de_server: Add join game endpoint

Relates to DigitalExtinction#255.

crates/server/src/db.rs

@@ -1,5 +1,6 @@
 pub const SQLITE_CONSTRAINT_PRIMARYKEY: &str = "1555";
 pub const SQLITE_CONSTRAINT_UNIQUE: &str = "2067";
+pub const SQLITE_CONSTRAINT_FOREIGNKEY: &str = "787";
 
 #[macro_export]
 macro_rules! db_error {

crates/server/src/games/db.rs

@@ -7,7 +7,7 @@ use thiserror::Error;
 use super::model::{Game, GameConfig};
 use crate::{
     auth::model::MAX_USERNAME_LEN,
-    db::{SQLITE_CONSTRAINT_PRIMARYKEY, SQLITE_CONSTRAINT_UNIQUE},
+    db::{SQLITE_CONSTRAINT_FOREIGNKEY, SQLITE_CONSTRAINT_PRIMARYKEY, SQLITE_CONSTRAINT_UNIQUE},
     db_error,
     games::model::{MAX_GAME_NAME_LEN, MAX_MAP_NAME_LEN},
 };
@@ -88,6 +88,10 @@ impl Games {
         Ok(())
     }
 
+    pub(super) async fn add_player(&self, username: &str, game: &str) -> Result<(), AdditionError> {
+        Self::add_player_inner(self.pool, false, username, game).await
+    }
+
     async fn add_player_inner<'c, E>(
         executor: E,
         author: bool,
@@ -104,6 +108,11 @@ impl Games {
             .execute(executor)
             .await;
 
+        db_error!(
+            result,
+            AdditionError::UserOrGameDoesNotExist,
+            SQLITE_CONSTRAINT_FOREIGNKEY
+        );
         db_error!(
             result,
             AdditionError::AlreadyInAGame,
@@ -206,6 +215,8 @@ pub(super) enum CreationError {
 pub(super) enum AdditionError {
     #[error("User is already in another game")]
     AlreadyInAGame,
+    #[error("The user or the game does not exist")]
+    UserOrGameDoesNotExist,
     #[error("A database error encountered")]
     Database(#[source] sqlx::Error),
     #[error(transparent)]

crates/server/src/games/endpoints.rs

@@ -13,6 +13,7 @@ pub(super) fn configure(cfg: &mut web::ServiceConfig) {
         web::scope("/games")
             .service(create)
             .service(list)
+            .service(join)
             .service(leave),
     );
 }
@@ -58,6 +59,31 @@ async fn list(games: web::Data<Games>) -> impl Responder {
     }
 }
 
+#[put("/{name}/join")]
+async fn join(
+    claims: web::ReqData<Claims>,
+    games: web::Data<Games>,
+    path: web::Path<String>,
+) -> impl Responder {
+    let name = path.into_inner();
+
+    match games.add_player(claims.username(), name.as_str()).await {
+        Ok(_) => HttpResponse::Ok().finish(),
+        Err(AdditionError::AlreadyInAGame) => {
+            warn!("Game joining error: a user is already in a different game.");
+            HttpResponse::Forbidden().json("User is already in a different game.")
+        }
+        Err(AdditionError::UserOrGameDoesNotExist) => {
+            warn!("Game joining error: the game or the user does not exist");
+            HttpResponse::NotFound().json("Game not found.")
+        }
+        Err(error) => {
+            error!("Error while adding a player to a game: {:?}", error);
+            HttpResponse::InternalServerError().finish()
+        }
+    }
+}
+
 #[put("/{name}/leave")]
 async fn leave(
     claims: web::ReqData<Claims>,

docs/content/lobby/openapi.yaml

@@ -100,6 +100,28 @@ paths:
         "409":
           description: A different game with the same name already exists.
 
+  /a/games/{name}/join:
+    put:
+      summary: Join the game.
+      description: >-
+        Join the game. The client must not be part of another game (including
+        this one).
+      security:
+        - bearerAuth: []
+      parameters:
+        - name: name
+          in: path
+          required: true
+          schema:
+            type: string
+      responses:
+        "200":
+          description: The user successfully joined the game.
+        "403":
+          description: The user is already part of a game.
+        "404":
+          description: The game does not exist.
+
   /a/games/{name}/leave:
     put:
       summary: Leave or abandon a game.