/**
  * Import post.
  *
  * @param Post $post
  */
 public function import_post(Post $post)
 {
     // Notify listeners that post is about to be imported.
     do_action('sme_post_import', $post, $this->batch);
     $publish_status_changed = false;
     /*
      * Create object that can keep track of differences between stage and
      * production post.
      */
     $post_diff = new Post_Env_Diff($post->get_id());
     $post_diff->set_stage_status($post->get_post_status());
     // Check if post has any parent.
     if ($post->get_parent() !== null) {
         $post_diff->set_parent_guid($post->get_parent()->get_guid());
     }
     /*
      * Check if post already exist on production, if it does then update the
      * old version of the post rather then creating a new post.
      */
     if (($prod_revision = $this->post_dao->get_by_guid($post->get_guid())) !== null) {
         /*
          * This is an existing post.
          */
         $post_diff->set_prod_id($prod_revision->get_id());
         $post->set_id($prod_revision->get_id());
         $this->post_dao->update_post($post);
     } else {
         /*
          * This is a new post.
          */
         // Turn published posts into drafts for now.
         if ($post->get_post_status() == 'publish') {
             $post->set_post_status('draft');
             $publish_status_changed = true;
         }
         // Insert post.
         $this->post_dao->insert($post);
         // Reset publish status.
         if ($publish_status_changed) {
             $post->set_post_status('publish');
         }
         // Store new production ID in diff.
         $post_diff->set_prod_id($post->get_id());
     }
     // Add post diff to array of post diffs.
     $this->add_post_diff($post_diff);
     // Clear old post/taxonomy relationships.
     foreach ($post->get_post_taxonomy_relationships() as $post_taxonomy) {
         $this->post_taxonomy_dao->clear_post_taxonomy_relationships($post_taxonomy);
     }
     // Import post/taxonomy relationships.
     foreach ($post->get_post_taxonomy_relationships() as $post_taxonomy) {
         // Import taxonomy.
         $this->import_taxonomy($post_taxonomy->get_taxonomy());
         $this->post_taxonomy_dao->insert($post_taxonomy);
     }
     // Notify listeners that post has been imported.
     do_action('sme_post_imported', $post, $this->batch);
 }