require 'bindata'
require 'bigdecimal'

class WangRec < BinData::Record
  string  :cust_no, :read_length => 6
  string  :doc_date, :read_length => 6
  string  :doc_no,  :read_length => 6
  string  :doc_type,  :read_length => 1
  string  :apply_to_no, :read_length => 6
  string  :cust_no_alt, :read_length => 6
  string  :apply_to_no_alt, :read_length => 6
  string  :doc_due_date,    :read_length => 6
  string  :amt1,            :read_length => 6 
  string  :amt2,            :read_length => 5
  string  :ref,             :read_length => 30
  string  :slsmn1,          :read_length => 3
  string  :slsmn2,          :read_length => 3
  string  :slsmn3,          :read_length => 3
  string  :amt3,            :read_length => 5
end

def packed(packed_field, dec_pos) 
  unpkd_field = packed_field.unpack('H12')
  num, sign = unpkd_field[0][0..-2], unpkd_field[-1]
  unless sign == 'f'
    amt = num.insert(0, '-')
  end

  if dec_pos > 0
    dec_amt = amt.insert((dec_pos + 1) * -1, '.')
  end
  
  return dec_amt.to_f 

end

wang_aropnfile = File.open('../data/wangdata/AROPNFIL.bin', 'rb')

count = 0

while !wang_aropnfile.eof?
  rec = WangRec.read(wang_aropnfile)
  amt1 = packed(rec.amt1, 2)
  puts "#{rec.cust_no} #{rec.doc_type} #{rec.doc_date} #{amt1}"
  
  count += 1
end

puts count