<?php
/**
 * Part of the Joomla Framework Archive 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\Archive;

use Joomla\Filesystem\File;
use Joomla\Filesystem\Folder;
use Joomla\Filesystem\Path;

/**
 * ZIP format adapter for the Archive package
 *
 * The ZIP compression code is partially based on code from:
 * Eric Mueller <eric@themepark.com>
 * http://www.zend.com/codex.php?id=535&single=1
 *
 * Deins125 <webmaster@atlant.ru>
 * http://www.zend.com/codex.php?id=470&single=1
 *
 * The ZIP compression date code is partially based on code from
 * Peter Listiak <mlady@users.sourceforge.net>
 *
 * This class is inspired from and draws heavily in code and concept from the Compress package of
 * The Horde Project <http://www.horde.org>
 *
 * @contributor  Chuck Hagenbuch <chuck@horde.org>
 * @contributor  Michael Slusarz <slusarz@horde.org>
 * @contributor  Michael Cochrane <mike@graftonhall.co.nz>
 *
 * @since  1.0
 */
class Zip implements ExtractableInterface
{
	/**
	 * ZIP compression methods.
	 *
	 * @var    array
	 * @since  1.0
	 */
	private const METHODS = [
		0x0 => 'None',
		0x1 => 'Shrunk',
		0x2 => 'Super Fast',
		0x3 => 'Fast',
		0x4 => 'Normal',
		0x5 => 'Maximum',
		0x6 => 'Imploded',
		0x8 => 'Deflated',
	];

	/**
	 * Beginning of central directory record.
	 *
	 * @var    string
	 * @since  1.0
	 */
	private const CTRL_DIR_HEADER = "\x50\x4b\x01\x02";

	/**
	 * End of central directory record.
	 *
	 * @var    string
	 * @since  1.0
	 */
	private const CTRL_DIR_END = "\x50\x4b\x05\x06\x00\x00\x00\x00";

	/**
	 * Beginning of file contents.
	 *
	 * @var    string
	 * @since  1.0
	 */
	private const FILE_HEADER = "\x50\x4b\x03\x04";

	/**
	 * ZIP file data buffer
	 *
	 * @var    string
	 * @since  1.0
	 */
	private $data;

	/**
	 * ZIP file metadata array
	 *
	 * @var    array
	 * @since  1.0
	 */
	private $metadata;

	/**
	 * Holds the options array.
	 *
	 * @var    array|\ArrayAccess
	 * @since  1.0
	 */
	protected $options = [];

	/**
	 * Create a new Archive object.
	 *
	 * @param   array|\ArrayAccess  $options  An array of options or an object that implements \ArrayAccess
	 *
	 * @since   1.0
	 * @throws  \InvalidArgumentException
	 */
	public function __construct($options = [])
	{
		if (!\is_array($options) && !($options instanceof \ArrayAccess))
		{
			throw new \InvalidArgumentException(
				'The options param must be an array or implement the ArrayAccess interface.'
			);
		}

		$this->options = $options;
	}

	/**
	 * Create a ZIP compressed file from an array of file data.
	 *
	 * @param   string  $archive  Path to save archive.
	 * @param   array   $files    Array of files to add to archive.
	 *
	 * @return  boolean  True if successful.
	 *
	 * @since   1.0
	 * @todo    Finish Implementation
	 */
	public function create($archive, $files)
	{
		$contents = [];
		$ctrldir  = [];

		foreach ($files as $file)
		{
			$this->addToZipFile($file, $contents, $ctrldir);
		}

		return $this->createZipFile($contents, $ctrldir, $archive);
	}

	/**
	 * Extract a ZIP compressed file to a given path
	 *
	 * @param   string  $archive      Path to ZIP archive to extract
	 * @param   string  $destination  Path to extract archive into
	 *
	 * @return  boolean  True if successful
	 *
	 * @since   1.0
	 * @throws  \RuntimeException
	 */
	public function extract($archive, $destination)
	{
		if (!is_file($archive))
		{
			throw new \RuntimeException('Archive does not exist at ' . $archive);
		}

		if (static::hasNativeSupport())
		{
			return $this->extractNative($archive, $destination);
		}

		return $this->extractCustom($archive, $destination);
	}

	/**
	 * Tests whether this adapter can unpack files on this computer.
	 *
	 * @return  boolean  True if supported
	 *
	 * @since   1.0
	 */
	public static function isSupported()
	{
		return self::hasNativeSupport() || \extension_loaded('zlib');
	}

	/**
	 * Method to determine if the server has native zip support for faster handling
	 *
	 * @return  boolean  True if php has native ZIP support
	 *
	 * @since   1.0
	 */
	public static function hasNativeSupport()
	{
		return \extension_loaded('zip');
	}

	/**
	 * Checks to see if the data is a valid ZIP file.
	 *
	 * @param   string  $data  ZIP archive data buffer.
	 *
	 * @return  boolean  True if valid, false if invalid.
	 *
	 * @since   1.0
	 */
	public function checkZipData($data)
	{
		return strpos($data, self::FILE_HEADER) !== false;
	}

	/**
	 * Extract a ZIP compressed file to a given path using a php based algorithm that only requires zlib support
	 *
	 * @param   string  $archive      Path to ZIP archive to extract.
	 * @param   string  $destination  Path to extract archive into.
	 *
	 * @return  boolean  True if successful
	 *
	 * @since   1.0
	 * @throws  \RuntimeException
	 */
	protected function extractCustom($archive, $destination)
	{
		$this->data     = null;
		$this->metadata = null;

		$this->data = file_get_contents($archive);

		if (!$this->data)
		{
			throw new \RuntimeException('Unable to read archive');
		}

		if (!$this->readZipInfo($this->data))
		{
			throw new \RuntimeException('Get ZIP Information failed');
		}

		foreach ($this->metadata as $i => $metadata)
		{
			$lastPathCharacter = substr($metadata['name'], -1, 1);

			if ($lastPathCharacter !== '/' && $lastPathCharacter !== '\\')
			{
				$buffer = $this->getFileData($i);
				$path   = Path::clean($destination . '/' . $metadata['name']);

				if (!$this->isBelow($destination, $destination . '/' . $metadata['name']))
				{
					throw new \RuntimeException('Unable to write outside of destination path', 100);
				}

				// Make sure the destination folder exists
				if (!Folder::create(\dirname($path)))
				{
					throw new \RuntimeException('Unable to create destination folder');
				}

				if (!File::write($path, $buffer))
				{
					throw new \RuntimeException('Unable to write file');
				}
			}
		}

		return true;
	}

	/**
	 * Extract a ZIP compressed file to a given path using native php api calls for speed
	 *
	 * @param   string  $archive      Path to ZIP archive to extract
	 * @param   string  $destination  Path to extract archive into
	 *
	 * @return  boolean  True on success
	 *
	 * @throws  \RuntimeException
	 * @since   1.0
	 */
	protected function extractNative($archive, $destination)
	{
		$zip = new \ZipArchive;

		if ($zip->open($archive) !== true)
		{
			throw new \RuntimeException('Unable to open archive');
		}

		// Make sure the destination folder exists
		if (!Folder::create($destination))
		{
			throw new \RuntimeException('Unable to create destination folder ' . \dirname($destination));
		}

		// Read files in the archive
		for ($index = 0; $index < $zip->numFiles; $index++)
		{
			$file = $zip->getNameIndex($index);

			if (substr($file, -1) === '/')
			{
				continue;
			}

			$buffer = $zip->getFromIndex($index);

			if ($buffer === false)
			{
				throw new \RuntimeException('Unable to read ZIP entry');
			}

			if (!$this->isBelow($destination, $destination . '/' . $file))
			{
				throw new \RuntimeException('Unable to write outside of destination path', 100);
			}

			if (File::write($destination . '/' . $file, $buffer) === false)
			{
				throw new \RuntimeException('Unable to write ZIP entry to file ' . $destination . '/' . $file);
			}
		}

		$zip->close();

		return true;
	}

	/**
	 * Get the list of files/data from a ZIP archive buffer.
	 *
	 * <pre>
	 * KEY: Position in zipfile
	 * VALUES: 'attr'  --  File attributes
	 *         'crc'   --  CRC checksum
	 *         'csize' --  Compressed file size
	 *         'date'  --  File modification time
	 *         'name'  --  Filename
	 *         'method'--  Compression method
	 *         'size'  --  Original file size
	 *         'type'  --  File type
	 * </pre>
	 *
	 * @param   string  $data  The ZIP archive buffer.
	 *
	 * @return  boolean True on success
	 *
	 * @since   1.0
	 * @throws  \RuntimeException
	 */
	private function readZipInfo($data)
	{
		$entries = [];

		// Find the last central directory header entry
		$fhLast = strpos($data, self::CTRL_DIR_END);

		do
		{
			$last = $fhLast;
		}
		while (($fhLast = strpos($data, self::CTRL_DIR_END, $fhLast + 1)) !== false);

		// Find the central directory offset
		$offset = 0;

		if ($last)
		{
			$endOfCentralDirectory = unpack(
				'vNumberOfDisk/vNoOfDiskWithStartOfCentralDirectory/vNoOfCentralDirectoryEntriesOnDisk/' .
				'vTotalCentralDirectoryEntries/VSizeOfCentralDirectory/VCentralDirectoryOffset/vCommentLength',
				substr($data, $last + 4)
			);
			$offset = $endOfCentralDirectory['CentralDirectoryOffset'];
		}

		// Get details from central directory structure.
		$fhStart    = strpos($data, self::CTRL_DIR_HEADER, $offset);
		$dataLength = \strlen($data);

		do
		{
			if ($dataLength < $fhStart + 31)
			{
				throw new \RuntimeException('Invalid ZIP Data');
			}

			$info = unpack('vMethod/VTime/VCRC32/VCompressed/VUncompressed/vLength', substr($data, $fhStart + 10, 20));
			$name = substr($data, $fhStart + 46, $info['Length']);

			$entries[$name] = [
				'attr'       => null,
				'crc'        => sprintf('%08s', dechex($info['CRC32'])),
				'csize'      => $info['Compressed'],
				'date'       => null,
				'_dataStart' => null,
				'name'       => $name,
				'method'     => self::METHODS[$info['Method']],
				'_method'    => $info['Method'],
				'size'       => $info['Uncompressed'],
				'type'       => null,
			];

			$entries[$name]['date'] = mktime(
				($info['Time'] >> 11) & 0x1f,
				($info['Time'] >> 5) & 0x3f,
				($info['Time'] << 1) & 0x3e,
				($info['Time'] >> 21) & 0x07,
				($info['Time'] >> 16) & 0x1f,
				(($info['Time'] >> 25) & 0x7f) + 1980
			);

			if ($dataLength < $fhStart + 43)
			{
				throw new \RuntimeException('Invalid ZIP data');
			}

			$info = unpack('vInternal/VExternal/VOffset', substr($data, $fhStart + 36, 10));

			$entries[$name]['type'] = ($info['Internal'] & 0x01) ? 'text' : 'binary';
			$entries[$name]['attr'] = (($info['External'] & 0x10) ? 'D' : '-') . (($info['External'] & 0x20) ? 'A' : '-')
				. (($info['External'] & 0x03) ? 'S' : '-') . (($info['External'] & 0x02) ? 'H' : '-') . (($info['External'] & 0x01) ? 'R' : '-');
			$entries[$name]['offset'] = $info['Offset'];

			// Get details from local file header since we have the offset
			$lfhStart = strpos($data, self::FILE_HEADER, $entries[$name]['offset']);

			if ($dataLength < $lfhStart + 34)
			{
				throw new \RuntimeException('Invalid ZIP Data');
			}

			$info                         = unpack('vMethod/VTime/VCRC32/VCompressed/VUncompressed/vLength/vExtraLength', substr($data, $lfhStart + 8, 25));
			$name                         = substr($data, $lfhStart + 30, $info['Length']);
			$entries[$name]['_dataStart'] = $lfhStart + 30 + $info['Length'] + $info['ExtraLength'];

			// Bump the max execution time because not using the built in php zip libs makes this process slow.
			@set_time_limit(ini_get('max_execution_time'));
		}
		while (($fhStart = strpos($data, self::CTRL_DIR_HEADER, $fhStart + 46)) !== false);

		$this->metadata = array_values($entries);

		return true;
	}

	/**
	 * Returns the file data for a file by offset in the ZIP archive
	 *
	 * @param   integer  $key  The position of the file in the archive.
	 *
	 * @return  string  Uncompressed file data buffer.
	 *
	 * @since   1.0
	 */
	private function getFileData(int $key): string
	{
		if ($this->metadata[$key]['_method'] == 0x8)
		{
			return gzinflate(substr($this->data, $this->metadata[$key]['_dataStart'], $this->metadata[$key]['csize']));
		}

		if ($this->metadata[$key]['_method'] == 0x0)
		{
			// Files that aren't compressed.
			return substr($this->data, $this->metadata[$key]['_dataStart'], $this->metadata[$key]['csize']);
		}

		if ($this->metadata[$key]['_method'] == 0x12)
		{
			// If bz2 extension is loaded use it
			if (\extension_loaded('bz2'))
			{
				return bzdecompress(substr($this->data, $this->metadata[$key]['_dataStart'], $this->metadata[$key]['csize']));
			}
		}

		return '';
	}

	/**
	 * Converts a UNIX timestamp to a 4-byte DOS date and time format (date in high 2-bytes, time in low 2-bytes allowing magnitude comparison).
	 *
	 * @param   integer  $unixtime  The current UNIX timestamp.
	 *
	 * @return  integer  The current date in a 4-byte DOS format.
	 *
	 * @since   1.0
	 */
	protected function unix2DosTime($unixtime = null)
	{
		$timearray = $unixtime === null ? getdate() : getdate($unixtime);

		if ($timearray['year'] < 1980)
		{
			$timearray['year']    = 1980;
			$timearray['mon']     = 1;
			$timearray['mday']    = 1;
			$timearray['hours']   = 0;
			$timearray['minutes'] = 0;
			$timearray['seconds'] = 0;
		}

		return (($timearray['year'] - 1980) << 25) | ($timearray['mon'] << 21) | ($timearray['mday'] << 16) | ($timearray['hours'] << 11) |
			($timearray['minutes'] << 5) | ($timearray['seconds'] >> 1);
	}

	/**
	 * Adds a "file" to the ZIP archive.
	 *
	 * @param   array  $file      File data array to add
	 * @param   array  $contents  An array of existing zipped files.
	 * @param   array  $ctrldir   An array of central directory information.
	 *
	 * @return  void
	 *
	 * @since   1.0
	 * @todo    Review and finish implementation
	 */
	private function addToZipFile(array &$file, array &$contents, array &$ctrldir): void
	{
		$data = &$file['data'];
		$name = str_replace('\\', '/', $file['name']);

		// See if time/date information has been provided.
		$ftime = null;

		if (isset($file['time']))
		{
			$ftime = $file['time'];
		}

		// Get the hex time.
		$dtime    = dechex($this->unix2DosTime($ftime));
		$hexdtime = \chr(hexdec($dtime[6] . $dtime[7])) . \chr(hexdec($dtime[4] . $dtime[5])) . \chr(hexdec($dtime[2] . $dtime[3]))
			. \chr(hexdec($dtime[0] . $dtime[1]));

		// Begin creating the ZIP data.
		$fr = self::FILE_HEADER;

		// Version needed to extract.
		$fr .= "\x14\x00";

		// General purpose bit flag.
		$fr .= "\x00\x00";

		// Compression method.
		$fr .= "\x08\x00";

		// Last modification time/date.
		$fr .= $hexdtime;

		// "Local file header" segment.
		$uncLen = \strlen($data);
		$crc    = crc32($data);
		$zdata  = gzcompress($data);
		$zdata  = substr(substr($zdata, 0, -4), 2);
		$cLen   = \strlen($zdata);

		// CRC 32 information.
		$fr .= pack('V', $crc);

		// Compressed filesize.
		$fr .= pack('V', $cLen);

		// Uncompressed filesize.
		$fr .= pack('V', $uncLen);

		// Length of filename.
		$fr .= pack('v', \strlen($name));

		// Extra field length.
		$fr .= pack('v', 0);

		// File name.
		$fr .= $name;

		// "File data" segment.
		$fr .= $zdata;

		// Add this entry to array.
		$oldOffset  = \strlen(implode('', $contents));
		$contents[] = &$fr;

		// Add to central directory record.
		$cdrec = self::CTRL_DIR_HEADER;

		// Version made by.
		$cdrec .= "\x00\x00";

		// Version needed to extract
		$cdrec .= "\x14\x00";

		// General purpose bit flag
		$cdrec .= "\x00\x00";

		// Compression method
		$cdrec .= "\x08\x00";

		// Last mod time/date.
		$cdrec .= $hexdtime;

		// CRC 32 information.
		$cdrec .= pack('V', $crc);

		// Compressed filesize.
		$cdrec .= pack('V', $cLen);

		// Uncompressed filesize.
		$cdrec .= pack('V', $uncLen);

		// Length of filename.
		$cdrec .= pack('v', \strlen($name));

		// Extra field length.
		$cdrec .= pack('v', 0);

		// File comment length.
		$cdrec .= pack('v', 0);

		// Disk number start.
		$cdrec .= pack('v', 0);

		// Internal file attributes.
		$cdrec .= pack('v', 0);

		// External file attributes -'archive' bit set.
		$cdrec .= pack('V', 32);

		// Relative offset of local header.
		$cdrec .= pack('V', $oldOffset);

		// File name.
		$cdrec .= $name;

		// Save to central directory array.
		$ctrldir[] = &$cdrec;
	}

	/**
	 * Creates the ZIP file.
	 *
	 * Official ZIP file format: http://www.pkware.com/appnote.txt
	 *
	 * @param   array   $contents  An array of existing zipped files.
	 * @param   array   $ctrlDir   An array of central directory information.
	 * @param   string  $path      The path to store the archive.
	 *
	 * @return  boolean  True if successful
	 *
	 * @since   1.0
	 * @todo	Review and finish implementation
	 */
	private function createZipFile(array $contents, array $ctrlDir, string $path): bool
	{
		$data = implode('', $contents);
		$dir  = implode('', $ctrlDir);

		/*
		 * Buffer data:
		 * Total # of entries "on this disk".
		 * Total # of entries overall.
		 * Size of central directory.
		 * Offset to start of central dir.
		 * ZIP file comment length.
		 */
		$buffer = $data . $dir . self::CTRL_DIR_END .
		pack('v', \count($ctrlDir)) .
		pack('v', \count($ctrlDir)) .
		pack('V', \strlen($dir)) .
		pack('V', \strlen($data)) .
		"\x00\x00";

		return File::write($path, $buffer);
	}

	/**
	 * Check if a path is below a given destination path
	 *
	 * @param   string  $destination
	 * @param   string  $path
	 *
	 * @return  boolean
	 */
	private function isBelow($destination, $path): bool
	{
		$absoluteRoot = Path::clean(Path::resolve($destination));
		$absolutePath = Path::clean(Path::resolve($path));

		return strpos($absolutePath, $absoluteRoot) === 0;
	}
}
