<?php

class OBUpdate20210211 extends OBUpdate {

  public function items () {
    $updates   = array();
    $updates[] = "Drop foreign keys for schedules_media_cache, then re-add the constraint to player_id. (Quickest way to make sure there is no constraint to schedule_id, which can actually reference multiple tables)";
    return $updates;
  }

  public function run () {

    $this->db->query('START TRANSACTION;');

    /* Drop foreign keys for schedules_media_cache, then re-add the constraint to
       player_id. (Quickest way to make sure there is no constraint to schedule_id,
       which can actually reference multiple tables) */

    // Get all foreign keys to schedules media cache.
    $result = $this->db->query("SELECT `CONSTRAINT_NAME` FROM information_schema.TABLE_CONSTRAINTS
      WHERE information_schema.TABLE_CONSTRAINTS.CONSTRAINT_TYPE = 'FOREIGN KEY'
      AND information_schema.TABLE_CONSTRAINTS.TABLE_SCHEMA = '" . OB_DB_NAME . "'
      AND information_schema.TABLE_CONSTRAINTS.TABLE_NAME = 'schedules_media_cache';");

    // Remove all the foreign keys.
    foreach ($this->db->assoc_list() as $foreign_key) {
      $this->db->query("ALTER TABLE `schedules_media_cache` DROP FOREIGN KEY " . $foreign_key['CONSTRAINT_NAME'] . ";");
    }

    // Add the constraint to player ID back in.
    $this->db->query('ALTER TABLE `schedules_media_cache` ADD FOREIGN KEY (`player_id`) REFERENCES `players`(`id`) ON DELETE CASCADE ON UPDATE CASCADE;');

    $this->db->query('COMMIT;');
    if ($this->db->error()) return false;

    return true;
  }
}