implement subscription saving

ttbp/ttbp.go

@@ -139,18 +139,30 @@ func SortPostsByRecent(posts []Post) []Post {
 }
 
 type Subscriptions struct {
-	users []User
+	users []string
 }
 
 func GetSubscriptions() *Subscriptions {
+	file, err := os.OpenFile(path.Join(os.Getenv("HOME"), ".ttbp/config/subs"), os.O_RDONLY|os.O_CREATE, 0644)
+	if err != nil {
+		return &Subscriptions{}
+	}
+	defer file.Close()
+
+	var users []string
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		users = append(users, scanner.Text())
+	}
+
 	return &Subscriptions{
-		users: []User{},
+		users: users,
 	}
 }
 
 func (subscriptions *Subscriptions) IsSubscribed(user User) bool {
 	for _, sub := range subscriptions.users {
-		if sub.Name == user.Name {
+		if sub == user.Name {
 			return true
 		}
 	}
@@ -158,14 +170,34 @@ func (subscriptions *Subscriptions) IsSubscribed(user User) bool {
 }
 
 func (subscriptions *Subscriptions) Subscribe(user User) {
-	subscriptions.users = append(subscriptions.users, user)
+	subscriptions.users = append(subscriptions.users, user.Name)
+	subscriptions.write()
 }
 
 func (subscriptions *Subscriptions) Unsubscribe(user User) {
 	for i, sub := range subscriptions.users {
-		if sub.Name == user.Name {
+		if sub == user.Name {
 			subscriptions.users = append(subscriptions.users[:i], subscriptions.users[i+1:]...)
+			subscriptions.write()
 			return
 		}
 	}
 }
+
+func (subscriptions *Subscriptions) write() {
+	file, err := os.Create(path.Join(os.Getenv("HOME"), ".ttbp/config/subs"))
+	if err != nil {
+		return
+	}
+	defer file.Close()
+
+	writer := bufio.NewWriter(file)
+	for _, line := range subscriptions.users {
+		_, err := writer.WriteString(line + "\n")
+		if err != nil {
+			return
+		}
+	}
+
+	writer.Flush()
+}