<?php

use splitbrain\PHPArchive\Zip;
use splitbrain\PHPArchive\ArchiveIOException;

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */

/**
 * Description of AppEngineZip
 *
 * @author michael
 */
class AppEngineZip extends Zip {
    //protected $complevel = 0;

    /**
     * Extract an existing ZIP archive
     *
     * The $strip parameter allows you to strip a certain number of path components from the filenames
     * found in the tar file, similar to the --strip-components feature of GNU tar. This is triggered when
     * an integer is passed as $strip.
     * Alternatively a fixed string prefix may be passed in $strip. If the filename matches this prefix,
     * the prefix will be stripped. It is recommended to give prefixes with a trailing slash.
     *
     * By default this will extract all files found in the archive. You can restrict the output using the $include
     * and $exclude parameter. Both expect a full regular expression (including delimiters and modifiers). If
     * $include is set only files that match this expression will be extracted. Files that match the $exclude
     * expression will never be extracted. Both parameters can be used in combination. Expressions are matched against
     * stripped filenames as described above.
     *
     * @param string     $outdir  the target directory for extracting
     * @param int|string $strip   either the number of path components or a fixed prefix to strip
     * @param string     $exclude a regular expression of files to exclude
     * @param string     $include a regular expression of files to include
     * @throws ArchiveIOException
     * @return FileInfo[]
     */
    function extractCloudStorage($outdir, $strip = '', $exclude = '', $include = '') {
	if ($this->closed || !$this->file) {
	    throw new ArchiveIOException('Can not read from a closed archive');
	}

	$outdir = rtrim($outdir, '/');

	$extracted = array();

	$cdir = $this->readCentralDir();
	$pos_entry = $cdir['offset']; // begin of the central file directory

	for ($i = 0; $i < $cdir['entries']; $i++) {
	    // read file header
	    @fseek($this->fh, $pos_entry);
	    $header = $this->readCentralFileHeader();
	    $header['index'] = $i;
	    $pos_entry = ftell($this->fh); // position of the next file in central file directory
	    fseek($this->fh, $header['offset']); // seek to beginning of file header
	    $header = $this->readFileHeader($header);
	    $fileinfo = $this->header2fileinfo($header);

	    // apply strip rules
	    $fileinfo->strip($strip);

	    // skip unwanted files
	    if (!strlen($fileinfo->getPath()) || !$fileinfo->match($include, $exclude)) {
		continue;
	    }

	    $extracted[] = $fileinfo;

	    // create output directory
	    $output = $outdir . '/' . $fileinfo->getPath();
	    $directory = ($header['folder']) ? $output : dirname($output);

	    // nothing more to do for directories
	    if ($fileinfo->getIsdir()) {
		continue;
	    }
	    
	    // compressed files are written to temporary .gz file first
	    if ($header['compression'] == 0) {
		$extractto = $output;
		$context = stream_context_create([]);
	    } else {
		$extractto = $output;
		$context = stream_context_create([
		    'gs' => [
			'Content-Encoding' => 'gzip',
		    ]
		]);
	    }

	    // open file for writing
	    $fp = fopen($extractto, "wb", false, $context);
	    if (!$fp) {
		throw new ArchiveIOException('Could not open file for writing: ' . $extractto);
	    }

	    // prepend compression header
	    if ($header['compression'] != 0) {
		$binary_data = pack(
			'va1a1Va1a1', 0x8b1f, chr($header['compression']), chr(0x00), time(), chr(0x00), chr(3)
		);
		fwrite($fp, $binary_data, 10);
	    }

	    // read the file and store it on disk
	    $size = $header['compressed_size'];
	    while ($size != 0) {
		$read_size = ($size < 2048 ? $size : 2048);
		$buffer = fread($this->fh, $read_size);
		$binary_data = pack('a' . $read_size, $buffer);
		fwrite($fp, $binary_data, $read_size);
		$size -= $read_size;
	    }

	    // finalize compressed file
	    if ($header['compression'] != 0) {
		$binary_data = pack('VV', $header['crc'], $header['size']);
		fwrite($fp, $binary_data, 8);
	    }

	    // close file
	    fclose($fp);

	    touch($output, $fileinfo->getMtime());
	    //FIXME what about permissions?
	}

	$this->close();
	return $extracted;
    }

}