message content autodetection

Author: George Gabolaev

bot.go

@@ -49,9 +49,8 @@ func (b *Bot) GetFileInfo(fileID string) (*File, error) {
 // NewMessage returns new message
 func (b *Bot) NewMessage(chatID string) *Message {
 	return &Message{
-		client:      b.client,
-		Chat:        Chat{ID: chatID},
-		ContentType: Text,
+		client: b.client,
+		Chat:   Chat{ID: chatID},
 	}
 }
 
@@ -126,7 +125,7 @@ func (b *Bot) NewChat(id string) *Chat {
 // SendMessage sends a message, passed as an argument.
 // This method fills the argument with ID of sent message and returns an error if any.
 func (b *Bot) SendMessage(message *Message) error {
-	return b.client.SendTextMessage(message)
+	return message.Send()
 }
 
 // EditMessage edit a message passed as an argument.

message.go

@@ -3,14 +3,16 @@ package goicqbot
 import (
 	"fmt"
 	"os"
+	"path/filepath"
 )
 
 //go:generate easyjson -all message.go
 
 type MessageContentType uint8
 
 const (
-	Text MessageContentType = iota
+	Unknown MessageContentType = iota
+	Text
 	OtherFile
 	Voice
 )
@@ -101,6 +103,26 @@ func (m *Message) Send() error {
 		}
 	case Text:
 		return m.client.SendTextMessage(m)
+	case Unknown:
+		// need to autodetect
+		if m.FileID != "" {
+			// voice message's fileID always starts with 'I'
+			if m.FileID[0] == voiceMessageLeadingRune {
+				return m.client.SendVoiceMessage(m)
+			}
+			return m.client.SendFileMessage(m)
+		}
+
+		if m.File != nil {
+			if voiceMessageSupportedExtensions[filepath.Ext(m.File.Name())] {
+				return m.client.UploadVoice(m)
+			}
+			return m.client.UploadFile(m)
+		}
+
+		if m.Text != "" {
+			return m.client.SendTextMessage(m)
+		}
 	}
 
 	return fmt.Errorf("cannot send message or file without data")

voice.go

@@ -0,0 +1,13 @@
+package goicqbot
+
+var (
+	voiceMessageSupportedExtensions = map[string]bool{
+		".aac": true,
+		".ogg": true,
+		".m4a": true,
+	}
+)
+
+const (
+	voiceMessageLeadingRune = 'I'
+)