#!/usr/bin/python

# (c) 2012, Michael DeHaan <michael.dehaan@gmail.com>
#
# This file is part of Ansible
#
# Ansible 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.
#
# Ansible 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 Ansible.  If not, see <http://www.gnu.org/licenses/>.
#

import sys
import os
import shlex
import shutil
import syslog

try:
    import hashlib
    HAVE_HASHLIB=True
except ImportError:
    import md5
    HAVE_HASHLIB=False

# ===========================================
# convert arguments of form a=b c=d
# to a dictionary
# FIXME: make more idiomatic

def dump_kv(vars):
    return " ".join("%s='%s'" % (k,v) for (k,v) in vars.items())

def exit_kv(rc=0, **kwargs):
    if 'path' in kwargs:
        add_path_info(kwargs)
    print dump_kv(kwargs)
    sys.exit(rc)

def local_md5(filename):
     ''' compute local md5sum, return None if file is not present '''
     if os.path.exists(filename):
         md5val=None
         if os.path.exists(filename):
             if HAVE_HASHLIB:
                 md5val=hashlib.md5(file(filename).read()).hexdigest()
             else:
                 md5val=md5.new(file(filename).read()).hexdigest()
         return md5val
     else:
         return None

# ===========================================

if len(sys.argv) == 1:
    exit_kv(rc=1, failed=1, msg="incorrect number of arguments given")

argfile = sys.argv[1]
if not os.path.exists(argfile):
    exit_kv(rc=1, failed=1, msg="file %s does not exist" % (argfile))

args = open(argfile, 'r').read()
items = shlex.split(args)
syslog.openlog('ansible-%s' % os.path.basename(__file__))
syslog.syslog(syslog.LOG_NOTICE, 'Invoked with %s' % args)


params = {}
for x in items:
    (k, v) = x.split("=")
    params[k] = v

src  = params['src']
dest = params['dest']
if src:
    src = os.path.expanduser(src)
if dest:
    dest = os.path.expanduser(dest)

md5sum_src = None
# raise an error if there is no src file
if not os.path.exists(src):
    exit_kv(rc=1, failed=1, msg="Source %s failed to transfer" % (src))
if not os.access(src, os.R_OK):
    exit_kv(rc=1, failed=1, msg="Source %s not readable" % (src))
md5sum_src = local_md5(src)

md5sum_dest = None
# check if there is no dest file
if os.path.exists(dest):
    # raise an error if copy has no permission on dest
    if not os.access(dest, os.W_OK):
        exit_kv(rc=1, failed=1, msg="Destination %s not writable" % (dest))
    if not os.access(dest, os.R_OK):
        exit_kv(rc=1, failed=1, msg="Destination %s not readable" % (dest))
    md5sum_dest = local_md5(dest)
else:
    if not os.access(os.path.dirname(dest), os.W_OK):
        exit_kv(rc=1, failed=1, msg="Destination %s not writable" % (os.path.dirname(dest)))

if md5sum_src != md5sum_dest:
    # was os.system("cp %s %s" % (src, dest))
    try:
        shutil.copyfile(src, dest)
    except shutil.Error:
        exit_kv(rc=1, failed=1, msg="failed to copy: %s and %s are the same" % (src, dest)) 
    except IOError:
        exit_kv(rc=1, failed=1, msg="failed to copy: %s to %s" % (src, dest)) 
    changed = True
else:
    changed = False

# mission accomplished
#print "md5sum=%s changed=%s" % (md5sum_src, changed)
exit_kv(dest=dest, src=src, md5sum=md5sum_src, changed=changed)