use std::time::{SystemTime, UNIX_EPOCH};
use serde::{Deserialize, Serialize};
#[derive(Debug, Clone, Copy, Serialize, Deserialize, PartialEq, Eq)]
#[serde(rename_all = "snake_case")]
pub enum TimerKind {
Stopwatch,
Countdown,
Alarm,
}
impl TimerKind {
pub fn as_str(self) -> &'static str {
match self {
Self::Stopwatch => "stopwatch",
Self::Countdown => "countdown",
Self::Alarm => "alarm",
}
}
pub fn counts_down(self) -> bool {
matches!(self, Self::Countdown | Self::Alarm)
}
}
#[derive(Debug, Clone, Copy, Serialize, Deserialize, PartialEq, Eq)]
#[serde(rename_all = "snake_case")]
pub enum TimerStatus {
Running,
Paused,
Done,
Stopped,
Cancelled,
}
impl TimerStatus {
pub fn as_str(self) -> &'static str {
match self {
Self::Running => "running",
Self::Paused => "paused",
Self::Done => "done",
Self::Stopped => "stopped",
Self::Cancelled => "cancelled",
}
}
pub fn is_active(self) -> bool {
matches!(self, Self::Running | Self::Paused)
}
pub fn is_final(self) -> bool {
!self.is_active()
}
}
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct TimerTask {
pub id: u64,
pub kind: TimerKind,
pub status: TimerStatus,
pub note: Option<String>,
pub duration_millis: Option<u64>,
#[serde(default)]
pub target_at_millis: Option<u64>,
pub accumulated_millis: u64,
pub run_started_at_millis: Option<u64>,
pub created_at_millis: u64,
pub last_touched_at_millis: u64,
pub finished_at_millis: Option<u64>,
}
impl TimerTask {
pub fn new(
id: u64,
kind: TimerKind,
duration_millis: Option<u64>,
note: Option<String>,
now: u64,
) -> Self {
Self {
id,
kind,
status: TimerStatus::Running,
note: note.filter(|note| !note.trim().is_empty()),
duration_millis,
target_at_millis: None,
accumulated_millis: 0,
run_started_at_millis: Some(now),
created_at_millis: now,
last_touched_at_millis: now,
finished_at_millis: None,
}
}
pub fn new_alarm(id: u64, target_at_millis: u64, note: Option<String>, now: u64) -> Self {
Self {
id,
kind: TimerKind::Alarm,
status: TimerStatus::Running,
note: note.filter(|note| !note.trim().is_empty()),
duration_millis: None,
target_at_millis: Some(target_at_millis),
accumulated_millis: 0,
run_started_at_millis: None,
created_at_millis: now,
last_touched_at_millis: now,
finished_at_millis: None,
}
}
pub fn elapsed_millis(&self, now: u64) -> u64 {
let current_run = self
.run_started_at_millis
.map(|started| now.saturating_sub(started))
.unwrap_or(0);
self.accumulated_millis.saturating_add(current_run)
}
pub fn display_millis(&self, now: u64) -> u64 {
match self.kind {
TimerKind::Stopwatch => self.elapsed_millis(now),
TimerKind::Countdown => self
.duration_millis
.unwrap_or_default()
.saturating_sub(self.elapsed_millis(now)),
TimerKind::Alarm if self.status.is_active() => self
.target_at_millis
.unwrap_or_default()
.saturating_sub(now),
TimerKind::Alarm => self.accumulated_millis,
}
}
pub fn is_due(&self, now: u64) -> bool {
if self.status != TimerStatus::Running {
return false;
}
match self.kind {
TimerKind::Stopwatch => false,
TimerKind::Countdown => {
self.elapsed_millis(now) >= self.duration_millis.unwrap_or_default()
}
TimerKind::Alarm => now >= self.target_at_millis.unwrap_or_default(),
}
}
pub fn complete(&mut self, now: u64) {
self.accumulated_millis = self.duration_millis.unwrap_or_default();
self.run_started_at_millis = None;
self.status = TimerStatus::Done;
self.finished_at_millis = Some(now);
self.last_touched_at_millis = now;
}
pub fn pause(&mut self, now: u64) -> Result<(), &'static str> {
if self.kind == TimerKind::Alarm {
return Err("alarms cannot be paused; cancel the alarm instead");
}
if self.status != TimerStatus::Running {
return Err("timer is not running");
}
self.accumulated_millis = self.elapsed_millis(now);
self.run_started_at_millis = None;
self.status = TimerStatus::Paused;
self.last_touched_at_millis = now;
Ok(())
}
pub fn resume(&mut self, now: u64) -> Result<(), &'static str> {
if self.kind == TimerKind::Alarm {
return Err("alarms cannot be resumed");
}
if self.status != TimerStatus::Paused {
return Err("timer is not paused");
}
self.run_started_at_millis = Some(now);
self.status = TimerStatus::Running;
self.last_touched_at_millis = now;
Ok(())
}
pub fn toggle_pause(&mut self, now: u64) -> Result<(), &'static str> {
match self.status {
TimerStatus::Running => self.pause(now),
TimerStatus::Paused => self.resume(now),
_ => Err("timer has already finished"),
}
}
pub fn stop(&mut self, now: u64) -> Result<(), &'static str> {
if !self.status.is_active() {
return Err("timer has already finished");
}
self.accumulated_millis = match self.kind {
TimerKind::Alarm => self.display_millis(now),
TimerKind::Stopwatch | TimerKind::Countdown => self.elapsed_millis(now),
};
self.run_started_at_millis = None;
self.status = match self.kind {
TimerKind::Stopwatch => TimerStatus::Stopped,
TimerKind::Countdown | TimerKind::Alarm => TimerStatus::Cancelled,
};
self.finished_at_millis = Some(now);
self.last_touched_at_millis = now;
Ok(())
}
}
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct TimerView {
pub id: u64,
pub kind: TimerKind,
pub status: TimerStatus,
pub note: Option<String>,
pub value_millis: u64,
#[serde(default)]
pub target_at_millis: Option<u64>,
}
impl TimerView {
pub fn from_task(task: &TimerTask, now: u64) -> Self {
Self {
id: task.id,
kind: task.kind,
status: task.status,
note: task.note.clone(),
value_millis: task.display_millis(now),
target_at_millis: task.target_at_millis,
}
}
}
pub fn now_millis() -> u64 {
SystemTime::now()
.duration_since(UNIX_EPOCH)
.unwrap_or_default()
.as_millis()
.try_into()
.unwrap_or(u64::MAX)
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn countdown_uses_a_deadline_instead_of_ticks() {
let task = TimerTask::new(1, TimerKind::Countdown, Some(15_000), None, 1_000);
assert_eq!(task.display_millis(6_250), 9_750);
assert!(!task.is_due(15_999));
assert!(task.is_due(16_000));
}
#[test]
fn pause_and_resume_preserve_elapsed_time() {
let mut task = TimerTask::new(1, TimerKind::Stopwatch, None, None, 1_000);
task.pause(6_000).unwrap();
assert_eq!(task.display_millis(20_000), 5_000);
task.resume(20_000).unwrap();
assert_eq!(task.display_millis(23_000), 8_000);
}
#[test]
fn stop_has_kind_specific_final_state() {
let mut stopwatch = TimerTask::new(1, TimerKind::Stopwatch, None, None, 0);
stopwatch.stop(1_000).unwrap();
assert_eq!(stopwatch.status, TimerStatus::Stopped);
let mut countdown = TimerTask::new(2, TimerKind::Countdown, Some(5_000), None, 0);
countdown.stop(1_000).unwrap();
assert_eq!(countdown.status, TimerStatus::Cancelled);
}
#[test]
fn alarm_tracks_an_absolute_deadline_and_cannot_pause() {
let mut alarm = TimerTask::new_alarm(3, 10_000, Some("breakfast".to_owned()), 1_000);
assert_eq!(alarm.display_millis(4_000), 6_000);
assert!(!alarm.is_due(9_999));
assert!(alarm.is_due(10_000));
assert_eq!(
alarm.pause(5_000),
Err("alarms cannot be paused; cancel the alarm instead")
);
alarm.stop(5_000).unwrap();
assert_eq!(alarm.status, TimerStatus::Cancelled);
assert_eq!(alarm.display_millis(9_000), 5_000);
}
#[test]
fn old_state_without_alarm_target_still_deserializes() {
let task: TimerTask = serde_json::from_value(serde_json::json!({
"id": 1,
"kind": "countdown",
"status": "running",
"note": null,
"duration_millis": 60000,
"accumulated_millis": 0,
"run_started_at_millis": 1000,
"created_at_millis": 1000,
"last_touched_at_millis": 1000,
"finished_at_millis": null
}))
.unwrap();
assert_eq!(task.kind, TimerKind::Countdown);
assert_eq!(task.target_at_millis, None);
}
}