def sign_up(redis: Redis):
"""Signs up a user. Algorithm:
Algorithm:
----------
1. Increment 'user_id'.
2. Sanity check, if username or password is empty, raise exception.
3. Check if the user exists.
4. Store username and password in a 'user' HSET.
5. Store the primary key (user_id) in 'users' HSET for easy fetching.
Parameters:
-----------
redis (Redis): Redis instance
Returns:
--------
None
"""
username = input("Input your username: "******"Input your password: "******"users", username):
raise DuplicateUserError()
user_id = redis.incr("next_user_id")
user_data = {
"uid": user_id,
"username": username,
"password": password,
"registration_date": int(time()),
"modification_date": int(time()),
}
redis.hset(f"user:{user_id}", mapping=user_data)
redis.hset("users", username, user_id)
print("You have been successfully signed up!")
def other_profile(redis: Redis) -> None:
"""Try to look at other people's profile.
Algorithm:
----------
1. Take input of username.
2. Sanity check, if blank raise an exception.
3. Check if user exists.
4. Fetch the 'user_id' in 'users' HSET.
5. Fetch the user's data in 'user' HSET.
6. Display our data.
Parameters:
-----------
redis (Redis): Redis instance
Returns:
--------
None
"""
target_username = input("Enter the username that you want to see: ")
if is_string_blank(target_username):
raise EmptyInputError()
if not redis.hget("users", target_username):
raise UserDoesNotExistError()
uid = redis.hget("users", target_username)
user_data = redis.hgetall(f"user:{uid}")
tweet_data = redis.lrange(f"tweet_user:{uid}", 0, -1)
following_data = redis.zrange(f"following:{uid}", 0, -1)
followers_data = redis.zrange(f"followers:{uid}", 0, -1)
print("Their personal data:")
print(user_data)
print("\nTheir tweets:")
for item in tweet_data:
post = redis.hgetall(f"tweet:{item}")
print(post)
print("\nTheir following:")
for item in following_data:
user = redis.hgetall(f"user:{item}")
print(user)
print("\nTheir followers:")
for item in followers_data:
user = redis.hgetall(f"user:{item}")
print(user)
def sign_in(redis: Redis) -> Union[int, bool]:
"""Logs in a user with an algorithm.
Algorithm:
----------
1. Get username and password.
2. Sanity check, ensure that inputs are fulfilled.
3. Check if username exists. If yes, fetch data from 'user' HSET.
4. Check if passwords match.
Parameters:
-----------
redis (Redis): Redis instance
Returns:
--------
int or None: Either integer or boolean
"""
username = input("Input your username: "******"Input your password: "******"users", username)
if not user_id:
print("Wrong username or password!")
return False
real_password = redis.hget(f"user:{user_id}", "password")
if password != real_password:
print("Wrong username or password!")
return False
print("You have been successfully authenticated!")
return user_id
def follow(redis: Redis, uid: int) -> None:
"""Follows another user.
Algorithm:
----------
1. Enter the username of someone that one wants to follow.
2. Sanity check, if the string is blank, raise an exception.
3. Check if user ID exists.
4. Fetch the user id from 'users' hash.
5. If the current user wants to follow themselves, then raise an exception.
6. Create a mapping to store data in zset (sorted set).
7. Store 'following' and 'followers' with the suitable IDs.
Parameters:
-----------
redis (Redis): Redis instance
uid (int): User id
Returns:
--------
None
"""
follow_username = input("Enter the username of someone to follow: ")
if is_string_blank(follow_username):
raise EmptyInputError()
if not redis.hexists("users", follow_username):
raise UserDoesNotExistError()
user_id_to_be_followed = redis.hget("users", follow_username)
if user_id_to_be_followed == uid:
raise FollowError()
following_mapping = {user_id_to_be_followed: int(time())}
followers_mapping = {uid: int(time())}
redis.zadd(f"following:{uid}", following_mapping)
redis.zadd(f"followers:{user_id_to_be_followed}", followers_mapping)
print(f"You have successfully followed {follow_username}")
def tweet(redis: Redis, uid: int) -> None:
"""Send a tweet connected to the user's account.
Algorithm:
----------
1. Get tweet.
2. Sanity check, if tweet is blank, raise an exception.
3. Increment 'tweet_id', as it is a standalone entity.
4. Store our tweet data in a HSET.
5. Store our tweet identifier for a certain user in LPUSH (list).
6. Store the reference to the tweet in an LPUSH (list) for the global timeline.
7. Trim the 'timeline' Redis list to the latest 1000 tweet references.
Parameters:
-----------
redis (Redis): Redis instance
uid (int): User id
Returns:
--------
None
"""
content = input("What's on your mind: ")
if is_string_blank(content):
raise EmptyInputError()
tweet_data = {
"uid": uid,
"content": content,
"date_posted": int(time()),
"date_modified": int(time()),
}
tweet_id = redis.incr("next_tweet_id")
redis.hset(f"tweet:{tweet_id}", mapping=tweet_data)
redis.lpush(f"tweet_user:{uid}", tweet_id)
redis.lpush("timeline", tweet_id)
redis.ltrim("timeline", 0, 1000)
print("Tweet has been successfully inserted!")
def unfollow(redis: Redis, uid: int) -> None:
"""Unfollows a user.
Algorithm:
----------
1. Get the sorted set of the user.
2. Sanity check, if the user id is blank, raise an exception.
3. Get the targeted user ID.
4. If user does not exist, raise an exception.
5. If targeted user is not in the 'following' of the current user, raise an exception.
6. Remove from the sorted set of the current user, and change the suitable followers/following.
Parameters:
-----------
redis (Redis): Redis instance
uid (int): User id
Returns:
-------
None
"""
username_to_be_unfollowed = input(
"Enter the username that you want to unfollow: ")
user_id_to_be_unfollowed = redis.hget("users", username_to_be_unfollowed)
if is_string_blank(username_to_be_unfollowed):
raise EmptyInputError()
if not user_id_to_be_unfollowed:
raise UserDoesNotExistError()
if not redis.zscore(f"following:{uid}", user_id_to_be_unfollowed):
raise UserIsNotYourFollowingError()
redis.zrem(f"following:{uid}", user_id_to_be_unfollowed)
redis.zrem(f"followers:{user_id_to_be_unfollowed}", uid)
print(
f"You have succesfully unfollowed a person with username {username_to_be_unfollowed}!"
)
def update_profile(redis: Redis, uid: int) -> None:
"""Updates a user.
Algorithm:
----------
1. Get the input.
2. Sanity checks.
3. Check for duplicate username.
4. Update the hash for 'user:id'.
Parameters:
-----------
redis (Redis): Redis instance
uid (int): User id
Returns:
--------
"""
new_username = input("Enter your new username here: ")
if is_string_blank(new_username):
raise EmptyInputError()
if redis.hexists("users", new_username):
raise DuplicateUserError()
new_user_data = {
"username": new_username,
"modification_date": int(time())
}
old_username = redis.hget(f"user:{uid}", "username")
redis.hset(f"user:{uid}", mapping=new_user_data)
redis.hdel("users", old_username)
redis.hset("users", new_username, uid)
print("Your personal data has been successfully updated!")