module QldTranslinkRt

# File lib/qld_translink_rt.rb, line 25
def decode(body)
  TransitRealtime::FeedMessage.decode(body)
end

# File lib/qld_translink_rt.rb, line 72
def departures_for_stops(stop_ids, message:, time: Time.now, limit: QldConfig::MAX_DEPARTURES)
  ids = Array(stop_ids).map(&:to_s).to_set
  return [] if ids.empty? || message.nil?

  rows = []
  Array(message.entity).each do |entity|
    trip_update = entity.trip_update
    next unless trip_update

    route_id = trip_update.trip&.route_id.to_s
    Array(trip_update.stop_time_update).each do |stu|
      next unless ids.include?(stu.stop_id.to_s)

      departure = stu.departure || stu.arrival
      next unless departure&.time

      at = Time.at(departure.time.to_i)
      next if at < time - 60

      rows << {
        route_id: route_id,
        stop_id: stu.stop_id.to_s,
        time: at,
        delay_sec: departure.delay.to_i
      }
    end
  end
  rows.sort_by { |row| row[:time] }.first(limit)
end

# File lib/qld_translink_rt.rb, line 13
def fetch_feed(region:, feed:, fetch: nil)
  url = QldConfig.transit_feed_url(region: region, feed: feed)
  body = if fetch
           fetch.call(url)
         else
           RabbotHttp.fetch(url, user_agent: "Rabbot/1.0 (qld translink rt)")
         end
  decode(body)
rescue StandardError
  nil
end

# File lib/qld_translink_rt.rb, line 53
def mode_filter(mode)
  !mode.to_s.strip.empty?
end

# File lib/qld_translink_rt.rb, line 57
def mode_matches?(mode, route_type)
  case mode.to_s.downcase
  when "train", "rail"
    route_type == 2
  when "bus"
    route_type == 3
  when "ferry"
    route_type == 4
  when "tram"
    route_type == 0
  else
    true
  end
end

# File lib/qld_translink_rt.rb, line 29
def parse_alerts(message, mode: nil)
  return [] unless message

  Array(message.entity).filter_map do |entity|
    alert = entity.alert
    next unless alert

    header = alert.header_text&.translation&.first&.text.to_s.strip
    description = alert.description_text&.translation&.first&.text.to_s.squeeze(" ").strip
    next if header.empty? && description.empty?

    route_type = alert.informed_entity&.first&.route_type
    if mode_filter(mode) && route_type && !mode_matches?(mode, route_type)
      next
    end

    {
      id: entity.id.to_s,
      header: header,
      description: description[0, 160]
    }
  end
end

# File lib/qld_translink_rt.rb, line 102
def reachable?(region: QldConfig::DEFAULT_REGION, fetch: nil)
  msg = fetch_feed(region: region, feed: FEED_ALERTS, fetch: fetch)
  !msg.nil? && msg.entity.any?
rescue StandardError
  false
end