1 files changed, 50 insertions, 0 deletions
diff --git a/src/move_snake.rs b/src/move_snake.rs
new file mode 100644
index 0000000..453e795
--- /dev/null
+++ b/src/move_snake.rs
@@ -0,0 +1,50 @@
+use core::time::Duration;
+
+use alloc::vec::Vec;
+use rand::RngExt;
+use tortuise_script::{random::TortuiseRng, time::Instant, ScriptContext, TortuiseScript};
+
+use crate::{Position, APPLE_LOCATION, DIRECTION, GRID_SIZE, NEXT_MOVE_TIME, SNAKE_CELLS};
+
+pub const MOVE_SNAKE: TortuiseScript = TortuiseScript {
+    update: |context: ScriptContext| {
+        let mut apple_location = APPLE_LOCATION.get_mut(&context);
+        let mut snake_cells = SNAKE_CELLS.get_mut(&context);
+        let mut next_move = NEXT_MOVE_TIME.get_mut(&context);
+        let direction = DIRECTION.get(&context);
+
+        let mut available_squares =
+            Vec::with_capacity((GRID_SIZE * GRID_SIZE) as usize - snake_cells.len());
+        for i in 0..GRID_SIZE {
+            for j in 0..GRID_SIZE {
+                let position = Position {
+                    x: i as i16,
+                    y: j as i16,
+                };
+                if !snake_cells.contains(&position) {
+                    available_squares.push(position);
+                }
+            }
+        }
+
+        let mut rng = TortuiseRng::new();
+        let time = Instant::now(&context);
+        if time > *next_move {
+            if snake_cells[0] == *apple_location {
+                *apple_location = available_squares[rng.random_range(0..available_squares.len())];
+                let new_head = Position {
+                    x: snake_cells[0].x + direction.x,
+                    y: snake_cells[0].y + direction.y,
+                };
+                snake_cells.insert(0, new_head);
+            }
+            *next_move += Duration::from_millis(200);
+            for i in (1..snake_cells.len()).rev() {
+                snake_cells[i] = snake_cells[i - 1];
+            }
+            snake_cells[0].x += direction.x;
+            snake_cells[0].y += direction.y;
+        }
+    },
+    ..TortuiseScript::empty()
+};