1 files changed, 45 insertions, 0 deletions
diff --git a/planetwars-matchrunner/src/match_log.rs b/planetwars-matchrunner/src/match_log.rs
new file mode 100644
index 0000000..9991f99
--- /dev/null
+++ b/planetwars-matchrunner/src/match_log.rs
@@ -0,0 +1,45 @@
+use std::path::Path;
+
+use serde::{Deserialize, Serialize};
+use tokio::{fs::File, io::AsyncWriteExt};
+
+use planetwars_rules::protocol::State;
+use tokio::sync::mpsc;
+
+#[derive(Serialize, Deserialize, Debug)]
+#[serde(tag = "type")]
+pub enum MatchLogMessage {
+    #[serde(rename = "gamestate")]
+    GameState(State),
+    #[serde(rename = "stderr")]
+    StdErr(StdErrMessage),
+}
+
+#[derive(Serialize, Deserialize, Debug)]
+pub struct StdErrMessage {
+    pub player_id: u32,
+    pub message: String,
+}
+
+pub type MatchLogger = mpsc::UnboundedSender<MatchLogMessage>;
+
+pub async fn create_log_sink(log_file_path: &Path) -> MatchLogger {
+    let (tx, rx) = mpsc::unbounded_channel();
+    let log_file = File::create(log_file_path)
+        .await
+        .expect("Could not create log file");
+    tokio::spawn(run_log_sink(rx, log_file));
+    return tx;
+}
+
+async fn run_log_sink(mut rx: mpsc::UnboundedReceiver<MatchLogMessage>, mut file: File) {
+    while let Some(message) = rx.recv().await {
+        let json = serde_json::to_string(&message).expect("failed to serialize message");
+        file.write_all(json.as_bytes())
+            .await
+            .expect("failed to write log message to file");
+        file.write_all(b"\n")
+            .await
+            .expect("failed to write newline log message to file");
+    }
+}