module SunbusRssRoutes

# File lib/sunbus/rss_routes.rb, line 33
def matching_items(items, query, region:)
  regional = SunbusRss.filter_by_region(items, region: region)
  regional.select { |item| title_matches_query?(item[:title], query) }
end

# File lib/sunbus/rss_routes.rb, line 18
def parse_route_from_link(link)
  match = link.to_s.match(ROUTE_LINK_PATTERN)
  return nil unless match

  { prefix: match[1].upcase, number: match[2] }
end

# File lib/sunbus/rss_routes.rb, line 38
def route_numbers_from_items(items)
  items.filter_map { |item| parse_route_from_link(item[:link])&.fetch(:number) }.uniq
end

# File lib/sunbus/rss_routes.rb, line 61
def stops_for_query(query, feed:, region:, fetch:, limit: SunbusConfig::MAX_STOPS)
  body = SunbusRss.fetch_feed(SunbusRss::FEED_BUS, fetch: fetch)
  items = matching_items(SunbusRss.parse_items(body), query, region: region)
  route_numbers = route_numbers_from_items(items)
  stops_on_routes(feed, route_numbers, limit: limit)
end

# File lib/sunbus/rss_routes.rb, line 42
def stops_on_routes(feed, route_numbers, limit:)
  return [] if route_numbers.empty?

  numbers = route_numbers.map(&:to_s).to_set
  route_ids = feed[:routes].each_value.filter_map do |route|
    route[:route_id] if numbers.include?(route[:route_short_name].to_s)
  end
  return [] if route_ids.empty?

  trip_ids = feed[:trips].each_value.filter_map do |trip|
    trip[:trip_id] if route_ids.include?(trip[:route_id])
  end
  stop_ids = trip_ids.flat_map do |trip_id|
    feed[:stop_times][trip_id].map { |row| row[:stop_id] }
  end.uniq

  feed[:stops].select { |stop| stop_ids.include?(stop[:stop_id]) }.first(limit)
end

# File lib/sunbus/rss_routes.rb, line 25
def title_matches_query?(title, query)
  name = SunbusStopSearch.normalize_text(title)
  tokens = SunbusStopSearch.query_tokens(query)
  return false if tokens.empty?

  tokens.all? { |token| name.include?(token) }
end