"""Handle the management of resource/user groups."""
import json
from uuid import UUID, uuid4
from typing import Any, Sequence, Iterable, Optional, NamedTuple
from flask import g
from pymonad.maybe import Just, Maybe, Nothing
from gn3.auth import db
from gn3.auth.dictify import dictify
from gn3.auth.authentication.users import User, user_by_id, DUMMY_USER
from ..checks import authorised_p
from ..privileges import Privilege
from ..errors import NotFoundError, AuthorisationError, InconsistencyError
from ..roles.models import (
Role, create_role, revoke_user_role_by_name, assign_user_role_by_name)
class Group(NamedTuple):
"""Class representing a group."""
group_id: UUID
group_name: str
group_metadata: dict[str, Any]
def dictify(self):
"""Return a dict representation of `Group` objects."""
return {
"group_id": self.group_id, "group_name": self.group_name,
"group_metadata": self.group_metadata
}
DUMMY_GROUP = Group(
group_id=UUID("77cee65b-fe29-4383-ae41-3cb3b480cc70"),
group_name="GN3_DUMMY_GROUP",
group_metadata={
"group-description": "This is a dummy group to use as a placeholder"
})
class GroupRole(NamedTuple):
"""Class representing a role tied/belonging to a group."""
group_role_id: UUID
group: Group
role: Role
def dictify(self) -> dict[str, Any]:
"""Return a dict representation of `GroupRole` objects."""
return {
"group_role_id": self.group_role_id, "group": dictify(self.group),
"role": dictify(self.role)
}
class GroupCreationError(AuthorisationError):
"""Raised whenever a group creation fails"""
class MembershipError(AuthorisationError):
"""Raised when there is an error with a user's membership to a group."""
def __init__(self, user: User, groups: Sequence[Group]):
"""Initialise the `MembershipError` exception object."""
groups_str = ", ".join(group.group_name for group in groups)
error_description = (
f"User '{user.name} ({user.email})' is a member of {len(groups)} "
f"groups ({groups_str})")
super().__init__(f"{type(self).__name__}: {error_description}.")
def user_membership(conn: db.DbConnection, user: User) -> Sequence[Group]:
"""Returns all the groups that a member belongs to"""
query = (
"SELECT groups.group_id, group_name, groups.group_metadata "
"FROM group_users INNER JOIN groups "
"ON group_users.group_id=groups.group_id "
"WHERE group_users.user_id=?")
with db.cursor(conn) as cursor:
cursor.execute(query, (str(user.user_id),))
groups = tuple(Group(row[0], row[1], json.loads(row[2]))
for row in cursor.fetchall())
return groups
@authorised_p(
privileges = ("system:group:create-group",),
error_description = (
"You do not have the appropriate privileges to enable you to "
"create a new group."),
oauth2_scope = "profile group")
def create_group(
conn: db.DbConnection, group_name: str, group_leader: User,
group_description: Optional[str] = None) -> Group:
"""Create a new group."""
user_groups = user_membership(conn, group_leader)
if len(user_groups) > 0:
raise MembershipError(group_leader, user_groups)
with db.cursor(conn) as cursor:
new_group = __save_group__(
cursor, group_name,(
{"group_description": group_description}
if group_description else {}))
add_user_to_group(cursor, new_group, group_leader)
revoke_user_role_by_name(cursor, group_leader, "group-creator")
assign_user_role_by_name(cursor, group_leader, "group-leader")
return new_group
@authorised_p(("group:role:create-role",),
error_description="Could not create the group role")
def create_group_role(
conn: db.DbConnection, group: Group, role_name: str,
privileges: Iterable[Privilege]) -> GroupRole:
"""Create a role attached to a group."""
with db.cursor(conn) as cursor:
group_role_id = uuid4()
role = create_role(cursor, role_name, privileges)
cursor.execute(
("INSERT INTO group_roles(group_role_id, group_id, role_id) "
"VALUES(?, ?, ?)"),
(str(group_role_id), str(group.group_id), str(role.role_id)))
return GroupRole(group_role_id, group, role)
def authenticated_user_group(conn) -> Maybe:
"""
Returns the currently authenticated user's group.
Look into returning a Maybe object.
"""
user = g.user
with db.cursor(conn) as cursor:
cursor.execute(
("SELECT groups.* FROM group_users "
"INNER JOIN groups ON group_users.group_id=groups.group_id "
"WHERE group_users.user_id = ?"),
(str(user.user_id),))
groups = tuple(Group(UUID(row[0]), row[1], json.loads(row[2] or "{}"))
for row in cursor.fetchall())
if len(groups) > 1:
raise MembershipError(user, groups)
if len(groups) == 1:
return Just(groups[0])
return Nothing
def user_group(cursor: db.DbCursor, user: User) -> Maybe[Group]:
"""Returns the given user's group"""
cursor.execute(
("SELECT groups.group_id, groups.group_name, groups.group_metadata "
"FROM group_users "
"INNER JOIN groups ON group_users.group_id=groups.group_id "
"WHERE group_users.user_id = ?"),
(str(user.user_id),))
groups = tuple(
Group(UUID(row[0]), row[1], json.loads(row[2] or "{}"))
for row in cursor.fetchall())
if len(groups) > 1:
raise MembershipError(user, groups)
if len(groups) == 1:
return Just(groups[0])
return Nothing
def is_group_leader(cursor: db.DbCursor, user: User, group: Group):
"""Check whether the given `user` is the leader of `group`."""
ugroup = user_group(cursor, user).maybe(
False, lambda val: val) # type: ignore[arg-type, misc]
if not group:
# User cannot be a group leader if not a member of ANY group
return False
if not ugroup == group:
# User cannot be a group leader if not a member of THIS group
return False
cursor.execute(
("SELECT roles.role_name FROM user_roles LEFT JOIN roles "
"ON user_roles.role_id = roles.role_id WHERE user_id = ?"),
(str(user.user_id),))
role_names = tuple(row[0] for row in cursor.fetchall())
return "group-leader" in role_names
def all_groups(conn: db.DbConnection) -> Maybe[Sequence[Group]]:
"""Retrieve all existing groups"""
with db.cursor(conn) as cursor:
cursor.execute("SELECT * FROM groups")
res = cursor.fetchall()
if res:
return Just(tuple(
Group(row["group_id"], row["group_name"],
json.loads(row["group_metadata"])) for row in res))
return Nothing
def __save_group__(
cursor: db.DbCursor, group_name: str,
group_metadata: dict[str, Any]) -> Group:
"""Save a group to db"""
the_group = Group(uuid4(), group_name, group_metadata)
cursor.execute(
("INSERT INTO groups "
"VALUES(:group_id, :group_name, :group_metadata) "
"ON CONFLICT (group_id) DO UPDATE SET "
"group_name=:group_name, group_metadata=:group_metadata"),
{"group_id": str(the_group.group_id), "group_name": the_group.group_name,
"group_metadata": json.dumps(the_group.group_metadata)})
return the_group
def add_user_to_group(cursor: db.DbCursor, the_group: Group, user: User):
"""Add `user` to `the_group` as a member."""
cursor.execute(
("INSERT INTO group_users VALUES (:group_id, :user_id) "
"ON CONFLICT (group_id, user_id) DO NOTHING"),
{"group_id": str(the_group.group_id), "user_id": str(user.user_id)})
@authorised_p(
privileges = ("system:group:view-group",),
error_description = (
"You do not have the appropriate privileges to access the list of users"
" in the group."))
def group_users(conn: db.DbConnection, group_id: UUID) -> Iterable[User]:
"""Retrieve all users that are members of group with id `group_id`."""
with db.cursor(conn) as cursor:
cursor.execute(
"SELECT u.* FROM group_users AS gu INNER JOIN users AS u "
"ON gu.user_id = u.user_id WHERE gu.group_id=:group_id",
{"group_id": str(group_id)})
results = cursor.fetchall()
return (User(UUID(row["user_id"]), row["email"], row["name"])
for row in results)
@authorised_p(
privileges = ("system:group:view-group",),
error_description = (
"You do not have the appropriate privileges to access the group."))
def group_by_id(conn: db.DbConnection, group_id: UUID) -> Group:
"""Retrieve a group by its ID"""
with db.cursor(conn) as cursor:
cursor.execute("SELECT * FROM groups WHERE group_id=:group_id",
{"group_id": str(group_id)})
row = cursor.fetchone()
if row:
return Group(
UUID(row["group_id"]),
row["group_name"],
json.loads(row["group_metadata"]))
raise NotFoundError(f"Could not find group with ID '{group_id}'.")
@authorised_p(("system:group:view-group", "system:group:edit-group"),
error_description=("You do not have the appropriate authorisation"
" to act upon the join requests."),
oauth2_scope="profile group")
def join_requests(conn: db.DbConnection, user: User):
"""List all the join requests for the user's group."""
with db.cursor(conn) as cursor:
group = user_group(cursor, user).maybe(DUMMY_GROUP, lambda grp: grp)# type: ignore[misc]
if group != DUMMY_GROUP and is_group_leader(cursor, user, group):
cursor.execute(
"SELECT gjr.*, u.email, u.name FROM group_join_requests AS gjr "
"INNER JOIN users AS u ON gjr.requester_id=u.user_id "
"WHERE gjr.group_id=? AND gjr.status='PENDING'",
(str(group.group_id),))
return tuple(dict(row)for row in cursor.fetchall())
raise AuthorisationError(
"You do not have the appropriate authorisation to access the "
"group's join requests.")
@authorised_p(("system:group:view-group", "system:group:edit-group"),
error_description=("You do not have the appropriate authorisation"
" to act upon the join requests."),
oauth2_scope="profile group")
def accept_reject_join_request(
conn: db.DbConnection, request_id: UUID, user: User, status: str) -> dict:
"""Accept/Reject a join request."""
assert status in ("ACCEPTED", "REJECTED"), f"Invalid status '{status}'."
with db.cursor(conn) as cursor:
group = user_group(cursor, user).maybe(DUMMY_GROUP, lambda grp: grp) # type: ignore[misc]
cursor.execute("SELECT * FROM group_join_requests WHERE request_id=?",
(str(request_id),))
row = cursor.fetchone()
if row:
if group.group_id == UUID(row["group_id"]):
the_user = user_by_id(conn, UUID(row["requester_id"])).maybe(# type: ignore[misc]
DUMMY_USER, lambda usr: usr)
if the_user == DUMMY_USER:
raise InconsistencyError(
"Could not find user associated with join request.")
if status == "ACCEPTED":
add_user_to_group(cursor, group, the_user)
revoke_user_role_by_name(cursor, the_user, "group-creator")
cursor.execute(
"UPDATE group_join_requests SET status=? "
"WHERE request_id=?",
(status, str(request_id)))
return {"request_id": request_id, "status": status}
raise AuthorisationError(
"You cannot act on other groups join requests")
raise NotFoundError(f"Could not find request with ID '{request_id}'")
