Do not automatically create accounts; use enum to show this instead.

Instead of automatically creating a user account entry for any user
executing a command, we use an Account enum which covers both
registered and "transient" unregistered users. If a user registers,
the context has the actual user instance available, with state and
everything. If a user is unregistered, then the account is considered
transient for the request, with only the username available.

src/bin/dicebot-cmd.rs

@@ -4,7 +4,7 @@ use tenebrous_dicebot::commands::ResponseExtractor;
 use tenebrous_dicebot::context::{Context, RoomContext};
 use tenebrous_dicebot::db::sqlite::Database;
 use tenebrous_dicebot::error::BotError;
-use tenebrous_dicebot::models::User;
+use tenebrous_dicebot::models::Account;
 use url::Url;
 
 #[tokio::main]
@@ -27,7 +27,7 @@ async fn main() -> Result<(), BotError> {
 
     let context = Context {
         db: db,
-        user: User::default(),
+        account: Account::default(),
         matrix_client: &matrix_sdk::Client::new(homeserver)
             .expect("Could not create matrix client"),
         room: RoomContext {

src/bot/command_execution.rs

@@ -1,8 +1,8 @@
 use crate::commands::{execute_command, ExecutionError, ExecutionResult, ResponseExtractor};
 use crate::context::{Context, RoomContext};
 use crate::db::sqlite::Database;
-use crate::db::Users;
 use crate::error::BotError;
+use crate::logic;
 use crate::matrix;
 use futures::stream::{self, StreamExt};
 use matrix_sdk::{self, identifiers::EventId, room::Joined, Client};
@@ -78,7 +78,7 @@ async fn create_context<'a>(
         matrix_client: client,
         room: room_ctx,
         username: &sender,
-        user: db.get_or_create_user(&sender).await?,
+        account: logic::get_account(db, &sender).await?,
         message_body: &command,
     })
 }

src/cofd/dice.rs

@@ -483,7 +483,7 @@ mod tests {
             .unwrap();
 
         let ctx = Context {
-            user: crate::models::User::default(),
+            account: crate::models::Account::default(),
             db: db,
             matrix_client: &matrix_sdk::Client::new(homeserver).unwrap(),
             room: dummy_room!(),
@@ -524,7 +524,7 @@ mod tests {
 
         let homeserver = Url::parse("http://example.com").unwrap();
         let ctx = Context {
-            user: crate::models::User::default(),
+            account: crate::models::Account::default(),
             db: db,
             matrix_client: &matrix_sdk::Client::new(homeserver).unwrap(),
             room: dummy_room!(),
@@ -562,7 +562,7 @@ mod tests {
 
         let homeserver = Url::parse("http://example.com").unwrap();
         let ctx = Context {
-            user: crate::models::User::default(),
+            account: crate::models::Account::default(),
             db: db.clone(),
             matrix_client: &matrix_sdk::Client::new(homeserver).unwrap(),
             room: dummy_room!(),

src/commands/mod.rs

@@ -201,7 +201,7 @@ mod tests {
         let homeserver = Url::parse("http://example.com").unwrap();
 
         let ctx = Context {
-            user: crate::models::User::default(),
+            account: crate::models::Account::default(),
             db: db,
             matrix_client: &matrix_sdk::Client::new(homeserver).unwrap(),
             room: secure_room!(),
@@ -223,7 +223,7 @@ mod tests {
         let homeserver = Url::parse("http://example.com").unwrap();
 
         let ctx = Context {
-            user: crate::models::User::default(),
+            account: crate::models::Account::default(),
             db: db,
             matrix_client: &matrix_sdk::Client::new(homeserver).unwrap(),
             room: secure_room!(),
@@ -245,7 +245,7 @@ mod tests {
         let homeserver = Url::parse("http://example.com").unwrap();
 
         let ctx = Context {
-            user: crate::models::User::default(),
+            account: crate::models::Account::default(),
             db: db,
             matrix_client: &matrix_sdk::Client::new(homeserver).unwrap(),
             room: dummy_room!(),
@@ -267,7 +267,7 @@ mod tests {
         let homeserver = Url::parse("http://example.com").unwrap();
 
         let ctx = Context {
-            user: crate::models::User::default(),
+            account: crate::models::Account::default(),
             db: db,
             matrix_client: &matrix_sdk::Client::new(homeserver).unwrap(),
             room: dummy_room!(),
@@ -298,7 +298,7 @@ mod tests {
         let homeserver = Url::parse("http://example.com").unwrap();
 
         let ctx = Context {
-            user: crate::models::User::default(),
+            account: crate::models::Account::default(),
             db: db,
             matrix_client: &matrix_sdk::Client::new(homeserver).unwrap(),
             room: dummy_room!(),

src/context.rs

@@ -1,6 +1,6 @@
 use crate::db::sqlite::Database;
 use crate::error::BotError;
-use crate::models::User;
+use crate::models::{Account, User};
 use matrix_sdk::identifiers::{RoomId, UserId};
 use matrix_sdk::room::Joined;
 use matrix_sdk::Client;
@@ -15,7 +15,7 @@ pub struct Context<'a> {
     pub room: RoomContext<'a>,
     pub username: &'a str,
     pub message_body: &'a str,
-    pub user: User,
+    pub account: Account,
 }
 
 impl Context<'_> {

src/cthulhu/dice.rs

@@ -504,7 +504,7 @@ mod tests {
 
         let homeserver = Url::parse("http://example.com").unwrap();
         let ctx = Context {
-            user: crate::models::User::default(),
+            account: crate::models::Account::default(),
             db: db,
             matrix_client: &matrix_sdk::Client::new(homeserver).unwrap(),
             room: dummy_room!(),
@@ -541,7 +541,7 @@ mod tests {
 
         let homeserver = Url::parse("http://example.com").unwrap();
         let ctx = Context {
-            user: crate::models::User::default(),
+            account: crate::models::Account::default(),
             db: db,
             matrix_client: &matrix_sdk::Client::new(homeserver).unwrap(),
             room: dummy_room!(),
@@ -578,7 +578,7 @@ mod tests {
 
         let homeserver = Url::parse("http://example.com").unwrap();
         let ctx = Context {
-            user: crate::models::User::default(),
+            account: crate::models::Account::default(),
             db: db,
             matrix_client: &matrix_sdk::Client::new(homeserver).unwrap(),
             room: dummy_room!(),

src/db/mod.rs

@@ -16,8 +16,6 @@ pub(crate) trait DbState {
 
 #[async_trait]
 pub(crate) trait Users {
-    async fn get_or_create_user(&self, username: &str) -> Result<User, DataError>;
-
     async fn upsert_user(&self, user: &User) -> Result<(), DataError>;
 
     async fn get_user(&self, username: &str) -> Result<Option<User>, DataError>;

src/db/sqlite/users.rs

@@ -76,21 +76,6 @@ impl Users for Database {
         Ok(user_row)
     }
 
-    //TODO should this logic be moved further up into logic.rs maybe?
-    async fn get_or_create_user(&self, username: &str) -> Result<User, DataError> {
-        let maybe_user = self.get_user(username).await?;
-
-        match maybe_user {
-            Some(user) => Ok(user),
-            None => {
-                info!("Creating unregistered account for {}", username);
-                let user = User::unregistered(&username);
-                self.upsert_user(&user).await?;
-                Ok(user)
-            }
-        }
-    }
-
     async fn authenticate_user(
         &self,
         username: &str,
@@ -119,48 +104,6 @@ mod tests {
             .unwrap()
     }
 
-    #[tokio::test(flavor = "multi_thread", worker_threads = 1)]
-    async fn get_or_create_user_no_user_exists() {
-        let db = create_db().await;
-
-        let user = db
-            .get_or_create_user("@test:example.com")
-            .await
-            .expect("User creation didn't work.");
-
-        assert_eq!(user.username, "@test:example.com");
-
-        let user_again = db
-            .get_user("@test:example.com")
-            .await
-            .expect("User retrieval didn't work.")
-            .expect("No user returned from option.");
-
-        assert_eq!(user, user_again);
-    }
-
-    #[tokio::test(flavor = "multi_thread", worker_threads = 1)]
-    async fn get_or_create_user_when_user_exists() {
-        let db = create_db().await;
-
-        let user = User {
-            username: "myuser".to_string(),
-            password: Some("abc".to_string()),
-            account_status: AccountStatus::Registered,
-            active_room: Some("myroom".to_string()),
-        };
-
-        let insert_result = db.upsert_user(&user).await;
-        assert!(insert_result.is_ok());
-
-        let user_again = db
-            .get_or_create_user("myuser")
-            .await
-            .expect("User retrieval didn't work.");
-
-        assert_eq!(user, user_again);
-    }
-
     #[tokio::test(flavor = "multi_thread", worker_threads = 1)]
     async fn create_and_get_full_user_test() {
         let db = create_db().await;

src/logic.rs

@@ -1,7 +1,10 @@
-use crate::context::Context;
-use crate::db::Variables;
 use crate::error::{BotError, DiceRollingError};
 use crate::parser::dice::{Amount, Element};
+use crate::{context::Context, models::Account};
+use crate::{
+    db::{sqlite::Database, Users, Variables},
+    models::TransientUser,
+};
 use argon2::{self, Config, Error as ArgonError};
 use futures::stream::{self, StreamExt, TryStreamExt};
 use rand::Rng;
@@ -50,3 +53,71 @@ pub(crate) fn hash_password(raw_password: &str) -> Result<String, ArgonError> {
     let config = Config::default();
     argon2::hash_encoded(raw_password.as_bytes(), &salt, &config)
 }
+
+pub(crate) async fn get_account(db: &Database, username: &str) -> Result<Account, BotError> {
+    Ok(db
+        .get_user(username)
+        .await?
+        .map(|user| Account::Registered(user))
+        .unwrap_or_else(|| {
+            Account::Transient(TransientUser {
+                username: username.to_owned(),
+            })
+        }))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::db::Users;
+    use crate::models::{AccountStatus, User};
+
+    async fn create_db() -> Database {
+        let db_path = tempfile::NamedTempFile::new_in(".").unwrap();
+        crate::db::sqlite::migrator::migrate(db_path.path().to_str().unwrap())
+            .await
+            .unwrap();
+
+        Database::new(db_path.path().to_str().unwrap())
+            .await
+            .unwrap()
+    }
+
+    #[tokio::test(flavor = "multi_thread", worker_threads = 1)]
+    async fn get_account_no_user_exists() {
+        let db = create_db().await;
+
+        let account = get_account(&db, "@test:example.com")
+            .await
+            .expect("Account retrieval didn't work");
+
+        assert!(matches!(account, Account::Transient(_)));
+
+        let user = account.transient_user().unwrap();
+        assert_eq!(user.username, "@test:example.com");
+    }
+
+    #[tokio::test(flavor = "multi_thread", worker_threads = 1)]
+    async fn get_or_create_user_when_user_exists() {
+        let db = create_db().await;
+
+        let user = User {
+            username: "myuser".to_string(),
+            password: Some("abc".to_string()),
+            account_status: AccountStatus::Registered,
+            active_room: Some("myroom".to_string()),
+        };
+
+        let insert_result = db.upsert_user(&user).await;
+        assert!(insert_result.is_ok());
+
+        let account = get_account(&db, "myuser")
+            .await
+            .expect("Account retrieval did not work");
+
+        assert!(matches!(account, Account::Registered(_)));
+
+        let user_again = account.registered_user().unwrap();
+        assert_eq!(user, user_again);
+    }
+}

src/models.rs

@@ -10,9 +10,9 @@ pub struct RoomInfo {
 #[derive(Eq, PartialEq, Clone, Copy, Debug, sqlx::Type)]
 #[sqlx(rename_all = "snake_case")]
 pub enum AccountStatus {
-    /// User is not registered, which means the "account" only exists
+    /// Account is not registered, which means a transient "account"
-    /// for state management in the bot. No privileged actions
+    /// with limited information exists only for the duration of the
-    /// possible.
+    /// command request.
     NotRegistered,
 
     /// User account is fully registered, either via Matrix directly,
@@ -30,6 +30,62 @@ impl Default for AccountStatus {
     }
 }
 
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub enum Account {
+    /// A registered user account, stored in the database.
+    Registered(User),
+
+    /// A transient account. Not stored in the database. Represents a
+    /// user in a public channel that has not registered directly with
+    /// the bot yet.
+    Transient(TransientUser),
+}
+
+impl Account {
+    /// Gets the account status. For registered users, this is their
+    /// actual account status (fully registered or awaiting
+    /// activation). For transient users, this is
+    /// AccountStatus::NotRegistered.
+    pub fn account_status(&self) -> AccountStatus {
+        match self {
+            Self::Registered(user) => user.account_status,
+            Self::Transient(_) => AccountStatus::NotRegistered,
+        }
+    }
+
+    /// Consume self into an Option<User> instance, which will be Some
+    /// if this account has a registered user, and None otherwise.
+    pub fn registered_user(self) -> Option<User> {
+        match self {
+            Self::Registered(user) => Some(user),
+            _ => None,
+        }
+    }
+
+    /// Consume self into an Option<TransientUser> instance, which
+    /// will be Some if this account has a non-registered user, and
+    /// None otherwise.
+    pub fn transient_user(self) -> Option<TransientUser> {
+        match self {
+            Self::Transient(user) => Some(user),
+            _ => None,
+        }
+    }
+}
+
+impl Default for Account {
+    fn default() -> Self {
+        Account::Transient(TransientUser {
+            username: "".to_string(),
+        })
+    }
+}
+
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct TransientUser {
+    pub username: String,
+}
+
 #[derive(Eq, PartialEq, Clone, Debug, Default, sqlx::FromRow)]
 pub struct User {
     pub username: String,