more features

message-handler.go

@@ -0,0 +1,221 @@
+package main
+
+import (
+	"fmt"
+	"io"
+
+	messages "git.tornberg.me/go-cart-actor/proto"
+	"google.golang.org/protobuf/proto"
+)
+
+var Handlers = map[uint16]MessageHandler{
+	AddRequestType:     &AddRequestHandler{},
+	AddItemType:        &AddItemHandler{},
+	ChangeQuantityType: &ChangeQuantityHandler{},
+	SetDeliveryType:    &SetDeliveryHandler{},
+	RemoveItemType:     &RemoveItemHandler{},
+	RemoveDeliveryType: &RemoveDeliveryHandler{},
+}
+
+func GetMessageHandler(t uint16) (MessageHandler, error) {
+	h, ok := Handlers[t]
+	if !ok {
+		return nil, fmt.Errorf("no handler for type %d", t)
+	}
+	return h, nil
+}
+
+type MessageHandler interface {
+	Write(*Message, io.Writer) error
+	Read(data []byte) (interface{}, error)
+	Is(*Message) bool
+}
+type TypedMessageHandler struct {
+	Type uint16
+}
+
+type AddRequestHandler struct {
+	TypedMessageHandler
+}
+
+func (h *AddRequestHandler) Write(m *Message, w io.Writer) error {
+	messageBytes, err := proto.Marshal(m.Content.(*messages.AddRequest))
+	if err != nil {
+		return err
+	}
+	w.Write(messageBytes)
+	return nil
+}
+
+func (h *AddRequestHandler) Read(data []byte) (interface{}, error) {
+	msg := &messages.AddRequest{}
+
+	err := proto.Unmarshal(data, msg)
+	if err != nil {
+		return nil, err
+	}
+	return msg, nil
+}
+
+func (h *AddRequestHandler) Is(m *Message) bool {
+	if m.Type != AddRequestType {
+		return false
+	}
+	_, ok := m.Content.(*messages.AddRequest)
+	return ok
+}
+
+type AddItemHandler struct {
+	TypedMessageHandler
+}
+
+func (h *AddItemHandler) Write(m *Message, w io.Writer) error {
+	messageBytes, err := proto.Marshal(m.Content.(*messages.AddItem))
+	if err != nil {
+		return err
+	}
+	w.Write(messageBytes)
+	return nil
+}
+
+func (h *AddItemHandler) Read(data []byte) (interface{}, error) {
+	msg := &messages.AddItem{}
+
+	err := proto.Unmarshal(data, msg)
+	if err != nil {
+		return nil, err
+	}
+	return msg, nil
+}
+
+func (h *AddItemHandler) Is(m *Message) bool {
+	if m.Type != AddItemType {
+		return false
+	}
+	_, ok := m.Content.(*messages.AddItem)
+	return ok
+}
+
+type ChangeQuantityHandler struct {
+	TypedMessageHandler
+}
+
+func (h *ChangeQuantityHandler) Write(m *Message, w io.Writer) error {
+	messageBytes, err := proto.Marshal(m.Content.(*messages.ChangeQuantity))
+	if err != nil {
+		return err
+	}
+	w.Write(messageBytes)
+	return nil
+}
+
+func (h *ChangeQuantityHandler) Read(data []byte) (interface{}, error) {
+	msg := &messages.ChangeQuantity{}
+
+	err := proto.Unmarshal(data, msg)
+	if err != nil {
+		return nil, err
+	}
+	return msg, nil
+}
+
+func (h *ChangeQuantityHandler) Is(m *Message) bool {
+	if m.Type != ChangeQuantityType {
+		return false
+	}
+	_, ok := m.Content.(*messages.ChangeQuantity)
+	return ok
+}
+
+type SetDeliveryHandler struct {
+	TypedMessageHandler
+}
+
+func (h *SetDeliveryHandler) Write(m *Message, w io.Writer) error {
+	messageBytes, err := proto.Marshal(m.Content.(*messages.SetDelivery))
+	if err != nil {
+		return err
+	}
+	w.Write(messageBytes)
+	return nil
+}
+
+func (h *SetDeliveryHandler) Read(data []byte) (interface{}, error) {
+	msg := &messages.SetDelivery{}
+
+	err := proto.Unmarshal(data, msg)
+	if err != nil {
+		return nil, err
+	}
+	return msg, nil
+}
+
+func (h *SetDeliveryHandler) Is(m *Message) bool {
+	if m.Type != ChangeQuantityType {
+		return false
+	}
+	_, ok := m.Content.(*messages.SetDelivery)
+	return ok
+}
+
+type RemoveItemHandler struct {
+	TypedMessageHandler
+}
+
+func (h *RemoveItemHandler) Write(m *Message, w io.Writer) error {
+	messageBytes, err := proto.Marshal(m.Content.(*messages.RemoveItem))
+	if err != nil {
+		return err
+	}
+	w.Write(messageBytes)
+	return nil
+}
+
+func (h *RemoveItemHandler) Read(data []byte) (interface{}, error) {
+	msg := &messages.RemoveItem{}
+
+	err := proto.Unmarshal(data, msg)
+	if err != nil {
+		return nil, err
+	}
+	return msg, nil
+}
+
+func (h *RemoveItemHandler) Is(m *Message) bool {
+	if m.Type != AddItemType {
+		return false
+	}
+	_, ok := m.Content.(*messages.RemoveItem)
+	return ok
+}
+
+type RemoveDeliveryHandler struct {
+	TypedMessageHandler
+}
+
+func (h *RemoveDeliveryHandler) Write(m *Message, w io.Writer) error {
+	messageBytes, err := proto.Marshal(m.Content.(*messages.RemoveDelivery))
+	if err != nil {
+		return err
+	}
+	w.Write(messageBytes)
+	return nil
+}
+
+func (h *RemoveDeliveryHandler) Read(data []byte) (interface{}, error) {
+	msg := &messages.RemoveDelivery{}
+
+	err := proto.Unmarshal(data, msg)
+	if err != nil {
+		return nil, err
+	}
+	return msg, nil
+}
+
+func (h *RemoveDeliveryHandler) Is(m *Message) bool {
+	if m.Type != AddItemType {
+		return false
+	}
+	_, ok := m.Content.(*messages.RemoveDelivery)
+	return ok
+}