module SunbusRss

# File lib/sunbus/rss.rb, line 71
def alerts(region:, fetch: nil, limit: MAX_ITEMS)
  body = fetch_feed(FEED_BUS, fetch: fetch)
  filter_by_region(parse_items(body), region: region).first(limit)
end

# File lib/sunbus/rss.rb, line 60
def ascii_title(text)
  text.to_s.gsub(/[^\x20-\x7E]/, "").strip
end

# File lib/sunbus/rss.rb, line 20
def fetch_feed(url, fetch: nil)
  if fetch
    fetch.call(url)
  else
    RabbotHttp.fetch(url, user_agent: USER_AGENT)
  end
end

# File lib/sunbus/rss.rb, line 64
def filter_by_region(items, region:)
  label = SunbusConfig.region_rss_category(region)
  items.select do |item|
    item[:categories].any? { |category| category.match?(/\b#{Regexp.escape(label)}\b/i) }
  end
end

# File lib/sunbus/rss.rb, line 32
def item_categories(node)
  REXML::XPath.match(node, ".//*[local-name()='category']").filter_map do |category|
    text = category.text.to_s.strip
    text unless text.empty?
  end
end

# File lib/sunbus/rss.rb, line 76
def notices(region:, fetch: nil, limit: MAX_ITEMS)
  body = fetch_feed(FEED_NOTICES, fetch: fetch)
  filter_by_region(parse_items(body), region: region).first(limit)
end

# File lib/sunbus/rss.rb, line 39
def parse_item(node)
  title = ascii_title(rss_element_text(node, "title"))
  return nil if title.empty?

  {
    title: title,
    link: rss_element_text(node, "link"),
    description: rss_element_text(node, "description"),
    categories: item_categories(node)
  }
end

# File lib/sunbus/rss.rb, line 51
def parse_items(xml)
  doc = REXML::Document.new(xml.to_s)
  REXML::XPath.match(doc, "//*[local-name()='item' or local-name()='entry']").filter_map do |node|
    parse_item(node)
  end
rescue REXML::ParseException, StandardError
  []
end

# File lib/sunbus/rss.rb, line 28
def rss_element_text(node, name)
  REXML::XPath.first(node, ".//*[local-name()='#{name}']")&.text.to_s.strip
end