<?php
/**
* LiteSpeed File Operator Library Class
* Append/Replace content to a file
*
* @since 1.1.0
*/
namespace LiteSpeed;

defined( 'WPINC' ) || exit;

class File {
	const MARKER = 'LiteSpeed Operator';

	function __construct() {
		// nothing to do here
	}

	/**
	 * Detect if an URL is 404
	 *
	 * @since  3.3
	 */
	public static function is_404( $url ) {
		$response = wp_remote_get( $url );
		$code = wp_remote_retrieve_response_code( $response );
		if ( $code == 404 ) {
			return true;
		}

		return false;
	}

	/**
	 *	Delete folder
	 *
	 * @since 2.1
	 */
	public static function rrmdir( $dir ) {

		$files = array_diff( scandir( $dir ), array( '.', '..' ) );

		foreach ( $files as $file ) {
			is_dir( "$dir/$file" ) ? self::rrmdir( "$dir/$file" ) : unlink( "$dir/$file" );
		}

		return rmdir( $dir );
	}

	public static function count_lines($filename) {
		if ( ! file_exists($filename) ) {
			return 0;
		}

		$file = new \SplFileObject($filename);
		$file->seek(PHP_INT_MAX);
		return $file->key() + 1;
	}

	/**
	 * Read data from file
	 *
	 * @since 1.1.0
	 * @param string $filename
	 * @param int $start_line
	 * @param int $lines
	 */
	public static function read($filename, $start_line = null, $lines = null) {
		if ( ! file_exists($filename) ) {
			return '';
		}

		if ( ! is_readable($filename) ) {
			return false;
		}

		if ( $start_line !== null ) {
			$res = array();
			$file = new \SplFileObject($filename);
			$file->seek($start_line);

			if ( $lines === null) {
				while ( ! $file->eof() ) {
					$res[] = rtrim($file->current(), "\n");
					$file->next();
				}
			}
			else{
				for ( $i=0; $i < $lines; $i++ ) {
					if ( $file->eof() ) {
						break;
					}
					$res[] = rtrim($file->current(), "\n");
					$file->next();
				}
			}

			unset($file);
			return $res;
		}

		$content = file_get_contents( $filename );

		$content = self::remove_zero_space( $content );

		return $content;
	}

	/**
	 * Append data to file
	 *
	 * @since 1.1.5
	 * @access public
	 * @param string $filename
	 * @param string $data
	 * @param boolean $mkdir
	 * @param boolean $silence Used to avoid WP's functions are used
	 */
	public static function append( $filename, $data, $mkdir = false, $silence = true ) {
		return self::save( $filename, $data, $mkdir, true, $silence );
	}

	/**
	 * Save data to file
	 *
	 * @since 1.1.0
	 * @param string $filename
	 * @param string $data
	 * @param boolean $mkdir
	 * @param boolean $append If the content needs to be appended
	 * @param boolean $silence Used to avoid WP's functions are used
	 */
	public static function save( $filename, $data, $mkdir = false, $append = false, $silence = true ) {
		$error = false;
		$folder = dirname( $filename );

		// mkdir if folder does not exist
		if ( ! file_exists( $folder ) ) {
			if ( ! $mkdir ) {
				return $silence ? false : sprintf( __( 'Folder does not exist: %s', 'litespeed-cache' ), $folder );
			}

			set_error_handler( 'litespeed_exception_handler' );

			try {
				mkdir( $folder, 0755, true );
			}
			catch ( \ErrorException $ex ) {
				return $silence ? false : sprintf( __( 'Can not create folder: %1$s. Error: %2$s', 'litespeed-cache' ), $folder, $ex->getMessage() );
			}

			restore_error_handler();
		}

		if ( ! file_exists( $filename ) ) {
			if ( ! is_writable( $folder ) ) {
				return $silence ? false : sprintf( __( 'Folder is not writable: %s.', 'litespeed-cache' ), $folder );
			}
			set_error_handler( 'litespeed_exception_handler' );
			try {
				touch( $filename );
			}
			catch ( \ErrorException $ex ){
				return $silence ? false : sprintf( __( 'File %s is not writable.', 'litespeed-cache' ), $filename );
			}
			restore_error_handler();
		}
		elseif ( ! is_writeable( $filename ) ) {
			return $silence ? false : sprintf( __( 'File %s is not writable.', 'litespeed-cache' ), $filename );
		}

		$data = self::remove_zero_space( $data );

		$ret = file_put_contents( $filename, $data, $append ? FILE_APPEND : LOCK_EX );
		if ( $ret === false ) {
			return $silence ? false : sprintf( __( 'Failed to write to %s.', 'litespeed-cache' ), $filename );
		}

		return true;
	}

	/**
	 * Remove Unicode zero-width space <200b><200c>
	 *
	 * @since 2.1.2
	 * @since 2.9 changed to public
	 */
	public static function remove_zero_space( $content ) {
		if ( is_array( $content ) ) {
			$content = array_map( __CLASS__ . '::remove_zero_space', $content );
			return $content;
		}

		// Remove UTF-8 BOM if present
		if ( substr( $content, 0, 3 ) === "\xEF\xBB\xBF" ) {
			$content = substr( $content, 3 );
		}

		$content = str_replace( "\xe2\x80\x8b", '', $content );
		$content = str_replace( "\xe2\x80\x8c", '', $content );
		$content = str_replace( "\xe2\x80\x8d", '', $content );

		return $content;
	}

	/**
	 * Appends an array of strings into a file (.htaccess ), placing it between
	 * BEGIN and END markers.
	 *
	 * Replaces existing marked info. Retains surrounding
	 * data. Creates file if none exists.
	 *
	 * @param string       $filename  Filename to alter.
	 * @param string       $marker    The marker to alter.
	 * @param array|string $insertion The new content to insert.
	 * @param bool 	       $prepend Prepend insertion if not exist.
	 * @return bool True on write success, false on failure.
	 */
	public static function insert_with_markers($filename, $insertion = false, $marker = false, $prepend = false) {
		if ( !$marker ) {
			$marker = self::MARKER;
		}

		if ( !$insertion ) {
			$insertion = array();
		}

		return self::_insert_with_markers($filename, $marker, $insertion, $prepend);//todo: capture exceptions
	}

	/**
	 * Return wrapped block data with marker
	 *
	 * @param string $insertion
	 * @param string $marker
	 * @return string The block data
	 */
	public static function wrap_marker_data($insertion, $marker = false) {
		if ( ! $marker ) {
			$marker = self::MARKER;
		}
		$start_marker = "# BEGIN {$marker}";
		$end_marker   = "# END {$marker}";

		$new_data = implode( "\n", array_merge(
			array( $start_marker ),
			$insertion,
			array( $end_marker )
		) );
		return $new_data;
	}

	/**
	 * Touch block data from file, return with marker
	 *
	 * @param string $filename
	 * @param string $marker
	 * @return string The current block data
	 */
	public static function touch_marker_data($filename, $marker = false) {
		if( ! $marker ) {
			$marker = self::MARKER;
		}

		$result = self::_extract_from_markers($filename, $marker);

		if( ! $result ) {
			return false;
		}

		$start_marker = "# BEGIN {$marker}";
		$end_marker   = "# END {$marker}";
		$new_data = implode( "\n", array_merge(
			array( $start_marker ),
			$result,
			array( $end_marker )
		) );
		return $new_data;
	}

	/**
	 * Extracts strings from between the BEGIN and END markers in the .htaccess file.
	 *
	 * @param string $filename
	 * @param string $marker
	 * @return array An array of strings from a file (.htaccess ) from between BEGIN and END markers.
	 */
	public static function extract_from_markers($filename, $marker = false) {
		if( ! $marker ) {
			$marker = self::MARKER;
		}
		return self::_extract_from_markers($filename, $marker);
	}

	/**
	 * Extracts strings from between the BEGIN and END markers in the .htaccess file.
	 *
	 * @param string $filename
	 * @param string $marker
	 * @return array An array of strings from a file (.htaccess ) from between BEGIN and END markers.
	 */
	private static function _extract_from_markers( $filename, $marker ) {
		$result = array();

		if (!file_exists($filename) ) {
			return $result;
		}

		if ( $markerdata = explode( "\n", implode( '', file($filename) ) ) ) {
			$state = false;
			foreach ( $markerdata as $markerline ) {
				if ( strpos($markerline, '# END ' . $marker) !== false ) {
					$state = false;
				}
				if ( $state ) {
					$result[] = $markerline;
				}
				if (strpos($markerline, '# BEGIN ' . $marker) !== false) {
					$state = true;
				}
			}
		}

		return array_map('trim', $result);
	}

	/**
	 * Inserts an array of strings into a file (.htaccess ), placing it between BEGIN and END markers.
	 *
	 * Replaces existing marked info. Retains surrounding data. Creates file if none exists.
	 *
	 * NOTE: will throw error if failed
	 *
	 * @since 3.0-
	 * @since  3.0 Throw errors if failed
	 * @access private
	 */
	private static function _insert_with_markers( $filename, $marker, $insertion, $prepend = false) {
		if ( ! file_exists( $filename ) ) {
			if ( ! is_writable( dirname( $filename ) ) ) {
				Error::t( 'W', dirname( $filename ) );
			}

			set_error_handler("litespeed_exception_handler");
			try {
				touch( $filename );
			} catch ( \ErrorException $ex ) {
				Error::t( 'W', $filename );
			}
			restore_error_handler();
		}
		elseif ( ! is_writeable( $filename ) ) {
			Error::t( 'W', $filename );
		}

		if ( ! is_array( $insertion ) ) {
			$insertion = explode( "\n", $insertion );
		}

		$start_marker = "# BEGIN {$marker}";
		$end_marker   = "# END {$marker}";

		$fp = fopen( $filename, 'r+' );
		if ( ! $fp ) {
			Error::t( 'W', $filename );
		}

		// Attempt to get a lock. If the filesystem supports locking, this will block until the lock is acquired.
		flock( $fp, LOCK_EX );

		$lines = array();
		while ( ! feof($fp) ) {
			$lines[] = rtrim(fgets($fp), "\r\n" );
		}

		// Split out the existing file into the preceding lines, and those that appear after the marker
		$pre_lines = $post_lines = $existing_lines = array();
		$found_marker = $found_end_marker = false;
		foreach ( $lines as $line ) {
			if ( ! $found_marker && false !== strpos($line, $start_marker) ) {
				$found_marker = true;
				continue;
			}
			elseif ( ! $found_end_marker && false !== strpos($line, $end_marker) ) {
				$found_end_marker = true;
				continue;
			}

			if ( ! $found_marker ) {
				$pre_lines[] = $line;
			}
			elseif ( $found_marker && $found_end_marker ) {
				$post_lines[] = $line;
			}
			else {
				$existing_lines[] = $line;
			}
		}

		// Check to see if there was a change
		if ( $existing_lines === $insertion ) {
			flock($fp, LOCK_UN);
			fclose($fp);

			return true;
		}

		// Check if need to prepend data if not exist
		if( $prepend && ! $post_lines ) {
			// Generate the new file data
			$new_file_data = implode( "\n", array_merge(
				array( $start_marker ),
				$insertion,
				array( $end_marker ),
				$pre_lines
			) );

		}
		else {
			// Generate the new file data
			$new_file_data = implode( "\n", array_merge(
				$pre_lines,
				array( $start_marker ),
				$insertion,
				array( $end_marker ),
				$post_lines
			) );
		}


		// Write to the start of the file, and truncate it to that length
		fseek($fp, 0);
		$bytes = fwrite($fp, $new_file_data);
		if ( $bytes ) {
			ftruncate($fp, ftell($fp));
		}
		fflush($fp);
		flock($fp, LOCK_UN);
		fclose($fp);

		return (bool) $bytes;
	}
}


