#!/usr/bin/env python
#
#    Synchronize.py: this file is part of the GRS suite
#    Copyright (C) 2015  Anthony G. Basile
#
#    This program is free software: you can redistribute it and/or modify
#    it under the terms of the GNU General Public License as published by
#    the Free Software Foundation, either version 3 of the License, or
#    (at your option) any later version.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU General Public License for more details.
#
#    You should have received a copy of the GNU General Public License
#    along with this program.  If not, see <http://www.gnu.org/licenses/>.

import os
from grs.Constants import CONST
from grs.Execute import Execute

class Synchronize():
    """ Either clone or pull a remote git repository for a GRS system.  """

    def __init__(self, remote_repo, branch, libdir=CONST.LIBDIR, logfile=CONST.LOGFILE):
        self.remote_repo = remote_repo
        self.branch = branch
        self.local_repo = libdir
        self.logfile = logfile

    def sync(self):
        if self.isgitdir():
            # If the local repo exists, then make it pristine an pull
            cmd = 'git -C %s reset HEAD --hard' % self.local_repo
            Execute(cmd, timeout=60, logfile=self.logfile)
            cmd = 'git -C %s clean -f -x -d' % self.local_repo
            Execute(cmd, timeout=60, logfile=self.logfile)
            cmd = 'git -C %s pull' % self.local_repo
            Execute(cmd, timeout=60, logfile=self.logfile)
        else:
            # else clone afresh.
            cmd = 'git clone %s %s' % (self.remote_repo, self.local_repo)
            Execute(cmd, timeout=60, logfile=self.logfile)

        # Make sure we're on the correct branch for the desired GRS system.
        cmd = 'git -C %s checkout %s' % (self.local_repo, self.branch)
        Execute(cmd, timeout=60, logfile=self.logfile)

        # If there is a .gitmodules, then init/update the submodules
        git_modulesfile = os.path.join(self.local_repo, '.gitmodules')
        if os.path.isfile(git_modulesfile):
            # Recursively update any submodules following the remote branch
            cmd = 'git -C %s submodule update --init --recursive --remote' % self.local_repo
            Execute(cmd, timeout=60, logfile=self.logfile)


    def isgitdir(self):
        """ If there is a .git/config file, assume its a local git repository. """
        git_configdir = os.path.join(self.local_repo, '.git')
        git_configfile = os.path.join(git_configdir, 'config')
        return os.path.isdir(git_configdir) and os.path.isfile(git_configfile)