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

# (c) 2013, Yap Sok Ann
# Written by Yap Sok Ann <sokann@gmail.com>
# Based on apt module written by Matthew Williams <matthew@flowroute.com>
#
# This module 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 software 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 software.  If not, see <http://www.gnu.org/licenses/>.


DOCUMENTATION = '''
---
module: portage
short_description: Package manager for Gentoo
description:
  - Manages Gentoo packages

version_added: "1.4"

options:
  package:
    description:
      - Package atom or set, e.g. C(sys-apps/foo) or C(>foo-2.13) or C(@world)
    required: false
    default: null

  state:
    description:
      - State of the package atom
    required: false
    default: "present"
    choices: [ "present", "installed", "emerged", "absent", "removed", "unmerged" ]

  update:
    description:
      - Update packages to the best version available (--update)
    required: false
    default: null
    choices: [ "yes" ]

  deep:
    description:
      - Consider the entire dependency tree of packages (--deep)
    required: false
    default: null
    choices: [ "yes" ]

  newuse:
    description:
      - Include installed packages where USE flags have changed (--newuse)
    required: false
    default: null
    choices: [ "yes" ]

  oneshot:
    description:
      - Do not add the packages to the world file (--oneshot)
    required: false
    default: null
    choices: [ "yes" ]

  noreplace:
    description:
      - Do not re-emerge installed packages (--noreplace)
    required: false
    default: null
    choices: [ "yes" ]

  nodeps:
    description:
      - Only merge packages but not their dependencies (--nodeps)
    required: false
    default: null
    choices: [ "yes" ]

  onlydeps:
    description:
      - Only merge packages' dependencies but not the packages (--onlydeps)
    required: false
    default: null
    choices: [ "yes" ]

  depclean:
    description:
      - Remove packages not needed by explicitly merged packages (--depclean)
      - If no package is specified, clean up the world's dependencies
      - Otherwise, --depclean serves as a dependency aware version of --unmerge
    required: false
    default: null
    choices: [ "yes" ]

  quiet:
    description:
      - Run emerge in quiet mode (--quiet)
    required: false
    default: null
    choices: [ "yes" ]

  verbose:
    description:
      - Run emerge in verbose mode (--verbose)
    required: false
    default: null
    choices: [ "yes" ]

  sync:
    description:
      - Sync package repositories first
      - If yes, perform "emerge --sync"
      - If web, perform "emerge-webrsync"
    required: false
    default: null
    choices: [ "yes", "web" ]

requirements: [ gentoolkit ]
author: Yap Sok Ann
notes:  []
'''

EXAMPLES = '''
# Make sure package foo is installed
- portage: package=foo state=present

# Make sure package foo is not installed
- portage: package=foo state=absent

# Update package foo to the "best" version
- portage: package=foo update=yes

# Sync repositories and update world
- portage: package=@world update=yes deep=yes sync=yes

# Remove unneeded packages
- portage: depclean=yes

# Remove package foo if it is not explicitly needed
- portage: package=foo state=absent depclean=yes
'''


import os
import pipes


def query_package(module, package, action):
    if package.startswith('@'):
        return query_set(module, package, action)
    return query_atom(module, package, action)


def query_atom(module, atom, action):
    cmd = '%s list %s' % (module.equery_path, atom)

    rc, out, err = module.run_command(cmd)
    return rc == 0


def query_set(module, set, action):
    system_sets = [
        '@live-rebuild',
        '@module-rebuild',
        '@preserved-rebuild',
        '@security',
        '@selected',
        '@system',
        '@world',
        '@x11-module-rebuild',
    ]

    if set in system_sets:
        if action == 'unmerge':
            module.fail_json(msg='set %s cannot be removed' % set)
        return False

    world_sets_path = '/var/lib/portage/world_sets'
    if not os.path.exists(world_sets_path):
        return False

    cmd = 'grep %s %s' % (set, world_sets_path)

    rc, out, err = module.run_command(cmd)
    return rc == 0


def sync_repositories(module, webrsync=False):
    if module.check_mode:
        module.fail_json(msg='check mode not supported by sync')

    if webrsync:
        webrsync_path = module.get_bin_path('emerge-webrsync', required=True)
        cmd = '%s --quiet' % webrsync_path
    else:
        cmd = '%s --sync --quiet' % module.emerge_path

    rc, out, err = module.run_command(cmd)
    if rc != 0:
        module.fail_json(msg='could not sync package repositories')


# Note: In the 3 functions below, equery is done one-by-one, but emerge is done
# in one go. If that is not desirable, split the packages into multiple tasks
# instead of joining them together with comma.


def emerge_packages(module, packages):
    p = module.params

    if not (p['update'] or p['noreplace']):
        for package in packages:
            if not query_package(module, package, 'emerge'):
                break
        else:
            module.exit_json(changed=False, msg='Packages already present.')

    args = []
    for flag in [
        'update', 'deep', 'newuse',
        'oneshot', 'noreplace',
        'nodeps', 'onlydeps',
        'quiet', 'verbose',
    ]:
        if p[flag]:
            args.append('--%s' % flag)

    cmd, (rc, out, err) = run_emerge(module, packages, *args)
    if rc != 0:
        module.fail_json(
            cmd=cmd, rc=rc, stdout=out, stderr=err,
            msg='Packages not installed.',
        )

    changed = True
    for line in out.splitlines():
        if line.startswith('>>> Emerging (1 of'):
            break
    else:
        changed = False

    module.exit_json(
        changed=changed, cmd=cmd, rc=rc, stdout=out, stderr=err,
        msg='Packages installed.',
    )


def unmerge_packages(module, packages):
    p = module.params

    for package in packages:
        if query_package(module, package, 'unmerge'):
            break
    else:
        module.exit_json(changed=False, msg='Packages already absent.')

    args = ['--unmerge']

    for flag in ['quiet', 'verbose']:
        if p[flag]:
            args.append('--%s' % flag)

    cmd, (rc, out, err) = run_emerge(module, packages, *args)

    if rc != 0:
        module.fail_json(
            cmd=cmd, rc=rc, stdout=out, stderr=err,
            msg='Packages not removed.',
        )

    module.exit_json(
        changed=True, cmd=cmd, rc=rc, stdout=out, stderr=err,
        msg='Packages removed.',
    )


def cleanup_packages(module, packages):
    p = module.params

    if packages:
        for package in packages:
            if query_package(module, package, 'unmerge'):
                break
        else:
            module.exit_json(changed=False, msg='Packages already absent.')

    args = ['--depclean']

    for flag in ['quiet', 'verbose']:
        if p[flag]:
            args.append('--%s' % flag)

    cmd, (rc, out, err) = run_emerge(module, packages, *args)
    if rc != 0:
        module.fail_json(cmd=cmd, rc=rc, stdout=out, stderr=err)

    removed = 0
    for line in out.splitlines():
        if not line.startswith('Number removed:'):
            continue
        parts = line.split(':')
        removed = int(parts[1].strip())
    changed = removed > 0

    module.exit_json(
        changed=changed, cmd=cmd, rc=rc, stdout=out, stderr=err,
        msg='Depclean completed.',
    )


def run_emerge(module, packages, *args):
    args = list(args)

    if module.check_mode:
        args.append('--pretend')

    cmd = [module.emerge_path] + args + packages
    return cmd, module.run_command(cmd)


portage_present_states = ['present', 'emerged', 'installed']
portage_absent_states = ['absent', 'unmerged', 'removed']


def main():
    module = AnsibleModule(
        argument_spec=dict(
            package=dict(default=None, aliases=['name']),
            state=dict(
                default=portage_present_states[0],
                choices=portage_present_states + portage_absent_states,
            ),
            update=dict(default=None, choices=['yes']),
            deep=dict(default=None, choices=['yes']),
            newuse=dict(default=None, choices=['yes']),
            oneshot=dict(default=None, choices=['yes']),
            noreplace=dict(default=None, choices=['yes']),
            nodeps=dict(default=None, choices=['yes']),
            onlydeps=dict(default=None, choices=['yes']),
            depclean=dict(default=None, choices=['yes']),
            quiet=dict(default=None, choices=['yes']),
            verbose=dict(default=None, choices=['yes']),
            sync=dict(default=None, choices=['yes', 'web']),
        ),
        required_one_of=[['package', 'sync', 'depclean']],
        mutually_exclusive=[['nodeps', 'onlydeps'], ['quiet', 'verbose']],
        supports_check_mode=True,
    )

    module.emerge_path = module.get_bin_path('emerge', required=True)
    module.equery_path = module.get_bin_path('equery', required=True)

    p = module.params

    if p['sync']:
        sync_repositories(module, webrsync=(p['sync'] == 'web'))
        if not p['package']:
            return

    packages = p['package'].split(',') if p['package'] else []

    if p['depclean']:
        if packages and p['state'] not in portage_absent_states:
            module.fail_json(
                msg='Depclean can only be used with package when the state is '
                    'one of: %s' % portage_absent_states,
            )

        cleanup_packages(module, packages)

    elif p['state'] in portage_present_states:
        emerge_packages(module, packages)

    elif p['state'] in portage_absent_states:
        unmerge_packages(module, packages)


# this is magic, see lib/ansible/module_common.py
#<<INCLUDE_ANSIBLE_MODULE_COMMON>>

main()