<?php

/*
 * This file is part of MailSo.
 *
 * (c) 2014 Usenko Timur
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace MailSo\Base\StreamWrappers;

/**
 * @category MailSo
 * @package Base
 * @subpackage StreamWrappers
 * https://www.php.net/streamwrapper
 */
class SubStreams
{
	/** @var resource|null */
	public $context;

	/**
	 * @var string
	 */
	const STREAM_NAME = 'mailsosubstreams';

	private static array $aStreams = array();

	private array $aSubStreams;

	private int $iIndex;

	private string $sBuffer;

	private bool $bIsEnd;

	private int $iPos;

	/**
	 * @return resource|bool
	 */
	public static function CreateStream(array $aSubStreams)
	{
		$sHashName = \MailSo\Base\Utils::Sha1Rand();

		self::$aStreams[$sHashName] = \array_map(function ($mItem) {
			return \is_resource($mItem) ? $mItem :
				\MailSo\Base\ResourceRegistry::CreateMemoryResourceFromString($mItem);
		}, $aSubStreams);

		return \fopen(self::STREAM_NAME.'://'.$sHashName, 'rb');
	}

	public function stream_open(string $sPath) : bool
	{
		$this->aSubStreams = array();

		$bResult = false;
		$aPath = \parse_url($sPath);

		if (isset($aPath['host'], $aPath['scheme']) &&
			\strlen($aPath['host']) && \strlen($aPath['scheme']) &&
			self::STREAM_NAME === $aPath['scheme'])
		{
			$sHashName = $aPath['host'];
			if (isset(self::$aStreams[$sHashName]) &&
				\is_array(self::$aStreams[$sHashName]) &&
				\count(self::$aStreams[$sHashName]))
			{
				$this->iIndex = 0;
				$this->iPos = 0;
				$this->bIsEnd = false;
				$this->sBuffer = '';
				$this->aSubStreams = self::$aStreams[$sHashName];
			}

			$bResult = \count($this->aSubStreams);
		}

		return $bResult;
	}

	public function stream_read(int $iCount) : string
	{
		$sReturn = '';
		$mCurrentPart = null;
		if ($iCount > 0) {
			if ($iCount < \strlen($this->sBuffer)) {
				$sReturn = \substr($this->sBuffer, 0, $iCount);
				$this->sBuffer = \substr($this->sBuffer, $iCount);
			} else {
				$sReturn = $this->sBuffer;
				while ($iCount > 0) {
					$mCurrentPart = isset($this->aSubStreams[$this->iIndex])
						? $this->aSubStreams[$this->iIndex]
						: null;
					if (null === $mCurrentPart) {
						$this->bIsEnd = true;
						$this->sBuffer = '';
						$iCount = 0;
						break;
					}

					if (\is_resource($mCurrentPart)) {
						if (!\feof($mCurrentPart)) {
							$sReadResult = \fread($mCurrentPart, 8192);
							if (false === $sReadResult) {
								return false;
							}
							$sReturn .= $sReadResult;
						} else {
							++$this->iIndex;
						}
					}

					$iLen = \strlen($sReturn);
					if ($iCount < $iLen) {
						$this->sBuffer = \substr($sReturn, $iCount);
						$sReturn = \substr($sReturn, 0, $iCount);
						$iCount = 0;
					} else {
						$iCount -= $iLen;
					}
				}
			}

			$this->iPos += \strlen($sReturn);
			return $sReturn;
		}

		return false;
	}

	public function stream_write() : int
	{
		return 0;
	}

	public function stream_tell() : int
	{
		return $this->iPos;
	}

	public function stream_eof() : bool
	{
		return $this->bIsEnd;
	}

	public function stream_stat() : array
	{
		return array(
			'dev' => 2,
			'ino' => 0,
			'mode' => 33206,
			'nlink' => 1,
			'uid' => 0,
			'gid' => 0,
			'rdev' => 2,
			'size' => 0,
			'atime' => 1061067181,
			'mtime' => 1056136526,
			'ctime' => 1056136526,
			'blksize' => -1,
			'blocks' => -1
		);
	}

	public function stream_seek() : bool
	{
//		$this->iPos = $offset;
//		foreach ($this->aSubStreams as $rStream) \fseek($rStream, $offset, $whence);
		return false;
	}
}

\stream_wrapper_register(SubStreams::STREAM_NAME, SubStreams::class);