translit

#!/usr/bin/python3

import sys, os, re

if len(sys.argv) < 2:
  print('Usage: translit src.txt [> output.txt]')
  print('   Or: cat src.txt | translit - [> output.txt]')
  sys.exit(1)

def remove_uppercase (text):
  def f (match):
    g = match.group()
    if g.isupper(): return g.title()
    return g
  return re.sub("\w+", f, text, flags=re.I)

def replace_keep_case (text, rule):
  def f (match):
    g = match.group()
    if g.islower(): return rule[1].lower()
    if g.istitle(): return rule[1].title()
    if g.isupper(): return rule[1].upper()
    return rule[1]
  return re.sub(rule[0], f, text, flags=re.I)
  
rules_file = os.path.dirname(os.path.abspath(__file__)) + '/translit_rules'
with open(rules_file) as f:
  rule_lines = f.readlines()
rules = []
for line in rule_lines:
  rule_src = line.replace('\n', '').split(' -> ')
  if len(rule_src) == 2 and rule_src[0].strip() != '' and rule_src[0].strip()[0] != '#':
    if rule_src[1] == '[]':
      rules.append([ rule_src[0].strip(), '' ])
    else:
      rules.append([ rule_src[0].strip(), rule_src[1].strip() ])
  
src_filename = sys.argv[1]

if src_filename == "-":
  lines = sys.stdin.readlines()
else:
  with open(src_filename) as f:
    lines = f.readlines()
  
output = ''

for line in lines:
  output_line = remove_uppercase(line)
  for rule in rules:
    output_line = replace_keep_case(output_line, rule)
  output = output + output_line
  
print(output)