aboutsummaryrefslogtreecommitdiff
path: root/gn_auth/auth/authorisation/resources/groups/models.py
blob: e8c349214088231844e2b49df25a7d3b6ecc0744 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
"""Handle the management of resource/user groups."""
import json
from uuid import UUID, uuid4
from functools import reduce
from dataclasses import dataclass
from typing import Any, Sequence, Iterable, Optional

from flask import g
from pymonad.maybe import Just, Maybe, Nothing

from gn_auth.auth.db import sqlite3 as db
from gn_auth.auth.authentication.users import User, user_by_id

from gn_auth.auth.authorisation.checks import authorised_p
from gn_auth.auth.authorisation.privileges import Privilege
from gn_auth.auth.authorisation.resources.base import Resource
from gn_auth.auth.authorisation.resources.errors import MissingGroupError
from gn_auth.auth.authorisation.errors import (
    NotFoundError, AuthorisationError, InconsistencyError)
from gn_auth.auth.authorisation.roles.models import (
    Role, create_role, check_user_editable, revoke_user_role_by_name,
    assign_user_role_by_name)


@dataclass(frozen=True)
class Group:
    """Class representing a group."""
    group_id: UUID
    group_name: str
    group_metadata: dict[str, Any]


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"
    })


@dataclass(frozen=True)
class GroupRole:
    """Class representing a role tied/belonging to a group."""
    group_role_id: UUID
    group: Group
    role: 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."""
    def resource_category_by_key(
            cursor: db.DbCursor, category_key: str):
        """Retrieve a resource category by its key."""
        cursor.execute(
            "SELECT * FROM resource_categories WHERE "
            "resource_category_key=?",
            (category_key,))
        results = cursor.fetchone()
        if results:
            return dict(results)
        raise NotFoundError(
            f"Could not find a ResourceCategory with key '{category_key}'")

    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 {}))
        group_resource = {
            "group_id": str(new_group.group_id),
            "resource_id": str(uuid4()),
            "resource_name": group_name,
            "resource_category_id": str(
                resource_category_by_key(
                    cursor, "group")["resource_category_id"]
            ),
            "public": 0
        }
        cursor.execute(
            "INSERT INTO resources VALUES "
            "(:resource_id, :resource_name, :resource_category_id, :public)",
            group_resource)
        cursor.execute(
            "INSERT INTO group_resources(resource_id, group_id) "
            "VALUES(:resource_id, :group_id)",
            group_resource)
        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,
            UUID(str(group_resource["resource_id"])),
            "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(conn: db.DbConnection, user: User) -> Maybe[Group]:
    """Returns the given user's group"""
    with db.cursor(conn) as cursor:
        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(conn: db.DbConnection, user: User, group: Group) -> bool:
    """Check whether the given `user` is the leader of `group`."""

    ugroup = user_group(conn, 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

    with db.cursor(conn) as cursor:
        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(conn, user).maybe(
            DUMMY_GROUP, lambda grp: grp)  # type: ignore[misc]
        if group != DUMMY_GROUP and is_group_leader(conn, 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(conn, 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"]):
                try:
                    the_user = user_by_id(conn, UUID(row["requester_id"]))
                    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}
                except NotFoundError as nfe:
                    raise InconsistencyError(
                        "Could not find user associated with join request."
                    ) from nfe
            raise AuthorisationError(
                "You cannot act on other groups join requests")
        raise NotFoundError(f"Could not find request with ID '{request_id}'")


def __organise_privileges__(acc, row):
    role_id = UUID(row["role_id"])
    role = acc.get(role_id, False)
    if role:
        return {
            **acc,
            role_id: Role(
                role.role_id, role.role_name,
                bool(int(row["user_editable"])),
                role.privileges + (
                    Privilege(row["privilege_id"],
                              row["privilege_description"]),))
        }
    return {
        **acc,
        role_id: Role(
            UUID(row["role_id"]), row["role_name"],
            bool(int(row["user_editable"])),
            (Privilege(row["privilege_id"], row["privilege_description"]),))
    }

# @authorised_p(("group:role:view",),
#               "Insufficient privileges to view role",
#               oauth2_scope="profile group role")


def group_role_by_id(
        conn: db.DbConnection, group: Group, group_role_id: UUID) -> GroupRole:
    """Retrieve GroupRole from id by its `group_role_id`."""
    # TODO: do privileges check before running actual query
    # the check commented out above doesn't work correctly
    with db.cursor(conn) as cursor:
        cursor.execute(
            "SELECT gr.group_role_id, r.*, p.* "
            "FROM group_roles AS gr "
            "INNER JOIN roles AS r ON gr.role_id=r.role_id "
            "INNER JOIN role_privileges AS rp ON rp.role_id=r.role_id "
            "INNER JOIN privileges AS p ON p.privilege_id=rp.privilege_id "
            "WHERE gr.group_role_id=? AND gr.group_id=?",
            (str(group_role_id), str(group.group_id)))
        rows = cursor.fetchall()
        if rows:
            roles: tuple[Role, ...] = tuple(reduce(
                __organise_privileges__, rows, {}).values())
            assert len(roles) == 1
            return GroupRole(group_role_id, group, roles[0])
        raise NotFoundError(
            f"Group role with ID '{group_role_id}' does not exist.")


@authorised_p(("group:role:edit-role",),
              "You do not have the privilege to edit a role.",
              oauth2_scope="profile group role")
def add_privilege_to_group_role(conn: db.DbConnection, group_role: GroupRole,
                                privilege: Privilege) -> GroupRole:
    """Add `privilege` to `group_role`."""
    # TODO: do privileges check.
    check_user_editable(group_role.role)
    with db.cursor(conn) as cursor:
        cursor.execute(
            "INSERT INTO role_privileges(role_id,privilege_id) "
            "VALUES (?, ?) ON CONFLICT (role_id, privilege_id) "
            "DO NOTHING",
            (str(group_role.role.role_id), str(privilege.privilege_id)))
        return GroupRole(
            group_role.group_role_id,
            group_role.group,
            Role(group_role.role.role_id,
                 group_role.role.role_name,
                 group_role.role.user_editable,
                 group_role.role.privileges + (privilege,)))


@authorised_p(("group:role:edit-role",),
              "You do not have the privilege to edit a role.",
              oauth2_scope="profile group role")
def delete_privilege_from_group_role(
        conn: db.DbConnection, group_role: GroupRole,
        privilege: Privilege) -> GroupRole:
    """Delete `privilege` to `group_role`."""
    # TODO: do privileges check.
    check_user_editable(group_role.role)
    with db.cursor(conn) as cursor:
        cursor.execute(
            "DELETE FROM role_privileges WHERE "
            "role_id=? AND privilege_id=?",
            (str(group_role.role.role_id), str(privilege.privilege_id)))
        return GroupRole(
            group_role.group_role_id,
            group_role.group,
            Role(group_role.role.role_id,
                 group_role.role.role_name,
                 group_role.role.user_editable,
                 tuple(priv for priv in group_role.role.privileges
                       if priv != privilege)))


def resource_owner(conn: db.DbConnection, resource: Resource) -> Group:
    """Return the user group that owns the resource."""
    with db.cursor(conn) as cursor:
        cursor.execute(
            "SELECT g.* FROM resource_ownership AS ro "
            "INNER JOIN groups AS g ON ro.group_id=g.group_id "
            "WHERE ro.resource_id=?",
            (str(resource.resource_id),))
        row = cursor.fetchone()
        if row:
            return Group(
                UUID(row["group_id"]),
                row["group_name"],
                json.loads(row["group_metadata"]))

    raise MissingGroupError("Resource has no 'owning' group.")


def add_resources_to_group(conn: db.DbConnection,
                           resources: tuple[Resource, ...],
                           group: Group):
    """Link the resources to the admin group."""
    with db.cursor(conn) as cursor:
        cursor.executemany(
            "INSERT INTO resource_ownership VALUES(:group_id, :resource_id) "
            "ON CONFLICT (group_id, resource_id) DO NOTHING",
            tuple({
                "group_id": str(group.group_id),
                "resource_id": str(rsc.resource_id)
            } for rsc in resources))