<?php

namespace Box\Spout\Writer\Common\Helper;

/**
 * Class ZipHelper
 * This class provides helper functions to create zip files
 *
 * @package Box\Spout\Writer\Common\Helper
 */
class ZipHelper {

	const ZIP_EXTENSION = '.zip';

	/** Controls what to do when trying to add an existing file */
	const EXISTING_FILES_SKIP      = 'skip';
	const EXISTING_FILES_OVERWRITE = 'overwrite';

	/** @var string Path of the folder where the zip file will be created */
	protected $tmpFolderPath;

	/** @var \ZipArchive The ZipArchive instance */
	protected $zip;

	/**
	 * @param string $tmpFolderPath Path of the temp folder where the zip file will be created
	 */
	public function __construct( $tmpFolderPath ) {
		 $this->tmpFolderPath = $tmpFolderPath;
	}

	/**
	 * Returns the already created ZipArchive instance or
	 * creates one if none exists.
	 *
	 * @return \ZipArchive
	 */
	protected function createOrGetZip() {
		if ( ! isset( $this->zip ) ) {
			$this->zip   = new \ZipArchive();
			$zipFilePath = $this->getZipFilePath();

			$this->zip->open( $zipFilePath, \ZipArchive::CREATE | \ZipArchive::OVERWRITE );
		}

		return $this->zip;
	}

	/**
	 * @return string Path where the zip file of the given folder will be created
	 */
	public function getZipFilePath() {
		return $this->tmpFolderPath . self::ZIP_EXTENSION;
	}

	/**
	 * Adds the given file, located under the given root folder to the archive.
	 * The file will be compressed.
	 *
	 * Example of use:
	 *   addFileToArchive('/tmp/xlsx/foo', 'bar/baz.xml');
	 *   => will add the file located at '/tmp/xlsx/foo/bar/baz.xml' in the archive, but only as 'bar/baz.xml'
	 *
	 * @param string $rootFolderPath Path of the root folder that will be ignored in the archive tree.
	 * @param string $localFilePath Path of the file to be added, under the root folder
	 * @param string|void $existingFileMode Controls what to do when trying to add an existing file
	 * @return void
	 */
	public function addFileToArchive( $rootFolderPath, $localFilePath, $existingFileMode = self::EXISTING_FILES_OVERWRITE ) {
		$this->addFileToArchiveWithCompressionMethod(
			$rootFolderPath,
			$localFilePath,
			$existingFileMode,
			\ZipArchive::CM_DEFAULT
		);
	}

	/**
	 * Adds the given file, located under the given root folder to the archive.
	 * The file will NOT be compressed.
	 *
	 * Example of use:
	 *   addUncompressedFileToArchive('/tmp/xlsx/foo', 'bar/baz.xml');
	 *   => will add the file located at '/tmp/xlsx/foo/bar/baz.xml' in the archive, but only as 'bar/baz.xml'
	 *
	 * @param string $rootFolderPath Path of the root folder that will be ignored in the archive tree.
	 * @param string $localFilePath Path of the file to be added, under the root folder
	 * @param string|void $existingFileMode Controls what to do when trying to add an existing file
	 * @return void
	 */
	public function addUncompressedFileToArchive( $rootFolderPath, $localFilePath, $existingFileMode = self::EXISTING_FILES_OVERWRITE ) {
		$this->addFileToArchiveWithCompressionMethod(
			$rootFolderPath,
			$localFilePath,
			$existingFileMode,
			\ZipArchive::CM_STORE
		);
	}

	/**
	 * Adds the given file, located under the given root folder to the archive.
	 * The file will NOT be compressed.
	 *
	 * Example of use:
	 *   addUncompressedFileToArchive('/tmp/xlsx/foo', 'bar/baz.xml');
	 *   => will add the file located at '/tmp/xlsx/foo/bar/baz.xml' in the archive, but only as 'bar/baz.xml'
	 *
	 * @param string $rootFolderPath Path of the root folder that will be ignored in the archive tree.
	 * @param string $localFilePath Path of the file to be added, under the root folder
	 * @param string $existingFileMode Controls what to do when trying to add an existing file
	 * @param int $compressionMethod The compression method
	 * @return void
	 */
	protected function addFileToArchiveWithCompressionMethod( $rootFolderPath, $localFilePath, $existingFileMode, $compressionMethod ) {
		$zip = $this->createOrGetZip();

		if ( ! $this->shouldSkipFile( $zip, $localFilePath, $existingFileMode ) ) {
			$normalizedFullFilePath = $this->getNormalizedRealPath( $rootFolderPath . '/' . $localFilePath );
			$zip->addFile( $normalizedFullFilePath, $localFilePath );

			if ( self::canChooseCompressionMethod() ) {
				$zip->setCompressionName( $localFilePath, $compressionMethod );
			}
		}
	}

	/**
	 * @return bool Whether it is possible to choose the desired compression method to be used
	 */
	public static function canChooseCompressionMethod() {
		// setCompressionName() is a PHP7+ method...
		return ( method_exists( new \ZipArchive(), 'setCompressionName' ) );
	}

	/**
	 * @param string $folderPath Path to the folder to be zipped
	 * @param string|void $existingFileMode Controls what to do when trying to add an existing file
	 * @return void
	 */
	public function addFolderToArchive( $folderPath, $existingFileMode = self::EXISTING_FILES_OVERWRITE ) {
		 $zip = $this->createOrGetZip();

		$folderRealPath = $this->getNormalizedRealPath( $folderPath ) . '/';
		$itemIterator   = new \RecursiveIteratorIterator( new \RecursiveDirectoryIterator( $folderPath, \RecursiveDirectoryIterator::SKIP_DOTS ), \RecursiveIteratorIterator::SELF_FIRST );

		foreach ( $itemIterator as $itemInfo ) {
			$itemRealPath  = $this->getNormalizedRealPath( $itemInfo->getPathname() );
			$itemLocalPath = str_replace( $folderRealPath, '', $itemRealPath );

			if ( $itemInfo->isFile() && ! $this->shouldSkipFile( $zip, $itemLocalPath, $existingFileMode ) ) {
				$zip->addFile( $itemRealPath, $itemLocalPath );
			}
		}
	}

	/**
	 * @param \ZipArchive $zip
	 * @param string $itemLocalPath
	 * @param string $existingFileMode
	 * @return bool Whether the file should be added to the archive or skipped
	 */
	protected function shouldSkipFile( $zip, $itemLocalPath, $existingFileMode ) {
		// Skip files if:
		//   - EXISTING_FILES_SKIP mode chosen
		//   - File already exists in the archive
		return ( $existingFileMode === self::EXISTING_FILES_SKIP && $zip->locateName( $itemLocalPath ) !== false );
	}

	/**
	 * Returns canonicalized absolute pathname, containing only forward slashes.
	 *
	 * @param string $path Path to normalize
	 * @return string Normalized and canonicalized path
	 */
	protected function getNormalizedRealPath( $path ) {
		 $realPath = realpath( $path );
		return str_replace( DIRECTORY_SEPARATOR, '/', $realPath );
	}

	/**
	 * Closes the archive and copies it into the given stream
	 *
	 * @param resource $streamPointer Pointer to the stream to copy the zip
	 * @return void
	 */
	public function closeArchiveAndCopyToStream( $streamPointer ) {
		 $zip = $this->createOrGetZip();
		$zip->close();
		unset( $this->zip );

		$this->copyZipToStream( $streamPointer );
	}

	/**
	 * Streams the contents of the zip file into the given stream
	 *
	 * @param resource $pointer Pointer to the stream to copy the zip
	 * @return void
	 */
	protected function copyZipToStream( $pointer ) {
		$zipFilePointer = fopen( $this->getZipFilePath(), 'r' );
		stream_copy_to_stream( $zipFilePointer, $pointer );
		fclose( $zipFilePointer );
	}
}