feat: add an "undo" command

This puts a task back in the TODO state.

Some refactoring here lets us reuse the same code for handling both
cmdDo and cmdUndo.

2 files changed, 29 insertions, 2 deletions

diff --git a/cmds.go b/cmds.go
index 5791546..38be692 100644
--- a/cmds.go
+++ b/cmds.go
@@ -43,7 +43,7 @@ func (ctrl controller) cmdAdd(task string) error {
 	})
 }
 
-func (ctrl controller) cmdDo(taskIndex int) error {
+func (ctrl controller) toggleDo(taskIndex int, status bool) error {
 	return ctrl.db.Update(func(tx *bbolt.Tx) error {
 		taskBucket := tx.Bucket(ctrl.tasksBucketName)
 		ttBytes := taskBucket.Get(itob(uint64(taskIndex)))
@@ -53,7 +53,7 @@ func (ctrl controller) cmdDo(taskIndex int) error {
 			return fmt.Errorf("can't unmarshal: %w", err)
 		}
 
-		tt.Done = true
+		tt.Done = status
 
 		buf, err := json.Marshal(tt)
 		if err != nil {
@@ -64,6 +64,14 @@ func (ctrl controller) cmdDo(taskIndex int) error {
 	})
 }
 
+func (ctrl controller) cmdDo(taskIndex int) error {
+	return ctrl.toggleDo(taskIndex, true)
+}
+
+func (ctrl controller) cmdUndo(taskIndex int) error {
+	return ctrl.toggleDo(taskIndex, false)
+}
+
 func (ctrl controller) cmdList() error {
 	return ctrl.db.View(func(tx *bbolt.Tx) error {
 		// Assume bucket exists and has keys
diff --git a/main.go b/main.go
index 85bfa26..7838fcb 100644
--- a/main.go
+++ b/main.go
@@ -82,6 +82,25 @@ func main() {
 				},
 			},
 			{
+				Name:    "undo",
+				Aliases: []string{"u"},
+				Usage:   "reset a task on the list",
+				Arguments: []cli.Argument{
+					&cli.IntArg{
+						Name: "taskIndex",
+					},
+				},
+				Action: func(ctx context.Context, cmd *cli.Command) error {
+					taskIndex := cmd.IntArg("taskIndex")
+
+					if taskIndex <= 0 {
+						return fmt.Errorf("invalid 'undo' argument: %d", taskIndex)
+					}
+
+					return ctrl.cmdUndo(taskIndex)
+				},
+			},
+			{
 				Name:    "list",
 				Aliases: []string{"l"},
 				Usage:   "list pending tasks",