#!/usr/bin/ruby

class App

  def initialize file
    @file = file
    @cntl = {}
  end

  def getrec(fp)
    irec = 1
    loop do
      head = fp.read(16)
      break if head.nil?
      recl, recn, vrecl, update = head.unpack('Na4NN')
      body = fp.read(recl - 8)
      attrs = {
	:nr => irec,
	:precl => recl,
	:name => recn,
	:vrecl => vrecl,
	:update => Time.at(update).utc
      }
      yield(head + body[0, vrecl - 12], attrs)
      irec = irec.succ
    end
  end

  def nwptime i
    Time.at((i - 61726 * 1440) * 60).utc
  end

  def dumpfile fp
    getrec(fp) do |rec, attrs|
      case attrs[:name]
      when 'CNTL'
        type, bts, bt, ftu, nm, nv, nz, ne = rec.unpack('x16a16a12Na4N4')
	@cntl[:type] = type
	@cntl[:bt] = nwptime(bt)
	proj, nx, ny, ir, jr, latr, lonr, di, dj = rec.unpack('x68a4NNg6')
	lats, lons, latt, lont, lato, lono, latp, lonp, v = rec.unpack('x104g8a4')
	puts <<-EOL
##{attrs[:nr]} CNTL
  type=#{type.inspect}
  bt=#{@cntl[:bt].strftime('%Y-%m-%dT%H:%M:%SZ')}
  ftu=#{ftu} nm=#{nm} nv=#{nv} nz=#{nz} ne=#{ne}
  proj=#{proj} nx=#{nx} ny=#{ny}
  basepoint=(#{ir}, #{jr}; #{latr}, #{lonr})
  distance=(#{di}, #{dj})
  standard=(#{lats}, #{lons}; #{latt}, #{lont})
  others=(#{lato}, #{lono}; #{latp}, #{lonp})
  value=#{v}
EOL
      when 'DATA'
        m, vt, vt2, z, z2, e, nx, ny, pa, mi = rec.unpack('x16a4NNa6a6a6x2NNa4a4')
	ft = (nwptime(vt) - @cntl[:bt]) / 3600.0
	vt2 = (vt2 == 1) ? '' : "/vt2=#{vt2}"
	puts <<-EOL
##{attrs[:nr]} m=#{m.inspect} ft=#{ft}#{vt2} z=#{z} e=#{e.inspect} nx=#{nx} ny=#{ny} pack=#{pa} miss=#{mi}
EOL
      else
	printf("#%u rec=%04s size=%u\n",
	attrs[:nr], attrs[:name], rec.size) unless 'DATA' == attrs[:name]
      end
    end
  end

  def run
    File.open(@file, 'r') {|fp|
      fp.binmode
      dumpfile fp
    }
  end

end

for file in ARGV
  App.new(file).run
end