From e5b81a3ff9bca2c7c55b94b7b256d04111936c9a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Max=20K=C3=A4nner?= <max.kaenner@gmail.com>
Date: Mon, 30 Sep 2024 18:34:47 +0200
Subject: [PATCH] return None if no valid move was found

---
 battlesnake/src/logic.rs | 9 ++++-----
 battlesnake/src/main.rs  | 6 +++---
 2 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/battlesnake/src/logic.rs b/battlesnake/src/logic.rs
index b28a137..9f0ee07 100644
--- a/battlesnake/src/logic.rs
+++ b/battlesnake/src/logic.rs
@@ -138,7 +138,7 @@ pub fn end(_game: &Game, _turn: i32, _board: &Board, _you: &Battlesnake) {
 // move is called on every turn and returns your next move
 // Valid moves are "up", "down", "left", or "right"
 // See https://docs.battlesnake.com/api/example-move for available data
-pub fn get_move(game: &Game, turn: i32, board: &Board, you: &Battlesnake) -> Move {
+pub fn get_move(game: &Game, turn: i32, board: &Board, you: &Battlesnake) -> Option<Move> {
     let moves = enum_iterator::all()
         .filter(|&direction| !you.is_direction_death(direction, game, board))
         .collect::<Vec<_>>();
@@ -151,12 +151,11 @@ pub fn get_move(game: &Game, turn: i32, board: &Board, you: &Battlesnake) -> Mov
     // Choose a random move from the safe ones
     let chosen = safe_moves
         .choose(&mut rand::thread_rng())
-        .or_else(|| moves.choose(&mut rand::thread_rng()))
-        .unwrap_or(&Direction::Up);
+        .or_else(|| moves.choose(&mut rand::thread_rng()))?;
 
     info!("MOVE {}: {:?}", turn, chosen);
-    Move {
+    Some(Move {
         r#move: *chosen,
         shout: None,
-    }
+    })
 }
diff --git a/battlesnake/src/main.rs b/battlesnake/src/main.rs
index b64dbbc..a4b8187 100644
--- a/battlesnake/src/main.rs
+++ b/battlesnake/src/main.rs
@@ -201,15 +201,15 @@ fn handle_start(start_req: Json<GameState>) -> Status {
 }
 
 #[post("/move", format = "json", data = "<move_req>")]
-fn handle_move(move_req: Json<GameState>) -> Json<Move> {
+fn handle_move(move_req: Json<GameState>) -> Option<Json<Move>> {
     let response = logic::get_move(
         &move_req.game,
         move_req.turn,
         &move_req.board,
         &move_req.you,
-    );
+    )?;
 
-    Json(response)
+    Some(Json(response))
 }
 
 #[post("/end", format = "json", data = "<end_req>")]