namespace :db do
  desc 'S3へのDBバックアップ'
  task backup: :environment do
    # loggerの設定
    logger = Logger.new('log/cron.log', 5, 10.megabytes)
    logger.info('start db:backup')
 
    t = Time.current
    backup_file = "tmp/backups/#{t.strftime('%Y-%m-%d')}_dbname.dump"
 
    `mkdir -p tmp/backups`
    `pg_dump -U postgres -Fc dbname_#{Rails.env} > #{backup_file}`
 
    send_to_s3(backup_file)
 
    # localファイルの削除
    File.delete(backup_file)
 
    logger.info('end db:backup')
  end
 
  # s3へのバックアップ
  def send_to_s3(file_path)
    s3 = AWS::S3.new
    bucket = s3.buckets['xxxxx']
 
    file_name = File.basename(file_path)
    bucket.objects["backups/#{file_name}"].write(file: file_path)
 
    delete_olds(bucket)
  end
 
  # 7日前のものは削除
  def delete_olds(bucket)
    bucket.objects.each do |obj|
      date_str = obj.key.match(/[0-9]{4}-[0-9]{2}-[0-9]{2}/)[0]
      if (Date.today.days_ago(7) > date_str.to_date)
        obj.delete
      end
    end
  end
end