Friends functionality (#90)

### Description

Implements and closes #86

### Game

Robocraft

### Please confirm

- [x] I am the legal owner or represent the owner of all work submitted
- [x] I consent to my submission being added to this FOSS project
- [ ] This PR used LLMs to generate some or all of the code changes

Reviewed-on: https://git.ngram.ca/OpenJam/rc-servers/pulls/90
Co-authored-by: NG (Graham) <ngniusness@gmail.com>
Co-committed-by: NG (Graham) <ngniusness@gmail.com>

rc_database/src/migration/m20260215_000001_create_friend_table.rs

@@ -0,0 +1,53 @@
+use sea_orm_migration::prelude::*;
+
+pub struct Migration;
+
+impl MigrationName for Migration {
+    fn name(&self) -> &str {
+        "m20260215_000001_create_friend_table"
+    }
+}
+
+#[async_trait::async_trait]
+impl MigrationTrait for Migration {
+    // Define how to apply this migration: Create the Friends table.
+    async fn up(&self, manager: &SchemaManager) -> Result<(), DbErr> {
+        manager
+            .create_table(
+                Table::create()
+                    .table(crate::schema::friend::Entity)
+                    .col(
+                        ColumnDef::new(crate::schema::friend::Column::Id)
+                            .integer()
+                            .not_null()
+                            .auto_increment()
+                            .primary_key(),
+                    )
+                    .col(ColumnDef::new(crate::schema::factory::vehicle::Column::CreationTime).big_integer().not_null())
+                    .col(ColumnDef::new(crate::schema::friend::Column::FriendSource).integer().not_null())
+                    .foreign_key(
+                        ForeignKey::create()
+                            .name("fk-friends-friend_source")
+                            .from(crate::schema::friend::Entity, crate::schema::friend::Column::FriendSource)
+                            .to(crate::schema::user::Entity, crate::schema::user::Column::Id),
+                    )
+                    .col(ColumnDef::new(crate::schema::friend::Column::FriendTarget).integer().not_null())
+                    .foreign_key(
+                        ForeignKey::create()
+                            .name("fk-friends-friend_target")
+                            .from(crate::schema::friend::Entity, crate::schema::friend::Column::FriendTarget)
+                            .to(crate::schema::user::Entity, crate::schema::user::Column::Id),
+                    )
+                    .col(ColumnDef::new(crate::schema::friend::Column::State).string().not_null())
+                    .to_owned(),
+            )
+            .await
+    }
+
+    // Define how to rollback this migration: Drop the Friends table.
+    async fn down(&self, manager: &SchemaManager) -> Result<(), DbErr> {
+        manager
+            .drop_table(Table::drop().table(crate::schema::friend::Entity).to_owned())
+            .await
+    }
+}

rc_database/src/migration/mod.rs

@@ -15,6 +15,7 @@ mod m20250918_000001_add_player_variant;
 mod m20251228_000001_create_score_table;
 #[cfg(feature = "factory")]
 mod m20260126_000001_create_factory_vehicle_table;
+mod m20260215_000001_create_friend_table;
 
 pub struct Migrator;
 
@@ -37,6 +38,7 @@ impl MigratorTrait for Migrator {
             Box::new(m20251228_000001_create_score_table::Migration),
             #[cfg(feature = "factory")]
             Box::new(m20260126_000001_create_factory_vehicle_table::Migration),
+            Box::new(m20260215_000001_create_friend_table::Migration),
         ]
     }
 }

rc_database/src/schema/friend.rs

@@ -0,0 +1,59 @@
+use sea_orm::entity::prelude::*;
+
+#[derive(Clone, Debug, PartialEq, Eq, DeriveEntityModel)]
+#[sea_orm(table_name = "friends")]
+pub struct Model {
+    #[sea_orm(primary_key)]
+    pub id: i32,
+    pub creation_time: i64, // seconds since unix epoch
+    pub friend_source: i32,
+    pub friend_target: i32,
+    pub state: FriendStatus,
+}
+
+#[derive(Copy, Clone, Debug, EnumIter, DeriveRelation)]
+pub enum Relation {
+    #[sea_orm(
+        belongs_to = "super::user::Entity",
+        from = "Column::FriendSource",
+        to = "super::user::Column::Id"
+    )]
+    Source,
+    #[sea_orm(
+        belongs_to = "super::user::Entity",
+        from = "Column::FriendTarget",
+        to = "super::user::Column::Id"
+    )]
+    Target,
+}
+
+/*impl Related<super::user::Entity> for Entity {
+    fn to() -> RelationDef {
+        Relation::Source.def()
+    }
+}*/
+
+impl Related<super::user::Entity> for Entity {
+    fn to() -> RelationDef {
+        Relation::Target.def()
+    }
+}
+
+impl ActiveModelBehavior for ActiveModel {}
+
+#[derive(Clone, Debug, PartialEq, Eq, EnumIter, DeriveActiveEnum)]
+#[sea_orm(rs_type = "String", db_type = "String(StringLen::None)", rename_all = "PascalCase")]
+pub enum FriendStatus {
+    InviteSent,
+    InvitePending,
+    Accepted,
+    Declined,
+    Cancelled,
+    Removed,
+}
+
+pub const FINAL_STATUSES: [FriendStatus; 3] = [
+    FriendStatus::Declined,
+    FriendStatus::Cancelled,
+    FriendStatus::Removed,
+];

rc_database/src/schema/mod.rs

@@ -12,6 +12,7 @@ pub mod game_event;
 pub mod multiplayer_game_score;
 #[cfg(feature = "factory")]
 pub mod factory;
+pub mod friend;
 
 pub fn parse_int_csv(s: &str) -> Vec<u32> {
     s.split(',').filter_map(|i_as_s| {

rc_database/src/schema/user.rs

@@ -27,6 +27,8 @@ pub enum Relation {
     Player,
     #[sea_orm(has_many = "super::factory::vehicle::Entity")]
     FactoryUploads,
+    #[sea_orm(has_many = "super::friend::Entity")]
+    Friends, // this will probably join the wrong column (i.e. in the wrong direction)
 }
 
 impl Related<super::permissions::Entity> for Entity {
@@ -65,4 +67,10 @@ impl Related<super::factory::vehicle::Entity> for Entity {
     }
 }
 
+impl Related<super::friend::Entity> for Entity {
+    fn to() -> RelationDef {
+        Relation::Friends.def()
+    }
+}
+
 impl ActiveModelBehavior for ActiveModel {}

rc_database/src/wrapper.rs

@@ -1,5 +1,5 @@
 use sea_orm_migration::MigratorTrait;
-use sea_orm::{ActiveModelTrait, ColumnTrait, EntityTrait, PaginatorTrait, QueryFilter, QueryOrder, QuerySelect, TransactionTrait};
+use sea_orm::{ActiveModelTrait, ColumnTrait, EntityTrait, PaginatorTrait, QueryFilter, QueryOrder, QuerySelect, TransactionTrait, sea_query::ExprTrait};
 
 pub struct Database {
     orm: std::sync::Arc<sea_orm::DatabaseConnection>,
@@ -39,6 +39,30 @@ impl Database {
             .await
     }
 
+    pub async fn user_by_public_id(&self, public_id: String) -> Result<Option<crate::schema::user::Model>, sea_orm::DbErr> {
+        crate::schema::user::Entity::find()
+            .filter(crate::schema::user::Column::PublicId.eq(public_id))
+            .one(self.orm.as_ref())
+            .await
+    }
+
+    pub async fn user_by_some_social_id(&self, public_id: String) -> Result<Option<crate::schema::user::Model>, sea_orm::DbErr> {
+        let lower_public_id = public_id.to_lowercase();
+        crate::schema::user::Entity::find()
+            .filter(sea_orm::sea_query::Expr::expr(
+                    sea_orm::sea_query::Func::lower(crate::schema::user::Column::DisplayName.into_expr())
+                ).eq(&lower_public_id).or(
+                    sea_orm::sea_query::Func::lower(crate::schema::user::Column::PublicId.into_expr())
+                        .eq(&lower_public_id)
+                ).or(
+                    sea_orm::sea_query::Func::lower(crate::schema::user::Column::Email.into_expr())
+                        .eq(&lower_public_id)
+                )
+            )
+            .one(self.orm.as_ref())
+            .await
+    }
+
     pub async fn user_by_steam_id(&self, steam_id: u64) -> Result<Option<crate::schema::user::Model>, sea_orm::DbErr> {
         crate::schema::user::Entity::find()
             .filter(crate::schema::user::Column::SteamId.eq(Some(steam_id.to_string())))
@@ -89,6 +113,14 @@ impl Database {
             .await
     }
 
+    pub async fn user_auxs_by_user_ids_and_descriptor(&self, user_ids: impl std::iter::IntoIterator<Item=i32>, descriptor: crate::schema::user_aux::Descriptor) -> Result<Vec<crate::schema::user_aux::Model>, sea_orm::DbErr> {
+        crate::schema::user_aux::Entity::find()
+            .filter(crate::schema::user_aux::Column::UserId.is_in(user_ids))
+            .filter(crate::schema::user_aux::Column::Descriptor.eq(descriptor))
+            .all(self.orm.as_ref())
+            .await
+    }
+
     pub async fn insert_user_aux(&self, entities: Vec<crate::schema::user_aux::ActiveModel>) -> Result<(), sea_orm::DbErr> {
         crate::schema::user_aux::Entity::insert_many(entities.into_iter()).exec(self.orm.as_ref()).await?;
         Ok(())
@@ -552,6 +584,43 @@ impl Database {
             .await
     }
 
+    pub async fn friends_by_user_id(&self, user_id: i32, status_not_in: impl IntoIterator<Item=crate::schema::friend::FriendStatus>) -> Result<Vec<(crate::schema::friend::Model, crate::schema::user::Model)>, sea_orm::DbErr> {
+        Ok(crate::schema::friend::Entity::find()
+            .find_also_related(crate::schema::user::Entity)
+            .filter(crate::schema::friend::Column::FriendSource.eq(user_id))
+            .filter(crate::schema::friend::Column::State.is_not_in(status_not_in))
+            .order_by_asc(crate::schema::friend::Column::CreationTime)
+            .all(self.orm.as_ref())
+            .await?
+            .into_iter()
+            .filter_map(|(friend, user_opt)| user_opt.map(|user| (friend, user)))
+            .collect())
+    }
+
+    pub async fn insert_friends(&self, entities: impl std::iter::IntoIterator<Item=crate::schema::friend::ActiveModel>) -> Result<(), sea_orm::DbErr> {
+        crate::schema::friend::Entity::insert_many(entities).exec(self.orm.as_ref()).await?;
+        Ok(())
+    }
+
+    pub async fn update_friends_state(&self, user_id_1: i32, user_id_2: i32, state: crate::schema::friend::FriendStatus) -> Result<(), sea_orm::DbErr> {
+        crate::schema::friend::Entity::update_many()
+            .filter(
+                sea_orm::sea_query::Condition::any()
+                    .add(
+                        sea_orm::sea_query::Expr::expr(crate::schema::friend::Column::FriendSource.eq(user_id_1))
+                            .and(crate::schema::friend::Column::FriendTarget.eq(user_id_2))
+                    ).add(
+                        sea_orm::sea_query::Expr::expr(crate::schema::friend::Column::FriendSource.eq(user_id_2))
+                            .and(crate::schema::friend::Column::FriendTarget.eq(user_id_1))
+                    )
+            )
+            .filter(crate::schema::friend::Column::State.is_not_in(crate::schema::friend::FINAL_STATUSES))
+            .col_expr(crate::schema::friend::Column::State, sea_orm::sea_query::Expr::value(state))
+            .exec(self.orm.as_ref())
+            .await?;
+        Ok(())
+    }
+
     pub async fn metrics(&self) -> super::DatabaseMetrics {
         self.metrics.lock().unwrap().snapshot()
     }