<?php

namespace Tenweb_Manager {

  class MigrationContent extends Migration
  {

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

    /**
     * @param string $run_type
     */
    public static function set_up($run_type = 'run')
    {
      if ($run_type == 'run') {
        $migration_content = new self();
        $migration_content->run($run_type);
      }
      if ($run_type == 'restart') {
        $migration_content = self::get_object_file_content();
        $migration_content->run($run_type);
      }
    }


    /**
     * @param $run_type
     *
     * @throws \Exception
     */
    public function run($run_type)
    {
      if ($run_type == "run") {
        // check if zip extension exists
        if ($this->check_if_zip_extension_exists() === false) {
          throw new \Exception("PHP zip 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 archive
      $this->create_archive();

    }


    /**
     * function for crating archive from wp-content dir
     *
     * @throws \Exception
     */
    private function create_archive()
    {
      $this->archive_path = self::get_tmp_dir() . "/" . self::MIGRATION_ARCHIVE;

      // initialize archive object
      $this->zip = new \ZipArchive();

      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($files)) {
          foreach ($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
              $this->add_file_to_zip($file_path, $relative_path);
            } else {
              $this->zip->addEmptyDir($relative_path);
            }
            $this->files_count++;
            if ($this->files_count % 600 == 0) {
              $this->archive_reload();
            }
          }
        }
      }

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

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

    }

    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')
        )
      ));
    }

    /**
     *
     */
    private function restart()
    {
      $this->write_object_file();
      @$this->zip->close();
      self::restart_request();
      die();
    }

    /**
     * @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;
      }
    }

    /**
     *
     * @throws \Exception
     */
    private function add_external_files_to_archive()
    {
      // add config json to archive
      $this->add_file_to_zip(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_zip(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_zip(ABSPATH . "/wp-config.php", "wp-config.php");
    }

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

      return true;
    }

    /**
     * @param      $file_path
     * @param      $file_relative_path
     *
     * @throws \Exception
     */
    private function add_file_to_zip($file_path, $file_relative_path)
    {
      if ($this->zip->addFile($file_path, $file_relative_path) !== true) {
        throw new \Exception("Unable to add " . $file_relative_path . " to zip");
      }
    }

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

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

      return unserialize($content);
    }

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

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

    /**
     * @return array
     */
    private function get_content_files()
    {
      $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);
      }

      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' );
      $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;
    }

  }

}