* edit text, correct typos

* format changes

* update docs for user management

docs/tech/security.md

@@ -24,6 +24,8 @@ Three authorization roles (also called groups, not to be mistaken for in-game ro
 - can manipulate with the exercises (start, stop, create, or remove)
 - can add/remove trainees to/from teams of an exercise
 - inherits all trainee permissions
+- can be added to team (to simulate trainees), in such case they will only see the data of the given team,
+  BUT they will still posses the instructor role and can manipulate with the exercise (even they are assigned only to team)
 
 **TRAINEE**
 
@@ -36,7 +38,7 @@ Three authorization roles (also called groups, not to be mistaken for in-game ro
 
 Users with the ADMIN role can be added to the access control lists to be shown in exercises
 (if the admin acts as an instructor for some reason),
-but it is not necessary because ADMIN has control over every resource on the platform, whether he is assigned to it or not.
+but it is not necessary because ADMINs have control over every resource on the platform, whether they are assigned to it or not.
 
 ## User onboarding
 
@@ -77,22 +79,106 @@ As a separator for the column, you can use either `,` or `;`.
 
 An example of such a file can be [downloaded](https://gitlab.fi.muni.cz/inject/inject-docs/-/raw/main/docs/tech/example_csv.csv?ref_type=heads&inline=false).
 
+The CSV file can be also used for the bulk adding of a new tags. If the platform detects username
+(email) that already exists on the platform it skips the creation and sending of the credentials and
+only adds new tags for such users. Meaning that if you modify tags in a CSV that you already used
+for the account creations you will achieve bulk adding of a new tags (no other fields will be changes).
+
 ### Manually using CLI
 
 Another way of adding users is manually via the console:
 
- - List the running Docker containers to find the **NAME** of the backend container:
-    ```
-    docker ps
-    ```
- - Execute a shell session in the backend container. Replace `CONTAINERNAME` with the actual container **NAME** of the backend service:
-    ```
-    docker exec -it CONTAINERNAME python manage.py shell
-    ```
+- List the running Docker containers to find the **NAME** of the backend container:
+  ```
+  docker ps
+  ```
+- Execute a shell session in the backend container. Replace `CONTAINERNAME` with the actual container **NAME** of the backend service:
+
+  ```
+  docker exec -it CONTAINERNAME python manage.py shell
+  ```
 
 - Create a user using the Django shell. Replace `email@test.com` and `password` with your desired user credentials.:
 
-    ``` python
-    from user.models import User
-    User.objects.create_user(username="email@test.com", password="password")
-    ```
+  ```python
+  from user.models import User
+  User.objects.create_user(username="email@test.com", password="password")
+  ```
\ No newline at end of file
+
+## Assigning users to exercise
+
+There are multiple ways to assign users to an exercise
+
+### Manual assignment
+
+You can assign users 'manually' by adding one or multiple
+users to team or remove them utilizing the list of all present users on the platform.
+This use case is ideal for situations when the distribution of users into teams
+is uncertain during the preparation or for the situations when you need to edit
+semi-automatically created assignments.
+
+### Semi-automatic assignment
+
+You can utilize one of the three options for semi-automatic assignment:
+
+- **Assign equally**: The platform will automatically assign selected users to teams
+  while trying to preserve balance between teams. Possible cases and their behavior:
+
+  - _Number of users < number of teams_: First _n_ teams will be assigned one user each.
+    The rest number (number_of_teams - number_of_users) of teams will be left empty.
+
+  - _Number of users = number of teams_: Every team will have assigned exactly one user.
+
+  - _Number of users > number of teams_: Starting with the first user, placing them on the
+    first team. Then, moving to the second user and placing them on the second team, and so on.
+    Once a user is assigned to the last team, the algorithm loops back around and assign
+    the next user to the first team again. This continues until all users are assigned to a team.\
+    Example situation – assigning 10 users (user1 to user10) to 3 teams
+    would end up with this distribution:
+    - team1: user1, user4, user7, user10
+    - team2: user2, user5, user8
+    - team3: user3, user6, user9
+  - WARNING: This feature does not work with _role exercise_.
+
+- **Assign by tags**: The platform automatically distributes users to teams based on the tags
+  (with chosen prefix) of the selected users. Let's illustrate this functionality on the example:
+  - Image we have users (trainees) and their tags in the brackets (these tags were assigned
+    via CSV file):
+    - trainee1 (PowerPlantTTX-team1, HealthCareEX-team3)
+    - trainee2 (PowerPlantTTX-team1, HealthCareEX-team2)
+    - trainee3 (PowerPlantTTX-team3, HealthCareEX-team3)
+    - trainee4 (PowerPlantTTX-team2, HealthCareEX-team1)
+  - Now, we want to assign trainees 1-4 to our tabletop exercise about power plant crisis.
+    We knew beforehand how we want to distribute them to teams in this exercise and created
+    the appropriate tags. We used `PowerPlantTTX` or `PowerPlantTTX-` as our prefix to
+    distinguish between other tags.
+  - The platform will now take the selected users and finds a tag with a given prefix
+    (which must be provided, in our case `PowerPlantTTX`) for each user. The users
+    will be assigned by lexicographic ordering of suffix parts. In this case:
+    - trainee1 and trainee2 will be assigned to the first team
+    - trainee4 will be assigned to second team
+    - trainee3 will be assigned to the third team
+  - If we used `HealthCareEX` as wanted prefix for the user assignment we would end up with:
+    - trainee4 in the first team
+    - trainee2 in the second team
+    - trainee1 and trainee3 in the third team
+  - Following **rules have to be complied** with to make this assignment by tags possible:
+    - Prefix parts have to be unique (which can be achieved by making them long enough).
+      If we had tags `EXERCISE_t1` and `EX_t1` and we would want to use the `EX_t1` we would
+      need to use prefix `EX`, which would also match with `EXERCISE_t1` and could cause
+      incorrect assignment (if we used prefix `EX_`we would dodge the match with other tag).
+      To simplify the prefix is checked as a match for the first characters of the tags.
+    - Prefix match is case sensitive.
+    - Suffixes can have any values, which can be lexicographically ordered (correct examples
+      where `Exercise` or `Exercise-` are the prefix):
+      - Exercise-1, Exercise-2, Exercise-3 (those with 1 will be assigned to first team, those with 2 to second...)
+      - Exercise-a, Exercise-b, Exercise-c (those with _a_ will be assigned to first team, those with _b_ to second...)
+      - Exercise-t1, Exercise-t2, Exercise-t3 (those with _t1_ will be assigned to first team, those with _t2_ to second...)
+    - If there are more tags matching the prefix than the number of present teams, the operation will fail. Either the number
+      of teams has to be increased, users with tags that exceed number of teams would need to be removed from selection,
+      or the exceeding tags would need to be removed.
+  - WARNING: This feature does not work with _role exercise_.
+- **Copy existing assignment**: The platform copies assignments of users and teams from a selected exercise.
+  - Requires that the exercises matches in the number of teams, otherwise fails.
+  - Simply transfers assignment meaning the members of the first team from a selected exercise
+    will be members of the first team in the current exercise.