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

# Copyright: (c) 2021, Sergey Mikhaltsov <metanovii@gmail.com>
# Copyright: (c) 2020, Zainab Alsaffar <Zainab.Alsaffar@mail.rit.edu>
# 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 = r'''
---
module: gitlab_project_members
short_description: Manage project members on GitLab Server
version_added: 2.2.0
description:
    - This module allows to add and remove members to/from a project, or change a member's access level in a project on GitLab.
author:
    - Sergey Mikhaltsov (@metanovii)
    - Zainab Alsaffar (@zanssa)
requirements:
    - python-gitlab python module <= 1.15.0
    - owner or maintainer rights to project on the GitLab server
options:
    api_token:
        description:
            - A personal access token to authenticate with the GitLab API.
        required: true
        type: str
    validate_certs:
        description:
            - Whether or not to validate TLS/SSL certificates when supplying a HTTPS endpoint.
            - Should only be set to C(false) if you can guarantee that you are talking to the correct server
              and no man-in-the-middle attack can happen.
        default: true
        type: bool
    api_username:
        description:
            - The username to use for authentication against the API.
        type: str
    api_password:
        description:
            - The password to use for authentication against the API.
        type: str
    api_url:
        description:
            - The resolvable endpoint for the API.
        type: str
    project:
        description:
            - The name of the GitLab project the member is added to/removed from.
        required: true
        type: str
    gitlab_user:
        description:
            - The username of the member to add to/remove from the GitLab project.
        required: true
        type: str
    access_level:
        description:
            - The access level for the user.
            - Required if I(state=present), user state is set to present.
        type: str
        choices: ['guest', 'reporter', 'developer', 'maintainer']
    state:
        description:
            - State of the member in the project.
            - On C(present), it adds a user to a GitLab project.
            - On C(absent), it removes a user from a GitLab project.
        choices: ['present', 'absent']
        default: 'present'
        type: str
notes:
    - Supports C(check_mode).
'''

EXAMPLES = r'''
- name: Add a user to a GitLab Project
  community.general.gitlab_project_members:
    api_url: 'https://gitlab.example.com'
    api_token: 'Your-Private-Token'
    validate_certs: True
    project: projectname
    gitlab_user: username
    access_level: developer
    state: present

- name: Remove a user from a GitLab project
  community.general.gitlab_project_members:
    api_url: 'https://gitlab.example.com'
    api_token: 'Your-Private-Token'
    validate_certs: False
    project: projectname
    gitlab_user: username
    state: absent
'''

RETURN = r''' # '''

from ansible.module_utils.api import basic_auth_argument_spec
from ansible.module_utils.basic import AnsibleModule, missing_required_lib

from ansible_collections.community.general.plugins.module_utils.gitlab import gitlabAuthentication

import traceback

try:
    import gitlab
    HAS_PY_GITLAB = True
except ImportError:
    GITLAB_IMP_ERR = traceback.format_exc()
    HAS_PY_GITLAB = False


class GitLabProjectMembers(object):
    def __init__(self, module, gl):
        self._module = module
        self._gitlab = gl

    def get_project(self, project_name):
        project_exists = self._gitlab.projects.list(search=project_name)
        if project_exists:
            return project_exists[0].id

    def get_user_id(self, gitlab_user):
        user_exists = self._gitlab.users.list(username=gitlab_user)
        if user_exists:
            return user_exists[0].id

    # get all members in a project
    def get_members_in_a_project(self, gitlab_project_id):
        project = self._gitlab.projects.get(gitlab_project_id)
        return project.members.list()

    # check if the user is a member of the project
    def is_user_a_member(self, members, gitlab_user_id):
        for member in members:
            if member.id == gitlab_user_id:
                return True
        return False

    # add user to a project
    def add_member_to_project(self, gitlab_user_id, gitlab_project_id, access_level):
        try:
            project = self._gitlab.projects.get(gitlab_project_id)
            add_member = project.members.create(
                {'user_id': gitlab_user_id, 'access_level': access_level})

            if add_member:
                return add_member.username

        except (gitlab.exceptions.GitlabCreateError) as e:
            self._module.fail_json(
                msg="Failed to add member to the project, project ID %s: %s" % (gitlab_project_id, e))

    # remove user from a project
    def remove_user_from_project(self, gitlab_user_id, gitlab_project_id):
        try:
            project = self._gitlab.projects.get(gitlab_project_id)
            project.members.delete(gitlab_user_id)

        except (gitlab.exceptions.GitlabDeleteError) as e:
            self._module.fail_json(
                msg="Failed to remove member from GitLab project, ID %s: %s" % (gitlab_project_id, e))

    # get user's access level
    def get_user_access_level(self, members, gitlab_user_id):
        for member in members:
            if member.id == gitlab_user_id:
                return member.access_level

    # update user's access level in a project
    def update_user_access_level(self, members, gitlab_user_id, access_level):
        for member in members:
            if member.id == gitlab_user_id:
                try:
                    member.access_level = access_level
                    member.save()
                except (gitlab.exceptions.GitlabCreateError) as e:
                    self._module.fail_json(
                        msg="Failed to update the access level for the member, %s: %s" % (gitlab_user_id, e))


def main():
    argument_spec = basic_auth_argument_spec()
    argument_spec.update(dict(
        api_token=dict(type='str', required=True, no_log=True),
        project=dict(type='str', required=True),
        gitlab_user=dict(type='str', required=True),
        state=dict(type='str', default='present', choices=['present', 'absent']),
        access_level=dict(type='str', required=False, choices=['guest', 'reporter', 'developer', 'maintainer'])
    ))

    module = AnsibleModule(
        argument_spec=argument_spec,
        mutually_exclusive=[
            ['api_username', 'api_token'],
            ['api_password', 'api_token'],
        ],
        required_together=[
            ['api_username', 'api_password'],
        ],
        required_one_of=[
            ['api_username', 'api_token'],
        ],
        required_if=[
            ['state', 'present', ['access_level']],
        ],
        supports_check_mode=True,
    )

    if not HAS_PY_GITLAB:
        module.fail_json(msg=missing_required_lib('python-gitlab', url='https://python-gitlab.readthedocs.io/en/stable/'), exception=GITLAB_IMP_ERR)

    gitlab_project = module.params['project']
    gitlab_user = module.params['gitlab_user']
    state = module.params['state']
    access_level = module.params['access_level']

    # convert access level string input to int
    if access_level:
        access_level_int = {
            'guest': gitlab.GUEST_ACCESS,
            'reporter': gitlab.REPORTER_ACCESS,
            'developer': gitlab.DEVELOPER_ACCESS,
            'maintainer': gitlab.MAINTAINER_ACCESS
        }

        access_level = access_level_int[access_level]

    # connect to gitlab server
    gl = gitlabAuthentication(module)

    project = GitLabProjectMembers(module, gl)

    gitlab_user_id = project.get_user_id(gitlab_user)
    gitlab_project_id = project.get_project(gitlab_project)

    # project doesn't exist
    if not gitlab_project_id:
        module.fail_json(msg="project '%s' not found." % gitlab_project)

    # user doesn't exist
    if not gitlab_user_id:
        if state == 'absent':
            module.exit_json(changed=False, result="user '%s' not found, and thus also not part of the project" % gitlab_user)
        else:
            module.fail_json(msg="user '%s' not found." % gitlab_user)

    members = project.get_members_in_a_project(gitlab_project_id)
    is_user_a_member = project.is_user_a_member(members, gitlab_user_id)

    # check if the user is a member in the project
    if not is_user_a_member:
        if state == 'present':
            # add user to the project
            if not module.check_mode:
                project.add_member_to_project(gitlab_user_id, gitlab_project_id, access_level)
            module.exit_json(changed=True, result="Successfully added user '%s' to the project." % gitlab_user)
        # state as absent
        else:
            module.exit_json(changed=False, result="User, '%s', is not a member in the project. No change to report" % gitlab_user)
    # in case that a user is a member
    else:
        if state == 'present':
            # compare the access level
            user_access_level = project.get_user_access_level(members, gitlab_user_id)
            if user_access_level == access_level:
                module.exit_json(changed=False, result="User, '%s', is already a member in the project. No change to report" % gitlab_user)
            else:
                # update the access level for the user
                if not module.check_mode:
                    project.update_user_access_level(members, gitlab_user_id, access_level)
                module.exit_json(changed=True, result="Successfully updated the access level for the user, '%s'" % gitlab_user)
        else:
            # remove the user from the project
            if not module.check_mode:
                project.remove_user_from_project(gitlab_user_id, gitlab_project_id)
            module.exit_json(changed=True, result="Successfully removed user, '%s', from the project" % gitlab_user)


if __name__ == '__main__':
    main()