#!/usr/bin/python
# Copyright (c) 2017, Ansible Project
# GNU General Public License v3.0+ (see LICENSES/GPL-3.0-or-later.txt or https://www.gnu.org/licenses/gpl-3.0.txt)
# SPDX-License-Identifier: GPL-3.0-or-later

from __future__ import annotations

DOCUMENTATION = r"""
module: ipa_user
author: Thomas Krahn (@Nosmoht)
short_description: Manage FreeIPA users
description:
  - Add, modify and delete user within IPA server.
attributes:
  check_mode:
    support: full
  diff_mode:
    support: none
options:
  displayname:
    description: Display name.
    type: str
  update_password:
    description:
      - Set password for a user.
    type: str
    default: 'always'
    choices: [always, on_create]
  givenname:
    description:
      - First name.
      - If user does not exist and O(state=present), the usage of O(givenname) is required.
    type: str
  krbpasswordexpiration:
    description:
      - Date at which the user password expires.
      - In the format YYYYMMddHHmmss.
      - For example V(20180121182022) expires on 21 January 2018 at 18:20:22.
    type: str
  loginshell:
    description: Login shell.
    type: str
  mail:
    description:
      - List of mail addresses assigned to the user.
      - If an empty list is passed all assigned email addresses are deleted.
      - If None is passed email addresses are not checked nor changed.
    type: list
    elements: str
  password:
    description:
      - Password for a user.
      - It is not set for an existing user unless O(update_password=always), which is the default.
    type: str
  sn:
    description:
      - Surname.
      - If user does not exist and O(state=present), the usage of O(sn) is required.
    type: str
  sshpubkey:
    description:
      - List of public SSH key.
      - If an empty list is passed all assigned public keys are deleted.
      - If None is passed SSH public keys are not checked nor changed.
    type: list
    elements: str
  state:
    description: State to ensure.
    default: "present"
    choices: ["absent", "disabled", "enabled", "present"]
    type: str
  telephonenumber:
    description:
      - List of telephone numbers assigned to the user.
      - If an empty list is passed all assigned telephone numbers are deleted.
      - If None is passed telephone numbers are not checked nor changed.
    type: list
    elements: str
  title:
    description: Title.
    type: str
  uid:
    description: Uid of the user.
    required: true
    aliases: ["name"]
    type: str
  uidnumber:
    description:
      - Account Settings UID/Posix User ID number.
    type: str
  gidnumber:
    description:
      - Posix Group ID.
    type: str
  homedirectory:
    description:
      - Default home directory of the user.
    type: str
    version_added: '0.2.0'
  userauthtype:
    description:
      - The authentication type to use for the user.
      - To remove all authentication types from the user, use an empty list V([]).
      - The choice V(idp) and V(passkey) has been added in community.general 8.1.0.
    choices: ["password", "radius", "otp", "pkinit", "hardened", "idp", "passkey"]
    type: list
    elements: str
    version_added: '1.2.0'
extends_documentation_fragment:
  - community.general.ipa.documentation
  - community.general.ipa.connection_notes
  - community.general.attributes

requirements:
  - base64
  - hashlib
"""

EXAMPLES = r"""
- name: Ensure pinky is present and always reset password
  community.general.ipa_user:
    name: pinky
    state: present
    krbpasswordexpiration: 20200119235959
    givenname: Pinky
    sn: Acme
    mail:
      - pinky@acme.com
    telephonenumber:
      - '+555123456'
    sshpubkey:
      - ssh-rsa ....
      - ssh-dsa ....
    uidnumber: '1001'
    gidnumber: '100'
    homedirectory: /home/pinky
    ipa_host: ipa.example.com
    ipa_user: admin
    ipa_pass: topsecret

- name: Ensure brain is absent
  community.general.ipa_user:
    name: brain
    state: absent
    ipa_host: ipa.example.com
    ipa_user: admin
    ipa_pass: topsecret

- name: Ensure pinky is present but don't reset password if already exists
  community.general.ipa_user:
    name: pinky
    state: present
    givenname: Pinky
    sn: Acme
    password: zounds
    ipa_host: ipa.example.com
    ipa_user: admin
    ipa_pass: topsecret
    update_password: on_create

- name: Ensure pinky is present and using one time password and RADIUS authentication
  community.general.ipa_user:
    name: pinky
    state: present
    userauthtype:
      - otp
      - radius
    ipa_host: ipa.example.com
    ipa_user: admin
    ipa_pass: topsecret
"""

RETURN = r"""
user:
  description: User as returned by IPA API.
  returned: always
  type: dict
"""

import base64
import hashlib
import traceback

from ansible.module_utils.basic import AnsibleModule
from ansible_collections.community.general.plugins.module_utils.ipa import IPAClient, ipa_argument_spec


class UserIPAClient(IPAClient):
    def __init__(self, module, host, port, protocol):
        super().__init__(module, host, port, protocol)

    def user_find(self, name):
        return self._post_json(method="user_find", name=None, item={"all": True, "uid": name})

    def user_add(self, name, item):
        return self._post_json(method="user_add", name=name, item=item)

    def user_mod(self, name, item):
        return self._post_json(method="user_mod", name=name, item=item)

    def user_del(self, name):
        return self._post_json(method="user_del", name=name)

    def user_disable(self, name):
        return self._post_json(method="user_disable", name=name)

    def user_enable(self, name):
        return self._post_json(method="user_enable", name=name)


def get_user_dict(
    displayname=None,
    givenname=None,
    krbpasswordexpiration=None,
    loginshell=None,
    mail=None,
    nsaccountlock=False,
    sn=None,
    sshpubkey=None,
    telephonenumber=None,
    title=None,
    userpassword=None,
    gidnumber=None,
    uidnumber=None,
    homedirectory=None,
    userauthtype=None,
):
    user = {}
    if displayname is not None:
        user["displayname"] = displayname
    if krbpasswordexpiration is not None:
        user["krbpasswordexpiration"] = f"{krbpasswordexpiration}Z"
    if givenname is not None:
        user["givenname"] = givenname
    if loginshell is not None:
        user["loginshell"] = loginshell
    if mail is not None:
        user["mail"] = mail
    user["nsaccountlock"] = nsaccountlock
    if sn is not None:
        user["sn"] = sn
    if sshpubkey is not None:
        user["ipasshpubkey"] = sshpubkey
    if telephonenumber is not None:
        user["telephonenumber"] = telephonenumber
    if title is not None:
        user["title"] = title
    if userpassword is not None:
        user["userpassword"] = userpassword
    if gidnumber is not None:
        user["gidnumber"] = gidnumber
    if uidnumber is not None:
        user["uidnumber"] = uidnumber
    if homedirectory is not None:
        user["homedirectory"] = homedirectory
    if userauthtype is not None:
        user["ipauserauthtype"] = userauthtype

    return user


def get_user_diff(client, ipa_user, module_user):
    """
        Return the keys of each dict whereas values are different. Unfortunately the IPA
        API returns everything as a list even if only a single value is possible.
        Therefore some more complexity is needed.
        The method will check if the value type of module_user.attr is not a list and
        create a list with that element if the same attribute in ipa_user is list. In this way I hope that the method
        must not be changed if the returned API dict is changed.
    :param ipa_user:
    :param module_user:
    :return:
    """
    # sshpubkeyfp is the list of ssh key fingerprints. IPA doesn't return the keys itself but instead the fingerprints.
    # These are used for comparison.
    sshpubkey = None
    if "ipasshpubkey" in module_user:
        hash_algo = "md5"
        if "sshpubkeyfp" in ipa_user and ipa_user["sshpubkeyfp"][0][:7].upper() == "SHA256:":
            hash_algo = "sha256"
        module_user["sshpubkeyfp"] = [
            get_ssh_key_fingerprint(pubkey, hash_algo) for pubkey in module_user["ipasshpubkey"]
        ]
        # Remove the ipasshpubkey element as it is not returned from IPA but save its value to be used later on
        sshpubkey = module_user["ipasshpubkey"]
        del module_user["ipasshpubkey"]

    result = client.get_diff(ipa_data=ipa_user, module_data=module_user)

    # If there are public keys, remove the fingerprints and add them back to the dict
    if sshpubkey is not None:
        del module_user["sshpubkeyfp"]
        module_user["ipasshpubkey"] = sshpubkey
    return result


def get_ssh_key_fingerprint(ssh_key, hash_algo="sha256"):
    """
    Return the public key fingerprint of a given public SSH key
    in format "[fp] [comment] (ssh-rsa)" where fp is of the format:
    FB:0C:AC:0A:07:94:5B:CE:75:6E:63:32:13:AD:AD:D7
    for md5 or
    SHA256:[base64]
    for sha256
    Comments are assumed to be all characters past the second
    whitespace character in the sshpubkey string.
    :param ssh_key:
    :param hash_algo:
    :return:
    """
    parts = ssh_key.strip().split(None, 2)
    if len(parts) == 0:
        return None
    key_type = parts[0]
    key = base64.b64decode(parts[1].encode("ascii"))

    if hash_algo == "md5":
        fp_plain = hashlib.md5(key).hexdigest()
        key_fp = ":".join(a + b for a, b in zip(fp_plain[::2], fp_plain[1::2])).upper()
    elif hash_algo == "sha256":
        fp_plain = base64.b64encode(hashlib.sha256(key).digest()).decode("ascii").rstrip("=")
        key_fp = f"SHA256:{fp_plain}"
    if len(parts) < 3:
        return f"{key_fp} ({key_type})"
    else:
        comment = parts[2]
        return f"{key_fp} {comment} ({key_type})"


def ensure(module, client):
    state = module.params["state"]
    name = module.params["uid"]
    nsaccountlock = state == "disabled"

    module_user = get_user_dict(
        displayname=module.params.get("displayname"),
        krbpasswordexpiration=module.params.get("krbpasswordexpiration"),
        givenname=module.params.get("givenname"),
        loginshell=module.params["loginshell"],
        mail=module.params["mail"],
        sn=module.params["sn"],
        sshpubkey=module.params["sshpubkey"],
        nsaccountlock=nsaccountlock,
        telephonenumber=module.params["telephonenumber"],
        title=module.params["title"],
        userpassword=module.params["password"],
        gidnumber=module.params.get("gidnumber"),
        uidnumber=module.params.get("uidnumber"),
        homedirectory=module.params.get("homedirectory"),
        userauthtype=module.params.get("userauthtype"),
    )

    update_password = module.params.get("update_password")
    ipa_user = client.user_find(name=name)

    changed = False
    if state in ["present", "enabled", "disabled"]:
        if not ipa_user:
            changed = True
            if not module.check_mode:
                ipa_user = client.user_add(name=name, item=module_user)
        else:
            if update_password == "on_create":
                module_user.pop("userpassword", None)
            diff = get_user_diff(client, ipa_user, module_user)
            if len(diff) > 0:
                changed = True
                if not module.check_mode:
                    ipa_user = client.user_mod(name=name, item=module_user)
    else:
        if ipa_user:
            changed = True
            if not module.check_mode:
                client.user_del(name)

    return changed, ipa_user


def main():
    argument_spec = ipa_argument_spec()
    argument_spec.update(
        displayname=dict(type="str"),
        givenname=dict(type="str"),
        update_password=dict(type="str", default="always", choices=["always", "on_create"], no_log=False),
        krbpasswordexpiration=dict(type="str", no_log=False),
        loginshell=dict(type="str"),
        mail=dict(type="list", elements="str"),
        sn=dict(type="str"),
        uid=dict(type="str", required=True, aliases=["name"]),
        gidnumber=dict(type="str"),
        uidnumber=dict(type="str"),
        password=dict(type="str", no_log=True),
        sshpubkey=dict(type="list", elements="str"),
        state=dict(type="str", default="present", choices=["present", "absent", "enabled", "disabled"]),
        telephonenumber=dict(type="list", elements="str"),
        title=dict(type="str"),
        homedirectory=dict(type="str"),
        userauthtype=dict(
            type="list", elements="str", choices=["password", "radius", "otp", "pkinit", "hardened", "idp", "passkey"]
        ),
    )

    module = AnsibleModule(argument_spec=argument_spec, supports_check_mode=True)

    client = UserIPAClient(
        module=module,
        host=module.params["ipa_host"],
        port=module.params["ipa_port"],
        protocol=module.params["ipa_prot"],
    )

    # If sshpubkey is defined as None than module.params['sshpubkey'] is [None]. IPA itself returns None (not a list).
    # Therefore a small check here to replace list(None) by None. Otherwise get_user_diff() would return sshpubkey
    # as different which should be avoided.
    if module.params["sshpubkey"] is not None:
        if len(module.params["sshpubkey"]) == 1 and module.params["sshpubkey"][0] == "":
            module.params["sshpubkey"] = None

    try:
        client.login(username=module.params["ipa_user"], password=module.params["ipa_pass"])
        changed, user = ensure(module, client)
        module.exit_json(changed=changed, user=user)
    except Exception as e:
        module.fail_json(msg=f"{e}", exception=traceback.format_exc())


if __name__ == "__main__":
    main()