset >= 0) {
                    $this->position += $offset;

                    return true;
                }

                return false;

            case \SEEK_END:
                if (\strlen($this->buffers[$this->name]) + $offset >= 0) {
                    $this->position = \strlen($this->buffers[$this->name]) + $offset;

                    return true;
                }

                return false;

            default:
                return false;
        }
    }
}

// Register the stream
// phpcs:disable PSR1.Files.SideEffects
stream_wrapper_register('buffer', 'Joomla\\Filesystem\\Buffer');
// phpcs:enable PSR1.Files.SideEffects