From 429fed7893c0dae2816cc0e8ba9698dc0f401668 Mon Sep 17 00:00:00 2001
From: clfreville2 <clement.freville2@etu.uca.fr>
Date: Fri, 17 Mar 2023 11:55:45 +0100
Subject: [PATCH] Add a leaderboard with Redis

---
 board-server/Cargo.toml         |  2 ++
 board-server/src/leaderboard.rs | 62 +++++++++++++++++++++++++++++++++
 board-server/src/main.rs        |  1 +
 3 files changed, 65 insertions(+)
 create mode 100644 board-server/src/leaderboard.rs

diff --git a/board-server/Cargo.toml b/board-server/Cargo.toml
index 0a23f4f..f14cc12 100644
--- a/board-server/Cargo.toml
+++ b/board-server/Cargo.toml
@@ -15,3 +15,5 @@ tungstenite = "0.18.0"
 anyhow = "1.0.69"
 rand = "0.8.5"
 serde_json = "1.0.93"
+redis = { version = "0.22.3", features = ["aio", "async-std-comp"] }
+async-trait = "0.1.66"
diff --git a/board-server/src/leaderboard.rs b/board-server/src/leaderboard.rs
new file mode 100644
index 0000000..24d3429
--- /dev/null
+++ b/board-server/src/leaderboard.rs
@@ -0,0 +1,62 @@
+use async_trait::async_trait;
+use redis::{AsyncCommands, RedisError};
+use std::env;
+
+const LEADERBOARD: &str = "leaderboard";
+type LeaderboardEntry = (String, i32);
+
+#[async_trait]
+trait Leaderboard {
+    async fn add_score(&self, player_name: &str, score: i32) -> Result<(), RedisError>;
+    async fn get_highscores(&self) -> Result<Vec<LeaderboardEntry>, RedisError>;
+}
+
+struct RedisLeaderboard {
+    client: redis::Client,
+}
+
+impl RedisLeaderboard {
+    fn new(client: redis::Client) -> Self {
+        Self { client }
+    }
+}
+
+#[async_trait]
+impl Leaderboard for RedisLeaderboard {
+    async fn add_score(&self, player_name: &str, score: i32) -> Result<(), RedisError> {
+        let mut con = self.client.get_async_connection().await?;
+        con.zadd(LEADERBOARD, player_name, score).await?;
+        Ok(())
+    }
+
+    async fn get_highscores(&self) -> Result<Vec<LeaderboardEntry>, RedisError> {
+        let mut con = self.client.get_async_connection().await?;
+        let count: isize = con.zcard(LEADERBOARD).await?;
+        let leaderboard: Vec<LeaderboardEntry> =
+            con.zrange_withscores(LEADERBOARD, 0, count - 1).await?;
+        Ok(leaderboard)
+    }
+}
+
+struct InMemoryLeaderboard();
+
+#[async_trait]
+impl Leaderboard for InMemoryLeaderboard {
+    async fn add_score(&self, _: &str, _: i32) -> Result<(), RedisError> {
+        Ok(())
+    }
+
+    async fn get_highscores(&self) -> Result<Vec<LeaderboardEntry>, RedisError> {
+        Ok(Vec::new())
+    }
+}
+
+async fn provide_leaderboard() -> Box<dyn Leaderboard> {
+    match env::var("REDIS_HOSTNAME") {
+        Ok(redis_host_name) => match redis::Client::open(format!("redis://{redis_host_name}/")) {
+            Ok(client) => Box::new(RedisLeaderboard::new(client)),
+            Err(_) => Box::new(InMemoryLeaderboard()),
+        },
+        Err(_) => Box::new(InMemoryLeaderboard()),
+    }
+}
diff --git a/board-server/src/main.rs b/board-server/src/main.rs
index 8ae1539..c57d4bb 100644
--- a/board-server/src/main.rs
+++ b/board-server/src/main.rs
@@ -1,3 +1,4 @@
+mod leaderboard;
 mod player;
 mod room;