#!/usr/bin/env python

# The MIT License
#
# Copyright (c) 2010 Louis Opter <kalessin@kalessin.fr>
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.

import errno
import os
import shutil
import subprocess
import sys
import tarfile
import tempfile

class TempDir(object):
    """Wrap tempfile.mkdtemp to use the with statement"""

    def __init__(self):
        pass

    def __enter__(self):
        self.__path = tempfile.mkdtemp()
        return self.__path

    def __exit__(self, exc_type, exc_value, traceback):
        shutil.rmtree(self.__path)

def status(message):
    print '%s: %s.' % (os.path.basename(sys.argv[0]), message)

def die(message):
    status(message)
    status('a log has been recorded in %s' % log_path)
    sys.exit(1)

def hotcopy_repo():
    """Use trac-admin to hotcopy the trac environnement into `root'"""

    dest = os.path.join(root, name)
    if subprocess.call(['sudo', 'trac-admin', trac_env_root, 'hotcopy', dest],
                       stdout=log, stderr=log) != 0:
        die('error while copying the Trac environnement into a temporary directory')

    subprocess.call(['sudo', 'chown', '-R', 'ubuntu:ubuntu', dest])

    status('Trac environnement copied')

def archive_repo():
    """Create a tar bzipped archive of the trac environnement"""

    try:
        archive = tarfile.open(os.path.join(root, archive_name), 'w:bz2')
        archive.add(os.path.join(root, name), 'backup-tracenv-%s' % name)
        archive.close()
    except tarfile.TarError, ex:
        die('Can\'t create the tar archive %s: %s' % (archive_name, str(ex)))

    status('Archive %s created' % archive_name)

def send_repo():
    """Send the tar to archive using scp"""

    dest = sys.argv[2]
    archive = os.path.join(root, archive_name)
    if subprocess.call(['scp', archive, dest]) != 0:
        die('error while scpying %s to %s' % (archive_name, dest))

    status('Archive %s copied to "%s"' % (archive_name, dest))

if __name__ == '__main__':
    if len(sys.argv) != 3 or sys.argv[1] == '--help':
        print 'Usage: %s project-name [[user@]host:]path' % os.path.basename(sys.argv[0])
        sys.exit(0)

    # globals
    name = sys.argv[1]
    archive_name = 'backup-tracenv-%s.tar.bz2' % name
    log_path = os.path.join(os.getenv('TMP') or '/tmp/', name + '.log')
    trac_env_root = os.path.join('/var/trac/envs/', name)

    if not os.path.exists(trac_env_root):
        status('%s: %s' % (name, os.strerror(errno.ENOENT)))
        sys.exit(1)

    with open(log_path, 'w') as log:
        with TempDir() as root:
            status('root=%s' % root)
            hotcopy_repo()
            archive_repo()
            send_repo()
    os.remove(log_path)

    sys.exit(0)