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

# (c) 2015, Marius Gedminas <marius@pov.lt>
# (c) 2016, Matthew Gamble <git@matthewgamble.net>
#
# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)

from __future__ import absolute_import, division, print_function
__metaclass__ = type


DOCUMENTATION = '''
---
module: git_config
author:
  - Matthew Gamble (@djmattyg007)
  - Marius Gedminas (@mgedmin)
requirements: ['git']
short_description: Read and write git configuration
description:
  - The C(git_config) module changes git configuration by invoking 'git config'.
    This is needed if you don't want to use M(template) for the entire git
    config file (e.g. because you need to change just C(user.email) in
    /etc/.git/config).  Solutions involving M(command) are cumbersome or
    don't work correctly in check mode.
options:
  list_all:
    description:
      - List all settings (optionally limited to a given I(scope))
    type: bool
    default: 'no'
  name:
    description:
      - The name of the setting. If no value is supplied, the value will
        be read from the config if it has been set.
  repo:
    description:
      - Path to a git repository for reading and writing values from a
        specific repo.
  scope:
    description:
      - Specify which scope to read/set values from. This is required
        when setting config values. If this is set to local, you must
        also specify the repo parameter. It defaults to system only when
        not using I(list_all)=yes.
    choices: [ "local", "global", "system" ]
  state:
    description:
      - "Indicates the setting should be set/unset.
        This parameter has higher precedence than I(value) parameter:
        when I(state)=absent and I(value) is defined, I(value) is discarded."
    choices: [ 'present', 'absent' ]
    default: 'present'
  value:
    description:
      - When specifying the name of a single setting, supply a value to
        set that setting to the given value.
'''

EXAMPLES = '''
# Set some settings in ~/.gitconfig
- git_config:
    name: alias.ci
    scope: global
    value: commit

- git_config:
    name: alias.st
    scope: global
    value: status

# Unset some settings in ~/.gitconfig
- git_config:
    name: alias.ci
    scope: global
    state: absent

# Or system-wide:
- git_config:
    name: alias.remotev
    scope: system
    value: remote -v

- git_config:
    name: core.editor
    scope: global
    value: vim

# scope=system is the default
- git_config:
    name: alias.diffc
    value: diff --cached

- git_config:
    name: color.ui
    value: auto

# Make etckeeper not complain when invoked by cron
- git_config:
    name: user.email
    repo: /etc
    scope: local
    value: 'root@{{ ansible_fqdn }}'

# Read individual values from git config
- git_config:
    name: alias.ci
    scope: global

# scope: system is also assumed when reading values, unless list_all=yes
- git_config:
    name: alias.diffc

# Read all values from git config
- git_config:
    list_all: yes
    scope: global

# When list_all=yes and no scope is specified, you get configuration from all scopes
- git_config:
    list_all: yes

# Specify a repository to include local settings
- git_config:
    list_all: yes
    repo: /path/to/repo.git
'''

RETURN = '''
---
config_value:
  description: When list_all=no and value is not set, a string containing the value of the setting in name
  returned: success
  type: str
  sample: "vim"

config_values:
  description: When list_all=yes, a dict containing key/value pairs of multiple configuration settings
  returned: success
  type: dict
  sample:
    core.editor: "vim"
    color.ui: "auto"
    alias.diffc: "diff --cached"
    alias.remotev: "remote -v"
'''
from ansible.module_utils.basic import AnsibleModule
from ansible.module_utils.six.moves import shlex_quote


def main():
    module = AnsibleModule(
        argument_spec=dict(
            list_all=dict(required=False, type='bool', default=False),
            name=dict(type='str'),
            repo=dict(type='path'),
            scope=dict(required=False, type='str', choices=['local', 'global', 'system']),
            state=dict(required=False, type='str', default='present', choices=['present', 'absent']),
            value=dict(required=False)
        ),
        mutually_exclusive=[['list_all', 'name'], ['list_all', 'value'], ['list_all', 'state']],
        required_if=[('scope', 'local', ['repo'])],
        required_one_of=[['list_all', 'name']],
        supports_check_mode=True,
    )
    git_path = module.get_bin_path('git', True)

    params = module.params
    # We check error message for a pattern, so we need to make sure the messages appear in the form we're expecting.
    # Set the locale to C to ensure consistent messages.
    module.run_command_environ_update = dict(LANG='C', LC_ALL='C', LC_MESSAGES='C', LC_CTYPE='C')

    if params['name']:
        name = params['name']
    else:
        name = None

    if params['scope']:
        scope = params['scope']
    elif params['list_all']:
        scope = None
    else:
        scope = 'system'

    if params['state'] == 'absent':
        unset = 'unset'
        params['value'] = None
    else:
        unset = None

    if params['value']:
        new_value = params['value']
    else:
        new_value = None

    args = [git_path, "config", "--includes"]
    if params['list_all']:
        args.append('-l')
    if scope:
        args.append("--" + scope)
    if name:
        args.append(name)

    if scope == 'local':
        dir = params['repo']
    elif params['list_all'] and params['repo']:
        # Include local settings from a specific repo when listing all available settings
        dir = params['repo']
    else:
        # Run from root directory to avoid accidentally picking up any local config settings
        dir = "/"

    (rc, out, err) = module.run_command(' '.join(args), cwd=dir)
    if params['list_all'] and scope and rc == 128 and 'unable to read config file' in err:
        # This just means nothing has been set at the given scope
        module.exit_json(changed=False, msg='', config_values={})
    elif rc >= 2:
        # If the return code is 1, it just means the option hasn't been set yet, which is fine.
        module.fail_json(rc=rc, msg=err, cmd=' '.join(args))

    if params['list_all']:
        values = out.rstrip().splitlines()
        config_values = {}
        for value in values:
            k, v = value.split('=', 1)
            config_values[k] = v
        module.exit_json(changed=False, msg='', config_values=config_values)
    elif not new_value and not unset:
        module.exit_json(changed=False, msg='', config_value=out.rstrip())
    elif unset and not out:
        module.exit_json(changed=False, msg='no setting to unset')
    else:
        old_value = out.rstrip()
        if old_value == new_value:
            module.exit_json(changed=False, msg="")

    if not module.check_mode:
        if unset:
            args.insert(len(args) - 1, "--" + unset)
            cmd = ' '.join(args)
        else:
            new_value_quoted = shlex_quote(new_value)
            cmd = ' '.join(args + [new_value_quoted])
        (rc, out, err) = module.run_command(cmd, cwd=dir)
        if err:
            module.fail_json(rc=rc, msg=err, cmd=cmd)

    module.exit_json(
        msg='setting changed',
        diff=dict(
            before_header=' '.join(args),
            before=old_value + "\n",
            after_header=' '.join(args),
            after=(new_value or '') + "\n"
        ),
        changed=True
    )


if __name__ == '__main__':
    main()