<?php

class OBUpdate20190918 extends OBUpdate {

  public function items () {
    $updates   = array();
    $updates[] = 'Media stream and thumbnail version support.';

    return $updates;
  }

  public function run () {
    $this->db->query('ALTER TABLE `media` ADD `stream_version` SMALLINT UNSIGNED NULL DEFAULT NULL AFTER `dynamic_select`, ADD `thumbnail_version` SMALLINT UNSIGNED NULL DEFAULT NULL AFTER `stream_version`;');

    // check if media_streams exists, early return if it doesn't exist.
    $this->db->query('SHOW TABLES LIKE "media_streams"');
    if($this->db->num_rows()<1) return true;

    // copy data from streams table to media table
    $streams = $this->db->get('media_streams');
    foreach($streams as $stream)
    {
      $this->db->where('id',$stream['media_id']);
      $this->db->update('media',['stream_version'=>$stream['version']]);
    }

    // remove media streams table which is no longer used
    $this->db->query('DROP TABLE `media_streams`');

    return true;
  }
}