<?php 
/**
 * Envato file backup class
 *
 * Original class created by Human Made Limited http://hmn.md/. This version has 
 * removed database backups and altered namespacing for inclusion in the 
 * Envato WordPress Toolkit plugin to prevent conflicts.
 *
 * @package     WordPress
 * @subpackage  Envato WordPress Toolkit
 * @author      Derek Herman <derek@envato.com>, Human Made Limited
 * @since       1.4
 */ 
class Envato_Backup {
  /**
   * The path where the backup file should be saved
   *
   * @access    public
   * @since     1.4
   *
   * @var       string
   */
  public $path;
  
  /**
   * The filename of the backup file
   *
   * @access    public
   * @since     1.4
   *
   * @var       string
   */
  public $archive_filename;
  
  /**
   * The path to the zip command
   *
   * @access    public
   * @since     1.4
   *
   * @var       string
   */
  public $zip_command_path;
  
  /**
   * An array of exclude rules
   *
   * @access    public
   * @since     1.4
   *
   * @var       array
   */
  public $excludes;
  
  /**
   * The path that should be backed up
   *
   * @access    public
   * @since     1.4
   *
   * @var       string
   */
  public $root;
  
  /**
   * Store the current backup instance
   *
   * @access    public
   * @since     1.4
   *
   * @var       object
   * @static
   */
  private static $instance;
  
  /**
   * An array of all the files in root
   * excluding excludes
   *
   * @access    private
   * @since     1.4
   *
   * @var       array
   */
  private $files;
  
  /**
   * Contains an array of error
   *
   * @access    private
   * @since     1.4
   *
   * @var       mixed
   */
  private $errors;
  
  /**
   * Contains an array of warnings
   *
   * @access    private
   * @since     1.4
   *
   * @var       mixed
   */
  private $warnings;
  
  /**
   * The archive method used
   *
   * @access    private
   * @since     1.4
   *
   * @var       string
   */
  private $archive_method;

  /**
   * PHP5 constructor method.
   *
   * Sets up the default properties
   *
   * @access    public
   * @since     1.4
   *
   * @return    null
   */
  public function __construct() {
    
    $this->errors = array();
    
    set_error_handler( array( &$this, 'error_handler' ) );
    
    /* Defaults */
    $this->root = $this->conform_dir( ABSPATH );
    
    $this->path = $this->conform_dir( WP_CONTENT_DIR . '/envato-backups' );
    
    $this->archive_filename = strtolower( sanitize_file_name( get_bloginfo( 'name' ) . '.backup.' . date( 'Y-m-d-H-i-s', time() + ( current_time( 'timestamp' ) - time() ) ) . '.zip' ) );
    
    $this->zip_command_path = $this->guess_zip_command_path();
    
  }
  
  /**
   * Return the current instance
   *
   * @access    public
   * @since     1.4
   *
   * @static
   * @return    object
   */
  public static function get_instance() {
  
    if ( empty( self::$instance ) )
      self::$instance = new Envato_Backup();
  
    return self::$instance;
  
  }
  
  /**
   * The full filepath to the archive file.
   *
   * @access    public
   * @since     1.4
   *
   * @return    string
   */
  public function archive_filepath() {
    return trailingslashit( $this->path() ) . $this->archive_filename();
  }

  /**
   * Helper function to sanitize archive filename.
   *
   * @access    public
   * @since     1.4
   *
   * @return    string
   */
  public function archive_filename() {
    return strtolower( sanitize_file_name( remove_accents( $this->archive_filename ) ) );
  }
  
  /**
   * Helper function to sanitize the root directory path.
   *
   * @access    public
   * @since     1.4
   *
   * @return    string
   */
  public function root() {
    return $this->conform_dir( $this->root );
  }
  
  /**
   * Helper function to sanitize the archive directory path.
   *
   * @access    public
   * @since     1.4
   *
   * @return    string
   */
  public function path() {
    return $this->conform_dir( $this->path );
  }
  
  /**
   * Helper function to return the archive method.
   *
   * @access    public
   * @since     1.4
   *
   * @return    string
   */
  public function archive_method() {
    return $this->archive_method;
  }
  
  /**
   * Kick off a backup
   *
   * @access    public
   * @since     1.4
   *
   * @return    bool
   */
  public function backup() {
  
    do_action( 'envato_backup_started', $this );
  
    /* Zip everything up */
    $this->archive();
  
    do_action( 'envato_backup_complete', $this );
  
  }

  /**
   * Zip up all the files.
   *
   * Attempts to use the shell zip command, if
   * thats not available then it fallsback to
   * PHP ZipArchive and finally PclZip.
   *
   * @access    public
   * @since     1.4
   *
   * @return    null
   */
  public function archive() {
  
    do_action( 'envato_archive_started' );
    
    /* Do we have the path to the zip command */
    if ( $this->zip_command_path )
      $this->zip();
    
    /* If not or if the shell zip failed then use ZipArchive */
    if ( empty( $this->archive_verified ) && class_exists( 'ZipArchive' ) && empty( $this->skip_zip_archive ) )
      $this->zip_archive();
    
    /* If ZipArchive is unavailable or one of the above failed */
    if ( empty( $this->archive_verified ) )
      $this->pcl_zip();
    
    do_action( 'envato_archive_finished' );
  
  }

  /**
   * Zip using the native zip command
   *
   * @access    public
   * @since     1.4
   *
   * @return    null
   */
  public function zip() {
  
    $this->archive_method = 'zip';
  
    $this->warning( $this->archive_method, shell_exec( 'cd ' . escapeshellarg( $this->root() ) . ' && ' . escapeshellarg( $this->zip_command_path ) . ' -rq ' . escapeshellarg( $this->archive_filepath() ) . ' ./' . ' 2>&1' ) );
  
    $this->check_archive();
  
  }

  /**
   * Fallback for creating zip archives if zip command is unnavailable.
   *
   * @access    public
   * @since     1.4
   *
   * @param     string    $path
   * @return    null
   */
  public function zip_archive() {
  
    $this->errors_to_warnings( $this->archive_method );
    $this->archive_method = 'ziparchive';
    
    $zip = new ZipArchive();
    
    if ( ! class_exists( 'ZipArchive' ) || ! $zip->open( $this->archive_filepath(), ZIPARCHIVE::CREATE ) )
      return;
    
    $files_added = 0;
    
    foreach ( $this->files() as $file ) {
    
      if ( is_dir( trailingslashit( $this->root() ) . $file ) )
        $zip->addEmptyDir( trailingslashit( $file ) );
    
      elseif ( is_file( trailingslashit( $this->root() ) . $file ) )
        $zip->addFile( trailingslashit( $this->root() ) . $file, $file );
    
      if ( ++$files_added % 500 === 0 )
        if ( ! $zip->close() || ! $zip->open( $this->archive_filepath(), ZIPARCHIVE::CREATE ) )
          return;
    
    }
    
    if ( $zip->status )
      $this->warning( $this->archive_method, $zip->status );
    
    if ( $zip->statusSys )
      $this->warning( $this->archive_method, $zip->statusSys );
    
    $zip->close();
    
    $this->check_archive();
  
  }

  /**
   * Fallback for creating zip archives if both zip command 
   * and ZipArchive are unnavailable.
   *
   * Uses the PclZip library that ships with WordPress
   *
   * @access    public
   * @since     1.4
   *
   * @param     string    $path
   * @return    null
   */
  public function pcl_zip() {
  
    $this->errors_to_warnings( $this->archive_method );
    $this->archive_method = 'pclzip';
    
    global $_envato_backup_exclude_string;
    
    $_envato_backup_exclude_string = $this->exclude_string( 'regex' );
    
    $this->load_pclzip();
    
    $archive = new PclZip( $this->archive_filepath() );
    
    /* Zip up everything */
    if ( ! $archive->add( $this->root(), PCLZIP_OPT_REMOVE_PATH, $this->root(), PCLZIP_CB_PRE_ADD, 'envato_backup_pclzip_callback' ) )
      $this->warning( $this->archive_method, $archive->errorInfo( true ) );
    
    unset( $GLOBALS['_envato_backup_exclude_string'] );
    
    $this->check_archive();
  
  }

  /**
   * Verify that the archive is valid and contains all the files it should contain.
   *
   * @access    public
   * @since     1.4
   *
   * @return    bool
   */
  public function check_archive() {
  
    /* If we've already passed then no need to check again */
    if ( ! empty( $this->archive_verified ) )
      return true;
    
    if ( ! file_exists( $this->archive_filepath() ) )
      $this->error( $this->archive_method(), __( 'The backup file was not created', wpgrade::textdomain() ) );
    
    /* Verify using the zip command if possible */
    if ( $this->zip_command_path ) {
    
      $verify = shell_exec( escapeshellarg( $this->zip_command_path ) . ' -T ' . escapeshellarg( $this->archive_filepath() ) . ' 2> /dev/null' );
    
      if ( strpos( $verify, 'OK' ) === false )
        $this->error( $this->archive_method(), $verify );
    
    }
    
    /* If there are errors delete the backup file. */
    if ( $this->errors( $this->archive_method() ) && file_exists( $this->archive_filepath() ) )
      unlink( $this->archive_filepath() );
    
    if ( $this->errors( $this->archive_method() ) )
      return false;
    
    return $this->archive_verified = true;
  
  }

  /**
   * Generate the array of files to be backed up by looping through
   * root, ignored unreadable files and excludes
   *
   * @access    public
   * @since     1.4
   *
   * @return    array
   */
  public function files() {
  
    if ( ! empty( $this->files ) )
      return $this->files;
    
    $this->files = array();
    
    if ( defined( 'RecursiveDirectoryIterator::FOLLOW_SYMLINKS' ) ) {
    
      $filesystem = new RecursiveIteratorIterator( new RecursiveDirectoryIterator( $this->root(), RecursiveDirectoryIterator::FOLLOW_SYMLINKS ), RecursiveIteratorIterator::SELF_FIRST, RecursiveIteratorIterator::CATCH_GET_CHILD );
    
      $excludes = $this->exclude_string( 'regex' );
    
      foreach ( $filesystem as $file ) {
    
        if ( ! $file->isReadable() ) {
          $this->unreadable_files[] = $file->getPathName();
          continue;
        }
    
        $pathname = str_ireplace( trailingslashit( $this->root() ), '', $this->conform_dir( $file->getPathname() ) );
    
        /* Excludes */
        if ( $excludes && preg_match( '(' . $excludes . ')', $pathname ) )
          continue;
    
        $this->files[] = $pathname;
    
      }
    
    } else {
    
      $this->files = $this->files_fallback( $this->root() );
    
    }
    
    if ( ! empty( $this->unreadable_files ) )
      $this->warning( $this->archive_method(), __( 'The following files are unreadable and could not be backed up: ', wpgrade::textdomain() ) . implode( ', ', $this->unreadable_files ) );
    
    return $this->files;
  
  }

  /**
   * Fallback function for generating a filesystem array
   *
   * Used if RecursiveDirectoryIterator::FOLLOW_SYMLINKS isn't available
   *
   * @access    private
   * @since     1.4
   *
   * @param     string    $dir
   * @param     array     $files. (default: array())
   * @return    array
   */
  private function files_fallback( $dir, $files = array() ) {
    
    $handle = opendir( $dir );
    
    $excludes = $this->exclude_string( 'regex' );
    
    while ( $file = readdir( $handle ) ) :
    
      /* Ignore current dir and containing dir and any unreadable files or directories */
      if ( $file == '.' || $file == '..' )
        continue;
    
      $filepath = $this->conform_dir( trailingslashit( $dir ) . $file );
      $file = str_ireplace( trailingslashit( $this->root() ), '', $filepath );
    
      if ( ! is_readable( $filepath ) ) {
        $this->unreadable_files[] = $filepath;
        continue;
      }
    
      /* Skip the backups dir and any excluded paths */
      if ( ( $excludes && preg_match( '(' . $excludes . ')', $file ) ) )
        continue;
    
      $files[] = $file;
    
      if ( is_dir( $filepath ) )
        $files = $this->files_fallback( $filepath, $files );
    
    endwhile;
    
    return $files;
  
  }
  
  /**
   * Helper function to load the PclZip library.
   *
   * @access    private
   * @since     1.4
   *
   * @return    null
   */
  private function load_pclzip() {
  
    /* Load PclZip */
    if ( ! defined( 'PCLZIP_TEMPORARY_DIR' ) )
      define( 'PCLZIP_TEMPORARY_DIR', trailingslashit( $this->path() ) );
    
    require_once( ABSPATH . 'wp-admin/includes/class-pclzip.php' );
  
  }

  /**
   * Attempt to work out the path to the zip command
   *
   * @access    public
   * @since     1.4
   *
   * @return    string
   */
  public function guess_zip_command_path() {
  
    /* Check shell_exec is available and hasn't been explicitly bypassed */
    if ( ! $this->shell_exec_available() )
      return '';
    
    /* List of possible zip locations */
    $zip_locations = array(
      '/usr/bin/zip'
    );
    
    if ( is_null( shell_exec( 'hash zip 2>&1' ) ) )
      return 'zip';
    
    /* Find the one which works */
    foreach ( $zip_locations as $location )
      if ( @file_exists( $this->conform_dir( $location ) ) )
        return $location;
    
    return '';
  
  }

  /**
   * Generate the exclude param string for the zip backup
   *
   * Takes the exclude rules and formats them for use with either
   * the shell zip command or pclzip
   *
   * @access    public
   * @since     1.4
   *
   * @param     string    $context. (default: 'zip')
   * @return    string
   */
  public function exclude_string( $context = 'zip' ) {
  
    /* Return a comma separated list by default */
    $separator = ', ';
    $wildcard = '';
    
    /* The zip command */
    if ( $context == 'zip' ) {
      
      $wildcard = '*';
      $separator = ' -x ';
    
    /* The PclZip fallback library */
    } else if ( $context == 'regex' ) {
      
      $wildcard = '([\s\S]*?)';
      $separator = '|';
    
    }
    
    /* Sanitize the excludes */
    $excludes = array_filter( array_unique( array_map( 'trim', (array) $this->excludes ) ) );
    
    /* If path() is inside root(), exclude it */
    if ( strpos( $this->path(), $this->root() ) !== false )
      $excludes[] = trailingslashit( $this->path() );
    
    foreach( $excludes as $key => &$rule ) {
    
      $file = $absolute = $fragment = false;
      
      /* Files don't end with /  */
      if ( ! in_array( substr( $rule, -1 ), array( '\\', '/' ) ) ) {       
        $file = true;
      
      /* If rule starts with a / then treat as absolute path */
      } else if ( in_array( substr( $rule, 0, 1 ), array( '\\', '/' ) ) ) {        
        $absolute = true;
      
      /* Otherwise treat as dir fragment */
      } else {        
        $fragment = true;
        
      }
      
      /* Strip $this->root and conform */
      $rule = str_ireplace( $this->root(), '', untrailingslashit( $this->conform_dir( $rule ) ) );
      
      /* Strip the preceeding slash */
      if ( in_array( substr( $rule, 0, 1 ), array( '\\', '/' ) ) )
        $rule = substr( $rule, 1 );
      
      /* Escape string for regex */
      if ( $context == 'regex' )
        $rule = str_replace( '.', '\.', $rule );
      
      /* Convert any existing wildcards */
      if ( $wildcard != '*' && strpos( $rule, '*' ) !== false )
        $rule = str_replace( '*', $wildcard, $rule );
      
      /* Wrap directory fragments and files in wildcards for zip */
      if ( $context == 'zip' && ( $fragment || $file ) )
        $rule = $wildcard . $rule . $wildcard;
      
      /* Add a wildcard to the end of absolute url for zips */
      if ( $context == 'zip' && $absolute )
        $rule .= $wildcard;
      
      /* Add and end carrot to files for pclzip but only if it doesn't end in a wildcard */
      if ( $file && $context == 'regex' )
        $rule .= '$';
      
      /* Add a start carrot to absolute urls for pclzip */
      if ( $absolute && $context == 'regex' )
        $rule = '^' . $rule;
    
    }
    
    /* Escape shell args for zip command */
    if ( $context == 'zip' )
      $excludes = array_map( 'escapeshellarg', array_unique( $excludes ) );
    
    return implode( $separator, $excludes );
  
  }

  /**
   * Check whether safe mode is active or not
   *
   * @access    public
   * @since     1.4
   *
   * @return    bool
   */
  public function is_safe_mode_active() {
    
    if ( $safe_mode = ini_get( 'safe_mode' ) && strtolower( $safe_mode ) != 'off' )
      return true;
    
    return false;
  
  }

  /**
   * Check whether shell_exec has been disabled.
   *
   * @access    private
   * @since     1.4
   *
   * @return    bool
   */
  private function shell_exec_available() {
  
    /* Are we in Safe Mode */
    if ( $this->is_safe_mode_active() )
      return false;
    
    /* Is shell_exec disabled? */
    if ( in_array( 'shell_exec', array_map( 'trim', explode( ',', ini_get( 'disable_functions' ) ) ) ) )
      return false;
    
    /* Can we issue a simple echo command? */
    if ( ! @shell_exec( 'echo envatobackup' ) )
      return false;
    
    return true;
  
  }

  /**
   * Sanitize a directory path
   *
   * @access    public
   * @since     1.4
   *
   * @param     string    $dir
   * @param     bool      $recursive. (default: false)
   * @return    string    $dir
   */
  public function conform_dir( $dir, $recursive = false ) {
  
    /* Assume empty dir is root */
    if ( ! $dir )
      $dir = '/';
    
    /* Replace single forward slash (looks like double slash because we have to escape it) */
    $dir = str_replace( '\\', '/', $dir );
    $dir = str_replace( '//', '/', $dir );
    
    /* Remove the trailing slash */
    if ( $dir !== '/' )
      $dir = untrailingslashit( $dir );
    
    /* Carry on until completely normalized */
    if ( ! $recursive && $this->conform_dir( $dir, true ) != $dir )
      return $this->conform_dir( $dir );
    
    return (string) $dir;
  
  }

  /**
   * Get the errors
   *
   * @access    public
   * @since     1.4
   *
   * @param     string    $context
   * @return    mixed
   */
  public function errors( $context = null ) {
  
    if ( ! empty( $context ) )
      return isset( $this->errors[$context] ) ? $this->errors[$context] : array();
    
    return $this->errors;
  
  }

  /**
   * Add an error to the errors stack
   *
   * @access    private
   * @since     1.4
   *
   * @param     string    $context
   * @param     mixed     $error
   * @return    null
   */
  private function error( $context, $error ) {
  
    if ( empty( $context ) || empty( $error ) )
      return;
  
    $this->errors[$context][$_key = md5( implode( ':' , (array) $error ) )] = $error;
  
  }

  /**
   * Migrate errors to warnings
   *
   * @access    private
   * @since     1.4
   * 
   * @param     string    $context. (default: null)
   * @return    null
   */
  private function errors_to_warnings( $context = null ) {
  
    $errors = empty( $context ) ? $this->errors() : array( $context => $this->errors( $context ) );
    
    if ( empty( $errors ) )
      return;
    
    foreach ( $errors as $error_context => $errors )
      foreach( $errors as $error )
        $this->warning( $error_context, $error );
    
    if ( $context )
      unset( $this->errors[$context] );
    
    else
      $this->errors = array();
  
  }

  /**
   * Get the warnings
   *
   * @access    public
   * @since     1.4
   *
   * @return    null
   */
  public function warnings( $context = null ) {
  
    if ( ! empty( $context ) )
      return isset( $this->warnings[$context] ) ? $this->warnings[$context] : array();
  
    return $this->warnings;
  
  }

  /**
   * Add an warning to the warnings stack
   *
   * @access    private
   * @since     1.4
   *
   * @param     string    $context
   * @param     mixed     $warning
   * @return    null
   */
  private function warning( $context, $warning ) {
  
    if ( empty( $context ) || empty( $warning ) )
      return;
  
    $this->warnings[$context][$_key = md5( implode( ':' , (array) $warning ) )] = $warning;
  
  }

  /**
   * Custom error handler for catching errors
   *
   * @access    private
   * @since     1.4
   *
   * @param     string    $type
   * @param     string    $message
   * @param     string    $file
   * @param     string    $line
   * @return    null
   */
  public function error_handler( $type ) {
  
    if ( ( defined( 'E_DEPRECATED' ) && $type == E_DEPRECATED ) || ( defined( 'E_STRICT' ) && $type == E_STRICT ) || error_reporting() === 0 )
      return false;
    
    $args = func_get_args();
    
    $this->warning( 'php', array_splice( $args, 0, 4 ) );
    
    return false;
  
  }

}

/**
 * Add file callback for PclZip, excludes files
 * and sets the database dump to be stored in the root
 * of the zip
 *
 * @access    private
 * @since     1.4
 *
 * @param     string    $event
 * @param     array     &$file
 * @return    bool
 */
function envato_backup_pclzip_callback( $event, &$file ) {

  global $_envato_backup_exclude_string;
  
  /* Don't try to add unreadable files. */
  if ( ! is_readable( $file['filename'] ) || ! file_exists( $file['filename'] ) )
  return false;
  
  /* Match everything else past the exclude list */
  elseif ( $_envato_backup_exclude_string && preg_match( '(' . $_envato_backup_exclude_string . ')', $file['stored_filename'] ) )
  return false;
  
  return true;

}

/* End of file class-envato-backup.php */
/* Location: ./includes/class-envato-backup.php */