"""Test functions dealing with group management."""
from uuid import UUID

import pytest
from pymonad.maybe import Nothing

from gn3.auth import db
from gn3.auth.authentication.users import User
from gn3.auth.authorisation.roles import Role
from gn3.auth.authorisation.privileges import Privilege
from gn3.auth.authorisation.errors import AuthorisationError
from gn3.auth.authorisation.groups.models import (
    Group, GroupRole, user_group, create_group, create_group_role)

from tests.unit.auth import conftest

create_group_failure = {
    "status": "error",
    "message": "Unauthorised: Failed to create group."
}

uuid_fn = lambda : UUID("d32611e3-07fc-4564-b56c-786c6db6de2b")

GROUP = Group(UUID("9988c21d-f02f-4d45-8966-22c968ac2fbf"), "TheTestGroup",
              {"group_description": "The test group"})
PRIVILEGES = (
    Privilege(
        "group:resource:view-resource",
        "view a resource and use it in computations"),
    Privilege("group:resource:edit-resource", "edit/update a resource"))

@pytest.mark.unit_test
@pytest.mark.parametrize(
    "user,expected", tuple(zip(conftest.TEST_USERS[0:1], (
        Group(
            UUID("d32611e3-07fc-4564-b56c-786c6db6de2b"), "a_test_group",
            {"group_description": "A test group"}),
        create_group_failure, create_group_failure, create_group_failure,
        create_group_failure))))
def test_create_group(# pylint: disable=[too-many-arguments]
        fxtr_app, auth_testdb_path, mocker, fxtr_users, user, expected):# pylint: disable=[unused-argument]
    """
    GIVEN: an authenticated user
    WHEN: the user attempts to create a group
    THEN: verify they are only able to create the group if they have the
          appropriate privileges
    """
    mocker.patch("gn3.auth.authorisation.groups.models.uuid4", uuid_fn)
    mocker.patch("gn3.auth.authorisation.checks.require_oauth.acquire",
                 conftest.get_tokeniser(user))
    with db.connection(auth_testdb_path) as conn:
        assert create_group(
            conn, "a_test_group", user, "A test group") == expected

@pytest.mark.unit_test
@pytest.mark.parametrize("user", conftest.TEST_USERS[1:])
def test_create_group_raises_exception_with_non_privileged_user(# pylint: disable=[too-many-arguments]
        fxtr_app, auth_testdb_path, mocker, fxtr_users, user):# pylint: disable=[unused-argument]
    """
    GIVEN: an authenticated user, without appropriate privileges
    WHEN: the user attempts to create a group
    THEN: verify the system raises an exception
    """
    mocker.patch("gn3.auth.authorisation.groups.models.uuid4", uuid_fn)
    mocker.patch("gn3.auth.authorisation.checks.require_oauth.acquire",
                 conftest.get_tokeniser(user))
    with db.connection(auth_testdb_path) as conn:
        with pytest.raises(AuthorisationError):
            assert create_group(conn, "a_test_group", user, "A test group")

create_role_failure = {
    "status": "error",
    "message": "Unauthorised: Could not create the group role"
}

@pytest.mark.unit_test
@pytest.mark.parametrize(
    "user,expected", tuple(zip(conftest.TEST_USERS[0:1], (
        GroupRole(
            UUID("d32611e3-07fc-4564-b56c-786c6db6de2b"),
            GROUP,
            Role(UUID("d32611e3-07fc-4564-b56c-786c6db6de2b"),
                 "ResourceEditor", PRIVILEGES)),))))
def test_create_group_role(mocker, fxtr_users_in_group, user, expected):
    """
    GIVEN: an authenticated user
    WHEN: the user attempts to create a role, attached to a group
    THEN: verify they are only able to create the role if they have the
        appropriate privileges and that the role is attached to the given group
    """
    mocker.patch("gn3.auth.authorisation.groups.models.uuid4", uuid_fn)
    mocker.patch("gn3.auth.authorisation.roles.models.uuid4", uuid_fn)
    mocker.patch("gn3.auth.authorisation.checks.require_oauth.acquire",
                 conftest.get_tokeniser(user))
    conn, _group, _users = fxtr_users_in_group
    with db.cursor(conn) as cursor:
        assert create_group_role(
            conn, GROUP, "ResourceEditor", PRIVILEGES) == expected
        # cleanup
        cursor.execute(
            ("DELETE FROM group_roles "
             "WHERE group_role_id=? AND group_id=? AND role_id=?"),
            (str(uuid_fn()), str(GROUP.group_id), str(uuid_fn())))

@pytest.mark.unit_test
@pytest.mark.parametrize(
    "user,expected", tuple(zip(conftest.TEST_USERS[1:], (
        create_role_failure, create_role_failure, create_role_failure))))
def test_create_group_role_raises_exception_with_unauthorised_users(
        mocker, fxtr_users_in_group, user, expected):
    """
    GIVEN: an authenticated user
    WHEN: the user attempts to create a role, attached to a group
    THEN: verify they are only able to create the role if they have the
        appropriate privileges and that the role is attached to the given group
    """
    mocker.patch("gn3.auth.authorisation.groups.models.uuid4", uuid_fn)
    mocker.patch("gn3.auth.authorisation.roles.models.uuid4", uuid_fn)
    mocker.patch("gn3.auth.authorisation.checks.require_oauth.acquire",
                 conftest.get_tokeniser(user))
    conn, _group, _users = fxtr_users_in_group
    with pytest.raises(AuthorisationError):
        assert create_group_role(
            conn, GROUP, "ResourceEditor", PRIVILEGES) == expected

@pytest.mark.unit_test
def test_create_multiple_groups(mocker, fxtr_users):
    """
    GIVEN: An authenticated user with appropriate authorisation
    WHEN: The user attempts to create a new group, while being a member of an
      existing group
    THEN: The system should prevent that, and respond with an appropriate error
      message
    """
    mocker.patch("gn3.auth.authorisation.groups.models.uuid4", uuid_fn)
    user = User(
        UUID("ecb52977-3004-469e-9428-2a1856725c7f"), "group@lead.er",
        "Group Leader")
    mocker.patch("gn3.auth.authorisation.checks.require_oauth.acquire",
                 conftest.get_tokeniser(user))
    conn, _test_users = fxtr_users
    # First time, successfully creates the group
    assert create_group(conn, "a_test_group", user) == Group(
        UUID("d32611e3-07fc-4564-b56c-786c6db6de2b"), "a_test_group",
        {})
    # subsequent attempts should fail
    with pytest.raises(AuthorisationError):
        create_group(conn, "another_test_group", user)

@pytest.mark.unit_test
@pytest.mark.parametrize(
    "user,expected",
    tuple(zip(
        conftest.TEST_USERS,
        (([Group(UUID("9988c21d-f02f-4d45-8966-22c968ac2fbf"), "TheTestGroup", {})] * 3)
         + [Nothing]))))
def test_user_group(fxtr_users_in_group, user, expected):
    """
    GIVEN: A bunch of registered users, some of whom are members of a group, and
      others are not
    WHEN: a particular user's group is requested,
    THEN: return a Maybe containing the group that the user belongs to, or
      Nothing
    """
    conn, _group, _users = fxtr_users_in_group
    assert (
        user_group(conn, user).maybe(Nothing, lambda val: val)
        == expected)