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

# (c) 2013, André Paramés <git@andreparames.com>
# Based on the Git module by 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/>.

DOCUMENTATION = u'''
---
module: bzr
author: André Paramés
version_added: 0.0.1
short_description: Deploy software (or files) from bzr branches
description:
    - Manage I(bzr) branches to deploy files or software.
options:
    parent:
        required: true
        aliases: [ name ]
        description:
            - SSH or HTTP protocol address of the parent branch.
    dest:
        required: true
        description:
            - Absolute path of where the branch should be cloned to.
    version:
        required: false
        default: "head"
        description:
            - What version of the branch to clone.  This can be the
              bzr revno or revid.
    force:
        required: false
        default: "yes"
        choices: [ yes, no ]
        description:
            - If C(yes), any modified files in the working
              tree will be discarded.
examples:
    - code: "bzr parent=bzr+ssh://foosball.example.org/path/to/branch dest=/srv/checkout version=22"
      description: Example bzr checkout from Ansible Playbooks
'''

import re
import tempfile

def get_version(dest):
    ''' samples the version of the bzr branch'''
    os.chdir(dest)
    cmd = "bzr revno"
    revno = os.popen(cmd).read().strip()
    return revno

def clone(module, parent, dest, version):
    ''' makes a new bzr branch if it does not already exist '''
    dest_dirname = os.path.dirname(dest)
    try:
        os.makedirs(dest_dirname)
    except:
        pass
    os.chdir(dest_dirname)
    if version.lower() != 'head':
        cmd = "bzr branch -r %s %s %s" % (version, parent, dest)
    else:
        cmd = "bzr branch %s %s" % (parent, dest)
    return module.run_command(cmd, check_rc=True)

def has_local_mods(dest):
    os.chdir(dest)
    cmd = "bzr status -S"
    lines = os.popen(cmd).read().splitlines()
    lines = filter(lambda c: not re.search('^\\?\\?.*$', c), lines)
    return len(lines) > 0

def reset(module,dest,force):
    '''
    Resets the index and working tree to head.
    Discards any changes to tracked files in the working
    tree since that commit.
    '''
    os.chdir(dest)
    if not force and has_local_mods(dest):
        module.fail_json(msg="Local modifications exist in branch (force=no).")
    return module.run_command("bzr revert", check_rc=True)

def fetch(module, dest, version):
    ''' updates branch from remote sources '''
    os.chdir(dest)
    if version.lower() != 'head':
        (rc, out, err) = module.run_command("bzr pull -r %s" % version)
    else:
        (rc, out, err) = module.run_command("bzr pull")
    if rc != 0:
        module.fail_json(msg="Failed to pull")
    return (rc, out, err)

def switch_version(module, dest, version):
    ''' once pulled, switch to a particular revno or revid'''
    os.chdir(dest)
    cmd = ''
    if version.lower() != 'head':
        cmd = "bzr revert -r %s" % version
    else:
        cmd = "bzr revert"
    return module.run_command(cmd, check_rc=True)

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

def main():
    module = AnsibleModule(
        argument_spec = dict(
            dest=dict(required=True),
            parent=dict(required=True, aliases=['name']),
            version=dict(default='head'),
            force=dict(default='yes', type='bool')
        )
    )

    dest    = os.path.abspath(os.path.expanduser(module.params['dest']))
    parent  = module.params['parent']
    version = module.params['version']
    force   = module.params['force']

    bzrconfig = os.path.join(dest, '.bzr', 'branch', 'branch.conf')

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

    # if there is no bzr configuration, do a branch operation
    # else pull and switch the version
    before = None
    local_mods = False
    if not os.path.exists(bzrconfig):
        (rc, out, err) = clone(module, parent, dest, version)
    else:
        # else do a pull
        local_mods = has_local_mods(dest)
        before = get_version(dest)
        (rc, out, err) = reset(module, dest, force)
        if rc != 0:
            module.fail_json(msg=err)
        (rc, out, err) = fetch(module, dest, version)
        if rc != 0:
            module.fail_json(msg=err)

    # switch to version specified regardless of whether
    # we cloned or pulled
    (rc, out, err) = switch_version(module, dest, version)

    # 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()