Use an alias to create notes in alternate book directory

Instead of always creating notes in the primary notebook directory,
allow the 'new' command to be given an alias to lookup the directory
for in the configuration. If a match is found, the note will be created
in alternate directory.

cmd/new.go

@@ -2,6 +2,7 @@ package cmd
 
 import (
 	"fmt"
+	"github.com/spf13/viper"
 	"log"
 	"os"
 	"path/filepath"
@@ -14,10 +15,21 @@ import (
 var newCmd = &cobra.Command{
 	Use:   "new",
 	Short: "Create a new note",
+	Args:  cobra.MaximumNArgs(1),
 	Run: func(cmd *cobra.Command, args []string) {
 		dirs := bookDirs()
+		bookDir := dirs[0]
 
-		notePath := filepath.Join(dirs[0], strconv.Itoa(time.Now().Year()))
+		if len(args) > 0 {
+			bookAlias := args[0]
+
+			aliasIndex := aliasIndex(bookAlias)
+			if aliasIndex != -1 {
+				bookDir = dirs[aliasIndex]
+			}
+		}
+
+		notePath := filepath.Join(bookDir, strconv.Itoa(time.Now().Year()))
 		if err := os.MkdirAll(notePath, 0755); err != nil {
 			log.Fatalf("Error creating directory: %s", err)
 		}
@@ -37,6 +49,9 @@ var newCmd = &cobra.Command{
 }
 
 func init() {
+	newCmd.PersistentFlags().StringSlice("alias", []string{}, "aliases for notebook directories")
+	viper.BindPFlag("alias", newCmd.PersistentFlags().Lookup("alias"))
+
 	rootCmd.AddCommand(newCmd)
 }
 
@@ -61,3 +76,12 @@ func createNote(dir string) (*os.File, error) {
 
 	return note, nil
 }
+
+func aliasIndex(alias string) int {
+	for i, a := range viper.GetStringSlice("alias") {
+		if a == alias {
+			return i
+		}
+	}
+	return -1
+}