<?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';

	/**
	 * Detect if an URL is 404
	 *
	 * @since  3.3
	 */
	public static function is_404( $url ) {
		$response = wp_safe_remote_get($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, $silence = true ) {
		if (is_null($filename)) {
			return $silence ? false : __('Filename is empty!', 'litespeed-cache');
		}

		$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);
				// Create robots.txt file to forbid search engine indexes
				if (!file_exists(LITESPEED_STATIC_DIR . '/robots.txt')) {
					file_put_contents(LITESPEED_STATIC_DIR . '/robots.txt', "User-agent: *\nDisallow: /\n");
				}
			} 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'), $filename);
			}
			restore_error_handler();
		} elseif (!is_writable($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|false $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', $filename);
			}
			restore_error_handler();
		} elseif (!is_writable($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;
	}
}
