1use chrono::{DateTime, Utc};
 2use parking_lot::Mutex;
 3use std::time::{Duration, Instant};
 4
 5pub trait Clock {
 6    fn utc_now(&self) -> DateTime<Utc>;
 7    fn now(&self) -> Instant;
 8}
 9
10pub struct TestClock(Mutex<TestClockState>);
11
12struct TestClockState {
13    now: Instant,
14    utc_now: DateTime<Utc>,
15}
16
17impl TestClock {
18    pub fn new() -> Self {
19        const START_TIME: &str = "2025-07-01T23:59:58-00:00";
20        let utc_now = DateTime::parse_from_rfc3339(START_TIME).unwrap().to_utc();
21        Self(Mutex::new(TestClockState {
22            now: Instant::now(),
23            utc_now,
24        }))
25    }
26
27    pub fn set_utc_now(&self, now: DateTime<Utc>) {
28        let mut state = self.0.lock();
29        state.utc_now = now;
30    }
31
32    pub fn advance(&self, duration: Duration) {
33        let mut state = self.0.lock();
34        state.now += duration;
35        state.utc_now += duration;
36    }
37}
38
39impl Clock for TestClock {
40    fn utc_now(&self) -> DateTime<Utc> {
41        self.0.lock().utc_now
42    }
43
44    fn now(&self) -> Instant {
45        self.0.lock().now
46    }
47}