use std::time::Duration;

use crate::time::Instant;

/// StopWatch is a utility for record time cost in multi-stage tasks.
/// NOTE: Maybe it should be generic over somewhat Clock type?
pub struct StopWatch(Instant);

impl StopWatch {
    /// Create a new stopwatch via current time.
    pub fn by_now() -> Self {
        Self(Instant::now_coarse())
    }

    /// Get time elapsed since last lap (or creation if the first time).
    pub fn lap(&mut self) -> Duration {
        let elapsed = self.0.saturating_elapsed();
        self.0 = Instant::now_coarse();
        elapsed
    }
}