feat(cmd/note): add note command

feat(cmd/note): add basic note command function

this command will be used to add notes to the current workday entry

refactor(cmd/note): use cobra Args instead of conditionals

cobra provides a way to ensure a certain number of arguments are passed, we can use that instead of
checking it by hand with if statements

docs(cmd/note): add comments and description

cmd/note.go

@@ -1,28 +1,51 @@
 /*
 Copyright © 2023 NAME HERE <EMAIL ADDRESS>
-
 */
 package cmd
 
 import (
 	"fmt"
+	"time"
 
+	journal "github.com/deadpyxel/workday/internal"
 	"github.com/spf13/cobra"
 )
 
 // noteCmd represents the note command
 var noteCmd = &cobra.Command{
-	Use:   "note",
-	Short: "A brief description of your command",
-	Long: `A longer description that spans multiple lines and likely contains examples
-and usage of using your command. For example:
-
-Cobra is a CLI library for Go that empowers applications.
-This application is a tool to generate the needed files
-to quickly create a Cobra application.`,
-	Run: func(cmd *cobra.Command, args []string) {
-		fmt.Println("note called")
-	},
+	Use:   "note [note]",
+	Args:  cobra.ExactArgs(1),
+	Short: "Adds a note to the current workday entry",
+	Long: `The note command is used to add a note to the current workday entry.
+
+It requires a single argument, which is the note to be added. The note must be provided as a double-quoted string.
+If there is no entry for the current day, the command will print an error message and return an error.
+Otherwise, it will add the note to the current entry and save the updated journal entries back to the file`,
+	RunE: addNoteToCurrentDay,
+}
+
+// addNoteToCurrentDay adds a note to the current workday entry.
+// It first loads the existing journal entries from the file.
+// If there is no entry for the current day, it prints an error message and returns an error.
+// Otherwise, it adds the note to the current entry and saves the updated journal entries back to the file.
+func addNoteToCurrentDay(cmd *cobra.Command, args []string) error {
+	journalEntries, err := journal.LoadEntries("journal.json")
+	if err != nil {
+		return err
+	}
+
+	newNote := args[0]
+
+	now := time.Now()
+	currenctDayId := now.Format("20060102")
+	_, idx := journal.FetchEntryByID(currenctDayId, journalEntries)
+	if idx == -1 {
+		fmt.Println("Please run `workday start` first to create a new entry.")
+		return fmt.Errorf("Could not find any entry for the current day.")
+	}
+	journalEntries[idx].Notes = append(journalEntries[idx].Notes, newNote)
+	fmt.Println("Successfully added new note to current day.")
+	return nil
 }
 
 func init() {