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>

Cargo.lock

@@ -3013,18 +3013,14 @@ checksum = "7edddbd0b52d732b21ad9a5fab5c704c14cd949e5e9a1ec5929a24fded1b904c"
 
 [[package]]
 name = "polariton"
-version = "0.4.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6dcc388d509743a0419f5a5197a8c79e0f3fd484d5bd0b60e6f361887a8aa301"
+version = "0.6.0"
 dependencies = [
  "tokio",
 ]
 
 [[package]]
 name = "polariton_server"
-version = "0.4.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "51ea2a26537f7434f154e34d7c522ab10552442241e608e919d7cfc413ac3abc"
+version = "0.6.0"
 dependencies = [
  "async-trait",
  "log",

Cargo.toml

@@ -36,10 +36,10 @@ libfj = { version = "0.10" }
 log = "0.4"
 env_logger = "0.11"
 clap = { version = "4.5", features = [ "derive" ] }
-#polariton = { version = "0.5", path = "../polariton", features = [ "tokio-async" ] }
-#polariton_server = { version = "0.5", path = "../polariton/server", features = [ "tokio-async" ] }
-polariton = { version = "0.4", features = [ "tokio-async" ] }
-polariton_server = { version = "0.4", features = [ "tokio-async" ] }
+polariton = { version = "0.6", path = "../polariton", features = [ "tokio-async" ] }
+polariton_server = { version = "0.6", path = "../polariton/server", features = [ "tokio-async" ] }
+#polariton = { version = "0.6", features = [ "tokio-async" ] }
+#polariton_server = { version = "0.6", features = [ "tokio-async" ] }
 serde = { version = "1.0", features = [ "derive" ] }
 serde_json = "1.0"
 async-trait = "0.1"

rc_core/src/persist/user/mod.rs

@@ -11,7 +11,7 @@ mod inventory;
 pub use inventory::{UnlockedParts, UnlockOverride};
 
 mod traits;
-pub use traits::{UserProvider, User, UserToken, UserSlots, UserSlotData, VehicleData, UserAuthInfo, UserLoginInfo, UserAuthenticator, NewSlotData, UserId, RegistrationInfo, VehicleUploadData, ChatUser, AvatarInfo, GetAvatarInfo, ControlData, ControlType, CustomisationData, GetCustomisationData, SetSanction, SanctionType, LobbyUser, GameDescriptor, PlayerLobbyDescriptor, MultiplayerUser, PlayerScore, MultiplayerError, MultiplayerErrorCode, PlayerDescriptor, GameEventSetter, CurrentGameEvent, AuthError, IntercomUser, FakePlayers, ResolvedVehicle, CommonUser, IntercomListener, UserRole, SocialUser, CurrencyType, CurrencyOp, MatchRewards, SingleplayerUser, PurchaseResult, FactoryUser};
+pub use traits::{UserProvider, User, UserToken, UserSlots, UserSlotData, VehicleData, UserAuthInfo, UserLoginInfo, UserAuthenticator, NewSlotData, UserId, RegistrationInfo, VehicleUploadData, ChatUser, AvatarInfo, GetAvatarInfo, ControlData, ControlType, CustomisationData, GetCustomisationData, SetSanction, SanctionType, LobbyUser, GameDescriptor, PlayerLobbyDescriptor, MultiplayerUser, PlayerScore, MultiplayerError, MultiplayerErrorCode, PlayerDescriptor, GameEventSetter, CurrentGameEvent, AuthError, IntercomUser, FakePlayers, ResolvedVehicle, CommonUser, IntercomListener, UserRole, SocialUser, SocialUserC, CurrencyType, CurrencyOp, MatchRewards, SingleplayerUser, PurchaseResult, FactoryUser, FriendInviteReturn, FriendData, FriendInviteStatus};
 
 pub mod intercom;
 pub use intercom::generate_token as generate_intercom_token;

rc_core/src/persist/user/social.rs

@@ -1,7 +1,86 @@
 use super::account_json::UserData;
 
+impl UserData {
+    async fn apply_friend_state_to(&self, public_id: String, state: oj_rc_database::schema::friend::FriendStatus) -> Result<bool, polariton_server::operations::SimpleOpError> {
+        let target_user = self.db.user_by_public_id(public_id.clone()).await
+            .map_err(|e| {
+                log::error!("Failed to retrieve user {} to statify friend by user {}: {}", public_id, self.account.id, e);
+                polariton_server::operations::SimpleOpError::with_message(
+                    crate::data::error_codes::SocialErrorCode::DatabaseError as i16,
+                    format!("Failed to retrieve user to statify friend: {}", e),
+                )
+            })?;
+        if let Some(target_user) = target_user {
+            self.db.update_friends_state(target_user.id, self.account.id, state).await
+                .map_err(|e| {
+                    log::error!("Failed to update friend state of user {} by user {}: {}", target_user.id, self.account.id, e);
+                    polariton_server::operations::SimpleOpError::with_message(
+                        crate::data::error_codes::SocialErrorCode::DatabaseError as i16,
+                        format!("Failed to update friend state: {}", e),
+                    )
+                })?;
+            Ok(true)
+        } else {
+            log::debug!("Cannot statify non-existent user {} friend request", public_id);
+            Err(polariton_server::operations::SimpleOpError::with_message(
+                crate::data::error_codes::SocialErrorCode::UserDoesNotExist as i16,
+                format!("Failed to find user {} to statify friend", public_id),
+            ))
+        }
+    }
+}
+
 #[async_trait::async_trait]
 impl super::SocialUser for UserData {
+    async fn accept_friend(&self, username: String) -> Result<bool, polariton_server::operations::SimpleOpError> {
+        self.apply_friend_state_to(username, oj_rc_database::schema::friend::FriendStatus::Accepted).await
+    }
+
+    async fn decline_friend(&self, username: String) -> Result<bool, polariton_server::operations::SimpleOpError> {
+        self.apply_friend_state_to(username, oj_rc_database::schema::friend::FriendStatus::Declined).await
+    }
+
+    async fn cancel_friend(&self, username: String) -> Result<bool, polariton_server::operations::SimpleOpError> {
+        self.apply_friend_state_to(username, oj_rc_database::schema::friend::FriendStatus::Cancelled).await
+    }
+
+    async fn remove_friend(&self, username: String) -> Result<bool, polariton_server::operations::SimpleOpError> {
+        self.apply_friend_state_to(username, oj_rc_database::schema::friend::FriendStatus::Removed).await
+    }
+
+    async fn list_friends(&self) -> Result<Vec<super::FriendData>, polariton_server::operations::SimpleOpError> {
+        let friends = self.db.friends_by_user_id(self.account.id, oj_rc_database::schema::friend::FINAL_STATUSES).await
+            .map_err(|e| {
+                log::error!("Failed to retrieve friends for user {} : {}", self.account.id, e);
+                polariton_server::operations::SimpleOpError::with_message(
+                    crate::data::error_codes::SocialErrorCode::DatabaseError as i16,
+                    format!("Failed to retrieve friends: {}", e),
+                )
+            })?;
+        let friend_ids: Vec<i32> = friends.iter().map(|(_, user)| user.id).collect();
+        let friend_avatars = self.db.user_auxs_by_user_ids_and_descriptor(friend_ids, oj_rc_database::schema::user_aux::Descriptor::AvatarId).await
+            .map_err(|e| {
+                log::error!("Failed to retrieve friend avatars for user {} : {}", self.account.id, e);
+                polariton_server::operations::SimpleOpError::with_message(
+                    crate::data::error_codes::SocialErrorCode::DatabaseError as i16,
+                    format!("Failed to retrieve friend avatars: {}", e),
+                )
+            })?;
+        let friend_avatar_map: std::collections::HashMap<i32, u32> = friend_avatars.iter()
+            .filter_map(|avatar| avatar.data.parse().ok().map(|avatar_id| (avatar.user_id, avatar_id)))
+            .collect();
+        Ok(friends.into_iter()
+            .map(|(friend, user)| super::FriendData {
+                public_id: user.public_id,
+                display_name: user.display_name,
+                clan_name: None, // TODO clan
+                state: super::FriendInviteStatus::from_db(friend.state),
+                avatar_id: friend_avatar_map.get(&user.id).copied().unwrap_or(u32::MAX)
+            })
+            .collect()
+        )
+    }
+
     async fn has_unclaimed_match_rewards(&self) -> Result<bool, polariton_server::operations::SimpleOpError> {
         let count = self.db.count_score_by_user_id_and_claimed(self.account.id, false).await
             .map_err(|e| {
@@ -89,3 +168,91 @@ impl super::SocialUser for UserData {
         }
     }
 }
+
+#[async_trait::async_trait]
+impl <C> super::SocialUserC<C> for UserData {
+    async fn invite_friend(&self, username: String) -> Result<super::FriendInviteReturn<C>, polariton_server::operations::SimpleOpError> {
+        let target_user = self.db.user_by_some_social_id(username.clone()).await
+            .map_err(|e| {
+                log::error!("Failed to retrieve user {} by user {}: {}", username, self.account.id, e);
+                polariton_server::operations::SimpleOpError::with_message(
+                    crate::data::error_codes::SocialErrorCode::DatabaseError as i16,
+                    format!("Failed to retrieve user: {}", e),
+                )
+            })?;
+        if let Some(target_user) = target_user {
+            let now = chrono::Utc::now();
+            self.db.insert_friends([
+                // inviter -> invitee
+                oj_rc_database::schema::friend::ActiveModel {
+                    id: oj_rc_database::sea_orm::ActiveValue::NotSet,
+                    creation_time: oj_rc_database::sea_orm::ActiveValue::Set(now.timestamp()),
+                    friend_source: oj_rc_database::sea_orm::ActiveValue::Set(self.account.id),
+                    friend_target: oj_rc_database::sea_orm::ActiveValue::Set(target_user.id),
+                    state: oj_rc_database::sea_orm::ActiveValue::Set(oj_rc_database::schema::friend::FriendStatus::InviteSent),
+                },
+                // invitee -> inviter (reciprocal)
+                oj_rc_database::schema::friend::ActiveModel {
+                    id: oj_rc_database::sea_orm::ActiveValue::NotSet,
+                    creation_time: oj_rc_database::sea_orm::ActiveValue::Set(now.timestamp()),
+                    friend_source: oj_rc_database::sea_orm::ActiveValue::Set(target_user.id),
+                    friend_target: oj_rc_database::sea_orm::ActiveValue::Set(self.account.id),
+                    state: oj_rc_database::sea_orm::ActiveValue::Set(oj_rc_database::schema::friend::FriendStatus::InvitePending),
+                },
+            ]).await.map_err(|e| {
+                log::error!("Failed to retrieve user {} to send friend request by user {}: {}", username, self.account.id, e);
+                polariton_server::operations::SimpleOpError::with_message(
+                    crate::data::error_codes::SocialErrorCode::DatabaseError as i16,
+                    format!("Failed to retrieve user to send friend request: {}", e),
+                )
+            })?;
+            let my_user_avatar_aux = self.db.user_aux_by_user_id_and_descriptor(self.account.id, oj_rc_database::schema::user_aux::Descriptor::AvatarId).await.map_err(|e| {
+                log::error!("Failed to retrieve avatar for user {} (invite_friend): {}", self.account.id, e);
+                polariton_server::operations::SimpleOpError::with_message(
+                    crate::data::error_codes::SocialErrorCode::DatabaseError as i16,
+                    format!("Could not retrieve avatar: {}", e),
+                )
+            })?
+            .ok_or_else(|| {
+                log::error!("Failed to find avatar for user {}", self.account.id);
+                polariton_server::operations::SimpleOpError::with_message(
+                    crate::data::error_codes::SocialErrorCode::UnexpectedError as i16,
+                    format!("No avatar for user {}", self.account.id),
+                )
+            })?;
+            let target_user_avatar_aux = self.db.user_aux_by_user_id_and_descriptor(target_user.id, oj_rc_database::schema::user_aux::Descriptor::AvatarId).await.map_err(|e| {
+                log::error!("Failed to retrieve avatar for user {} (invite_friend): {}", target_user.id, e);
+                polariton_server::operations::SimpleOpError::with_message(
+                    crate::data::error_codes::SocialErrorCode::DatabaseError as i16,
+                    format!("Could not retrieve avatar: {}", e),
+                )
+            })?
+            .ok_or_else(|| {
+                log::error!("Failed to find avatar for user {} by user {}", target_user.id, self.account.id);
+                polariton_server::operations::SimpleOpError::with_message(
+                    crate::data::error_codes::SocialErrorCode::UnexpectedError as i16,
+                    format!("No avatar for user {}", target_user.id),
+                )
+            })?;
+            let my_avatar_id: Result<u32, _> = my_user_avatar_aux.data.parse();
+            let target_avatar_id: Result<i32, _> = target_user_avatar_aux.data.parse();
+            Ok(super::FriendInviteReturn {
+                target_public_id: target_user.public_id,
+                target_display_name: target_user.display_name,
+                my_clan_name: None, // TODO clan
+                target_clan_name: None, // TODO clan
+                my_avatar_id: my_avatar_id.unwrap_or(0),
+                target_player: polariton::operation::Typed::HashMap(vec![
+                    (polariton::operation::Typed::Str("useCustomAvatar".into()), polariton::operation::Typed::Bool(target_avatar_id.is_err())),
+                    (polariton::operation::Typed::Str("avatarId".into()), polariton::operation::Typed::Int(target_avatar_id.unwrap_or_default())),
+                ].into()),
+            })
+        } else {
+            log::debug!("Cannot invite non-existent user {}", username);
+            Err(polariton_server::operations::SimpleOpError::with_message(
+                crate::data::error_codes::SocialErrorCode::UserDoesNotExist as i16,
+                format!("Failed to find user {}", username),
+            ))
+        }
+    }
+}

rc_core/src/persist/user/traits.rs

@@ -73,7 +73,7 @@ pub trait UserAuthenticator {
 }
 
 #[async_trait::async_trait]
-pub trait User<C>: ChatUser + SocialUser + LobbyUser + MultiplayerUser + SingleplayerUser + IntercomUser + CommonUser + FactoryUser {
+pub trait User<C>: ChatUser + SocialUser + SocialUserC<C> + LobbyUser + MultiplayerUser + SingleplayerUser + IntercomUser + CommonUser + FactoryUser {
     async fn unlocked_parts(&self) -> Vec<u32>;
     async fn unlock_parts(&self, parts: &[u32]) -> Result<(), polariton_server::operations::SimpleOpError>;
     async fn selected_garage(&self) -> (String, u32);
@@ -453,11 +453,21 @@ pub enum CurrencyOp {
 
 #[async_trait::async_trait]
 pub trait SocialUser: Send + Sync {
+    async fn accept_friend(&self, username: String) -> Result<bool, polariton_server::operations::SimpleOpError>;
+    async fn decline_friend(&self, username: String) -> Result<bool, polariton_server::operations::SimpleOpError>;
+    async fn cancel_friend(&self, username: String) -> Result<bool, polariton_server::operations::SimpleOpError>;
+    async fn remove_friend(&self, username: String) -> Result<bool, polariton_server::operations::SimpleOpError>;
+    async fn list_friends(&self) -> Result<Vec<FriendData>, polariton_server::operations::SimpleOpError>;
     async fn has_unclaimed_match_rewards(&self) -> Result<bool, polariton_server::operations::SimpleOpError>;
     async fn get_unclaimed_match_rewards(&self) -> Result<MatchRewards, polariton_server::operations::SimpleOpError>;
     async fn claim_match_rewards(&self) -> Result<bool, polariton_server::operations::SimpleOpError>;
 }
 
+#[async_trait::async_trait]
+pub trait SocialUserC<C>: Send + Sync {
+    async fn invite_friend(&self, username: String) -> Result<FriendInviteReturn<C>, polariton_server::operations::SimpleOpError>;
+}
+
 pub struct MatchRewards {
     pub season_experience: i32,
     pub experience_award_base: i32,
@@ -471,6 +481,46 @@ pub struct MatchRewards {
     pub premium_robits_earned: i32,
 }
 
+pub struct FriendInviteReturn<C> {
+    pub target_public_id: String,
+    pub target_display_name: String,
+    pub my_clan_name: Option<String>,
+    pub target_clan_name: Option<String>,
+    pub my_avatar_id: u32,
+    pub target_player: polariton::operation::Typed<C>,
+}
+
+pub struct FriendData {
+    pub public_id: String,
+    pub display_name: String,
+    pub clan_name: Option<String>,
+    pub state: FriendInviteStatus, // FIXME don't directly pass database type
+    pub avatar_id: u32,
+}
+
+pub enum FriendInviteStatus {
+    InviteSent,
+    InvitePending,
+    Accepted,
+    Declined,
+    Cancelled,
+    Removed,
+}
+
+impl FriendInviteStatus {
+    #[inline]
+    pub(super) fn from_db(state: oj_rc_database::schema::friend::FriendStatus) -> Self {
+        match state {
+            oj_rc_database::schema::friend::FriendStatus::InviteSent => Self::InviteSent,
+            oj_rc_database::schema::friend::FriendStatus::InvitePending => Self::InvitePending,
+            oj_rc_database::schema::friend::FriendStatus::Accepted => Self::Accepted,
+            oj_rc_database::schema::friend::FriendStatus::Declined => Self::Declined,
+            oj_rc_database::schema::friend::FriendStatus::Cancelled => Self::Cancelled,
+            oj_rc_database::schema::friend::FriendStatus::Removed => Self::Removed,
+        }
+    }
+}
+
 #[async_trait::async_trait]
 pub trait SingleplayerUser: Send + Sync {
     // regular singleplayer and campaign mode

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()
     }

rc_social_room/src/data/custom.rs

@@ -1,21 +1,47 @@
 #[derive(Debug, Clone)]
 pub enum CustomType {
-    FriendInfo, // TODO actually serialise
+    FriendInfo(super::friend::FriendInfo), // TODO actually serialise
+    Unknown,
+}
+
+impl CustomType {
+    fn custom_ty(&self) -> u8 {
+        match self {
+            Self::FriendInfo(_) => 0,
+            Self::Unknown => 1,
+        }
+    }
 }
 
 pub struct CustomTypeSerdes;
 
 impl polariton::serdes::CustomSerdes<CustomType> for CustomTypeSerdes {
-    fn dump(_c: &CustomType, w: &mut dyn std::io::Write) -> std::io::Result<usize> {
-        let payload = vec![ // FIXME don't manually serialize
+    fn dump(c: &CustomType, w: &mut dyn std::io::Write) -> std::io::Result<usize> {
+        w.write_all(&[c.custom_ty()])?;
+        let mut buf = Vec::new();
+        let total_written_len = match c {
+            CustomType::FriendInfo(friend) => {
+                friend.dump(&mut std::io::Cursor::new(&mut buf))?
+            },
+            CustomType::Unknown => 0,
+        };
+        w.write_all(&(total_written_len as i16).to_be_bytes())?;
+        w.write_all(&buf)?;
+        Ok(3 + total_written_len)
+        /*let payload = vec![ // FIXME don't manually serialize
             0u8, // byte custom type
             0u8, 5u8, // short custom object size
             3u8, 0u8, 0u8, 0u8, 0u8, // content
-        ];
-        w.write(&payload)
+        ];*/
     }
 
-    fn parse(_r: &mut dyn std::io::Read) -> std::io::Result<CustomType> {
-        Ok(CustomType::FriendInfo)
+    fn parse(r: &mut dyn std::io::Read) -> std::io::Result<CustomType> {
+        let mut buf = [0u8; 3];
+        r.read_exact(&mut buf)?;
+        // TODO only read up up to size
+        match buf[0] {
+            0 => super::friend::FriendInfo::parse(r).map(CustomType::FriendInfo),
+            _ => Ok(CustomType::Unknown),
+        }
     }
 }

rc_social_room/src/data/friend.rs

@@ -16,4 +16,90 @@ impl AvatarInfo {
     }
 }
 
-// TODO pub struct FriendInfo {}
+#[derive(Debug, Clone)]
+pub struct FriendInfo {
+    pub status: InviteStatus,
+    pub is_online: bool,
+    pub public_id: String,
+    pub display_name: String,
+    pub clan_name: String,
+}
+
+impl FriendInfo {
+    pub(super) fn dump(&self, w: &mut dyn std::io::Write) -> std::io::Result<usize> {
+        w.write_all(&[
+            self.status.as_u8(),
+            self.is_online as u8,
+        ])?;
+        let mut total = 2;
+        total += oj_rc_core::data::write_str_for_binreader(&self.public_id, w)?;
+        total += oj_rc_core::data::write_str_for_binreader(&self.display_name, w)?;
+        total += oj_rc_core::data::write_str_for_binreader(&self.clan_name, w)?;
+        Ok(total)
+    }
+
+    pub(super) fn parse(r: &mut dyn std::io::Read) -> std::io::Result<Self> {
+        let mut buf = [0u8; 2];
+        r.read_exact(&mut buf)?;
+        let status = InviteStatus::from_u8(buf[0]).ok_or_else(|| std::io::Error::other(format!("Invalid invite status {}", buf[0])))?;
+        let is_online = buf[1] != 0;
+        let public_id = oj_rc_core::data::read_str_for_binwriter(r)?;
+        let display_name = oj_rc_core::data::read_str_for_binwriter(r)?;
+        let clan_name = oj_rc_core::data::read_str_for_binwriter(r)?;
+        Ok(Self {
+            status,
+            is_online,
+            public_id,
+            display_name,
+            clan_name,
+        })
+    }
+}
+
+#[repr(u8)]
+#[derive(Debug, Clone, Copy)]
+pub enum InviteStatus {
+    InviteSent = 0,
+    InvitePending = 1,
+    Accepted = 2,
+    None = 3
+}
+
+impl InviteStatus {
+    #[inline]
+    pub fn from_u8(num: u8) -> Option<Self> {
+        match num {
+            0 => Some(Self::InviteSent),
+            1 => Some(Self::InvitePending),
+            2 => Some(Self::Accepted),
+            3 => Some(Self::None),
+            _ => None,
+        }
+    }
+
+    #[inline]
+    pub fn as_u8(&self) -> u8 {
+        *self as u8
+    }
+
+    pub fn from_core(core: &oj_rc_core::persist::user::FriendInviteStatus) -> Self {
+        match core {
+            oj_rc_core::persist::user::FriendInviteStatus::InviteSent => Self::InviteSent,
+            oj_rc_core::persist::user::FriendInviteStatus::InvitePending => Self::InvitePending,
+            oj_rc_core::persist::user::FriendInviteStatus::Accepted => Self::Accepted,
+            oj_rc_core::persist::user::FriendInviteStatus::Declined
+            | oj_rc_core::persist::user::FriendInviteStatus::Cancelled
+            | oj_rc_core::persist::user::FriendInviteStatus::Removed => Self::None,
+        }
+    }
+
+    #[inline]
+    pub fn reciprocal(&self) -> Self {
+        match self {
+            Self::InviteSent => Self::InvitePending,
+            Self::InvitePending => Self::InviteSent,
+            Self::Accepted => Self::Accepted,
+            Self::None => Self::None,
+        }
+    }
+}

rc_social_room/src/events/friend_invite_accepted.rs

@@ -0,0 +1,28 @@
+pub struct FriendInviteAccepted {
+    pub friend_public_id: String,
+    pub friend_display_name: String,
+}
+
+impl FriendInviteAccepted {
+    pub const CODE: u8 = 1;
+
+    pub fn as_event_params<C>(&self) -> polariton::operation::ParameterTable<C> {
+        let mut params = std::collections::HashMap::with_capacity(2);
+        params.insert(1, polariton::operation::Typed::Str(self.friend_public_id.clone().into()));
+        params.insert(75, polariton::operation::Typed::Str(self.friend_display_name.clone().into()));
+        params.into()
+    }
+}
+
+impl <C: Send + 'static> polariton_server::events::IntoEvent<C> for FriendInviteAccepted {
+    const CHANNEL: u8 = 0;
+    const ENCRYPT: bool = true;
+    const RELIABLE: bool = true;
+
+    fn into_event(self) -> polariton::operation::Event<C> {
+        polariton::operation::Event {
+            code: Self::CODE,
+            params: self.as_event_params(),
+        }
+    }
+}

rc_social_room/src/events/friend_invite_cancelled.rs

@@ -0,0 +1,28 @@
+pub struct FriendInviteCancelled {
+    pub friend_public_id: String,
+    pub friend_display_name: String,
+}
+
+impl FriendInviteCancelled {
+    pub const CODE: u8 = 5;
+
+    pub fn as_event_params<C>(&self) -> polariton::operation::ParameterTable<C> {
+        let mut params = std::collections::HashMap::with_capacity(2);
+        params.insert(1, polariton::operation::Typed::Str(self.friend_public_id.clone().into()));
+        params.insert(75, polariton::operation::Typed::Str(self.friend_display_name.clone().into()));
+        params.into()
+    }
+}
+
+impl <C: Send + 'static> polariton_server::events::IntoEvent<C> for FriendInviteCancelled {
+    const CHANNEL: u8 = 0;
+    const ENCRYPT: bool = true;
+    const RELIABLE: bool = true;
+
+    fn into_event(self) -> polariton::operation::Event<C> {
+        polariton::operation::Event {
+            code: Self::CODE,
+            params: self.as_event_params(),
+        }
+    }
+}

rc_social_room/src/events/friend_invite_declined.rs

@@ -0,0 +1,28 @@
+pub struct FriendInviteDeclined {
+    pub friend_public_id: String,
+    pub friend_display_name: String,
+}
+
+impl FriendInviteDeclined {
+    pub const CODE: u8 = 2;
+
+    pub fn as_event_params<C>(&self) -> polariton::operation::ParameterTable<C> {
+        let mut params = std::collections::HashMap::with_capacity(2);
+        params.insert(1, polariton::operation::Typed::Str(self.friend_public_id.clone().into()));
+        params.insert(75, polariton::operation::Typed::Str(self.friend_display_name.clone().into()));
+        params.into()
+    }
+}
+
+impl <C: Send + 'static> polariton_server::events::IntoEvent<C> for FriendInviteDeclined {
+    const CHANNEL: u8 = 0;
+    const ENCRYPT: bool = true;
+    const RELIABLE: bool = true;
+
+    fn into_event(self) -> polariton::operation::Event<C> {
+        polariton::operation::Event {
+            code: Self::CODE,
+            params: self.as_event_params(),
+        }
+    }
+}

rc_social_room/src/events/friend_invite_received.rs

@@ -0,0 +1,42 @@
+pub struct FriendInviteReceived {
+    pub friend_public_id: String,
+    pub friend_display_name: String,
+    pub clan_name: Option<String>,
+    pub is_online: bool, // when would this ever be false?
+    pub avatar_id: u32, // direct from database; u32::MAX means it is a custom avatar
+}
+
+impl FriendInviteReceived {
+    pub const CODE: u8 = 0;
+
+    pub fn as_event_params<C>(&self) -> polariton::operation::ParameterTable<C> {
+        let mut params = std::collections::HashMap::with_capacity(8);
+        params.insert(1, polariton::operation::Typed::Str(self.friend_public_id.clone().into()));
+        params.insert(75, polariton::operation::Typed::Str(self.friend_display_name.clone().into()));
+        if let Some(clan_name) = &self.clan_name {
+            params.insert(31, polariton::operation::Typed::Str(clan_name.into()));
+        } else {
+            params.insert(31, polariton::operation::Typed::Null);
+        }
+
+        params.insert(2, polariton::operation::Typed::Bool(self.is_online));
+        params.insert(9, polariton::operation::Typed::HashMap(vec![
+            (polariton::operation::Typed::Str("useCustomAvatar".into()), polariton::operation::Typed::Bool(self.avatar_id == u32::MAX)),
+            (polariton::operation::Typed::Str("avatarId".into()), polariton::operation::Typed::Int(self.avatar_id.try_into().unwrap_or_default())),
+        ].into()));
+        params.into()
+    }
+}
+
+impl <C: Send + 'static> polariton_server::events::IntoEvent<C> for FriendInviteReceived {
+    const CHANNEL: u8 = 0;
+    const ENCRYPT: bool = true;
+    const RELIABLE: bool = true;
+
+    fn into_event(self) -> polariton::operation::Event<C> {
+        polariton::operation::Event {
+            code: Self::CODE,
+            params: self.as_event_params(),
+        }
+    }
+}

rc_social_room/src/events/friend_removed.rs

@@ -0,0 +1,28 @@
+pub struct FriendRemoved {
+    pub friend_public_id: String,
+    pub friend_display_name: String,
+}
+
+impl FriendRemoved {
+    pub const CODE: u8 = 3;
+
+    pub fn as_event_params<C>(&self) -> polariton::operation::ParameterTable<C> {
+        let mut params = std::collections::HashMap::with_capacity(2);
+        params.insert(1, polariton::operation::Typed::Str(self.friend_public_id.clone().into()));
+        params.insert(75, polariton::operation::Typed::Str(self.friend_display_name.clone().into()));
+        params.into()
+    }
+}
+
+impl <C: Send + 'static> polariton_server::events::IntoEvent<C> for FriendRemoved {
+    const CHANNEL: u8 = 0;
+    const ENCRYPT: bool = true;
+    const RELIABLE: bool = true;
+
+    fn into_event(self) -> polariton::operation::Event<C> {
+        polariton::operation::Event {
+            code: Self::CODE,
+            params: self.as_event_params(),
+        }
+    }
+}

rc_social_room/src/events/friend_status.rs

@@ -0,0 +1,33 @@
+#[derive(Clone)]
+pub struct FriendStatus {
+    pub friend_public_id: String,
+    pub friend_display_name: String,
+    pub is_online: bool,
+    pub invite_status: crate::data::friend::InviteStatus,
+}
+
+impl FriendStatus {
+    pub const CODE: u8 = 4;
+
+    pub fn as_event_params<C>(&self) -> polariton::operation::ParameterTable<C> {
+        let mut params = std::collections::HashMap::with_capacity(4);
+        params.insert(1, polariton::operation::Typed::Str(self.friend_public_id.clone().into()));
+        params.insert(75, polariton::operation::Typed::Str(self.friend_display_name.clone().into()));
+        params.insert(2, polariton::operation::Typed::Bool(self.is_online));
+        params.insert(3, polariton::operation::Typed::Byte(self.invite_status.as_u8()));
+        params.into()
+    }
+}
+
+impl <C: Send + 'static> polariton_server::events::IntoEvent<C> for FriendStatus {
+    const CHANNEL: u8 = 0;
+    const ENCRYPT: bool = true;
+    const RELIABLE: bool = true;
+
+    fn into_event(self) -> polariton::operation::Event<C> {
+        polariton::operation::Event {
+            code: Self::CODE,
+            params: self.as_event_params(),
+        }
+    }
+}

rc_social_room/src/events/mod.rs

@@ -0,0 +1,6 @@
+pub mod friend_invite_received;
+pub mod friend_invite_accepted;
+pub mod friend_invite_declined;
+pub mod friend_invite_cancelled;
+pub mod friend_removed;
+pub mod friend_status;

rc_social_room/src/main.rs

@@ -3,6 +3,9 @@ mod cli;
 
 mod data;
 mod operations;
+mod events;
+mod social_services;
+pub use social_services::SocialMesh;
 
 use oj_polariton_auth::Handshake;
 use tokio::net;
@@ -15,16 +18,30 @@ pub type UserTy = std::sync::Arc<oj_rc_core::UserState<crate::data::custom::Cust
 pub static START_TIMESTAMP_S: std::sync::atomic::AtomicI64 = std::sync::atomic::AtomicI64::new(0);
 pub static ONLINE_USERS: std::sync::atomic::AtomicU64 = std::sync::atomic::AtomicU64::new(0);
 
+pub struct InitConfig {
+    pub config: oj_rc_core::persist::config::ConfigImpl,
+    pub social: std::sync::Arc<SocialMesh>,
+}
+
 #[tokio::main]
 async fn main() -> std::io::Result<()> {
     env_logger::init();
     let args = cli::CliArgs::get();
     log::debug!("Got cli args {:?}", args);
 
-    let cubes = oj_rc_core::persist::config::ConfigImpl::load(&args.assets).expect("Bad config data");
-    let users = std::sync::Arc::new(oj_rc_core::persist::user::UserImpl::load(&args.data, &cubes).await.expect("Bad user data"));
+    let config = oj_rc_core::persist::config::ConfigImpl::load(&args.assets).expect("Bad config data");
+    let users = std::sync::Arc::new(oj_rc_core::persist::user::UserImpl::load(&args.data, &config).await.expect("Bad user data"));
+    let social = std::sync::Arc::new(SocialMesh::new());
 
-    let server = std::sync::Arc::new(polariton_server::Server::new(operations::handler(), polariton_server::events::EventsHandler::new()));
+    let init_ctx = InitConfig {
+        config,
+        social: social.clone(),
+    };
+
+    let server = std::sync::Arc::new(polariton_server::Server::new(
+        operations::handler(&init_ctx),
+        polariton_server::events::EventsHandler::new(),
+    ));
 
     let ip_addr: std::net::IpAddr = args.ip.parse().expect("Invalid IP address");
 
@@ -36,11 +53,11 @@ async fn main() -> std::io::Result<()> {
     if args.once {
         log::warn!("Handling first connection and then exiting");
         let (socket, address) = listener.accept().await?;
-        process_socket(socket, address, server.clone(), users.clone()).await;
+        process_socket(socket, address, server.clone(), users.clone(), social.clone()).await;
     } else {
         loop {
             let (socket, address) = listener.accept().await?;
-            tokio::spawn(process_socket(socket, address, server.clone(), users.clone()));
+            tokio::spawn(process_socket(socket, address, server.clone(), users.clone(), social.clone()));
         }
     }
     server.join();
@@ -48,7 +65,7 @@ async fn main() -> std::io::Result<()> {
     Ok(())
 }
 
-async fn process_socket(mut socket: net::TcpStream, address: std::net::SocketAddr, server: std::sync::Arc<polariton_server::Server<crate::UserTy, crate::data::custom::CustomType>>, users: std::sync::Arc<oj_rc_core::UserImpl>) {
+async fn process_socket(mut socket: net::TcpStream, address: std::net::SocketAddr, server: std::sync::Arc<polariton_server::Server<crate::UserTy, crate::data::custom::CustomType>>, users: std::sync::Arc<oj_rc_core::UserImpl>, social: std::sync::Arc<SocialMesh>) {
     log::debug!("Accepting connection from address {}", address);
     let enc = match do_connect_handshake(&mut socket).await {
         Some(x) => x,
@@ -65,9 +82,19 @@ async fn process_socket(mut socket: net::TcpStream, address: std::net::SocketAdd
     let ctx = polariton::packet::SerdesContext::from_boxed(op_ctx, enc);
     server.handle_async_with_channel_join(socket_r, socket_w, user_state.clone(), ctx, chann_tx, chann_rx).await;
     log::debug!("Goodbye connection from address {}", address);
-    ONLINE_USERS.fetch_sub(1, std::sync::atomic::Ordering::SeqCst);
+    ONLINE_USERS.store(social.online_count_read().await - 1, std::sync::atomic::Ordering::SeqCst);
     if let Ok(user_info) = user_state.user() {
         update_status(user_info.as_ref().as_ref()).await;
+        if let Ok(friends) = user_info.list_friends().await {
+            for friend in friends {
+                social.send_event_to(&friend.public_id, crate::events::friend_status::FriendStatus {
+                    friend_public_id: user_info.public_id().to_owned(),
+                    friend_display_name: user_info.display_name().to_owned(),
+                    is_online: false,
+                    invite_status: crate::data::friend::InviteStatus::from_core(&friend.state).reciprocal(),
+                }).await;
+            }
+        }
     }
 }
 

rc_social_room/src/operations/friend_accept.rs

@@ -0,0 +1,36 @@
+use polariton_server::operations::{SimpleOpError, SimpleOperation, SimpleOpImpl};
+use polariton::operation::{ParameterTable, Typed};
+
+const CODE: u8 = 1;
+
+const USERNAME_PARAM_KEY: u8 = 1; // str; in & out
+const IS_ONLINE_PARAM_KEY: u8 = 2; // bool; out
+
+pub(super) struct FriendRequestAccepter {
+    social: std::sync::Arc<crate::SocialMesh>,
+}
+
+#[async_trait::async_trait]
+impl SimpleOperation<crate::data::custom::CustomType> for FriendRequestAccepter {
+    type User = crate::UserTy;
+    const CODE: u8 = CODE;
+
+    async fn handle(&self, mut params: ParameterTable<crate::data::custom::CustomType>, user: &Self::User) -> Result<ParameterTable<crate::data::custom::CustomType>, SimpleOpError> {
+        if let Some(Typed::Str(username)) = params.remove(&USERNAME_PARAM_KEY) {
+            let user_info = user.user()?;
+            user_info.accept_friend(username.string.clone()).await?;
+            self.social.send_event_to(&username.string, crate::events::friend_invite_accepted::FriendInviteAccepted {
+                friend_public_id: user_info.public_id().to_owned(),
+                friend_display_name: user_info.display_name().to_owned(),
+            }).await;
+            params.insert(IS_ONLINE_PARAM_KEY, Typed::Bool(true)); // when would this ever not be true??
+        }
+        Ok(params)
+    }
+}
+
+pub(super) fn friend_accept_provider(init_ctx: &crate::InitConfig) -> SimpleOpImpl<crate::data::custom::CustomType, crate::UserTy, FriendRequestAccepter> {
+    SimpleOpImpl::new(FriendRequestAccepter {
+        social: init_ctx.social.clone(),
+    })
+}

rc_social_room/src/operations/friend_cancel.rs

@@ -0,0 +1,34 @@
+use polariton_server::operations::{SimpleOpError, SimpleOperation, SimpleOpImpl};
+use polariton::operation::{ParameterTable, Typed};
+
+const CODE: u8 = 5;
+
+const USERNAME_PARAM_KEY: u8 = 1; // str; in & out
+
+pub(super) struct FriendRequestCanceller {
+    social: std::sync::Arc<crate::SocialMesh>,
+}
+
+#[async_trait::async_trait]
+impl SimpleOperation<crate::data::custom::CustomType> for FriendRequestCanceller {
+    type User = crate::UserTy;
+    const CODE: u8 = CODE;
+
+    async fn handle(&self, mut params: ParameterTable<crate::data::custom::CustomType>, user: &Self::User) -> Result<ParameterTable<crate::data::custom::CustomType>, SimpleOpError> {
+        if let Some(Typed::Str(username)) = params.remove(&USERNAME_PARAM_KEY) {
+            let user_info = user.user()?;
+            user_info.cancel_friend(username.string.clone()).await?;
+            self.social.send_event_to(&username.string, crate::events::friend_invite_cancelled::FriendInviteCancelled {
+                friend_public_id: user_info.public_id().to_owned(),
+                friend_display_name: user_info.display_name().to_owned(),
+            }).await;
+        }
+        Ok(params)
+    }
+}
+
+pub(super) fn friend_cancel_provider(init_ctx: &crate::InitConfig) -> SimpleOpImpl<crate::data::custom::CustomType, crate::UserTy, FriendRequestCanceller> {
+    SimpleOpImpl::new(FriendRequestCanceller {
+        social: init_ctx.social.clone(),
+    })
+}

rc_social_room/src/operations/friend_decline.rs

@@ -0,0 +1,34 @@
+use polariton_server::operations::{SimpleOpError, SimpleOperation, SimpleOpImpl};
+use polariton::operation::{ParameterTable, Typed};
+
+const CODE: u8 = 2;
+
+const USERNAME_PARAM_KEY: u8 = 1; // str; in & out
+
+pub(super) struct FriendRequestDecliner {
+    social: std::sync::Arc<crate::SocialMesh>,
+}
+
+#[async_trait::async_trait]
+impl SimpleOperation<crate::data::custom::CustomType> for FriendRequestDecliner {
+    type User = crate::UserTy;
+    const CODE: u8 = CODE;
+
+    async fn handle(&self, mut params: ParameterTable<crate::data::custom::CustomType>, user: &Self::User) -> Result<ParameterTable<crate::data::custom::CustomType>, SimpleOpError> {
+        if let Some(Typed::Str(username)) = params.remove(&USERNAME_PARAM_KEY) {
+            let user_info = user.user()?;
+            user_info.decline_friend(username.string.clone()).await?;
+            self.social.send_event_to(&username.string, crate::events::friend_invite_declined::FriendInviteDeclined {
+                friend_public_id: user_info.public_id().to_owned(),
+                friend_display_name: user_info.display_name().to_owned(),
+            }).await;
+        }
+        Ok(params)
+    }
+}
+
+pub(super) fn friend_decline_provider(init_ctx: &crate::InitConfig) -> SimpleOpImpl<crate::data::custom::CustomType, crate::UserTy, FriendRequestDecliner> {
+    SimpleOpImpl::new(FriendRequestDecliner {
+        social: init_ctx.social.clone(),
+    })
+}

rc_social_room/src/operations/friend_invite.rs

@@ -0,0 +1,46 @@
+use polariton_server::operations::{SimpleOpError, SimpleOperation, SimpleOpImpl};
+use polariton::operation::{ParameterTable, Typed};
+
+const CODE: u8 = 0;
+
+const USERNAME_PARAM_KEY: u8 = 1; // str; in & out
+const DISPLAY_NAME_PARAM_KEY: u8 = 75; // str; out
+const CLAN_NAME_PARAM_KEY: u8 = 31; // str; out TODO
+const USER_DATA_PARAM_KEY: u8 = 9; // hashtable; out
+
+pub(super) struct FriendRequestMaker {
+    social: std::sync::Arc<crate::SocialMesh>,
+}
+
+#[async_trait::async_trait]
+impl SimpleOperation<crate::data::custom::CustomType> for FriendRequestMaker {
+    type User = crate::UserTy;
+    const CODE: u8 = CODE;
+
+    async fn handle(&self, mut params: ParameterTable<crate::data::custom::CustomType>, user: &Self::User) -> Result<ParameterTable<crate::data::custom::CustomType>, SimpleOpError> {
+        if let Some(Typed::Str(username)) = params.remove(&USERNAME_PARAM_KEY) {
+            let user_info = user.user()?;
+            let resp = user_info.invite_friend(username.string).await?;
+            self.social.send_event_to(&resp.target_public_id, crate::events::friend_invite_received::FriendInviteReceived {
+                friend_public_id: user_info.public_id().to_owned(),
+                friend_display_name: user_info.display_name().to_owned(),
+                clan_name: resp.my_clan_name,
+                is_online: true,
+                avatar_id: resp.my_avatar_id,
+            }).await;
+            params.insert(USERNAME_PARAM_KEY, Typed::Str(resp.target_public_id.into()));
+            params.insert(DISPLAY_NAME_PARAM_KEY, Typed::Str(resp.target_display_name.into()));
+            if let Some(clan_name) = resp.target_clan_name {
+                params.insert(CLAN_NAME_PARAM_KEY, Typed::Str(clan_name.into()));
+            }
+            params.insert(USER_DATA_PARAM_KEY, resp.target_player);
+        }
+        Ok(params)
+    }
+}
+
+pub(super) fn friend_invite_provider(init_ctx: &crate::InitConfig) -> SimpleOpImpl<crate::data::custom::CustomType, crate::UserTy, FriendRequestMaker> {
+    SimpleOpImpl::new(FriendRequestMaker {
+        social: init_ctx.social.clone(),
+    })
+}

rc_social_room/src/operations/friend_list.rs

@@ -1,12 +1,14 @@
-use polariton_server::operations::SimpleFunc;
+use polariton_server::operations::{SimpleOpError, SimpleOperation, SimpleOpImpl};
 use polariton::operation::{ParameterTable, Typed, Arr};
 
 use crate::data::friend::*;
 
+const CODE: u8 = 4;
+
 const FRIENDS_PARAM_KEY: u8 = 5;
 const AVATAR_PARAM_KEY: u8 = 76;
 
-pub(super) fn friends_provider() -> SimpleFunc<4, crate::UserTy, impl (Fn(ParameterTable<crate::data::custom::CustomType>, &crate::UserTy) -> Result<ParameterTable<crate::data::custom::CustomType>, i16>) + Sync + Sync, crate::data::custom::CustomType> {
+/*pub(super) fn friends_provider() -> SimpleFunc<4, crate::UserTy, impl (Fn(ParameterTable<crate::data::custom::CustomType>, &crate::UserTy) -> Result<ParameterTable<crate::data::custom::CustomType>, i16>) + Sync + Sync, crate::data::custom::CustomType> {
     SimpleFunc::new(|params, _| {
         let mut params = params.to_dict();
         params.insert(FRIENDS_PARAM_KEY, Typed::Arr(Arr {
@@ -22,4 +24,74 @@ pub(super) fn friends_provider() -> SimpleFunc<4, crate::UserTy, impl (Fn(Parame
         }));
         Ok(params.into())
     })
+}*/
+
+pub(super) struct FriendsLister {
+    social: std::sync::Arc<crate::SocialMesh>,
+}
+
+#[async_trait::async_trait]
+impl SimpleOperation<crate::data::custom::CustomType> for FriendsLister {
+    type User = crate::UserTy;
+    const CODE: u8 = CODE;
+
+    async fn handle(&self, mut params: ParameterTable<crate::data::custom::CustomType>, user: &Self::User) -> Result<ParameterTable<crate::data::custom::CustomType>, SimpleOpError> {
+        let user_info = user.user()?;
+        let friends = user_info.list_friends().await?;
+        let mut friend_pub_ids = friends.iter().map(|friend| friend.public_id.clone()).collect();
+        self.social.filter_online_only(&mut friend_pub_ids).await;
+        let friends_online_pub_ids = friend_pub_ids;
+        // Typed::Custom(crate::data::custom::CustomType::FriendInfo)
+        params.insert(FRIENDS_PARAM_KEY, Typed::Arr(Arr {
+            ty: polariton::serdes::TypePrefix::Custom, // custom
+            items: friends.iter().map(|friend|
+                Typed::Custom(crate::data::custom::CustomType::FriendInfo(crate::data::friend::FriendInfo {
+                    status: crate::data::friend::InviteStatus::from_core(&friend.state),
+                    is_online: friends_online_pub_ids.contains(&friend.public_id),
+                    public_id: friend.public_id.clone(),
+                    display_name: friend.display_name.clone(),
+                    clan_name: friend.clan_name.clone().unwrap_or_default(),
+                }))
+            ).collect()
+        }));
+        params.insert(AVATAR_PARAM_KEY, Typed::Arr(Arr {
+            ty: polariton::serdes::TypePrefix::HashMap, // hashmap
+            items: friends.iter()
+                .map(|friend|
+                    AvatarInfo {
+                        name: friend.public_id.clone(),
+                        use_custom_avatar: friend.avatar_id == u32::MAX,
+                        avatar_id: friend.avatar_id.try_into().unwrap_or_default(),
+                    }.as_transmissible()
+                ).collect()
+        }));
+        tokio::task::spawn(send_online_event_to_friends(
+            friends.iter()
+                .filter(|friend| friends_online_pub_ids.contains(&friend.public_id))
+                .map(|friend| (
+                    friend.public_id.clone(),
+                    crate::events::friend_status::FriendStatus {
+                        friend_public_id: user_info.public_id().to_owned(),
+                        friend_display_name: user_info.display_name().to_owned(),
+                        is_online: true,
+                        invite_status: crate::data::friend::InviteStatus::from_core(&friend.state).reciprocal(),
+                    }
+                ))
+                .collect(),
+            self.social.clone(),
+        ));
+        Ok(params)
+    }
+}
+
+async fn send_online_event_to_friends(events: Vec<(String, crate::events::friend_status::FriendStatus)>, social: std::sync::Arc<crate::SocialMesh>) {
+    for (public_id, event) in events {
+        social.send_event_to(&public_id, event).await;
+    }
+}
+
+pub(super) fn friends_provider(init_ctx: &crate::InitConfig) -> SimpleOpImpl<crate::data::custom::CustomType, crate::UserTy, FriendsLister> {
+    SimpleOpImpl::new(FriendsLister {
+        social: init_ctx.social.clone(),
+    })
 }

rc_social_room/src/operations/friend_remove.rs

@@ -0,0 +1,34 @@
+use polariton_server::operations::{SimpleOpError, SimpleOperation, SimpleOpImpl};
+use polariton::operation::{ParameterTable, Typed};
+
+const CODE: u8 = 3;
+
+const USERNAME_PARAM_KEY: u8 = 1; // str; in & out
+
+pub(super) struct FriendRequestRemover {
+    social: std::sync::Arc<crate::SocialMesh>,
+}
+
+#[async_trait::async_trait]
+impl SimpleOperation<crate::data::custom::CustomType> for FriendRequestRemover {
+    type User = crate::UserTy;
+    const CODE: u8 = CODE;
+
+    async fn handle(&self, mut params: ParameterTable<crate::data::custom::CustomType>, user: &Self::User) -> Result<ParameterTable<crate::data::custom::CustomType>, SimpleOpError> {
+        if let Some(Typed::Str(username)) = params.remove(&USERNAME_PARAM_KEY) {
+            let user_info = user.user()?;
+            user_info.remove_friend(username.string.clone()).await?;
+            self.social.send_event_to(&username.string, crate::events::friend_removed::FriendRemoved {
+                friend_public_id: user_info.public_id().to_owned(),
+                friend_display_name: user_info.display_name().to_owned(),
+            }).await;
+        }
+        Ok(params)
+    }
+}
+
+pub(super) fn friend_remove_provider(init_ctx: &crate::InitConfig) -> SimpleOpImpl<crate::data::custom::CustomType, crate::UserTy, FriendRequestRemover> {
+    SimpleOpImpl::new(FriendRequestRemover {
+        social: init_ctx.social.clone(),
+    })
+}

rc_social_room/src/operations/mod.rs

@@ -10,15 +10,20 @@ mod platoon_data;
 mod calculate_mmr;
 mod previous_battle_rewards_get;
 mod previous_battle_rewards_claim;
+mod friend_invite;
+mod friend_accept;
+mod friend_decline;
+mod friend_cancel;
+mod friend_remove;
 
 use polariton_server::operations::OperationsHandler;
 
-pub fn handler() -> OperationsHandler<crate::UserTy, crate::data::custom::CustomType> {
+pub fn handler(init_ctx: &crate::InitConfig) -> OperationsHandler<crate::UserTy, crate::data::custom::CustomType> {
     OperationsHandler::<crate::UserTy, crate::data::custom::CustomType>::new()
         .modify(oj_rc_core::polariton::RcOpModifier)
-        .add(more_auth::MoreLobbyAuth)
+        .add(more_auth::more_lobby_auth(init_ctx))
         //.add(polariton_server::operations::Ack::<33, _>::default()) // get user clan info (this is equivalent to not being in a clan)
-        .add(friend_list::friends_provider()) // TODO friend object parsing Token: 0x0200169C RID: 5788
+        .add(friend_list::friends_provider(init_ctx)) // TODO friend object parsing Token: 0x0200169C RID: 5788
         .add(settings::settings_provider()) // TODO save settings persistently
         .add(polariton_server::operations::Ack::<43, _>::default()) // get my clan info (this is equivalent to not being in a clan)
         .add(clan_invite::clan_invites_provider())
@@ -32,7 +37,11 @@ pub fn handler() -> OperationsHandler<crate::UserTy, crate::data::custom::Custom
         .add(polariton_server::operations::Ack::<6, _>::default()) // AvatarUpdatedRequest, sent on services_room avatar_set success (just needs to be ack-ed; no params)
         .add(calculate_mmr::mmr_provider())
         .add(polariton_server::operations::Ack::<25, _>::default()) // save social settings, sent on escape menu settings save (should probably be saved someday...)
-        .add(polariton_server::operations::Ack::<0, _>::default()) // send friend request, can be sent from match leaderboard
+        .add(friend_invite::friend_invite_provider(init_ctx)) // send friend request, can be sent from match leaderboard
         .add(previous_battle_rewards_get::get_battle_rewards_provider())
         .add(previous_battle_rewards_claim::claim_battle_rewards_provider())
+        .add(friend_accept::friend_accept_provider(init_ctx))
+        .add(friend_decline::friend_decline_provider(init_ctx))
+        .add(friend_cancel::friend_cancel_provider(init_ctx))
+        .add(friend_remove::friend_remove_provider(init_ctx))
 }

rc_social_room/src/operations/more_auth.rs

@@ -1,7 +1,15 @@
 use polariton::operation::Typed;
 use polariton_server::operations::{Operation, OperationCode};
 
-pub struct MoreLobbyAuth;
+pub fn more_lobby_auth(init_ctx: &crate::InitConfig) -> MoreLobbyAuth {
+    MoreLobbyAuth {
+        social: init_ctx.social.clone(),
+    }
+}
+
+pub struct MoreLobbyAuth {
+    social: std::sync::Arc<crate::SocialMesh>,
+}
 
 impl MoreLobbyAuth {
     const AUTH_PAYLOAD_KEY: u8 = 245;
@@ -15,6 +23,10 @@ impl <C: Send + 'static> Operation<C> for MoreLobbyAuth {
         let params_dict = params.to_dict();
         if let Some(Typed::Str(auth_payload)) = params_dict.get(&Self::AUTH_PAYLOAD_KEY) {
             if user.update_with_auth(&auth_payload.string).await {
+                self.social.add_user(
+                    user.user().unwrap().public_id().to_owned(),
+                    user.event_sender().to_owned().downgrade(),
+                ).await;
                 crate::update_status(user.user().unwrap().as_ref().as_ref()).await;
                 let mut resp_params = std::collections::HashMap::with_capacity(1);
                 resp_params.insert(Self::AUTH_PAYLOAD_KEY, polariton::operation::Typed::Byte(0));

rc_social_room/src/social_services.rs

@@ -0,0 +1,59 @@
+/// Primarily keeps track of who is online so events can be sent to them.
+pub struct SocialMesh {
+    users: tokio::sync::RwLock<std::collections::HashMap<String, UserHandle>>,
+}
+
+struct UserHandle {
+    emitter: polariton_server::events::WeakEventEmitter<crate::data::custom::CustomType>,
+    is_alive: std::sync::atomic::AtomicBool,
+}
+
+impl SocialMesh {
+    pub fn new() -> Self {
+        Self {
+            users: tokio::sync::RwLock::new(std::collections::HashMap::new()),
+        }
+    }
+
+    pub async fn send_event_to(&self, public_id: &str, event: impl polariton_server::events::IntoEvent<crate::data::custom::CustomType>) -> bool {
+        let user_lock = self.users.read().await;
+        if let Some(user_handle) = user_lock.get(public_id) {
+            let is_success = user_handle.emitter.emit(event);
+            user_handle.is_alive.swap(is_success, std::sync::atomic::Ordering::SeqCst);
+            is_success
+        } else {
+            false
+        }
+    }
+
+    pub async fn add_user(
+        &self,
+        public_id: String,
+        emitter: polariton_server::events::WeakEventEmitter<crate::data::custom::CustomType>,
+    ) {
+        let mut user_lock = self.users.write().await;
+        Self::cleanup_dead_users(&mut user_lock).await;
+        user_lock.insert(public_id, UserHandle {
+            emitter,
+            is_alive: std::sync::atomic::AtomicBool::new(true),
+        });
+    }
+
+    /// Filter out offline users
+    pub async fn filter_online_only(&self, public_ids: &mut std::collections::HashSet<String>) {
+        let mut user_lock = self.users.write().await;
+        Self::cleanup_dead_users(&mut user_lock).await;
+        public_ids.retain(|public_id| user_lock.contains_key(public_id));
+    }
+
+    async fn cleanup_dead_users(users: &mut std::collections::HashMap<String, UserHandle>) {
+        users.retain(|_public_id, handle| handle.is_alive.load(std::sync::atomic::Ordering::SeqCst));
+    }
+
+    pub async fn online_count_read(&self) -> u64 {
+        let user_lock = self.users.read().await;
+        user_lock.iter()
+            .filter(|(_, handle)| handle.is_alive.load(std::sync::atomic::Ordering::SeqCst))
+            .count() as u64
+    }
+}