#! /usr/bin/env python3
# -*- coding: utf-8 -*-
# vim:fenc=utf-8
#
# Copyright © 2017 Kevin Lyda <kevin@phrye.com>
#
# Distributed under terms of the GPL license.

"""
COBOL utilities.
"""

import vim
import math

if vim.current.buffer.options['filetype'] == b'cobol':
  gap = {}
  last_line_no = 0
  lines = vim.current.buffer
  for i in range(len(lines)):
    if len(lines[i]) == 0 or lines[i][:6] == '      ':
      if not gap:
        gap['i'] = i
        gap['last_line_no'] = last_line_no
    else:
      try:
        last_line_no = int(lines[i][:6])
      except ValueError:
          raise ValueError('Malformed line - has non-numbers in columns 1-6')
      if gap:
        delta = math.floor((last_line_no - gap['last_line_no']) /
          (i - gap['i'] + 1))
        if delta > 1:
          new_line_no = gap['last_line_no'] + delta
          for j in range(gap['i'], i):
            lines[j] = ('%06d' % new_line_no) + lines[j][6:]
            new_line_no += delta
          gap = {}
  if gap:
    delta = 100
    new_line_no = gap['last_line_no'] + delta
    for j in range(gap['i'], len(lines)):
      lines[j] = ('%06d' % new_line_no) + lines[j][6:]
      new_line_no += delta
else:
  print('Not a COBOL file. This is a %s file' %
      vim.current.buffer.options['filetype'].decode('UTF-8'))