recator: use timer signals instead of shared.Message.TimeLeft

- remove shared.Message.TimeLeft
- modify Timer struct
  - add TimeLeft signal
  - add End and Abort signals
- add syncronised ticker
- update RunPomodoro to use goroutines for timer starts
  - add waitForTimer function

internal/pomodoro/pomodoro.go

@@ -9,6 +9,19 @@ import (
 var mu sync.Mutex // to synchronize access to shared state
 var timer Timer
 
+func waitForTimer(t Timer) bool {
+	for {
+		select {
+		case <-t.End:
+			return true
+		case <-t.Abort:
+			return false
+		case shared.Message.TimeLeft = <-t.TimeLeft:
+			// do nothing, just let the timer update the message
+		}
+	}
+}
+
 // RunPomodoro iterates the Pomodoro work/break sessions.
 func RunPomodoro() {
 	mu.Lock()
@@ -24,18 +37,21 @@ func RunPomodoro() {
 		shared.Message.Session = session
 
 		shared.Message.Mode = "Work"
-		if !timer.Start(pomodoroConfig.Work) {
+		go timer.Start(pomodoroConfig.Work)
+		if !waitForTimer(timer) {
 			break
 		}
 
-		if session > pomodoroConfig.Sessions {
+		if session < pomodoroConfig.Sessions {
 			shared.Message.Mode = "ShortBreak"
-			if !timer.Start(pomodoroConfig.ShortBreak) {
+			go timer.Start(pomodoroConfig.ShortBreak)
+			if !waitForTimer(timer) {
 				break
 			}
 		} else { // last phase, prepare for finish
 			shared.Message.Mode = "LongBreak"
-			if !timer.Start(pomodoroConfig.LongBreak) {
+			go timer.Start(pomodoroConfig.LongBreak)
+			if !waitForTimer(timer) {
 				break
 			}
 			shared.Message.Mode = "End"

internal/pomodoro/timer.go

@@ -1,47 +1,53 @@
 package pomodoro
 
 import (
-	"git.smsvc.net/pomodoro/GoTomato/internal/shared"
 	"time"
 )
 
 type Timer struct {
-	abort  chan bool
+	TimeLeft chan int  // time left
+	End      chan bool // signal on successful end
+	Abort    chan bool // signal on premature end
+	stop     chan bool
 	wait     chan bool
 	resume   chan bool
 }
 
 func (t Timer) Init() Timer {
 	return Timer{
-		abort:  make(chan bool, 1),
+		TimeLeft: make(chan int),
+		End:      make(chan bool, 1),
+		Abort:    make(chan bool, 1),
+		stop:     make(chan bool, 1),
 		wait:     make(chan bool, 1),
 		resume:   make(chan bool, 1),
 	}
 }
 
-func (t *Timer) Start(duration int) bool {
+func (t *Timer) Start(duration int) {
+	tick := time.NewTicker(time.Second)
 	for timeLeft := duration; timeLeft > 0; {
 		select {
-		case <-t.abort:
-			return false
+		case <-t.stop:
+			t.Abort <- true
+			return
 		case <-t.wait:
 			<-t.resume
-		default:
-			shared.Message.TimeLeft = timeLeft
-			time.Sleep(time.Second)
+			continue
+		case <-tick.C:
 			timeLeft--
+		default:
+			t.TimeLeft <- timeLeft
 		}
 	}
+	t.TimeLeft <- 0
 
-	// Final shared.Message when time reaches zero
-	shared.Message.TimeLeft = 0
-
-	return true
+	t.End <- true
 }
 
 func (t *Timer) Stop() {
 	t.resume <- true
-	t.abort <- true
+	t.stop <- true
 }
 
 func (t *Timer) Pause() {