fix(tgbot): build a client's individual links in-process

The bot's "individual links" and QR actions fetched the client's own
subscription over HTTP from the public URL it builds for display. With no
sub or web domain set that URL falls back to the machine's hostname, which
usually does not resolve (`lookup exhausted-reply: no such host`), and even
a resolvable name fails behind NAT, a firewall or a disabled sub server.

Both actions now ask InboundService.GetSubLinks, the in-process provider the
panel's links API already uses, with the host taken from that same URL so the
link addresses are unchanged. The now-unused pooled HTTP client goes too.

Closes #6597

internal/web/service/tgbot/tgbot_client.go

@@ -2,13 +2,11 @@ package tgbot
 
 import (
 	"context"
-	"encoding/base64"
 	"encoding/json"
 	"errors"
 	"fmt"
 	"html"
-	"io"
-	"net/http"
+	"net/url"
 	"slices"
 	"strconv"
 	"strings"
@@ -248,76 +246,42 @@ func (t *Tgbot) sendClientSubLinks(chatId int64, email string) {
 	t.SendMsgToTgbot(chatId, msg, inlineKeyboard)
 }
 
-// sendClientIndividualLinks fetches the subscription content (individual links) and sends it to the user
+// clientSubLinks builds the subscription's links in-process for the host subURL
+// names; fetching subURL instead fails whenever that host does not resolve here.
+func (t *Tgbot) clientSubLinks(email, subURL string) ([]string, error) {
+	u, err := url.Parse(subURL)
+	if err != nil {
+		return nil, err
+	}
+	_, client, err := t.inboundService.GetClientByEmail(email)
+	if err != nil || client == nil {
+		return nil, errors.New("client not found")
+	}
+	return t.inboundService.GetSubLinks(u.Hostname(), client.SubID)
+}
+
+// sendClientIndividualLinks sends the subscription's individual links to the user
 func (t *Tgbot) sendClientIndividualLinks(chatId int64, email string) {
-	// Build the HTML sub page URL; we'll call it with header Accept to get raw content
 	subURL, _, err := t.buildSubscriptionURLs(email)
 	if err != nil {
 		t.SendMsgToTgbot(chatId, t.I18nBot("tgbot.answers.errorOperation")+"\r\n"+err.Error())
 		return
 	}
-
-	// Try to fetch raw subscription links. Prefer plain text response.
-	req, err := http.NewRequestWithContext(context.Background(), http.MethodGet, subURL, nil)
+	links, err := t.clientSubLinks(email, subURL)
 	if err != nil {
 		t.SendMsgToTgbot(chatId, t.I18nBot("tgbot.answers.errorOperation")+"\r\n"+err.Error())
 		return
 	}
-	// Force plain text to avoid HTML page; controller respects Accept header
-	req.Header.Set("Accept", "text/plain, */*;q=0.1")
-
-	// Use optimized client with connection pooling
-	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
-	defer cancel()
-	req = req.WithContext(ctx)
-
-	resp, err := optimizedHTTPClient.Do(req)
-	if err != nil {
-		t.SendMsgToTgbot(chatId, t.I18nBot("tgbot.answers.errorOperation")+"\r\n"+err.Error())
-		return
-	}
-	defer resp.Body.Close()
-
-	bodyBytes, err := io.ReadAll(resp.Body)
-	if err != nil {
-		t.SendMsgToTgbot(chatId, t.I18nBot("tgbot.answers.errorOperation")+"\r\n"+err.Error())
-		return
-	}
-
-	// If service is configured to encode (Base64), decode it
-	encoded, _ := t.settingService.GetSubEncrypt()
-	var content string
-	if encoded {
-		decoded, err := base64.StdEncoding.DecodeString(string(bodyBytes))
-		if err != nil {
-			// fallback to raw text
-			content = string(bodyBytes)
-		} else {
-			content = string(decoded)
-		}
-	} else {
-		content = string(bodyBytes)
-	}
-
-	// Normalize line endings and trim
-	lines := strings.Split(strings.ReplaceAll(content, "\r\n", "\n"), "\n")
-	var cleaned []string
-	for _, l := range lines {
-		l = strings.TrimSpace(l)
-		if l != "" {
-			cleaned = append(cleaned, l)
-		}
-	}
-	if len(cleaned) == 0 {
+	if len(links) == 0 {
 		t.SendMsgToTgbot(chatId, t.I18nBot("tgbot.noResult"))
 		return
 	}
 
 	// Send in chunks to respect message length; use monospace formatting
 	const maxPerMessage = 50
-	for i := 0; i < len(cleaned); i += maxPerMessage {
-		j := min(i+maxPerMessage, len(cleaned))
-		chunk := cleaned[i:j]
+	for i := 0; i < len(links); i += maxPerMessage {
+		j := min(i+maxPerMessage, len(links))
+		chunk := links[i:j]
 		var msg strings.Builder
 		msg.WriteString(t.I18nBot("subscription.individualLinks"))
 		msg.WriteString(":\r\n")
@@ -375,51 +339,20 @@ func (t *Tgbot) sendClientQRLinks(chatId int64, email string) {
 	}
 
 	// Also generate a few individual links' QRs (first up to 5)
-	subPageURL := subURL
-	req, err := http.NewRequestWithContext(context.Background(), http.MethodGet, subPageURL, nil)
-	if err == nil {
-		req.Header.Set("Accept", "text/plain, */*;q=0.1")
-		ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
-		defer cancel()
-		req = req.WithContext(ctx)
-		if resp, err := optimizedHTTPClient.Do(req); err == nil {
-			body, _ := io.ReadAll(resp.Body)
-			_ = resp.Body.Close()
-			encoded, _ := t.settingService.GetSubEncrypt()
-			var content string
-			if encoded {
-				if dec, err := base64.StdEncoding.DecodeString(string(body)); err == nil {
-					content = string(dec)
-				} else {
-					content = string(body)
-				}
-			} else {
-				content = string(body)
-			}
-			lines := strings.Split(strings.ReplaceAll(content, "\r\n", "\n"), "\n")
-			var cleaned []string
-			for _, l := range lines {
-				l = strings.TrimSpace(l)
-				if l != "" {
-					cleaned = append(cleaned, l)
-				}
-			}
-			if len(cleaned) > 0 {
-				max := min(len(cleaned), 5)
-				for i := range max {
-					if png, err := createQR(cleaned[i], 320); err == nil {
-						// Use the email as filename for individual link QR
-						filename := email + ".png"
-						document := tu.Document(
-							tu.ID(chatId),
-							tu.FileFromBytes(png, filename),
-						)
-						_, _ = bot.SendDocument(context.Background(), document)
-						// Reduced delay for better performance
-						if i < max-1 { // Only delay between documents, not after the last one
-							time.Sleep(50 * time.Millisecond)
-						}
-					}
+	if links, err := t.clientSubLinks(email, subURL); err == nil {
+		max := min(len(links), 5)
+		for i := range max {
+			if png, err := createQR(links[i], 320); err == nil {
+				// Use the email as filename for individual link QR
+				filename := email + ".png"
+				document := tu.Document(
+					tu.ID(chatId),
+					tu.FileFromBytes(png, filename),
+				)
+				_, _ = bot.SendDocument(context.Background(), document)
+				// Reduced delay for better performance
+				if i < max-1 { // Only delay between documents, not after the last one
+					time.Sleep(50 * time.Millisecond)
 				}
 			}
 		}