added saving to a file and cleaned up magic numbers

go.mod

@@ -1,3 +1,10 @@
 module todo-app
 
 go 1.20
+
+require (
+	github.com/fatih/color v1.15.0 // indirect
+	github.com/mattn/go-colorable v0.1.13 // indirect
+	github.com/mattn/go-isatty v0.0.17 // indirect
+	golang.org/x/sys v0.6.0 // indirect
+)

main.go

@@ -4,6 +4,7 @@ import (
 	"bufio"
 	"fmt"
 	"os"
+	"strings"
 )
 
 func PrintMenu() {
@@ -11,17 +12,26 @@ func PrintMenu() {
 	fmt.Printf("1: List Todo\n")
 	fmt.Printf("2: Add Todo\n")
 	fmt.Printf("3: Remove Todo (via index)\n")
+	fmt.Printf("4: Save to file\n")
 
-	fmt.Printf("\n\n0: List menu again\n")
-	fmt.Printf("4: Quit\n\n> ")
+	fmt.Printf("\n\n0: Quit\n> ")
 
 }
 
+const (
+	QUIT   = 0
+	LIST   = 1
+	ADD    = 2
+	REMOVE = 3
+	SAVE   = 4
+)
+
 func main() {
 	fmt.Print("\033[H\033[2J") //clear
 	PrintMenu()
 	list := Todos{}
 	for {
+
 		var input int
 		n, err := fmt.Scanln(&input)
 		if n < 1 || err != nil {
@@ -29,12 +39,15 @@ func main() {
 		}
 
 		switch input {
-		case 0:
-			PrintMenu()
-		case 1:
-			list.ListTodo()
+		case QUIT:
+			fmt.Print("Quitting, goodbye!\n")
+			os.Exit(0)
+		case LIST:
+			if err := list.ListTodo(); err != nil {
+				fmt.Print(err)
+			}
 			PrintMenu()
-		case 2:
+		case ADD:
 			in := bufio.NewReader(os.Stdin)
 
 			fmt.Print("Add Title:\n> ")
@@ -46,7 +59,7 @@ func main() {
 			list.AddTodo(Todo{Title: title, Content: content})
 			fmt.Printf("Added %s to the list!\n", title)
 			PrintMenu()
-		case 3:
+		case REMOVE:
 			var index int
 			fmt.Printf("Which TODO to remove?\n> ")
 
@@ -58,9 +71,18 @@ func main() {
 				fmt.Print(err)
 			}
 			PrintMenu()
-		case 4:
-			fmt.Print("Quitting, goodbye!\n")
-			os.Exit(0)
+		case SAVE:
+			in := bufio.NewReader(os.Stdin)
+			fmt.Print("Save to file:\n> ")
+			filename, _ := in.ReadString('\n')
+			filename = strings.TrimSuffix(filename, "\n")
+
+			if err := list.SaveToFile(filename); err != nil {
+				fmt.Print(err)
+			} else {
+				fmt.Printf("%s saved!\n", filename)
+			}
+			PrintMenu()
 		default:
 			PrintMenu()
 		}

todo.go

@@ -3,8 +3,19 @@ package main
 import (
 	"errors"
 	"fmt"
+	"os"
+	"strconv"
+	"strings"
+
+	"github.com/fatih/color"
 )
 
+func check(err error) {
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "[ERR] %s", err)
+	}
+}
+
 type Todo struct {
 	Title   string
 	Content string
@@ -32,12 +43,56 @@ func (todo *Todos) RemoveTodo(index int) (err error) {
 	return nil
 }
 
-func (todo *Todos) ListTodo() int {
+func (todo *Todos) ListTodo() (err error) {
+	// Create a custom print function for convenience
+	id := color.New(color.Bold, color.FgGreen).PrintfFunc()
+	title := color.New(color.Bold, color.FgBlue).PrintfFunc()
+	content := color.New(color.Bold, color.FgWhite).PrintfFunc()
+
 	if len(todo.Items) == 0 {
-		return 0
+		return errors.New("[ERR] Todo list is empty!\n")
 	}
 	for k, v := range todo.Items {
-		fmt.Printf("%d:%s\n", k, v)
+		id("[%d]", k)
+		title("%s", v.Title)
+		content("%s\n", v.Content)
 	}
-	return 1
+	return nil
+}
+
+func (todo *Todos) SaveToFile(filename string) error {
+	var sb strings.Builder
+	var FILE *os.File
+
+	filename = filename + ".txt"
+	for k, v := range todo.Items {
+		fmt.Printf("#%d,%s,%s;\n", k, strings.ReplaceAll(v.Title, "\n", ""), strings.ReplaceAll(v.Content, "\n", ""))
+		sb.WriteString(strconv.Itoa(k))
+		sb.WriteString(",")
+		sb.WriteString(strings.ReplaceAll(v.Title, "\n", ""))
+		sb.WriteString(",")
+		sb.WriteString(strings.ReplaceAll(v.Content, "\n", ""))
+		sb.WriteString(";\n")
+	}
+
+	content := sb.String()
+
+	fmt.Println(content)
+
+	if _, err := os.Stat(filename); err != nil {
+		if FILE, err = os.Create(filename); err != nil {
+			return errors.New("[ERR] could not create file \n")
+		}
+		return errors.New("[ERR] file does not exist, creating one...\n")
+	}
+	FILE, _ = os.Create(filename) //errors already handled
+
+	if _, err := FILE.WriteString(content); err != nil {
+		return err
+		//return errors.New("[ERR] could not write to file\n")
+	}
+
+	sb.Reset()   //reset the string builder
+	FILE.Close() //close the file
+	return nil
 }