Add basic library code to manage projects, activities and times.

lib/timer.go

@@ -0,0 +1,117 @@
+package lib
+
+import (
+	"os"
+	"path/filepath"
+	"time"
+)
+
+type NoTimerActiveError struct{}
+
+func (e *NoTimerActiveError) Error() string {
+	return "No timer is currently active."
+}
+
+// StartTimer starts a new timer.
+func StartTimer() (*Time, error) {
+	// Stop active timer
+	activeTimer, _ := GetTimer()
+	if activeTimer != nil {
+		timer, stopErr := StopTimer()
+		if stopErr != nil {
+			return timer, stopErr
+		}
+	}
+
+	// Start new timer
+	newTimer := Time{
+		Start: time.Now(),
+	}
+
+	setErr := setTimer(&newTimer)
+	if setErr != nil {
+		return nil, setErr
+	}
+
+	return &newTimer, nil
+}
+
+// UpdateTimer sets the project and activity on the current timer.
+func UpdateTimer(project *Project, activity *Activity) (*Time, error) {
+	timer, timerErr := GetTimer()
+	if timerErr != nil {
+		return timer, timerErr
+	}
+	if timer == nil {
+		return nil, &NoTimerActiveError{}
+	}
+
+	timer.ProjectID = project.ID
+	timer.ActivityID = activity.ID
+
+	setError := setTimer(timer)
+	if setError != nil {
+		return timer, setError
+	}
+
+	return timer, nil
+}
+
+// StopTimer stops the current timer and records the resulting time entry.
+func StopTimer() (*Time, error) {
+	timer, timerErr := GetTimer()
+	if timerErr != nil {
+		return timer, timerErr
+	}
+	if timer == nil {
+		return nil, &NoTimerActiveError{}
+	}
+
+	timer.End = time.Now()
+	recordErr := SetTime(timer)
+	if recordErr != nil {
+		return timer, recordErr
+	}
+
+	file, fileErr := getTimerFile()
+	if fileErr != nil {
+		return timer, fileErr
+	}
+
+	removeErr := os.Remove(file)
+	if removeErr != nil {
+		return timer, removeErr
+	}
+
+	return nil, nil
+}
+
+// GetTimer returns the active timer.
+func GetTimer() (*Time, error) {
+	file, fileErr := getTimerFile()
+	if fileErr != nil {
+		return nil, fileErr
+	}
+
+	return readTime(file)
+}
+
+// setTimer persists a time entry as current timer. If there is already a current timer, it will be overwritten.
+func setTimer(entry *Time) error {
+	file, fileErr := getTimerFile()
+	if fileErr != nil {
+		return fileErr
+	}
+
+	return writeTime(entry, file)
+}
+
+// getTimerFile returns the file name for the timer.
+func getTimerFile() (string, error) {
+	folder, err := getDataDir("time")
+	if err != nil {
+		return "", err
+	}
+
+	return filepath.Join(folder, "timer.json"), nil
+}