#!/usr/bin/env python

import subprocess
import sys
import re

project = 'CUR'  # set to your project name in JIRA


issue_pattern = '{}-[\d]+'.format(project)
issue_output_format = '{}'

def read_current_message():
    with open(sys.argv[1], 'r') as f:
        return f.read()

def write_message(message):
    with open(sys.argv[1], 'w') as f:
        f.write(message)

def contains_message(message):
    return message and not message.lstrip().startswith("# Please enter the commit message for your changes.")


try:
    current_ref = subprocess.check_output('git symbolic-ref HEAD', shell=True)
except subprocess.CalledProcessError:
    print("add-issue-id-hook: Adding issue id failed. Are you in detached HEAD state?")
    sys.exit()

current_branch = current_ref[len('refs/heads/'):]

issue_match = re.search(issue_pattern, current_branch)
if issue_match:
    issue_output = issue_output_format.format(issue_match.group())

    original_message = read_current_message()
    if contains_message(original_message) and not original_message.startswith(issue_output):
        write_message('{0} {1}'.format(issue_output, original_message))