#!/usr/bin/ruby

# processes output of prep-liststn.rb

DISTANCE = 4
$count = 2

if /^N=(\d+)$/ === ARGV.last then
  $count = $1.to_i
  ARGV.pop
end

flat = Float(ARGV.shift)
flon = Float(ARGV.shift)
db = {}
for line in ARGF
  sid, attrs, pos, name, ahl = line.chomp.split(/\t/)
  unless /^([-+]\d\d\.\d*)([-+]\d\d\d\.\d*)\// === pos
    STDERR.puts "#{pos}: bad position format"
    next
  end
  lat, lon = $1.to_f, $2.to_f
  distance = Math.hypot(lat - flat, lon - flon)
  distance += 1 unless /P/ === attrs
  distance += 1 unless /N/ === attrs
  next unless distance < DISTANCE
  attrs = attrs.split(/,/)
  ahl = [ahl.sub(/([A-Z]{4}[0-9]{2} [A-Z]{4}).*/, "\\1")]
  if db.include? sid
    attrs = (attrs + db[sid][0]).uniq
    ahl = (ahl + db[sid][4]).uniq
  end
  db[sid] = [attrs, distance, pos, name, ahl]
end

stns = db.keys.sort{|a, b| db[a][1] <=> db[b][1]}

$count.times do |i|
  sid = stns[i]
  next unless sid
  attrs, distance, pos, name, ahl = db[sid]
  attrs = attrs.sort.reverse
  attrs.unshift(':') unless i.zero?
  puts [sid, attrs.join(','), pos, name, ahl.join(',')].join("\t")
end