fix #56: support --short for suggest

Author: kamilsk

docs/changelog.md

@@ -102,6 +102,7 @@
 
     $ maintainer github contribution suggest 2013-11
     $ maintainer github contribution suggest 2013
+    $ maintainer github contribution suggest --short 2013
     ```
 
 [calendar]: https://docs.github.com/en/account-and-profile/setting-up-and-managing-your-github-profile/managing-contribution-graphs-on-your-profile/viewing-contributions-on-your-profile#contributions-calendar

internal/command/github/contribution.go

@@ -337,6 +337,7 @@ func Contribution(cnf *config.Tool) *cobra.Command {
 			// dependencies and defaults
 			service := github.New(http.TokenSourcedClient(cmd.Context(), cnf.Token))
 			date := time.TruncateToYear(time.Now().UTC())
+			short, _ := cmd.Flags().GetBool("short")
 			weeks, target := 5, 5 // TODO:magic replace by params
 
 			// input validation: date(year,+month,+week{day})
@@ -421,9 +422,10 @@ func Contribution(cnf *config.Tool) *cobra.Command {
 			// data presentation
 			area := time.RangeByWeeks(suggest.Day, weeks, true).Shift(-time.Day) // Sunday
 			data := contribution.HistogramByWeekday(chm.Subset(area), false)
-			return view.Suggest(cmd, area, data, suggest, chm[suggest.Day])
+			return view.Suggest(cmd, area, data, suggest, chm[suggest.Day], short)
 		},
 	}
+	suggest.Flags().Bool("short", false, "returns only a suggested delta, e.g. -3119d")
 	cmd.AddCommand(&suggest)
 
 	return &cmd

internal/command/github/view/suggest.go

@@ -19,7 +19,14 @@ func Suggest(
 	histogram []contribution.HistogramByWeekdayRow,
 	suggest contribution.HistogramByWeekdayRow,
 	current int,
+	short bool,
 ) error {
+	delta := fmt.Sprintf("%dd", suggest.Day.Sub(time.Now().UTC())/time.Day)
+	if short {
+		printer.Println(delta)
+		return nil
+	}
+
 	data := convert(scope, histogram)
 	table := simpletable.New()
 
@@ -84,9 +91,9 @@ func Suggest(
 		Cells: []*simpletable.Cell{
 			{
 				Span: len(table.Header.Cells),
-				Text: fmt.Sprintf("Contributions for %s: %dd, %[4]d -> %[3]d",
+				Text: fmt.Sprintf("Contributions for %s: %s, %[4]d -> %[3]d",
 					suggest.Day.Format(time.RFC3339Day),
-					suggest.Day.Sub(time.Now().UTC())/time.Day,
+					delta,
 					suggest.Sum,
 					current,
 				),