import os
from subprocess import Popen, PIPE
import Bcfg2.Server.Plugin

# for debugging output only
import logging
logger = logging.getLogger('Bcfg2.Plugins.Git')

class Git(Bcfg2.Server.Plugin.Plugin,
          Bcfg2.Server.Plugin.Version):
    name = 'Git'
    __version__ = '$Id$'
    __author__ = 'bcfg-dev@mcs.anl.gov'

    def __init__(self, core, datastore):
        Bcfg2.Server.Plugin.Plugin.__init__(self, core, datastore)
        self.core = core
        self.datastore = datastore

        # path to git directory for bcfg2 repo
        git_dir = "%s/.git" % datastore

        # Read revision from bcfg2 repo
        if os.path.isdir(git_dir):
            self.get_revision()
        else:
            logger.error("%s is not a directory" % git_dir)
            raise Bcfg2.Server.Plugin.PluginInitError

        logger.debug("Initialized git plugin with git directory = %s" % git_dir)

    def get_revision(self):
        '''Read git revision information for the bcfg2 repository'''
        try:
            data = Popen(("env LC_ALL=C git ls-remote %s" %
                         (self.datastore)), shell=True,
                         stdout=PIPE).stdout.readlines()
            revline = [line.split('\t')[0].strip() for line in data if \
                       line.split('\t')[1].strip() == 'refs/heads/master'][-1]
            revision = revline
        except IndexError:
            logger.error("Failed to read git ls-remote; disabling git support")
            logger.error('''Ran command "git ls-remote %s"''' % \
                            (self.datastore))
            logger.error("Got output: %s" % data)
            raise Bcfg2.Server.Plugin.PluginInitError
        return revision