from difflib import Differ
from termcolor import colored

def color_print(buffer, line):
  # skip if the line isn't changed
  if line.startswith(' '):
    return
  # otherwise render deleted line in red and new line in green
  if line.startswith('-'):
    color = 'red'
  elif line.startswith('+'):
    color = 'green'
  else:
    color = 'white'
  buffer.append(colored(line, color))
  
def show_diff(live, revision, domain, rule):
  d = Differ()
  results = []
  # split origin text into a list of strings, then use Differ().compare()
  for line in d.compare(live.splitlines(keepends=True), revision.splitlines(keepends=True)):
    color_print(results, line)

  print(f'Processing {domain}/{rule}...')
  sys.stdout.writelines(results)
  print()