use enum for the direction

battlesnake/src/logic.rs

@@ -15,7 +15,7 @@ use rand::seq::SliceRandom;
 use serde_json::{json, Value};
 use std::collections::HashMap;
 
-use crate::{Battlesnake, Board, Coord, Game};
+use crate::{Battlesnake, Board, Coord, Direction, Game, Move};
 
 // info is called when you create your Battlesnake on play.battlesnake.com
 // and controls your Battlesnake's appearance
@@ -25,7 +25,7 @@ pub fn info() -> Value {
 
     json!({
         "apiversion": "1",
-        "author": "Der Informatiker",
+        "author": "der-informatiker",
         "color": "#00FFEE",
         "head": "smart-caterpillar",
         "tail": "mouse",
@@ -45,15 +45,12 @@ 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) -> Value {
+pub fn get_move(_game: &Game, turn: i32, board: &Board, you: &Battlesnake) -> Move {
-    let mut is_move_safe: HashMap<_, _> = vec![
+    use Direction::{Down, Left, Right, Up};
-        ("up", true),
+    let mut is_move_safe: HashMap<_, _> =
-        ("down", true),
+        vec![(Up, true), (Down, true), (Left, true), (Right, true)]
-        ("left", true),
+            .into_iter()
-        ("right", true),
+            .collect();
-    ]
-    .into_iter()
-    .collect();
 
     // We've included code to prevent your Battlesnake from moving backwards
     let my_head = &you.body[0]; // Coordinates of your head
@@ -61,30 +58,30 @@ pub fn get_move(_game: &Game, turn: i32, board: &Board, you: &Battlesnake) -> Va
 
     if my_neck.x < my_head.x {
         // Neck is left of head, don't move left
-        is_move_safe.insert("left", false);
+        is_move_safe.insert(Left, false);
     } else if my_neck.x > my_head.x {
         // Neck is right of head, don't move right
-        is_move_safe.insert("right", false);
+        is_move_safe.insert(Right, false);
     } else if my_neck.y < my_head.y {
         // Neck is below head, don't move down
-        is_move_safe.insert("down", false);
+        is_move_safe.insert(Down, false);
     } else if my_neck.y > my_head.y {
         // Neck is above head, don't move up
-        is_move_safe.insert("up", false);
+        is_move_safe.insert(Up, false);
     }
 
     // TODO: Step 1 - Prevent your Battlesnake from moving out of bounds
     if my_head.x == 0 {
-        is_move_safe.insert("left", false);
+        is_move_safe.insert(Left, false);
     }
     if my_head.x == board.width - 1 {
-        is_move_safe.insert("right", false);
+        is_move_safe.insert(Right, false);
     }
     if my_head.y == 0 {
-        is_move_safe.insert("down", false);
+        is_move_safe.insert(Down, false);
     }
     if my_head.y == board.height - 1 {
-        is_move_safe.insert("up", false);
+        is_move_safe.insert(Up, false);
     }
 
     // TODO: Step 2 - Prevent your Battlesnake from colliding with itself
@@ -92,25 +89,25 @@ pub fn get_move(_game: &Game, turn: i32, board: &Board, you: &Battlesnake) -> Va
         x: my_head.x - 1,
         y: my_head.y,
     }) {
-        is_move_safe.insert("left", false);
+        is_move_safe.insert(Left, false);
     }
     if you.body.contains(&Coord {
         x: my_head.x + 1,
         y: my_head.y,
     }) {
-        is_move_safe.insert("right", false);
+        is_move_safe.insert(Right, false);
     }
     if you.body.contains(&Coord {
         x: my_head.x,
         y: my_head.y - 1,
     }) {
-        is_move_safe.insert("down", false);
+        is_move_safe.insert(Down, false);
     }
     if you.body.contains(&Coord {
         x: my_head.x,
         y: my_head.y + 1,
     }) {
-        is_move_safe.insert("up", false);
+        is_move_safe.insert(Up, false);
     }
 
     // TODO: Step 3 - Prevent your Battlesnake from colliding with other Battlesnakes
@@ -124,11 +121,14 @@ pub fn get_move(_game: &Game, turn: i32, board: &Board, you: &Battlesnake) -> Va
         .collect::<Vec<_>>();
 
     // Choose a random move from the safe ones
-    let chosen = safe_moves.choose(&mut rand::thread_rng()).unwrap();
+    let chosen = safe_moves.choose(&mut rand::thread_rng()).unwrap_or(&Up);
 
     // TODO: Step 4 - Move towards food instead of random, to regain health and survive longer
     // let food = &board.food;
 
-    info!("MOVE {}: {}", turn, chosen);
+    info!("MOVE {}: {:?}", turn, chosen);
-    json!({ "move": chosen })
+    Move {
+        r#move: *chosen,
+        shout: None,
+    }
 }

battlesnake/src/main.rs

@@ -15,6 +15,29 @@ mod logic;
 // API and Response Objects
 // See https://docs.battlesnake.com/api
 
+#[derive(Debug, PartialEq, Eq, Hash, Clone, Copy, Deserialize, Serialize)]
+pub enum Direction {
+    #[serde(rename = "left")]
+    Left,
+    #[serde(rename = "up")]
+    Up,
+    #[serde(rename = "right")]
+    Right,
+    #[serde(rename = "down")]
+    Down,
+}
+
+#[derive(Debug, Deserialize, Serialize)]
+pub struct Move {
+    r#move: Direction,
+    #[serde(default, skip_serializing_if = "is_default")]
+    shout: Option<String>,
+}
+
+fn is_default<T: Default + PartialEq>(value: &T) -> bool {
+    *value == T::default()
+}
+
 #[derive(Deserialize, Serialize, Debug)]
 pub struct Game {
     id: String,
@@ -43,7 +66,7 @@ pub struct Battlesnake {
     shout: Option<String>,
 }
 
-#[derive(Debug, PartialEq, Eq, Clone, Copy,Deserialize, Serialize)]
+#[derive(Debug, PartialEq, Eq, Clone, Copy, Deserialize, Serialize)]
 pub struct Coord {
     x: i32,
     y: i32,
@@ -75,7 +98,7 @@ fn handle_start(start_req: Json<GameState>) -> Status {
 }
 
 #[post("/move", format = "json", data = "<move_req>")]
-fn handle_move(move_req: Json<GameState>) -> Json<Value> {
+fn handle_move(move_req: Json<GameState>) -> Json<Move> {
     let response = logic::get_move(
         &move_req.game,
         move_req.turn,