<?php

namespace Tenweb_Manager {


  class MigrationContent extends Migration
  {

    private $zip = null;
    private $archive_path = null;
    private $files = null;
    private $files_count = null;
    private $method;


    public function __construct()
    {

      parent::__construct();
      // if everything ok, create zip or tar archive
      $this->archive_path = self::get_tmp_dir() . "/" . self::getMigrationArchive();

      //tar.gz is set by default as prefered way to archive

      //to use gzencode function we need zlib
      if (extension_loaded('zlib')) {
        $this->method = 'gzip';
      } else {
        $this->method = 'zip';
      }
    }

    /**
     * @param string $run_type
     *
     * @throws \Exception
     */
    public static function set_up($run_type = 'run')
    {
      if ($run_type == 'run') {
        Helper::store_migration_log('run_type_'. current_time('timestamp'), 'Run type is run.');
        $migration_content = new self();
        $migration_content->run($run_type);
      }
      if ($run_type == 'restart') {
        Helper::store_migration_log('run_type_'. current_time('timestamp'), 'Run type is restart.');
        $migration_content = self::get_object_file_content();
        $migration_content->run($run_type);
      }
    }


    /**
     * @param $run_type
     *
     * @throws \Exception
     */
    public function run($run_type)
    {
      if ($run_type == "run") {
        // check if zip or zlib extension exists
        if ($this->check_if_zip_extension_exists() === false && $this->check_if_zlib_extension_exists() === false) {
          throw new \Exception("PHP zip or zlib extension is missing");
        }

        // check if config json exists
        if (!file_exists(self::get_tmp_dir() . "/" . self::MIGRATION_CONFIG_FILE_NAME)) {
          throw new \Exception("Config json file is missing");
        }

        // check if db sql exists
        if (!file_exists(self::get_tmp_dir() . "/" . self::MIGRATION_DB_FILE_NAME)) {
          throw new \Exception("Database file is missing");
        }
        $this->files = $this->get_content_files();
      }


      // if everything ok, create zip or tar archive
      if ($this->method == 'zip') {
        // initialize archive object
        $this->zip = new \ZipArchive();
        $this->create_zip_archive();
      } else {
        //create tar.gz file for import
        $this->zip = fopen($this->archive_path, 'ab');
        $this->create_tar_archive();
      }
    }

    /**
     * @return bool
     */
    private function check_if_zip_extension_exists()
    {
      if (!extension_loaded('zip')) {
        return false;
      }

      Helper::store_migration_log('zip_extension_exists', 'Zip extension exists.');
      return true;
    }

    /**
     * @return bool
     */
    private function check_if_zlib_extension_exists()
    {
      if (!extension_loaded('zlib')) {
        return false;
      }

      Helper::store_migration_log('zlib_extension_exists', 'Zlib extension exists.');
      return true;
    }

    /**
     * @return array
     */
    private function get_content_files()
    {
      Helper::store_migration_log('start_get_content_files', 'Starting get_content_files function.');
      $all_files = array();

      // get wp-content files
      $all_files['wp-content'] = $this->get_files(WP_CONTENT_DIR);

      // get media files
      $uploads_dir = Migration::get_uploads_dir();
      if (strpos($uploads_dir, WP_CONTENT_DIR) === false) {
        $uploads_dir_basename = str_replace(ABSPATH, '', $uploads_dir);
        $all_files[$uploads_dir_basename] = $this->get_files($uploads_dir);
      }

      Helper::store_migration_log('end_get_content_files', 'End get_content_files function.');
      return $all_files;
    }

    /**
     * @param $dir
     *
     * @return array
     */
    private function get_files($dir)
    {
      $files = array();

      $innerIterator = new \RecursiveDirectoryIterator($dir, \RecursiveIteratorIterator::LEAVES_ONLY);

      $iterator = new \RecursiveIteratorIterator(new \RecursiveCallbackFilterIterator($innerIterator, $this->get_filter()));

      foreach ($iterator as $file) {
        $file_path = $file->getRealPath();
        $files[] = $file_path;
      }

      return array_unique($files);
    }

    private function get_filter()
    {
      $excluded_files = array('imagecache', 'wp\-content\/w3tc', 'wp\-content\/w3\-', 'wp\-config\-sample\.php', 'mu\-plugins\/kinsta\-mu\-plugins\.php', '\.svn$', '\.git$', '\.log$', '\.tmp$', '\.listing$', '\.cache$', '\.bak$', '\.swp$', '\~', '_wpeprivate', 'wp\-content\/cache', 'ics\-importer\-cache', 'gt\-cache', 'plugins\/wpengine\-snapshot\/snapshots', 'uploads\/snapshots', 'wp\-content\/backups', 'wp\-content\/managewp', 'wp\-content\/upgrade', 'kinsta\-mu\-plugins', 'wp\-content\/advanced\-cache\.php', 'wp-content\/wp\-cache\-config\.php', 'wp\-content\/advanced\-cache\.php', 'wp-content\/wp\-cache\-config\.php');
      $excluded_files[] = preg_quote(self::get_tmp_dir(), '/');


      $filter = function ($file, $key, $iterator) use ($excluded_files) {
        return !preg_match("/(" . implode("|", $excluded_files) . ")/i", $file->getRealPath(), $matches);
      };

      return $filter;
    }

    /**
     * function for creating zip archive from wp-content dir
     *
     * @throws \Exception
     */
    private function create_zip_archive()
    {
      Helper::store_migration_log('start_create_zip_archive', 'Starting create_zip_archive function.');

      if ($this->zip->open($this->archive_path, \ZipArchive::CREATE) !== true) {
        throw new \Exception("Unable to open zip");
      }

      $all_files = $this->files;
      foreach ($all_files as $type => &$files) {
        if (!empty($files)) {
          $t = current_time('timestamp');
          Helper::store_migration_log('start_files_iteration_' . $t, 'Starting files iteration.');
          foreach ($files as $key => $file_path) {
            $this->check_for_restart();
            unset($files[$key]);
            $this->files = $all_files;

            if ($type == "wp-content") {
              $relative_path = $type . "/" . substr($file_path, strlen(WP_CONTENT_DIR) + 1);
            } else {
              $relative_path = $type . "/" . substr($file_path, strlen(ABSPATH . $type) + 1);
            }
            if (!is_dir($file_path)) {
              // add current file to archive
              $this->add_file_to_archive($file_path, $relative_path);
            } else {
              $this->zip->addEmptyDir($relative_path);
            }
            $this->files_count++;
            if ($this->files_count % 600 == 0) {
              $this->archive_reload();
            }
          }

          Helper::store_migration_log('end_files_iteration_' . $t, 'End files iteration.');
        }
      }

      // add other necessary files to zip
      $this->add_external_files_to_archive();

      // after all close
      @$this->zip->close();

      Helper::store_migration_log('end_create_zip_archive', 'End create_zip_archive function.');
    }

    /**
     * @return bool
     */
    private function check_for_restart()
    {
      $max_exec_time_server = ini_get('max_execution_time');
      $start = get_site_transient(TENWEB_PREFIX . "_migration_start_time");
      $script_exec_time = microtime(true) - $start;

      if ($script_exec_time >= ( (int)$max_exec_time_server - 5)) {
        $this->restart();

        return false;
      }
    }

    /**
     *
     */
    private function restart()
    {
      Helper::store_migration_log('start_restart_' . current_time('timestamp'), 'Starting restart.');
      $this->write_object_file();

      // close archives
      if ($this->method == 'zip') {
        @$this->zip->close();
      } else if ($this->method == 'gzip') {
        if (is_resource($this->zip)) {
          fclose($this->zip);
        }
      }

      Helper::store_migration_log('end_restart_' . current_time('timestamp'), 'End restart.');
      self::restart_request();
      die();
    }

    /**
     *
     */
    private function write_object_file()
    {
      $handle = fopen(self::get_tmp_dir() . '/content_object.php', 'w');

      $content = serialize($this);
      fwrite($handle, $content);
      fclose($handle);
    }

    private static function restart_request()
    {
      $url = add_query_arg(array('rest_route' => '/' . TENWEB_REST_NAMESPACE . '/restart_migration_file'), get_home_url() . "/");

      wp_remote_post($url, array('method' => 'POST', 'timeout' => 0.1, 'body' => array('tenweb_nonce' => wp_create_nonce('wp_rest'))));
    }

    /**
     * @param      $file_path
     * @param      $file_relative_path
     *
     * @return bool
     * @throws \Exception
     */
    private function add_file_to_archive($file_path, $file_relative_path)
    {

      if ($this->method == 'zip') {
        if ($this->zip->addFile($file_path, $file_relative_path) !== true) {
          throw new \Exception("Unable to add " . $file_relative_path . " to " . MigrationContent::getMigrationArchive() . " archive");
        }
      } else {
        //tar
        // Convert chars for archives file names
        if (function_exists('iconv') && stripos(PHP_OS, 'win') === 0) {
          $test = @iconv('ISO-8859-1', 'UTF-8', $file_relative_path);
          if ($test) {
            $file_relative_path = $test;
          }
        }
        if (!$this->add_file_to_tar($file_path, $file_relative_path)) {
          //error
          return false;
        }


      }

      return true;

    }

    private function add_file_to_tar($file_name, $name_in_archive)
    {
      $chunk_size = 1024 * 1024 * 4;
      $filename = $name_in_archive;
      $filename_prefix = "";

      // Split filename larger than 100 chars
      if (100 < strlen($name_in_archive)) {
        $filename_offset = strlen($name_in_archive) - 100;
        $split_pos = strpos($name_in_archive, '/', $filename_offset);

        if ($split_pos === false) {
          $split_pos = strrpos($name_in_archive, '/');
        }

        $filename = substr($name_in_archive, $split_pos + 1);
        $filename_prefix = substr($name_in_archive, 0, $split_pos);

        if (strlen($filename) > 100) {
          $filename = substr($filename, -100);
          trigger_error(
            sprintf(
            /* translators: $1 is the file name. */
              esc_html__('File name "%1$s" is too long to be saved correctly in %2$s archive!', 'backwpup'),
              $name_in_archive,
              $this->method
            ),
            E_USER_WARNING
          );
        }

        if (155 < strlen($filename_prefix)) {
          trigger_error(
            sprintf(
            /* translators: $1 is the file name to use in the archive. */
              esc_html__('File path "%1$s" is too long to be saved correctly in %2$s archive!', 'backwpup'),
              $name_in_archive,
              $this->method
            ),
            E_USER_WARNING
          );
        }
      }

      //get file stat
      $file_stat = stat($file_name);
      if (!$file_stat) {
        return true;
      }
      $file_stat['size'] = abs((int)$file_stat['size']);
      //open file
      if ($file_stat['size'] > 0) {
        if (!($fd = fopen($file_name, 'rb'))) {
          trigger_error(sprintf(__('Cannot open source file %s for archiving', 'buwd'), $file_name), E_USER_WARNING);

          return true;
        }
      }
      //Set file user/group name if linux
      $fileowner = "Unknown";
      $filegroup = "Unknown";
      if (function_exists('posix_getpwuid')) {
        $info = posix_getpwuid($file_stat['uid']);
        $fileowner = $info['name'];
        $info = posix_getgrgid($file_stat['gid']);
        $filegroup = $info['name'];
      }

      // Generate the TAR header for this file
      $chunk = $this->make_tar_headers(
        $filename,
        $file_stat['mode'],
        $file_stat['uid'],
        $file_stat['gid'],
        $file_stat['size'],
        $file_stat['mtime'],
        0,
        $fileowner,
        $filegroup,
        $filename_prefix
      );


      if (isset($fd) && is_resource($fd)) {
        // read/write files in 512 bite Blocks
        while (($content = fread($fd, 512)) != '') {
          $chunk .= pack("a512", $content);
          if (strlen($chunk) >= $chunk_size) {
            $chunk = gzencode($chunk);
            fwrite($this->zip, $chunk);
            $chunk = '';
          }

        }
        fclose($fd);
      }

      if (!empty($chunk)) {
        $chunk = gzencode($chunk);
        fwrite($this->zip, $chunk);
      }

      return true;
    }

    /**
     * Make Tar Headers
     *
     * @param string  $name     The name of the file or directory. Known as Item.
     * @param string  $mode     The permissions for the item.
     * @param integer $uid      The owner ID.
     * @param integer $gid      The group ID.
     * @param integer $size     The size of the item.
     * @param integer $mtime    The time of the last modification.
     * @param integer $typeflag The type of the item. 0 for File and 5 for Directory.
     * @param string  $owner    The owner Name.
     * @param string  $group    The group Name.
     * @param string  $prefix   The item prefix.
     *
     * @return mixed|string
     */
    private function make_tar_headers($name, $mode, $uid, $gid, $size, $mtime, $typeflag, $owner, $group, $prefix)
    {

      // Generate the TAR header for this file
      $chunk = pack("a100a8a8a8a12a12a8a1a100a6a2a32a32a8a8a155a12", $name, //name of file  100
        sprintf("%07o", $mode), //file mode  8
        sprintf("%07o", $uid), //owner user ID  8
        sprintf("%07o", $gid), //owner group ID  8
        sprintf("%011o", $size), //length of file in bytes  12
        sprintf("%011o", $mtime), //modify time of file  12
        "        ", //checksum for header  8
        $typeflag, //type of file  0 or null = File, 5=Dir
        "", //name of linked file  100
        "ustar", //USTAR indicator  6
        "00", //USTAR version  2
        $owner, //owner user name 32
        $group, //owner group name 32
        "", //device major number 8
        "", //device minor number 8
        $prefix, //prefix for file name 155
        ""); //fill block 12

      // Computes the unsigned Checksum of a file's header
      $checksum = 0;
      for ($i = 0; $i < 512; $i++) {
        $checksum += ord(substr($chunk, $i, 1));
      }

      $checksum = pack("a8", sprintf("%07o", $checksum));
      $chunk = substr_replace($chunk, $checksum, 148, 8);

      return $chunk;
    }

    /**
     * function for reloading zip archive
     */
    private function archive_reload()
    {
      if (!is_resource($this->zip) && get_class($this->zip) == "ZipArchive") {
        @$this->zip->close();
        $this->zip = new \ZipArchive();
        $this->zip->open($this->archive_path, \ZipArchive::CREATE);
      }
    }

    /**
     *
     * @throws \Exception
     */
    private function add_external_files_to_archive()
    {
      // add config json to archive
      $this->add_file_to_archive(self::get_tmp_dir() . "/" . self::MIGRATION_CONFIG_FILE_NAME, '10web_meta/' . self::MIGRATION_CONFIG_FILE_NAME);

      // add db sql file to archive
      $this->add_file_to_archive(self::get_tmp_dir() . "/" . self::MIGRATION_DB_FILE_NAME, '10web_meta/' . self::MIGRATION_DB_FILE_NAME);

      // add wp-config.php to archive
      $this->add_file_to_archive(ABSPATH . "/wp-config.php", "wp-config.php");
    }

    /**
     * function for crating tar archive from wp-content dir
     *
     * @throws \Exception
     */
    private function create_tar_archive()
    {
      Helper::store_migration_log('start_create_tar_archive', 'Starting create_tar_archive function.');

      $all_files = $this->files;
      foreach ($all_files as $type => &$files) {
        if (!empty($files)) {
          $t = current_time('timestamp');
          Helper::store_migration_log('start_files_iteration_' . $t, 'Starting files iteration.');

          foreach ($files as $key => $file_path) {
            $this->check_for_restart();
            unset($files[$key]);
            $this->files = $all_files;

            if ($type == "wp-content") {
              $relative_path = $type . "/" . substr($file_path, strlen(WP_CONTENT_DIR) + 1);
            } else {
              $relative_path = $type . "/" . substr($file_path, strlen(ABSPATH . $type) + 1);
            }
            // add current file to archive
            if (!is_dir($file_path)) {
              $this->add_file_to_archive($file_path, $relative_path);
            } else if ($this->dir_is_empty($file_path)) {
              $this->add_empty_folder_to_tar($file_path, $relative_path);
            }
            $this->files_count++;
          }

          Helper::store_migration_log('end_files_iteration_' . $t, 'End files iteration.');
        }
      }

      // add other necessary files to zip
      $this->add_external_files_to_archive();

      // after all close
      $this->close_tar_archive();

      Helper::store_migration_log('end_create_tar_archive', 'End create_tar_archive function.');
    }

    /**
     * @param $dir
     *
     * @return bool
     */
    public function dir_is_empty($dir)
    {
      $handle = opendir($dir);
      while (false !== ($entry = readdir($handle))) {
        if ($entry != "." && $entry != "..") {
          return false;
        }
      }

      return true;
    }

    /**
     * Tar an empty Folder to archive
     *
     * @param $folder_name
     * @param $name_in_archive
     *
     * @return bool True on success, false on failure.
     */
    private function add_empty_folder_to_tar($folder_name, $name_in_archive)
    {

      if (!is_resource($this->zip)) {
        return false;
      }

      $name_in_archive = trailingslashit($name_in_archive);

      $tar_filename = $name_in_archive;
      $tar_filename_prefix = '';

      // Split filename larger than 100 chars.
      if (100 < strlen($name_in_archive)) {
        $filename_offset = strlen($name_in_archive) - 100;
        $split_pos = strpos($name_in_archive, '/', $filename_offset);

        if ($split_pos === false) {
          $split_pos = strrpos(untrailingslashit($name_in_archive), '/');
        }

        $tar_filename = substr($name_in_archive, $split_pos + 1);
        $tar_filename_prefix = substr($name_in_archive, 0, $split_pos);

        if (strlen($tar_filename) > 100) {
          $tar_filename = substr($tar_filename, -100);
          trigger_error(sprintf(/* translators: $1 is the name of the folder. $2 is the archive name.*/
            esc_html__('Folder name "%1$s" is too long to be saved correctly in %2$s archive!', 'backwpup'), $name_in_archive, $this->method), E_USER_WARNING);
        }

        if (strlen($tar_filename_prefix) > 155) {
          trigger_error(sprintf(/* translators: $1 is the name of the folder. $2 is the archive name.*/
            esc_html__('Folder path "%1$s" is too long to be saved correctly in %2$s archive!', 'backwpup'), $name_in_archive, $this->method), E_USER_WARNING);
        }
      }

      $file_stat = @stat($folder_name);
      // Retrieve owner and group for the file.
      list( $owner, $group ) = $this->posix_getpwuid( $file_stat['uid'], $file_stat['gid'] );
      // Generate the TAR header for this file
      $header = $this->make_tar_headers($tar_filename, $file_stat['mode'], $file_stat['uid'], $file_stat['gid'], $file_stat['size'], $file_stat['mtime'], 5, $owner, $group, $tar_filename_prefix);

      $content = gzencode($header);

      fwrite($this->zip, $content);

      return true;
    }

    /**
     * @return mixed
     */
    private static function get_object_file_content()
    {
      $content = file_get_contents(self::get_tmp_dir() . '/content_object.php');

        return unserialize($content);
    }

      /**
       * Close
       *
       * Closing the archive
       *
       * @return void
       */
      public function close_tar_archive() {


          if ( ! is_resource( $this->zip ) ) {
              return;
          }

          // Write tar file end.
          if ( $this->method = 'gzip') {
              fwrite($this->zip, pack( 'a1024', '' ) );
          }

          fclose( $this->zip );
      }

      /**
       * Posix Get PW ID
       *
       * @param integer $uid The user ID.
       * @param integer $gid The group ID.
       *
       * @return array The owner and group in posix format
       */
      private function posix_getpwuid( $uid, $gid ) {
          // Set file user/group name if linux.
          $owner = esc_html__( 'Unknown', 'tenwebmanager' );
          $group = esc_html__( 'Unknown', 'tenwebmanager' );
          if ( function_exists( 'posix_getpwuid' ) ) {
              $info  = posix_getpwuid( $uid );
              $owner = $info['name'];
              $info  = posix_getgrgid( $gid );
              $group = $info['name'];
          }
          return array(
              $owner,
              $group,
          );
      }


  }
}