move util.rs to util/countdown.rs

src/util/countdown.rs

@@ -0,0 +1,40 @@
+use std::time::{Duration, Instant};
+
+pub struct Countdown {
+    pub i: usize,
+    pub i_original: usize,
+    pub i_string: String,
+    pub interval: Instant,
+    pub first_count: bool,
+}
+
+impl Countdown {
+    pub fn new(i: usize) -> Self {
+        Self {
+            i,
+            i_original: i,
+            i_string: String::new(),
+            interval: Instant::now(),
+            first_count: true,
+        }
+    }
+
+    pub fn reset(&mut self) {
+        *self = Self::new(self.i_original);
+    }
+
+    pub fn count(&mut self) {
+        if self.first_count {
+            self.interval = Instant::now();
+            self.first_count = false;
+        }
+        if self.interval.elapsed() >= Duration::from_secs(1) {
+            self.i -= 1;
+            self.interval = Instant::now();
+        }
+        self.i_string = self.i.to_string();
+        if self.i == 0 {
+            self.reset();
+        };
+    }
+}