feat: Enhance Telegram service with authentication status management and improve RSS feed generation error handling

internal/rss/generator.go

@@ -2,6 +2,8 @@ package rss
 
 import (
 	"encoding/xml"
+	"fmt"
+	"net/url"
 	"strconv"
 	"time"
 
@@ -40,23 +42,57 @@ type RSSGenerator struct {
 	logger *zap.Logger
 }
 
-func NewRSSGenerator(logger zap.Logger) *RSSGenerator {
-	return &RSSGenerator{logger: &logger}
+func NewRSSGenerator(logger *zap.Logger) *RSSGenerator {
+	return &RSSGenerator{logger: logger}
 }
 
 func (r *RSSGenerator) GenerateFeed(items []tg.MessageClass, channelId string) *RSSFeed {
+	if channelId == "" {
+		r.logger.Error("GenerateFeed called with empty channelId")
+		return nil
+	}
+
+	nowStr := time.Now().Format("Mon, 02 Jan 2006 15:04 MST")
+
 	rssChannel := &RSSChannel{
 		Title: "Recent posts from @" + channelId,
 		Link:  "https://t.me/" + channelId,
 		Description: "This feed contains the most recent posts from the Telegram channel @" + channelId + ". " +
 			"Stay updated with the latest news and updates from the channel.",
-		PubDate:       time.Now().Format("Mon, 02 Jan 2006 15:04 MST"),
-		LastBuildDate: time.Now().Format("Mon, 02 Jan 2006 15:04 MST"),
+		PubDate:       nowStr,
+		LastBuildDate: nowStr,
 		Generator:     "Telegram RSS Generator",
 	}
+
+	errorCount := 0
+
 	for _, m := range items {
-		rssChannel.Items = append(rssChannel.Items, *r.messageToItem(m, channelId))
+		if m == nil {
+			errorCount++
+			continue
+		}
+
+		item, err := r.messageToItem(m, channelId)
+		if err != nil {
+			r.logger.Error("failed to convert message to RSS item",
+				zap.String("channel", channelId),
+				zap.Int("message_id", m.GetID()),
+				zap.Error(err),
+			)
+			errorCount++
+			continue
+		}
+
+		rssChannel.Items = append(rssChannel.Items, *item)
 	}
+
+	if errorCount > 0 {
+		r.logger.Warn("feed generation completed with errors",
+			zap.String("channel", channelId),
+			zap.Int("failed", errorCount),
+		)
+	}
+
 	return &RSSFeed{
 		Version:   "2.0",
 		XmlnsAtom: "http://www.w3.org/2005/Atom",
@@ -64,12 +100,27 @@ func (r *RSSGenerator) GenerateFeed(items []tg.MessageClass, channelId string) *
 	}
 }
 
-func (r *RSSGenerator) messageToItem(msg tg.MessageClass, channelId string) *RSSItem {
+func (r *RSSGenerator) messageToItem(msg tg.MessageClass, channelId string) (*RSSItem, error) {
+	message, ok := msg.(*tg.Message)
+	if !ok {
+		return nil, fmt.Errorf("unsupported message type: %T", msg)
+	}
+
+	messageURL, err := url.Parse("https://t.me/" + channelId + "/" + strconv.Itoa(msg.GetID()))
+	if err != nil {
+		return nil, fmt.Errorf("failed to parse message URL: %w", err)
+	}
+
+	description := message.Message
+	if description == "" {
+		description = "No content"
+	}
+
 	return &RSSItem{
 		Title:       "Post by @" + channelId + " on Telegram",
-		Link:        "https://t.me/" + channelId + "/" + strconv.Itoa(msg.GetID()), // TODO: URL parse it
-		PubDate:     time.Unix(int64(msg.(*tg.Message).Date), 0).Format("Mon, 02 Jan 2006 15:04 MST"),
-		Description: msg.(*tg.Message).Message,
-		Guid:        "https://t.me/" + channelId + "/" + strconv.Itoa(msg.GetID()),
-	}
+		Link:        messageURL.String(),
+		PubDate:     time.Unix(int64(message.Date), 0).Format("Mon, 02 Jan 2006 15:04 MST"),
+		Description: description,
+		Guid:        messageURL.String(),
+	}, nil
 }