Update Telegram message on post update

notifications.go

@@ -31,7 +31,7 @@ func (a *goBlog) sendNotification(text string) {
 		log.Println("Failed to save notification:", err.Error())
 	}
 	if an := a.cfg.Notifications; an != nil {
-		_, err := a.send(an.Telegram, n.Text, "")
+		_, _, err := a.send(an.Telegram, n.Text, "")
 		if err != nil {
 			log.Println("Failed to send Telegram notification:", err.Error())
 		}

telegram.go

@@ -2,8 +2,10 @@ package main
 
 import (
 	"bytes"
+	"errors"
 	"log"
 	"net/url"
+	"strconv"
 
 	tgbotapi "github.com/go-telegram-bot-api/telegram-bot-api/v5"
 )
@@ -11,10 +13,61 @@ import (
 func (a *goBlog) initTelegram() {
 	a.pPostHooks = append(a.pPostHooks, func(p *post) {
 		if tg := a.cfg.Blogs[p.Blog].Telegram; tg.enabled() && p.isPublishedSectionPost() {
-			if html := tg.generateHTML(p.RenderedTitle, a.fullPostURL(p), a.shortPostURL(p)); html != "" {
-				if _, err := a.send(tg, html, "HTML"); err != nil {
-					log.Printf("Failed to send post to Telegram: %v", err)
+			// Generate HTML
+			html := tg.generateHTML(p.RenderedTitle, a.fullPostURL(p), a.shortPostURL(p))
+			if html == "" {
+				return
 			}
+			// Send message
+			chatId, msgId, err := a.send(tg, html, tgbotapi.ModeHTML)
+			if err != nil {
+				log.Printf("Failed to send post to Telegram: %v", err)
+				return
+			}
+			if chatId == 0 || msgId == 0 {
+				// Not sent
+				return
+			}
+			// Save chat and message id to post
+			err = a.db.replacePostParam(p.Path, "telegramchat", []string{strconv.FormatInt(chatId, 10)})
+			if err != nil {
+				log.Printf("Failed to save Telegram chat id: %v", err)
+			}
+			err = a.db.replacePostParam(p.Path, "telegrammsg", []string{strconv.Itoa(msgId)})
+			if err != nil {
+				log.Printf("Failed to save Telegram message id: %v", err)
+			}
+		}
+	})
+	a.pUpdateHooks = append(a.pUpdateHooks, func(p *post) {
+		if tg := a.cfg.Blogs[p.Blog].Telegram; tg.enabled() && p.isPublishedSectionPost() {
+			tgChat := p.firstParameter("telegramchat")
+			tgMsg := p.firstParameter("telegrammsg")
+			if tgChat == "" || tgMsg == "" {
+				// Not send to Telegram
+				return
+			}
+			// Parse tgChat to int64
+			chatId, err := strconv.ParseInt(tgChat, 10, 64)
+			if err != nil {
+				log.Printf("Failed to parse Telegram chat ID: %v", err)
+				return
+			}
+			// Parse tgMsg to int
+			messageId, err := strconv.Atoi(tgMsg)
+			if err != nil {
+				log.Printf("Failed to parse Telegram message ID: %v", err)
+				return
+			}
+			// Generate HTML
+			html := tg.generateHTML(p.RenderedTitle, a.fullPostURL(p), a.shortPostURL(p))
+			if html == "" {
+				return
+			}
+			// Send update
+			err = a.sendUpdate(tg, chatId, messageId, html, "HTML")
+			if err != nil {
+				log.Printf("Failed to send update to Telegram: %v", err)
 			}
 		}
 	})
@@ -48,13 +101,13 @@ func (tg *configTelegram) generateHTML(title, fullURL, shortURL string) string {
 	return message.String()
 }
 
-func (a *goBlog) send(tg *configTelegram, message, mode string) (int, error) {
+func (a *goBlog) send(tg *configTelegram, message, mode string) (int64, int, error) {
 	if !tg.enabled() {
-		return 0, nil
+		return 0, 0, nil
 	}
 	bot, err := tgbotapi.NewBotAPIWithClient(tg.BotToken, tgbotapi.APIEndpoint, a.httpClient)
 	if err != nil {
-		return 0, err
+		return 0, 0, err
 	}
 	msg := tgbotapi.MessageConfig{
 		BaseChat: tgbotapi.BaseChat{
@@ -65,7 +118,41 @@ func (a *goBlog) send(tg *configTelegram, message, mode string) (int, error) {
 	}
 	res, err := bot.Send(msg)
 	if err != nil {
-		return 0, err
+		return 0, 0, err
 	}
-	return res.MessageID, nil
+	return res.Chat.ID, res.MessageID, nil
+}
+
+func (a *goBlog) sendUpdate(tg *configTelegram, chatId int64, messageId int, message, mode string) error {
+	if !tg.enabled() {
+		return nil
+	}
+	bot, err := tgbotapi.NewBotAPIWithClient(tg.BotToken, tgbotapi.APIEndpoint, a.httpClient)
+	if err != nil {
+		return err
+	}
+	chat, err := bot.GetChat(tgbotapi.ChatInfoConfig{
+		ChatConfig: tgbotapi.ChatConfig{
+			SuperGroupUsername: tg.ChatID,
+		},
+	})
+	if err != nil {
+		return err
+	}
+	if chat.ID != chatId {
+		return errors.New("chat id mismatch")
+	}
+	msg := tgbotapi.EditMessageTextConfig{
+		BaseEdit: tgbotapi.BaseEdit{
+			ChatID:    chatId,
+			MessageID: messageId,
+		},
+		Text:      message,
+		ParseMode: mode,
+	}
+	_, err = bot.Send(msg)
+	if err != nil {
+		return err
+	}
+	return nil
 }

telegram_test.go

@@ -82,7 +82,7 @@ func Test_configTelegram_send(t *testing.T) {
 			return
 		}
 		rw.WriteHeader(http.StatusOK)
-		rw.Write([]byte(`{"ok":true,"result":{"message_id":123,"from":{"id":123456789,"is_bot":true,"first_name":"Test","username":"testbot"},"chat":{"id":123456789,"first_name":"Test","username":"testbot"},"date":1564181818,"text":"Message"}}`))
+		rw.Write([]byte(`{"ok":true,"result":{"message_id":123,"from":{"id":123456789,"is_bot":true,"first_name":"Test","username":"testbot"},"chat":{"id":789,"first_name":"Test","username":"testbot"},"date":1564181818,"text":"Message"}}`))
 	}))
 
 	tg := &configTelegram{
@@ -95,10 +95,11 @@ func Test_configTelegram_send(t *testing.T) {
 		httpClient: fakeClient.Client,
 	}
 
-	msgId, err := app.send(tg, "Message", "HTML")
+	chatId, msgId, err := app.send(tg, "Message", "HTML")
 	require.Nil(t, err)
 
 	assert.Equal(t, 123, msgId)
+	assert.Equal(t, int64(789), chatId)
 
 	assert.NotNil(t, fakeClient.req)
 	assert.Equal(t, http.MethodPost, fakeClient.req.Method)