require 'net/http'
require 'uri'
require 'time'

BASE = 'https://www.wis-jma.go.jp/d/o'
TIMEOUT = 120

if ARGV.empty?
  warn "Usage: ruby script.rb <path>"
  warn " path = CCCC/type/cat/subc like VHHH/Alphanumeric/Surface/SYNOP"
  exit 1
end

path = ARGV[0]
ENV['TZ']='UTC'

# UTC日付
date_str = Time.now.utc.strftime('%Y%m%d')

url = "#{BASE}/#{path}/#{date_str}/"
uri = URI.parse(url)

begin
  http = Net::HTTP.new(uri.host, uri.port)
  http.use_ssl = true
  http.open_timeout = TIMEOUT
  http.read_timeout = TIMEOUT

  res = http.get(uri.request_uri)

  unless res.code.to_i == 200
    warn "HTTP Error: #{res.code}"
    exit 1
  end

  body = res.body

  # 例: 2026-06-10 09:42
  regex = /(\d{4}-\d{2}-\d{2} \d{2}:\d{2})/

  times = []

  body.each_line do |line|
    if line =~ regex
      begin
        times << Time.strptime($1, '%Y-%m-%d %H:%M').utc
      rescue
        # 無視
      end
    end
  end

  if times.empty?
    warn "No timestamps found"
    puts "535"
    exit 1
  end

  latest = times.max
  now = Time.now.utc
  diff = now - latest

  # 指定フォーマットで出力
  puts "%6.3f" % diff

rescue Net::OpenTimeout
  warn "OpenTimeout"
  puts "505"
  exit 1
rescue Net::ReadTimeout
  warn "ReadTimeout"
  puts "515"
  exit 1
rescue => e
  warn "Error: #{e.message}"
  puts "525"
  exit 1
end