bump

#!/usr/bin/env python2

"""
A quick and dirty SemVer bump script.
"""

from __future__ import print_function

import argparse
from collections import namedtuple
import re
import sys

parser = argparse.ArgumentParser(description=__doc__)
group = parser.add_mutually_exclusive_group(required=True)
group.add_argument("-m", "--major", action="store_true", default=False, help="Bump the major part.")
group.add_argument("-n", "--minor", action="store_true", default=False, help="Bump the minor part.")
group.add_argument("-p", "--patch", action="store_true", default=False, help="Bump the patch part.")


class Version(namedtuple('Version', ['major', 'minor', 'patch'])):

  def bump_patch(self):
    return Version(self.major, self.minor, self.patch + 1)

  def bump_minor(self):
    return Version(self.major, self.minor + 1, 0)

  def bump_major(self):
    return Version(self.major + 1, 0, 0)

  def __str__(self):
    return "{0}.{1}.{2}".format(self.major, self.minor, self.patch)

__INITIAL__ = Version(0, 0, 0)


def main(opts):
  v = None
  try:
    with open("VERSION") as f:
      v = re.split(re.compile("\\.|-"), f.read()) or __INITIAL__
      v = Version(*map(int, v[0:3]))

  except ValueError:
    print("failed to parse the existing VERSION file, assuming v0.0.0")
    v = __INITIAL__

  except IOError:
    print("failed to find a VERSION file, assuming v0.0.0")
    v = __INITIAL__

  if opts.major:
    v = v.bump_major()

  elif opts.minor:
    v = v.bump_minor()

  elif opts.patch:
    v = v.bump_patch()

  print(v)

  open("VERSION", 'w').write(str(v))

  sys.exit(0)


if __name__ == "__main__":
  main(parser.parse_args())