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

# (c) 2013, Daniel Jaouen <dcj24@cornell.edu>
# (c) 2016, Indrajit Raychaudhuri <irc+code@indrajit.com>
#
# Based on homebrew (Andrew Dunham <andrew@du.nham.ca>)
#
# 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: homebrew_tap
author:
    - "Indrajit Raychaudhuri (@indrajitr)"
    - "Daniel Jaouen (@danieljaouen)"
short_description: Tap a Homebrew repository.
description:
    - Tap external Homebrew repositories.
options:
    name:
        description:
            - The GitHub user/organization repository to tap.
        required: true
        aliases: ['tap']
        type: list
        elements: str
    url:
        description:
            - The optional git URL of the repository to tap. The URL is not
              assumed to be on GitHub, and the protocol doesn't have to be HTTP.
              Any location and protocol that git can handle is fine.
            - I(name) option may not be a list of multiple taps (but a single
              tap instead) when this option is provided.
        required: false
        type: str
    state:
        description:
            - state of the repository.
        choices: [ 'present', 'absent' ]
        required: false
        default: 'present'
        type: str
requirements: [ homebrew ]
'''

EXAMPLES = '''
- name: Tap a Homebrew repository, state present
  homebrew_tap:
    name: homebrew/dupes

- name: Tap a Homebrew repository, state absent
  homebrew_tap:
    name: homebrew/dupes
    state: absent

- name: Tap a Homebrew repository, state present
  homebrew_tap:
    name: homebrew/dupes,homebrew/science
    state: present

- name: Tap a Homebrew repository using url, state present
  homebrew_tap:
    name: telemachus/brew
    url: 'https://bitbucket.org/telemachus/brew'
'''

import re

from ansible.module_utils.basic import AnsibleModule


def a_valid_tap(tap):
    '''Returns True if the tap is valid.'''
    regex = re.compile(r'^([\w-]+)/(homebrew-)?([\w-]+)$')
    return regex.match(tap)


def already_tapped(module, brew_path, tap):
    '''Returns True if already tapped.'''

    rc, out, err = module.run_command([
        brew_path,
        'tap',
    ])

    taps = [tap_.strip().lower() for tap_ in out.split('\n') if tap_]
    tap_name = re.sub('homebrew-', '', tap.lower())

    return tap_name in taps


def add_tap(module, brew_path, tap, url=None):
    '''Adds a single tap.'''
    failed, changed, msg = False, False, ''

    if not a_valid_tap(tap):
        failed = True
        msg = 'not a valid tap: %s' % tap

    elif not already_tapped(module, brew_path, tap):
        if module.check_mode:
            module.exit_json(changed=True)

        rc, out, err = module.run_command([
            brew_path,
            'tap',
            tap,
            url,
        ])
        if rc == 0:
            changed = True
            msg = 'successfully tapped: %s' % tap
        else:
            failed = True
            msg = 'failed to tap: %s' % tap

    else:
        msg = 'already tapped: %s' % tap

    return (failed, changed, msg)


def add_taps(module, brew_path, taps):
    '''Adds one or more taps.'''
    failed, unchanged, added, msg = False, 0, 0, ''

    for tap in taps:
        (failed, changed, msg) = add_tap(module, brew_path, tap)
        if failed:
            break
        if changed:
            added += 1
        else:
            unchanged += 1

    if failed:
        msg = 'added: %d, unchanged: %d, error: ' + msg
        msg = msg % (added, unchanged)
    elif added:
        changed = True
        msg = 'added: %d, unchanged: %d' % (added, unchanged)
    else:
        msg = 'added: %d, unchanged: %d' % (added, unchanged)

    return (failed, changed, msg)


def remove_tap(module, brew_path, tap):
    '''Removes a single tap.'''
    failed, changed, msg = False, False, ''

    if not a_valid_tap(tap):
        failed = True
        msg = 'not a valid tap: %s' % tap

    elif already_tapped(module, brew_path, tap):
        if module.check_mode:
            module.exit_json(changed=True)

        rc, out, err = module.run_command([
            brew_path,
            'untap',
            tap,
        ])
        if not already_tapped(module, brew_path, tap):
            changed = True
            msg = 'successfully untapped: %s' % tap
        else:
            failed = True
            msg = 'failed to untap: %s' % tap

    else:
        msg = 'already untapped: %s' % tap

    return (failed, changed, msg)


def remove_taps(module, brew_path, taps):
    '''Removes one or more taps.'''
    failed, unchanged, removed, msg = False, 0, 0, ''

    for tap in taps:
        (failed, changed, msg) = remove_tap(module, brew_path, tap)
        if failed:
            break
        if changed:
            removed += 1
        else:
            unchanged += 1

    if failed:
        msg = 'removed: %d, unchanged: %d, error: ' + msg
        msg = msg % (removed, unchanged)
    elif removed:
        changed = True
        msg = 'removed: %d, unchanged: %d' % (removed, unchanged)
    else:
        msg = 'removed: %d, unchanged: %d' % (removed, unchanged)

    return (failed, changed, msg)


def main():
    module = AnsibleModule(
        argument_spec=dict(
            name=dict(aliases=['tap'], type='list', required=True, elements='str'),
            url=dict(default=None, required=False),
            state=dict(default='present', choices=['present', 'absent']),
        ),
        supports_check_mode=True,
    )

    brew_path = module.get_bin_path(
        'brew',
        required=True,
        opt_dirs=['/usr/local/bin']
    )

    taps = module.params['name']
    url = module.params['url']

    if module.params['state'] == 'present':
        if url is None:
            # No tap URL provided explicitly, continue with bulk addition
            # of all the taps.
            failed, changed, msg = add_taps(module, brew_path, taps)
        else:
            # When an tap URL is provided explicitly, we allow adding
            # *single* tap only. Validate and proceed to add single tap.
            if len(taps) > 1:
                msg = "List of multiple taps may not be provided with 'url' option."
                module.fail_json(msg=msg)
            else:
                failed, changed, msg = add_tap(module, brew_path, taps[0], url)

        if failed:
            module.fail_json(msg=msg)
        else:
            module.exit_json(changed=changed, msg=msg)

    elif module.params['state'] == 'absent':
        failed, changed, msg = remove_taps(module, brew_path, taps)

        if failed:
            module.fail_json(msg=msg)
        else:
            module.exit_json(changed=changed, msg=msg)


if __name__ == '__main__':
    main()
