Merge branch 'feature/leaderboard'

18 files changed, 429 insertions, 112 deletions

diff --git a/planetwars-matchrunner/src/lib.rs b/planetwars-matchrunner/src/lib.rs
index b7a9e53..5aff793 100644
--- a/planetwars-matchrunner/src/lib.rs
+++ b/planetwars-matchrunner/src/lib.rs
@@ -38,7 +38,6 @@ pub struct PlayerInfo {
 }
 
 pub struct MatchPlayer {
-    pub name: String,
     pub bot_spec: Box<dyn BotSpec>,
 }
 
@@ -52,7 +51,11 @@ pub trait BotSpec: Send + Sync {
     ) -> Box<dyn PlayerHandle>;
 }
 
-pub async fn run_match(config: MatchConfig) {
+pub struct MatchOutcome {
+    pub winner: Option<usize>,
+}
+
+pub async fn run_match(config: MatchConfig) -> MatchOutcome {
     let pw_config = PwConfig {
         map_file: config.map_path,
         max_turns: 100,
@@ -103,8 +106,18 @@ pub async fn run_match(config: MatchConfig) {
     // )
     // .unwrap();
 
-    let match_state = pw_match::PwMatch::create(match_ctx, pw_config);
+    let mut match_state = pw_match::PwMatch::create(match_ctx, pw_config);
     match_state.run().await;
+
+    let final_state = match_state.match_state.state();
+    let survivors = final_state.living_players();
+    let winner = if survivors.len() == 1 {
+        Some(survivors[0])
+    } else {
+        None
+    };
+
+    MatchOutcome { winner }
 }
 
 // writing this as a closure causes lifetime inference errors
diff --git a/planetwars-matchrunner/src/pw_match.rs b/planetwars-matchrunner/src/pw_match.rs
index c9a7f7b..f5b803c 100644
--- a/planetwars-matchrunner/src/pw_match.rs
+++ b/planetwars-matchrunner/src/pw_match.rs
@@ -24,8 +24,8 @@ pub struct MatchConfig {
 }
 
 pub struct PwMatch {
-    match_ctx: MatchCtx,
-    match_state: PlanetWars,
+    pub match_ctx: MatchCtx,
+    pub match_state: PlanetWars,
 }
 
 impl PwMatch {
@@ -39,7 +39,7 @@ impl PwMatch {
         }
     }
 
-    pub async fn run(mut self) {
+    pub async fn run(&mut self) {
         while !self.match_state.is_finished() {
             let player_messages = self.prompt_players().await;
 
diff --git a/planetwars-server/migrations/2022-04-28-171349_create_rating/down.sql b/planetwars-server/migrations/2022-04-28-171349_create_rating/down.sql
new file mode 100644
index 0000000..8267412
--- /dev/null
+++ b/planetwars-server/migrations/2022-04-28-171349_create_rating/down.sql
@@ -0,0 +1,2 @@
+-- This file should undo anything in `up.sql`
+drop table ratings;
\ No newline at end of file
diff --git a/planetwars-server/migrations/2022-04-28-171349_create_rating/up.sql b/planetwars-server/migrations/2022-04-28-171349_create_rating/up.sql
new file mode 100644
index 0000000..39fe6fe
--- /dev/null
+++ b/planetwars-server/migrations/2022-04-28-171349_create_rating/up.sql
@@ -0,0 +1,7 @@
+-- Your SQL goes here
+-- this table could later be expanded to include more information,
+-- such as rating state (eg. number of matches played) or scope (eg. map)
+create table ratings (
+    bot_id integer PRIMARY KEY REFERENCES bots(id),
+    rating float NOT NULL
+)
\ No newline at end of file
diff --git a/planetwars-server/src/db/bots.rs b/planetwars-server/src/db/bots.rs
index d99a459..108c692 100644
--- a/planetwars-server/src/db/bots.rs
+++ b/planetwars-server/src/db/bots.rs
@@ -11,7 +11,7 @@ pub struct NewBot<'a> {
     pub name: &'a str,
 }
 
-#[derive(Queryable, Debug, PartialEq, Serialize, Deserialize)]
+#[derive(Queryable, Debug, Clone, PartialEq, Serialize, Deserialize)]
 pub struct Bot {
     pub id: i32,
     pub owner_id: Option<i32>,
diff --git a/planetwars-server/src/db/mod.rs b/planetwars-server/src/db/mod.rs
index 7a950c6..84ed2a6 100644
--- a/planetwars-server/src/db/mod.rs
+++ b/planetwars-server/src/db/mod.rs
@@ -1,4 +1,5 @@
 pub mod bots;
 pub mod matches;
+pub mod ratings;
 pub mod sessions;
 pub mod users;
diff --git a/planetwars-server/src/db/ratings.rs b/planetwars-server/src/db/ratings.rs
new file mode 100644
index 0000000..8262fed
--- /dev/null
+++ b/planetwars-server/src/db/ratings.rs
@@ -0,0 +1,54 @@
+use diesel::{prelude::*, PgConnection, QueryResult};
+use serde::{Deserialize, Serialize};
+
+use crate::db::bots::Bot;
+use crate::schema::{bots, ratings, users};
+
+#[derive(Queryable, Debug, Insertable, PartialEq, Serialize, Deserialize)]
+pub struct Rating {
+    pub bot_id: i32,
+    pub rating: f64,
+}
+
+pub fn get_rating(bot_id: i32, db_conn: &PgConnection) -> QueryResult<Option<f64>> {
+    ratings::table
+        .filter(ratings::bot_id.eq(bot_id))
+        .select(ratings::rating)
+        .first(db_conn)
+        .optional()
+}
+
+pub fn set_rating(bot_id: i32, rating: f64, db_conn: &PgConnection) -> QueryResult<usize> {
+    diesel::insert_into(ratings::table)
+        .values(Rating { bot_id, rating })
+        .on_conflict(ratings::bot_id)
+        .do_update()
+        .set(ratings::rating.eq(rating))
+        .execute(db_conn)
+}
+
+#[derive(Queryable, Serialize, Deserialize)]
+pub struct Author {
+    id: i32,
+    username: String,
+}
+
+#[derive(Queryable, Serialize, Deserialize)]
+pub struct RankedBot {
+    pub bot: Bot,
+    pub author: Option<Author>,
+    pub rating: f64,
+}
+
+pub fn get_bot_ranking(db_conn: &PgConnection) -> QueryResult<Vec<RankedBot>> {
+    bots::table
+        .left_join(users::table)
+        .inner_join(ratings::table)
+        .select((
+            bots::all_columns,
+            (users::id, users::username).nullable(),
+            ratings::rating,
+        ))
+        .order_by(ratings::rating.desc())
+        .get_results(db_conn)
+}
diff --git a/planetwars-server/src/lib.rs b/planetwars-server/src/lib.rs
index 51d6613..28d7a76 100644
--- a/planetwars-server/src/lib.rs
+++ b/planetwars-server/src/lib.rs
@@ -8,11 +8,14 @@ pub mod routes;
 pub mod schema;
 pub mod util;
 
+use std::net::SocketAddr;
 use std::ops::Deref;
 
 use bb8::{Pool, PooledConnection};
 use bb8_diesel::{self, DieselConnectionManager};
+use config::ConfigError;
 use diesel::{Connection, PgConnection};
+use modules::ranking::run_ranker;
 use serde::Deserialize;
 
 use axum::{
@@ -55,16 +58,16 @@ pub async fn seed_simplebot(pool: &ConnectionPool) {
     });
 }
 
-pub async fn prepare_db(database_url: &str) -> Pool<DieselConnectionManager<PgConnection>> {
+pub type DbPool = Pool<DieselConnectionManager<PgConnection>>;
+
+pub async fn prepare_db(database_url: &str) -> DbPool {
     let manager = DieselConnectionManager::<PgConnection>::new(database_url);
     let pool = bb8::Pool::builder().build(manager).await.unwrap();
     seed_simplebot(&pool).await;
     pool
 }
 
-pub async fn api(configuration: Configuration) -> Router {
-    let db_pool = prepare_db(&configuration.database_url).await;
-
+pub fn api() -> Router {
     Router::new()
         .route("/register", post(routes::users::register))
         .route("/login", post(routes::users::login))
@@ -88,21 +91,34 @@ pub async fn api(configuration: Configuration) -> Router {
             "/matches/:match_id/log",
             get(routes::matches::get_match_log),
         )
+        .route("/leaderboard", get(routes::bots::get_ranking))
         .route("/submit_bot", post(routes::demo::submit_bot))
         .route("/save_bot", post(routes::bots::save_bot))
-        .layer(AddExtensionLayer::new(db_pool))
 }
 
-pub async fn app() -> Router {
-    let configuration = config::Config::builder()
+pub fn get_config() -> Result<Configuration, ConfigError> {
+    config::Config::builder()
         .add_source(config::File::with_name("configuration.toml"))
         .add_source(config::Environment::with_prefix("PLANETWARS"))
-        .build()
-        .unwrap()
+        .build()?
         .try_deserialize()
-        .unwrap();
-    let api = api(configuration).await;
-    Router::new().nest("/api", api)
+}
+
+pub async fn run_app() {
+    let configuration = get_config().unwrap();
+    let db_pool = prepare_db(&configuration.database_url).await;
+
+    tokio::spawn(run_ranker(db_pool.clone()));
+
+    let api_service = Router::new()
+        .nest("/api", api())
+        .layer(AddExtensionLayer::new(db_pool))
+        .into_make_service();
+
+    // TODO: put in config
+    let addr = SocketAddr::from(([127, 0, 0, 1], 9000));
+
+    axum::Server::bind(&addr).serve(api_service).await.unwrap();
 }
 
 #[derive(Deserialize)]
diff --git a/planetwars-server/src/main.rs b/planetwars-server/src/main.rs
index 9bd283e..9ed77b3 100644
--- a/planetwars-server/src/main.rs
+++ b/planetwars-server/src/main.rs
@@ -1,16 +1,7 @@
-use std::net::SocketAddr;
-
 extern crate planetwars_server;
 extern crate tokio;
 
 #[tokio::main]
 async fn main() {
-    let app = planetwars_server::app().await;
-
-    let addr = SocketAddr::from(([127, 0, 0, 1], 9000));
-
-    axum::Server::bind(&addr)
-        .serve(app.into_make_service())
-        .await
-        .unwrap();
+    planetwars_server::run_app().await;
 }
diff --git a/planetwars-server/src/modules/matches.rs b/planetwars-server/src/modules/matches.rs
new file mode 100644
index 0000000..201c6d4
--- /dev/null
+++ b/planetwars-server/src/modules/matches.rs
@@ -0,0 +1,102 @@
+use std::path::PathBuf;
+
+use diesel::{PgConnection, QueryResult};
+use planetwars_matchrunner::{self as runner, docker_runner::DockerBotSpec, BotSpec, MatchConfig};
+use runner::MatchOutcome;
+use tokio::task::JoinHandle;
+
+use crate::{
+    db::{self, matches::MatchData},
+    util::gen_alphanumeric,
+    ConnectionPool, BOTS_DIR, MAPS_DIR, MATCHES_DIR,
+};
+
+const PYTHON_IMAGE: &str = "python:3.10-slim-buster";
+
+pub struct RunMatch<'a> {
+    log_file_name: String,
+    player_code_bundles: Vec<&'a db::bots::CodeBundle>,
+    match_id: Option<i32>,
+}
+
+impl<'a> RunMatch<'a> {
+    pub fn from_players(player_code_bundles: Vec<&'a db::bots::CodeBundle>) -> Self {
+        let log_file_name = format!("{}.log", gen_alphanumeric(16));
+        RunMatch {
+            log_file_name,
+            player_code_bundles,
+            match_id: None,
+        }
+    }
+
+    pub fn runner_config(&self) -> runner::MatchConfig {
+        runner::MatchConfig {
+            map_path: PathBuf::from(MAPS_DIR).join("hex.json"),
+            map_name: "hex".to_string(),
+            log_path: PathBuf::from(MATCHES_DIR).join(&self.log_file_name),
+            players: self
+                .player_code_bundles
+                .iter()
+                .map(|b| runner::MatchPlayer {
+                    bot_spec: code_bundle_to_botspec(b),
+                })
+                .collect(),
+        }
+    }
+
+    pub fn store_in_database(&mut self, db_conn: &PgConnection) -> QueryResult<MatchData> {
+        // don't store the same match twice
+        assert!(self.match_id.is_none());
+
+        let new_match_data = db::matches::NewMatch {
+            state: db::matches::MatchState::Playing,
+            log_path: &self.log_file_name,
+        };
+        let new_match_players = self
+            .player_code_bundles
+            .iter()
+            .map(|b| db::matches::MatchPlayerData {
+                code_bundle_id: b.id,
+            })
+            .collect::<Vec<_>>();
+
+        let match_data = db::matches::create_match(&new_match_data, &new_match_players, &db_conn)?;
+        self.match_id = Some(match_data.base.id);
+        Ok(match_data)
+    }
+
+    pub fn spawn(self, pool: ConnectionPool) -> JoinHandle<MatchOutcome> {
+        let match_id = self.match_id.expect("match must be saved before running");
+        let runner_config = self.runner_config();
+        tokio::spawn(run_match_task(pool, runner_config, match_id))
+    }
+}
+
+pub fn code_bundle_to_botspec(code_bundle: &db::bots::CodeBundle) -> Box<dyn BotSpec> {
+    let bundle_path = PathBuf::from(BOTS_DIR).join(&code_bundle.path);
+
+    Box::new(DockerBotSpec {
+        code_path: bundle_path,
+        image: PYTHON_IMAGE.to_string(),
+        argv: vec!["python".to_string(), "bot.py".to_string()],
+    })
+}
+
+async fn run_match_task(
+    connection_pool: ConnectionPool,
+    match_config: MatchConfig,
+    match_id: i32,
+) -> MatchOutcome {
+    let outcome = runner::run_match(match_config).await;
+
+    // update match state in database
+    let conn = connection_pool
+        .get()
+        .await
+        .expect("could not get database connection");
+
+    db::matches::set_match_state(match_id, db::matches::MatchState::Finished, &conn)
+        .expect("could not update match state");
+
+    return outcome;
+}
diff --git a/planetwars-server/src/modules/mod.rs b/planetwars-server/src/modules/mod.rs
index 57c1ef5..bea28e0 100644
--- a/planetwars-server/src/modules/mod.rs
+++ b/planetwars-server/src/modules/mod.rs
@@ -1,3 +1,5 @@
 // This module implements general domain logic, not directly
 // tied to the database or API layers.
 pub mod bots;
+pub mod matches;
+pub mod ranking;
diff --git a/planetwars-server/src/modules/ranking.rs b/planetwars-server/src/modules/ranking.rs
new file mode 100644
index 0000000..cc81f0f
--- /dev/null
+++ b/planetwars-server/src/modules/ranking.rs
@@ -0,0 +1,87 @@
+use crate::{db::bots::Bot, DbPool};
+
+use crate::db;
+use crate::modules::matches::RunMatch;
+use rand::seq::SliceRandom;
+use std::time::Duration;
+use tokio;
+
+const RANKER_INTERVAL: u64 = 60;
+const START_RATING: f64 = 0.0;
+const SCALE: f64 = 100.0;
+const MAX_UPDATE: f64 = 10.0;
+
+pub async fn run_ranker(db_pool: DbPool) {
+    // TODO: make this configurable
+    // play at most one match every n seconds
+    let mut interval = tokio::time::interval(Duration::from_secs(RANKER_INTERVAL));
+    let db_conn = db_pool
+        .get()
+        .await
+        .expect("could not get database connection");
+    loop {
+        interval.tick().await;
+        let bots = db::bots::find_all_bots(&db_conn).unwrap();
+        if bots.len() < 2 {
+            // not enough bots to play a match
+            continue;
+        }
+        let selected_bots: Vec<Bot> = {
+            let mut rng = &mut rand::thread_rng();
+            bots.choose_multiple(&mut rng, 2).cloned().collect()
+        };
+        play_ranking_match(selected_bots, db_pool.clone()).await;
+    }
+}
+
+async fn play_ranking_match(selected_bots: Vec<Bot>, db_pool: DbPool) {
+    let db_conn = db_pool.get().await.expect("could not get db pool");
+    let mut code_bundles = Vec::new();
+    for bot in &selected_bots {
+        let code_bundle = db::bots::active_code_bundle(bot.id, &db_conn)
+            .expect("could not get active code bundle");
+        code_bundles.push(code_bundle);
+    }
+
+    let code_bundle_refs = code_bundles.iter().map(|b| b).collect::<Vec<_>>();
+
+    let mut run_match = RunMatch::from_players(code_bundle_refs);
+    run_match
+        .store_in_database(&db_conn)
+        .expect("could not store match in db");
+    let outcome = run_match
+        .spawn(db_pool.clone())
+        .await
+        .expect("running match failed");
+
+    let mut ratings = Vec::new();
+    for bot in &selected_bots {
+        let rating = db::ratings::get_rating(bot.id, &db_conn)
+            .expect("could not get bot rating")
+            .unwrap_or(START_RATING);
+        ratings.push(rating);
+    }
+
+    // simple elo rating
+
+    let scores = match outcome.winner {
+        None => vec![0.5; 2],
+        Some(player_num) => {
+            // TODO: please get rid of this offset
+            let player_ix = player_num - 1;
+            let mut scores = vec![0.0; 2];
+            scores[player_ix] = 1.0;
+            scores
+        }
+    };
+
+    for i in 0..2 {
+        let j = 1 - i;
+
+        let scaled_difference = (ratings[j] - ratings[i]) / SCALE;
+        let expected = 1.0 / (1.0 + 10f64.powf(scaled_difference));
+        let new_rating = ratings[i] + MAX_UPDATE * (scores[i] - expected);
+        db::ratings::set_rating(selected_bots[i].id, new_rating, &db_conn)
+            .expect("could not update bot rating");
+    }
+}
diff --git a/planetwars-server/src/routes/bots.rs b/planetwars-server/src/routes/bots.rs
index 2cdea2a..3bbaa1a 100644
--- a/planetwars-server/src/routes/bots.rs
+++ b/planetwars-server/src/routes/bots.rs
@@ -12,6 +12,7 @@ use std::path::PathBuf;
 use thiserror;
 
 use crate::db::bots::{self, CodeBundle};
+use crate::db::ratings::{RankedBot, self};
 use crate::db::users::User;
 use crate::modules::bots::save_code_bundle;
 use crate::{DatabaseConnection, BOTS_DIR};
@@ -170,6 +171,12 @@ pub async fn list_bots(conn: DatabaseConnection) -> Result<Json<Vec<Bot>>, Statu
         .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)
 }
 
+pub async fn get_ranking(conn: DatabaseConnection) -> Result<Json<Vec<RankedBot>>, StatusCode> {
+    ratings::get_bot_ranking(&conn)
+        .map(Json)
+        .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)
+}
+
 // TODO: currently this only implements the happy flow
 pub async fn upload_code_multipart(
     conn: DatabaseConnection,
diff --git a/planetwars-server/src/routes/demo.rs b/planetwars-server/src/routes/demo.rs
index eb7f61f..7f7ba71 100644
--- a/planetwars-server/src/routes/demo.rs
+++ b/planetwars-server/src/routes/demo.rs
@@ -1,20 +1,16 @@
 use crate::db;
-use crate::db::matches::{FullMatchData, FullMatchPlayerData, MatchPlayerData, MatchState};
+use crate::db::matches::{FullMatchData, FullMatchPlayerData};
 use crate::modules::bots::save_code_bundle;
-use crate::util::gen_alphanumeric;
-use crate::{ConnectionPool, BOTS_DIR, MAPS_DIR, MATCHES_DIR};
+use crate::modules::matches::RunMatch;
+use crate::ConnectionPool;
 use axum::extract::Extension;
 use axum::Json;
 use hyper::StatusCode;
-use planetwars_matchrunner::BotSpec;
-use planetwars_matchrunner::{docker_runner::DockerBotSpec, run_match, MatchConfig, MatchPlayer};
 use serde::{Deserialize, Serialize};
-use std::path::PathBuf;
 
 use super::matches::ApiMatch;
 
-const PYTHON_IMAGE: &str = "python:3.10-slim-buster";
-const OPPONENT_NAME: &str = "simplebot";
+const DEFAULT_OPPONENT_NAME: &str = "simplebot";
 
 #[derive(Serialize, Deserialize, Debug)]
 pub struct SubmitBotParams {
@@ -29,16 +25,6 @@ pub struct SubmitBotResponse {
     pub match_data: ApiMatch,
 }
 
-fn code_bundle_to_botspec(code_bundle: &db::bots::CodeBundle) -> Box<dyn BotSpec> {
-    let bundle_path = PathBuf::from(BOTS_DIR).join(&code_bundle.path);
-
-    Box::new(DockerBotSpec {
-        code_path: bundle_path,
-        image: PYTHON_IMAGE.to_string(),
-        argv: vec!["python".to_string(), "bot.py".to_string()],
-    })
-}
-
 /// submit python code for a bot, which will face off
 /// with a demo bot. Return a played match.
 pub async fn submit_bot(
@@ -49,7 +35,7 @@ pub async fn submit_bot(
 
     let opponent_name = params
         .opponent_name
-        .unwrap_or_else(|| OPPONENT_NAME.to_string());
+        .unwrap_or_else(|| DEFAULT_OPPONENT_NAME.to_string());
 
     let opponent =
         db::bots::find_bot_by_name(&opponent_name, &conn).map_err(|_| StatusCode::BAD_REQUEST)?;
@@ -60,46 +46,11 @@ pub async fn submit_bot(
         // TODO: can we recover from this?
         .expect("could not save bot code");
 
-    let log_file_name = format!("{}.log", gen_alphanumeric(16));
-    // play the match
-    let match_config = MatchConfig {
-        map_path: PathBuf::from(MAPS_DIR).join("hex.json"),
-        map_name: "hex".to_string(),
-        log_path: PathBuf::from(MATCHES_DIR).join(&log_file_name),
-        players: vec![
-            MatchPlayer {
-                name: "player".to_string(),
-                bot_spec: code_bundle_to_botspec(&player_code_bundle),
-            },
-            MatchPlayer {
-                name: OPPONENT_NAME.to_string(),
-                bot_spec: code_bundle_to_botspec(&opponent_code_bundle),
-            },
-        ],
-    };
-
-    // store match in database
-    let new_match_data = db::matches::NewMatch {
-        state: MatchState::Playing,
-        log_path: &log_file_name,
-    };
-
-    let new_match_players = [
-        MatchPlayerData {
-            code_bundle_id: player_code_bundle.id,
-        },
-        MatchPlayerData {
-            code_bundle_id: opponent_code_bundle.id,
-        },
-    ];
-    let match_data = db::matches::create_match(&new_match_data, &new_match_players, &conn)
-        .expect("failed to create match");
-
-    tokio::spawn(run_match_task(
-        match_data.base.id,
-        match_config,
-        pool.clone(),
-    ));
+    let mut run_match = RunMatch::from_players(vec![&player_code_bundle, &opponent_code_bundle]);
+    let match_data = run_match
+        .store_in_database(&conn)
+        .expect("failed to save match");
+    run_match.spawn(pool.clone());
 
     // TODO: avoid clones
     let full_match_data = FullMatchData {
@@ -123,13 +74,3 @@ pub async fn submit_bot(
         match_data: api_match,
     }))
 }
-
-async fn run_match_task(match_id: i32, match_config: MatchConfig, connection_pool: ConnectionPool) {
-    run_match(match_config).await;
-    let conn = connection_pool
-        .get()
-        .await
-        .expect("could not get database connection");
-    db::matches::set_match_state(match_id, MatchState::Finished, &conn)
-        .expect("failed to update match state");
-}
diff --git a/planetwars-server/src/routes/matches.rs b/planetwars-server/src/routes/matches.rs
index 991a4b5..b61008d 100644
--- a/planetwars-server/src/routes/matches.rs
+++ b/planetwars-server/src/routes/matches.rs
@@ -52,7 +52,6 @@ pub async fn play_match(
             .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
 
         players.push(MatchPlayer {
-            name: bot.name.clone(),
             bot_spec: Box::new(DockerBotSpec {
                 code_path: PathBuf::from(BOTS_DIR).join(code_bundle.path),
                 image: "python:3.10-slim-buster".to_string(),
diff --git a/planetwars-server/src/schema.rs b/planetwars-server/src/schema.rs
index ae2e60c..812e05e 100644
--- a/planetwars-server/src/schema.rs
+++ b/planetwars-server/src/schema.rs
@@ -51,6 +51,16 @@ table! {
     use diesel::sql_types::*;
     use crate::db_types::*;
 
+    ratings (bot_id) {
+        bot_id -> Int4,
+        rating -> Float8,
+    }
+}
+
+table! {
+    use diesel::sql_types::*;
+    use crate::db_types::*;
+
     sessions (id) {
         id -> Int4,
         user_id -> Int4,
@@ -74,6 +84,15 @@ joinable!(bots -> users (owner_id));
 joinable!(code_bundles -> bots (bot_id));
 joinable!(match_players -> code_bundles (code_bundle_id));
 joinable!(match_players -> matches (match_id));
+joinable!(ratings -> bots (bot_id));
 joinable!(sessions -> users (user_id));
 
-allow_tables_to_appear_in_same_query!(bots, code_bundles, match_players, matches, sessions, users,);
+allow_tables_to_appear_in_same_query!(
+    bots,
+    code_bundles,
+    match_players,
+    matches,
+    ratings,
+    sessions,
+    users,
+);
diff --git a/web/pw-server/src/lib/components/Leaderboard.svelte b/web/pw-server/src/lib/components/Leaderboard.svelte
new file mode 100644
index 0000000..75e4807
--- /dev/null
+++ b/web/pw-server/src/lib/components/Leaderboard.svelte
@@ -0,0 +1,72 @@
+<script lang="ts">
+  import { onMount } from "svelte";
+
+  let leaderboard = [];
+
+  onMount(async () => {
+    const res = await fetch("/api/leaderboard", {
+      headers: {
+        "Content-Type": "application/json",
+      },
+    });
+
+    if (res.ok) {
+      leaderboard = await res.json();
+      console.log(leaderboard);
+    }
+  });
+
+  function formatRating(entry: object): any {
+    const rating = entry["rating"];
+    if (rating != null) {
+      return rating.toFixed(0);
+    } else {
+      // why does this happen?
+      return "-inf";
+    }
+  }
+</script>
+
+<div class="container">
+  <table class="leaderboard">
+    <tr class="leaderboard-row leaderboard-header">
+      <th class="leaderboard-rank" />
+      <th class="leaderboard-rating">Rating</th>
+      <th class="leaderboard-bot">Bot</th>
+      <th class="leaderboard-author">Author</th>
+    </tr>
+    {#each leaderboard as entry, index}
+      <tr class="leaderboard-row">
+        <td class="leaderboard-rank">{index + 1}</td>
+        <td class="leaderboard-rating">
+          {formatRating(entry)}
+        </td>
+        <td class="leaderboard-bot">{entry["bot"]["name"]}</td>
+        <td class="leaderboard-author">
+          {#if entry["author"]}
+            {entry["author"]["username"]}
+          {/if}
+        </td>
+      </tr>
+    {/each}
+  </table>
+</div>
+
+<style lang="scss">
+  .container {
+    overflow-y: scroll;
+    height: 100%;
+  }
+  .leaderboard {
+    margin: 18px auto;
+    text-align: center;
+  }
+
+  .leaderboard th,
+  .leaderboard td {
+    padding: 8px 16px;
+  }
+  .leaderboard-rank {
+    color: #333;
+  }
+</style>
diff --git a/web/pw-server/src/routes/index.svelte b/web/pw-server/src/routes/index.svelte
index 376b324..08dc60a 100644
--- a/web/pw-server/src/routes/index.svelte
+++ b/web/pw-server/src/routes/index.svelte
@@ -13,11 +13,13 @@
   import SubmitPane from "$lib/components/SubmitPane.svelte";
   import OutputPane from "$lib/components/OutputPane.svelte";
   import RulesView from "$lib/components/RulesView.svelte";
+  import Leaderboard from "$lib/components/Leaderboard.svelte";
 
   enum ViewMode {
     Editor,
     MatchVisualizer,
     Rules,
+    Leaderboard,
   }
 
   let matches = [];
@@ -111,10 +113,10 @@
     return log;
   }
 
-  function selectEditor() {
+  function setViewMode(viewMode_: ViewMode) {
     selectedMatchId = undefined;
     selectedMatchLog = undefined;
-    viewMode = ViewMode.Editor;
+    viewMode = viewMode_;
   }
 
   function selectRules() {
@@ -140,17 +142,24 @@
     <div
       class="editor-button sidebar-item"
       class:selected={viewMode === ViewMode.Editor}
-      on:click={selectEditor}
+      on:click={() => setViewMode(ViewMode.Editor)}
     >
       Editor
     </div>
     <div
       class="rules-button sidebar-item"
       class:selected={viewMode === ViewMode.Rules}
-      on:click={selectRules}
+      on:click={() => setViewMode(ViewMode.Rules)}
     >
       Rules
     </div>
+    <div
+      class="sidebar-item"
+      class:selected={viewMode === ViewMode.Leaderboard}
+      on:click={() => setViewMode(ViewMode.Leaderboard)}
+    >
+      Leaderboard
+    </div>
     <div class="sidebar-header">match history</div>
     <ul class="match-list">
       {#each matches as match}
@@ -175,6 +184,8 @@
       <EditorView {editSession} />
     {:else if viewMode === ViewMode.Rules}
       <RulesView />
+    {:else if viewMode === ViewMode.Leaderboard}
+      <Leaderboard />
     {/if}
   </div>
   <div class="sidebar-right">
@@ -220,16 +231,9 @@
     height: 100%;
   }
 
-  .editor-button {
-    padding: 15px;
-  }
-
-  .rules-button {
-    padding: 15px;
-  }
-
   .sidebar-item {
     color: #eee;
+    padding: 15px;
   }
 
   .sidebar-item:hover {