#!/usr/bin/python
# -*- coding: utf-8 -*-

# (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/>.

# I wanted to keep this simple at first, so for now this checks out
# from the given branch of a repo at a particular SHA or
# tag.  Latest is not supported, you should not be doing
# that. Contribs welcome! -- MPD

# requires subversion and grep on the client.

import re

def get_version(dest):
    ''' samples the version of the git repo '''
    os.chdir(dest)
    cmd = "svn info"
    revision = filter(lambda l: re.search('Revision',l) != None,os.popen(cmd).read().splitlines())
    url = filter(lambda l: re.search('^URL',l) != None,os.popen(cmd).read().splitlines())
    return [revision[0],url[0]]

def checkout(repo, dest):
    ''' makes a new svn repo if it does not already exist '''
    cmd = "svn co %s %s" % (repo, dest)
    cmd = subprocess.Popen(cmd, shell=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    (out, err) = cmd.communicate()
    rc = cmd.returncode
    return (rc, out, err)

def switch(repo, dest):
    ''' makes a new svn repo if it does not already exist '''
    cmd = "svn sw %s %s" % (repo, dest)
    cmd = subprocess.Popen(cmd, shell=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    (out, err) = cmd.communicate()
    rc = cmd.returncode
    return (rc, out, err)

def has_local_mods(dest):
    os.chdir(dest)
    cmd = "svn status"
    words = os.popen(cmd).read()
    splitup = words.splitlines()
    filtered = filter(lambda c: re.search('^\\?.*$',c) == None,splitup)
    return len(filtered) > 0

def reset(dest,force):
    '''
    Reset the repo:
     force: if true, then remove any local modifications. Else, fail if there are local modifications
    '''
    if has_local_mods(dest):
        if force:
            cmd = "svn revert -R ."
            cmd = subprocess.Popen(cmd, shell=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
            (out, err) = cmd.communicate()
            rc = cmd.returncode
            return (rc, out, err)
        else:
            return (-1,"ERROR: modified files exist in the repository.","")
    return (0,"","")

def update(module, dest, version):
    ''' update an existing svn repo '''
    os.chdir(dest)
    cmd = ''
    if version != 'HEAD':
        cmd = "svn up -r %s" % version
    else:
        cmd = "svn up"
    cmd = subprocess.Popen(cmd, shell=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    (out, err) = cmd.communicate()
    rc = cmd.returncode
    return (rc, out, err)

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

def main():
    module = AnsibleModule(
        argument_spec = dict(
            dest=dict(required=True),
            repo=dict(required=True, aliases=['name']),
            revision=dict(default='HEAD'),
            force=dict(default='no', choices=['yes', 'no'], aliases=['force'])
        )
    )

    dest     = module.params['dest']
    repo     = module.params['repo']
    revision = module.params['revision']
    force    = module.boolean(module.params['force'])

    rc, out, err, status = (0, None, None, None)

    # if there is no .svn folder, do a checkout
    # else update.
    before = None
    local_mods = False
    if not os.path.exists("%s/.svn" % (dest)):
        if os.path.exists(dest):
            module.fail_json(msg="%s folder already exists, but its not a subversion repository." % (dest))
        else:
            (rc, out, err) = checkout(repo, dest)
            if rc != 0:
                module.fail_json(msg=err)
    else:
        local_mods = has_local_mods(dest)
        # else do an update
        before = get_version(dest)
        (rc, out, err) = reset(dest,force)
        if rc != 0:
            module.fail_json(msg=err)
        (rc, out, err) = switch(repo, dest)
        if rc != 0:
            module.fail_json(msg=err)

    # handle errors from switch or pull
    if err.find('ERROR') != -1:
        module.fail_json(msg=err)

    # switch to version specified regardless of whether
    # we cloned or pulled
    (rc, out, err) = update(module, dest, revision)
    if rc != 0:
        module.fail_json(msg=err)

    # determine if we changed anything
    after = get_version(dest)
    changed = False

    if before != after or local_mods:
        changed = True

    module.exit_json(changed=changed, before=before, after=after)

# include magic from lib/ansible/module_common.py
#<<INCLUDE_ANSIBLE_MODULE_COMMON>>
main()