added friendships in backend

db/init.sql

@@ -1,17 +1,32 @@
 CREATE TABLE IF NOT EXISTS user_ (
-    id SERIAL PRIMARY KEY,
-    uuid UUID UNIQUE,
-    email TEXT UNIQUE,
-    username TEXT NOT NULL UNIQUE,
-    password_hash TEXT NOT NULL
+  id SERIAL PRIMARY KEY,
+  uuid UUID UNIQUE,
+  email TEXT UNIQUE,
+  username TEXT NOT NULL UNIQUE,
+  password_hash TEXT NOT NULL
+);
+
+CREATE TABLE IF NOT EXISTS friendship_ (
+  user_first  INT NOT NULL REFERENCES user_(id) ON DELETE CASCADE,
+  user_second INT NOT NULL REFERENCES user_(id) ON DELETE CASCADE,
+  created_at TIMESTAMPTZ NOT NULL DEFAULT now(),
+  PRIMARY KEY (user_first, user_second),
+);
+
+CREATE TABLE IF NOT EXISTS friend_request_ (
+  sender   INT NOT NULL REFERENCES user_(id) ON DELETE CASCADE,
+  receiver INT NOT NULL REFERENCES user_(id) ON DELETE CASCADE,
+  sent_at TIMESTAMPTZ NOT NULL DEFAULT now(),
+  PRIMARY KEY (sender, receiver),
+  CHECK (sender <> receiver)
 );
 
 CREATE TABLE IF NOT EXISTS room_ (
-    id SERIAL PRIMARY KEY,
-    uuid UUID UNIQUE,
-    owner INT NOT NULL REFERENCES user_(id) ON DELETE CASCADE,
-    name TEXT NOT NULL,
-    global BOOLEAN DEFAULT false
+  id SERIAL PRIMARY KEY,
+  uuid UUID UNIQUE,
+  owner INT NOT NULL REFERENCES user_(id) ON DELETE CASCADE,
+  name TEXT NOT NULL,
+  global BOOLEAN DEFAULT false
 );
 
 CREATE TABLE IF NOT EXISTS membership_ (
@@ -30,9 +45,9 @@ CREATE TABLE IF NOT EXISTS message_ (
 );
 
 CREATE TABLE ws_token_ (
-    token TEXT PRIMARY KEY,
-    room_id INT NOT NULL,
-    expires_at TIMESTAMPTZ NOT NULL
+  token TEXT PRIMARY KEY,
+  room_id INT NOT NULL,
+  expires_at TIMESTAMPTZ NOT NULL
 );
 
 -- Message timestamp creation

src/auth.rs

@@ -4,7 +4,10 @@ use jsonwebtoken::{DecodingKey, EncodingKey, Header, Validation, decode, encode}
 use password_hash::SaltString;
 use password_hash::rand_core::OsRng;
 
-use axum::http::{HeaderMap, StatusCode};
+use axum::{
+    Json,
+    http::{HeaderMap, StatusCode},
+};
 use uuid::Uuid;
 
 const DEFAULT_SECRET_KEY: &str = "43aaf85b92f1ae6fbcef7732c50a0904";
@@ -75,3 +78,10 @@ pub fn verify_jwt(headers: HeaderMap) -> Result<Claims, (StatusCode, String)> {
     .map(|data| data.claims)
     .map_err(|_| (StatusCode::UNAUTHORIZED, "Invalid token".to_string()))
 }
+
+pub async fn validate_token(
+    headers: HeaderMap,
+) -> Result<Json<serde_json::Value>, (StatusCode, String)> {
+    let _ = verify_jwt(headers)?;
+    Ok(Json(serde_json::json!({"valid": true})))
+}

src/db.rs

@@ -34,3 +34,11 @@ pub async fn username_from_uuid(
         .await
         .map_err(|_| (StatusCode::UNAUTHORIZED, String::from("Wrong token")))
 }
+
+pub async fn id_from_username(db: &PgPool, username: String) -> Result<i32, (StatusCode, String)> {
+    sqlx::query_scalar("SELECT id FROM user_ WHERE username = $1")
+        .bind(username)
+        .fetch_one(db)
+        .await
+        .map_err(|_| (StatusCode::NOT_FOUND, "User not found".into()))
+}

src/main.rs

@@ -48,6 +48,7 @@ async fn main() -> anyhow::Result<()> {
         .merge(routes::users::routes())
         .merge(routes::rooms::routes())
         .merge(routes::messages::routes())
+        .merge(routes::friends::routes())
         .merge(routes::ws::routes())
         .layer(Extension(db_pool))
         .layer(Extension(realtime))

src/routes/friends.rs

@@ -0,0 +1,174 @@
+use axum::{
+    Extension, Json, Router,
+    http::{HeaderMap, StatusCode},
+    routing::{get, post},
+};
+use sqlx::PgPool;
+use uuid::Uuid;
+
+use crate::db::user_id_from_uuid;
+use crate::{auth::verify_jwt, db::id_from_username};
+
+#[derive(sqlx::FromRow, serde::Serialize)]
+pub struct Friend {
+    pub uuid: Uuid,
+    pub username: String,
+}
+
+#[derive(sqlx::FromRow, serde::Serialize)]
+pub struct FriendRequest {
+    pub sender_uuid: Uuid,
+    pub sender_username: String,
+}
+
+#[derive(serde::Deserialize)]
+pub struct SendFriendRequestPayload {
+    pub receiver_username: String,
+}
+
+#[derive(serde::Deserialize)]
+pub struct AcceptFriendRequestPayload {
+    pub sender_uuid: Uuid,
+}
+
+pub fn routes() -> Router {
+    Router::new()
+        .route("/friends", get(list_friends))
+        .route("/friends/requests", get(list_requests))
+        .route("/friends/request", post(send_request))
+        .route("/friends/accept", post(accept_request))
+}
+
+async fn list_friends(
+    headers: HeaderMap,
+    Extension(db): Extension<PgPool>,
+) -> Result<Json<Vec<Friend>>, (StatusCode, String)> {
+    let claims = verify_jwt(headers)?;
+    let user_id = user_id_from_uuid(&db, claims.sub).await?;
+
+    let friends = sqlx::query_as::<_, Friend>(
+        r#"
+        SELECT u.uuid, u.username
+        FROM friendship_
+        JOIN user_ u
+          ON (u.id = friendship_.user_first AND friendship_.user_second = $1)
+          OR (u.id = friendship_.user_second AND friendship_.user_first = $1)
+        "#,
+    )
+    .bind(user_id)
+    .fetch_all(&db)
+    .await
+    .map_err(|_| {
+        (
+            StatusCode::INTERNAL_SERVER_ERROR,
+            "Could not list friends".into(),
+        )
+    })?;
+
+    Ok(Json(friends))
+}
+
+async fn list_requests(
+    headers: HeaderMap,
+    Extension(db): Extension<PgPool>,
+) -> Result<Json<Vec<FriendRequest>>, (StatusCode, String)> {
+    let claims = verify_jwt(headers)?;
+    let user_id = user_id_from_uuid(&db, claims.sub).await?;
+
+    let requests = sqlx::query_as::<_, FriendRequest>(
+        r#"
+        SELECT u.uuid AS sender_uuid, u.username AS sender_username
+        FROM friend_request_
+        JOIN user_ u ON u.id = friend_request_.sender
+        WHERE friend_request_.receiver = $1
+        "#,
+    )
+    .bind(user_id)
+    .fetch_all(&db)
+    .await
+    .map_err(|_| {
+        (
+            StatusCode::INTERNAL_SERVER_ERROR,
+            "Could not list friend requests".into(),
+        )
+    })?;
+
+    Ok(Json(requests))
+}
+
+async fn send_request(
+    headers: HeaderMap,
+    Extension(db): Extension<PgPool>,
+    Json(payload): Json<SendFriendRequestPayload>,
+) -> Result<StatusCode, (StatusCode, String)> {
+    let claims = verify_jwt(headers)?;
+
+    let sender_id = user_id_from_uuid(&db, claims.sub).await?;
+    let receiver_id = id_from_username(&db, payload.receiver_username).await?;
+
+    if sender_id == receiver_id {
+        return Err((
+            StatusCode::BAD_REQUEST,
+            "Cannot send a friend request to yourself".into(),
+        ));
+    }
+
+    sqlx::query("INSERT INTO friend_request_ (sender, receiver) VALUES ($1, $2)")
+        .bind(sender_id)
+        .bind(receiver_id)
+        .execute(&db)
+        .await
+        .map_err(|_| (StatusCode::CONFLICT, "Request already exists".into()))?;
+
+    Ok(StatusCode::CREATED)
+}
+
+async fn accept_request(
+    headers: HeaderMap,
+    Extension(db): Extension<PgPool>,
+    Json(payload): Json<AcceptFriendRequestPayload>,
+) -> Result<StatusCode, (StatusCode, String)> {
+    let claims = verify_jwt(headers)?;
+
+    let receiver_id = user_id_from_uuid(&db, claims.sub).await?;
+    let sender_id = user_id_from_uuid(&db, payload.sender_uuid).await?;
+
+    let (first, second) = if sender_id < receiver_id {
+        (sender_id, receiver_id)
+    } else {
+        (receiver_id, sender_id)
+    };
+
+    let mut tx = db
+        .begin()
+        .await
+        .map_err(|_| (StatusCode::INTERNAL_SERVER_ERROR, "DB error".into()))?;
+
+    let rows = sqlx::query("DELETE FROM friend_request_ WHERE sender = $1 AND receiver = $2")
+        .bind(sender_id)
+        .bind(receiver_id)
+        .execute(&mut *tx)
+        .await
+        .map_err(|_| (StatusCode::INTERNAL_SERVER_ERROR, "DB error".into()))?
+        .rows_affected();
+
+    if rows == 0 {
+        return Err((StatusCode::NOT_FOUND, "No such request".into()));
+    }
+
+    sqlx::query("INSERT INTO friendship_ (user_first, user_second) VALUES ($1, $2)")
+        .bind(first)
+        .bind(second)
+        .execute(&mut *tx)
+        .await
+        .map_err(|_| (StatusCode::CONFLICT, "Already friends".into()))?;
+
+    tx.commit().await.map_err(|_| {
+        (
+            StatusCode::INTERNAL_SERVER_ERROR,
+            "Could not accept friendship".into(),
+        )
+    })?;
+
+    Ok(StatusCode::CREATED)
+}

src/routes/mod.rs

@@ -1,3 +1,4 @@
+pub mod friends;
 pub mod messages;
 pub mod rooms;
 pub mod users;

src/routes/rooms.rs

@@ -81,7 +81,7 @@ async fn list_rooms(
     .bind(user_id)
     .fetch_all(&db)
     .await
-    .unwrap_or_else(|_| Vec::new());
+    .unwrap_or(Vec::new());
 
     Ok(Json(rooms))
 }

src/routes/users.rs

@@ -1,7 +1,7 @@
 use axum::{
     Extension, Json, Router,
     extract::Request,
-    http::{HeaderMap, StatusCode},
+    http::StatusCode,
     middleware::Next,
     response::Response,
     routing::{get, post},
@@ -11,7 +11,7 @@ use std::env;
 use uuid::Uuid;
 use validator::ValidateEmail;
 
-use crate::auth::{create_jwt, hash_password, verify_jwt, verify_password};
+use crate::auth::{create_jwt, hash_password, validate_token, verify_password};
 
 const DUMMY_HASH: &str = "$argon2id$v=19$m=4096,t=3,p=1$YWFhYWFhYWFhYWFhYWFhYQ$aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa";
 
@@ -149,10 +149,3 @@ pub async fn register_user(
         }),
     ))
 }
-
-async fn validate_token(
-    headers: HeaderMap,
-) -> Result<Json<serde_json::Value>, (StatusCode, String)> {
-    let _ = verify_jwt(headers)?;
-    Ok(Json(serde_json::json!({"valid": true})))
-}