Add upload and download methods to chat

chat.go

@@ -273,3 +273,35 @@ func (c *ChatAPI) Previous(count ...int) (*ChatAPI, error) {
 	c.keybase = k
 	return c, nil
 }
+
+func (c Chat) Upload(title string, filepath string) (ChatAPI, error) {
+	m := ChatAPI{
+		Params: &params{},
+	}
+	m.Method = "attach"
+	m.Params.Options.Channel = c.Channel
+	m.Params.Options.Filename = filepath
+	m.Params.Options.Title = title
+
+	r, err := chatAPIOut(c.keybase.Path, m)
+	if err != nil {
+		return ChatAPI{}, err
+	}
+	return r, nil
+}
+
+func (c Chat) Download(messageID int, filepath string) (ChatAPI, error) {
+	m := ChatAPI{
+		Params: &params{},
+	}
+	m.Method = "download"
+	m.Params.Options.Channel = c.Channel
+	m.Params.Options.Output = filepath
+	m.Params.Options.MessageID = messageID
+
+	r, err := chatAPIOut(c.keybase.Path, m)
+	if err != nil {
+		return ChatAPI{}, err
+	}
+	return r, nil
+}

types.go

@@ -200,6 +200,9 @@ type options struct {
 	MessageID  int        `json:"message_id"`
 	Message    message    `json:"message"`
 	Pagination pagination `json:"pagination"`
+	Filename   string     `json:"filename,omitempty"`
+	Title      string     `json:"title,omitempty"`
+	Output     string     `json:"output,omitempty"`
 }
 type params struct {
 	Options options `json:"options"`
@@ -416,6 +419,8 @@ type chat interface {
 	Edit(messageID int, message ...string) (ChatAPI, error)
 	React(messageID int, reaction string) (ChatAPI, error)
 	Send(message ...string) (ChatAPI, error)
+	Upload(title string, filepath string) (ChatAPI, error)
+	Download(messageID int, filepath string) (ChatAPI, error)
 }
 
 type chatAPI interface {