chore: add pause functionality

src/main.rs

@@ -20,8 +20,8 @@ fn main() {
     let mut domasi: Pomodoro = Default::default();
 
     match get_alert() {
-        Some(alert) => domasi.start_with_alert(alert),
-        None => domasi.start(),
+        Some(alert) => domasi.start(Some(alert)).unwrap(),
+        None => domasi.start(None).unwrap(),
     }
 }
 

src/pomodoro.rs

@@ -1,8 +1,9 @@
 use super::Alert;
+use crossterm::event::{self, Event, KeyCode, KeyModifiers};
+use crossterm::terminal::{disable_raw_mode, enable_raw_mode};
 use std::error::Error;
 use std::fmt::{Display, Formatter, Result as FmtResult};
 use std::io::{self, Write};
-use std::thread;
 use std::time::{Duration, Instant};
 
 #[derive(Debug, Copy, Clone, Default)]
@@ -18,34 +19,49 @@ static WORK_TIME: u64 = 1500; // Default: 1500 (25min)
 static SHORT_BREAK_TIME: u64 = 300; // Default: 300 (5min)
 static LONG_BREAK_TIME: u64 = 600; // Default: 600 (10min)
 
-static POLLING_RATE: Duration = Duration::from_millis(300);
+static POLLING_RATE: Duration = Duration::from_millis(100);
 impl Pomodoro {
     pub fn new() -> Self {
         Self::default()
     }
 
-    pub fn start_with_alert(&mut self, alert: Alert) {
+    pub fn start(&mut self, maybe_alert: Option<Alert>) -> crossterm::Result<()> {
+        enable_raw_mode()?;
+
         loop {
-            if let Status::Complete = self.poll(Some(&alert)) {
+            if let Status::Complete = self.poll(maybe_alert.as_ref()) {
                 break;
             }
 
-            Self::sleep();
+            if event::poll(POLLING_RATE)? {
+                if let Event::Key(key_event) = event::read()? {
+                    match key_event.code {
+                        KeyCode::Char('p') | KeyCode::Char('P') => {
+                            self.paused.toggle();
+
+                            if !self.paused.value {
+                                // Apply the elapsed time
+                                let duration = self.paused.duration;
+                                match self.wait_start {
+                                    Some(instant) => self.wait_start = Some(instant + duration),
+                                    None => {
+                                        unreachable!("Unable to resume from a non-existent timer.")
                                     }
                                 }
 
-    pub fn start(&mut self) {
-        loop {
-            if let Status::Complete = self.poll(None) {
-                break;
+                                self.paused = Default::default();
+                            }
+                        }
+                        KeyCode::Char('q') | KeyCode::Char('Q') => break,
+                        KeyCode::Char('c') if key_event.modifiers == KeyModifiers::CONTROL => break,
+                        _ => {}
+                    }
                 }
-
-            Self::sleep()
             }
         }
 
-    fn sleep() {
-        thread::sleep(POLLING_RATE);
+        disable_raw_mode()?;
+        Ok(())
     }
 
     fn notify_complete(&self) -> Result<(), Box<dyn Error>> {
@@ -116,6 +132,7 @@ impl Pomodoro {
                 };
 
                 self.paused.previous = Some(now);
+                self.display_paused();
             }
             Status::Active => self.display_time(),
             Status::NextState => {
@@ -140,7 +157,6 @@ impl Pomodoro {
             }
             Status::Complete => {
                 println!("\rPomodoro cycle complete!");
-
                 let _ = self.notify_complete();
             }
             Status::Inactive => {}
@@ -150,10 +166,18 @@ impl Pomodoro {
     }
 
     fn display_time(&self) {
-        if let Some(earlier) = self.wait_start {
-            let wait = Instant::now() - earlier;
-            let left: Clock = (Self::wait_times(self.state) - wait).into();
-            let _ = Self::print(&format!("\r{} {}", self.state, left));
+        if let Some(start) = self.wait_start {
+            let remainder: Clock = (Self::wait_times(self.state) - (Instant::now() - start)).into();
+            let _ = Self::print(&format!("\r{} {}", self.state, remainder));
+        }
+    }
+
+    fn display_paused(&self) {
+        if let Some(start) = self.wait_start {
+            let stop_time: Clock = (Self::wait_times(self.state)
+                - ((Instant::now() - self.paused.duration) - start))
+                .into();
+            let _ = Self::print(&format!("\r[PAUSED] {} {}", self.state, stop_time));
         }
     }
 
@@ -163,6 +187,9 @@ impl Pomodoro {
 
         // Empty String so that we can clear line before writing
         // from the most-left side of the terminal again.
+        //
+        // We write 24 spaces so that the entire line is always
+        // written over
         handle.write_all(b"\r                        ")?;
         handle.write_all(text.as_bytes())?;
         handle.flush()?;
@@ -274,6 +301,12 @@ struct PausedState {
     previous: Option<Instant>,
 }
 
+impl PausedState {
+    pub fn toggle(&mut self) {
+        self.value = !self.value;
+    }
+}
+
 #[derive(Debug, Copy, Clone)]
 enum Count {
     Increase,