1 files changed, 269 insertions, 0 deletions
diff --git a/gn_auth/auth/authorisation/users/collections/models.py b/gn_auth/auth/authorisation/users/collections/models.py
new file mode 100644
index 0000000..7577fa8
--- /dev/null
+++ b/gn_auth/auth/authorisation/users/collections/models.py
@@ -0,0 +1,269 @@
+"""Handle user collections."""
+import json
+from uuid import UUID, uuid4
+from datetime import datetime
+
+from redis import Redis
+from email_validator import validate_email, EmailNotValidError
+
+from gn3.auth.authorisation.errors import InvalidData, NotFoundError
+
+from ..models import User
+
+__OLD_REDIS_COLLECTIONS_KEY__ = "collections"
+__REDIS_COLLECTIONS_KEY__ = "collections2"
+
+class CollectionJSONEncoder(json.JSONEncoder):
+    """Serialise collection objects into JSON."""
+    def default(self, obj):# pylint: disable=[arguments-renamed]
+        if isinstance(obj, UUID):
+            return str(obj)
+        if isinstance(obj, datetime):
+            return obj.strftime("%b %d %Y %I:%M%p")
+        return json.JSONEncoder.default(self, obj)
+
+def __valid_email__(email:str) -> bool:
+    """Check for email validity."""
+    try:
+        validate_email(email, check_deliverability=True)
+    except EmailNotValidError as _enve:
+        return False
+    return True
+
+def __toggle_boolean_field__(
+        rconn: Redis, email: str, field: str):
+    """Toggle the valuen of a boolean field"""
+    mig_dict = json.loads(rconn.hget("migratable-accounts", email) or "{}")
+    if bool(mig_dict):
+        rconn.hset("migratable-accounts", email,
+                   json.dumps({**mig_dict, field: not mig_dict.get(field, True)}))
+
+def __build_email_uuid_bridge__(rconn: Redis):
+    """
+    Build a connection between new accounts and old user accounts.
+
+    The only thing that is common between the two is the email address,
+    therefore, we use that to link the two items.
+    """
+    old_accounts = {
+        account["email_address"]: {
+            "user_id": account["user_id"],
+            "collections-migrated": False,
+            "resources_migrated": False
+        } for account in (
+            acct for acct in
+            (json.loads(usr) for usr in rconn.hgetall("users").values())
+            if (bool(acct.get("email_address", False)) and
+                __valid_email__(acct["email_address"])))
+    }
+    if bool(old_accounts):
+        rconn.hset("migratable-accounts", mapping={
+            key: json.dumps(value) for key,value in old_accounts.items()
+        })
+    return old_accounts
+
+def __retrieve_old_accounts__(rconn: Redis) -> dict:
+    accounts = rconn.hgetall("migratable-accounts")
+    if accounts:
+        return {
+            key: json.loads(value) for key, value in accounts.items()
+        }
+    return __build_email_uuid_bridge__(rconn)
+
+def parse_collection(coll: dict) -> dict:
+    """Parse the collection as persisted in redis to a usable python object."""
+    created = coll.get("created", coll.get("created_timestamp"))
+    changed = coll.get("changed", coll.get("changed_timestamp"))
+    return {
+        "id": UUID(coll["id"]),
+        "name": coll["name"],
+        "created": datetime.strptime(created, "%b %d %Y %I:%M%p"),
+        "changed": datetime.strptime(changed, "%b %d %Y %I:%M%p"),
+        "num_members": int(coll["num_members"]),
+        "members": coll["members"]
+    }
+
+def dump_collection(pythoncollection: dict) -> str:
+    """Convert the collection from a python object to a json string."""
+    return json.dumps(pythoncollection, cls=CollectionJSONEncoder)
+
+def __retrieve_old_user_collections__(rconn: Redis, old_user_id: UUID) -> tuple:
+    """Retrieve any old collections relating to the user."""
+    return tuple(parse_collection(coll) for coll in
+                 json.loads(rconn.hget(
+                     __OLD_REDIS_COLLECTIONS_KEY__, str(old_user_id)) or "[]"))
+
+def user_collections(rconn: Redis, user: User) -> tuple[dict, ...]:
+    """Retrieve current user collections."""
+    collections = tuple(parse_collection(coll) for coll in json.loads(
+        rconn.hget(__REDIS_COLLECTIONS_KEY__, str(user.user_id)) or
+        "[]"))
+    old_accounts = __retrieve_old_accounts__(rconn)
+    if (user.email in old_accounts and
+        not old_accounts[user.email]["collections-migrated"]):
+        old_user_id = old_accounts[user.email]["user_id"]
+        collections = tuple({
+            coll["id"]: coll for coll in (
+                collections + __retrieve_old_user_collections__(
+                    rconn, UUID(old_user_id)))
+        }.values())
+        __toggle_boolean_field__(rconn, user.email, "collections-migrated")
+        rconn.hset(
+            __REDIS_COLLECTIONS_KEY__,
+            key=str(user.user_id),
+            value=json.dumps(collections, cls=CollectionJSONEncoder))
+    return collections
+
+def save_collections(rconn: Redis, user: User, collections: tuple[dict, ...]) -> tuple[dict, ...]:
+    """Save the `collections` to redis."""
+    rconn.hset(
+        __REDIS_COLLECTIONS_KEY__,
+        str(user.user_id),
+        json.dumps(collections, cls=CollectionJSONEncoder))
+    return collections
+
+def add_to_user_collections(rconn: Redis, user: User, collection: dict) -> dict:
+    """Add `collection` to list of user collections."""
+    ucolls = user_collections(rconn, user)
+    save_collections(rconn, user, ucolls + (collection,))
+    return collection
+
+def create_collection(rconn: Redis, user: User, name: str, traits: tuple) -> dict:
+    """Create a new collection."""
+    now = datetime.utcnow()
+    return add_to_user_collections(rconn, user, {
+        "id": uuid4(),
+        "name": name,
+        "created": now,
+        "changed": now,
+        "num_members": len(traits),
+        "members": traits
+    })
+
+def get_collection(rconn: Redis, user: User, collection_id: UUID) -> dict:
+    """Retrieve the collection with ID `collection_id`."""
+    colls = tuple(coll for coll in user_collections(rconn, user)
+                  if coll["id"] == collection_id)
+    if len(colls) == 0:
+        raise NotFoundError(
+            f"Could not find a collection with ID `{collection_id}` for user "
+            f"with ID `{user.user_id}`")
+    if len(colls) > 1:
+        err = InvalidData(
+            "More than one collection was found having the ID "
+            f"`{collection_id}` for user with ID `{user.user_id}`.")
+        err.error_code = 513
+        raise err
+    return colls[0]
+
+def __raise_if_collections_empty__(user: User, collections: tuple[dict, ...]):
+    """Raise an exception if no collections are found for `user`."""
+    if len(collections) < 1:
+        raise NotFoundError(f"No collections found for user `{user.user_id}`")
+
+def __raise_if_not_single_collection__(
+        user: User, collection_id: UUID, collections: tuple[dict, ...]):
+    """
+    Raise an exception there is zero, or more than one collection for `user`.
+    """
+    if len(collections) == 0:
+        raise NotFoundError(f"No collections found for user `{user.user_id}` "
+                            f"with ID `{collection_id}`.")
+    if len(collections) > 1:
+        err = InvalidData(
+            "More than one collection was found having the ID "
+            f"`{collection_id}` for user with ID `{user.user_id}`.")
+        err.error_code = 513
+        raise err
+
+def delete_collections(rconn: Redis,
+                       user: User,
+                       collection_ids: tuple[UUID, ...]) -> tuple[dict, ...]:
+    """
+    Delete collections with the given `collection_ids` returning the deleted
+    collections.
+    """
+    ucolls = user_collections(rconn, user)
+    save_collections(
+        rconn,
+        user,
+        tuple(coll for coll in ucolls if coll["id"] not in collection_ids))
+    return tuple(coll for coll in ucolls if coll["id"] in collection_ids)
+
+def add_traits(rconn: Redis,
+               user: User,
+               collection_id: UUID,
+               traits: tuple[str, ...]) -> dict:
+    """
+    Add `traits` to the `user` collection identified by `collection_id`.
+
+    Returns: The collection with the new traits added.
+    """
+    ucolls = user_collections(rconn, user)
+    __raise_if_collections_empty__(user, ucolls)
+
+    mod_col = tuple(coll for coll in ucolls if coll["id"] == collection_id)
+    __raise_if_not_single_collection__(user, collection_id, mod_col)
+    new_members = tuple(set(tuple(mod_col[0]["members"]) + traits))
+    new_coll = {
+        **mod_col[0],
+        "members": new_members,
+        "num_members": len(new_members)
+    }
+    save_collections(
+        rconn,
+        user,
+        (tuple(coll for coll in ucolls if coll["id"] != collection_id) +
+         (new_coll,)))
+    return new_coll
+
+def remove_traits(rconn: Redis,
+                  user: User,
+                  collection_id: UUID,
+                  traits: tuple[str, ...]) -> dict:
+    """
+    Remove `traits` from the `user` collection identified by `collection_id`.
+
+    Returns: The collection with the specified `traits` removed.
+    """
+    ucolls = user_collections(rconn, user)
+    __raise_if_collections_empty__(user, ucolls)
+
+    mod_col = tuple(coll for coll in ucolls if coll["id"] == collection_id)
+    __raise_if_not_single_collection__(user, collection_id, mod_col)
+    new_members = tuple(
+        trait for trait in mod_col[0]["members"] if trait not in traits)
+    new_coll = {
+        **mod_col[0],
+        "members": new_members,
+        "num_members": len(new_members)
+    }
+    save_collections(
+        rconn,
+        user,
+        (tuple(coll for coll in ucolls if coll["id"] != collection_id) +
+         (new_coll,)))
+    return new_coll
+
+def change_name(rconn: Redis,
+                user: User,
+                collection_id: UUID,
+                new_name: str) -> dict:
+    """
+    Change the collection's name.
+
+    Returns: The collection with the new name.
+    """
+    ucolls = user_collections(rconn, user)
+    __raise_if_collections_empty__(user, ucolls)
+
+    mod_col = tuple(coll for coll in ucolls if coll["id"] == collection_id)
+    __raise_if_not_single_collection__(user, collection_id, mod_col)
+
+    new_coll = {**mod_col[0], "name": new_name}
+    save_collections(
+        rconn,
+        user,
+        (tuple(coll for coll in ucolls if coll["id"] != collection_id) +
+         (new_coll,)))
+    return new_coll