middleware: implement first restrict examples

middleware/restrict.go

@@ -0,0 +1,47 @@
+package middleware
+
+import tele "gopkg.in/tucnak/telebot.v3"
+
+type RestrictConfig struct {
+	Chats   []tele.Recipient
+	In, Out tele.HandlerFunc
+}
+
+func Restrict(v RestrictConfig) tele.MiddlewareFunc {
+	return func(next tele.HandlerFunc) tele.HandlerFunc {
+		if v.In == nil {
+			v.In = next
+		}
+		if v.Out == nil {
+			v.Out = next
+		}
+		return func(c tele.Context) error {
+			for _, chat := range v.Chats {
+				if chat.Recipient() == c.Sender().Recipient() {
+					return v.In(c)
+				}
+			}
+			return v.Out(c)
+		}
+	}
+}
+
+func Whitelist(chats ...tele.Recipient) tele.MiddlewareFunc {
+	return func(next tele.HandlerFunc) tele.HandlerFunc {
+		return Restrict(RestrictConfig{
+			Chats: chats,
+			In:    next,
+			Out:   func(c tele.Context) error { return tele.ErrSkip },
+		})(next)
+	}
+}
+
+func Blacklist(chats ...tele.Recipient) tele.MiddlewareFunc {
+	return func(next tele.HandlerFunc) tele.HandlerFunc {
+		return Restrict(RestrictConfig{
+			Chats: chats,
+			Out:   next,
+			In:    func(c tele.Context) error { return tele.ErrSkip },
+		})(next)
+	}
+}