helpers.py

#!/usr/bin/env python3

import sys
import re

from config import Config

COMMANDS = ['help',
            'story_from_branch',
            'format_commit_message',
            'git_opts',
            'base_branch']

config = Config()


def _argnames(func):
    if callable(func):
        return ' '.join([
            n.upper() for n
            in func.func_code.co_varnames[:func.func_code.co_argcount]])
    else:
        return ''


def help():
    '''Displays this help message.'''
    print('Usage: %s COMMAND OPTIONS')
    print()
    print('The available COMMANDS are:')
    for command in COMMANDS:
        func = globals().get(command, None)
        if callable(func):
            print('    %-40s    %s' % (command + ' ' + _argnames(func),
                                       func.__doc__))
        else:
            print("    %-40s    Returns the value for %s (currently '%s')" % (
                command, command.upper(), resolve(command)))


def story_from_branch(branch_name):
    '''Extracts the story number from a branch name, based on
    the conventions defined in the .dhrc file.'''
    story_number = re.search(config.BRANCH_PATTERN, branch_name)
    if story_number is not None:
        print(story_number.group(1))
    else:
        print >> sys.stderr, 'Fatal: Could not get story number from branch'


def format_commit_message(story_num, message):
    '''Formats a commit message, given a story number, based on
    the conventions defined in the .dhrc file.'''
    print(config.COMMIT_PATTERN.format(
        story_num=story_num,
        message=message,
    ))


def resolve(prop):
    '''Resolves a basic property and sends it back to the user.'''
    return getattr(config, prop.upper(), '')


if __name__ == "__main__":
    if len(sys.argv) <= 1:
        help()
        sys.exit(1)

    prop = sys.argv[1]
    args = sys.argv[2:]
    if prop not in COMMANDS:
        print('Fatal: Unknown command: '+prop, file=sys.stderr)
        help()
        sys.exit(1)

    func = globals().get(prop, None)
    argcount = func.func_code.co_argcount if callable(func) else 0
    if len(args) != argcount:
        print('Usage: %s %s %s' % (sys.argv[0], prop, _argnames(func)),
              file=sys.stderr)
        sys.exit(1)

    if callable(func):
        func(*args)
    else:
        print(resolve(prop))