Enhance Telegram notification functionality

- Introduced functions to mask sensitive information and preview notification text for improved logging and security.
- Added detailed logging for notification sending process, including configuration details and response handling.
- Implemented checks to prevent sending notifications when bot token or chat ID is missing, with appropriate warnings logged.

src/notifications/telegram.ts

@@ -21,6 +21,30 @@ const TYPE_EMOJI: Record<string, string> = {
   custom: "📢",
 };
 
+const LOG_PREFIX = "[Telegram]";
+const PREVIEW_LIMIT = 240;
+
+function maskSecret(value: string, revealStart = 4, revealEnd = 4): string {
+  if (!value) return "missing";
+  if (value.length <= revealStart + revealEnd + 2) {
+    return `${value.slice(0, 1)}...${value.slice(-1)} (len=${value.length})`;
+  }
+  return `${value.slice(0, revealStart)}...${value.slice(-revealEnd)} (len=${value.length})`;
+}
+
+function maskChatId(value: string): string {
+  if (!value) return "missing";
+  if (value.length <= 4) return `***${value}`;
+  return `***${value.slice(-4)}`;
+}
+
+function previewText(text: string): string {
+  if (text.length <= PREVIEW_LIMIT) {
+    return text;
+  }
+  return `${text.slice(0, PREVIEW_LIMIT)}...`;
+}
+
 function formatNotificationMessage(notification: TradeNotification, accountLabel?: string): string {
   const levelEmoji = LEVEL_EMOJI[notification.level] ?? "";
   const typeEmoji = TYPE_EMOJI[notification.type] ?? "";
@@ -55,6 +79,7 @@ export class TelegramNotifier implements NotificationSender {
   private readonly config: TelegramConfig;
   private readonly baseUrl: string;
   private sendQueue: Promise<void> = Promise.resolve();
+  private disabledLogged = false;
 
   constructor(config: Partial<TelegramConfig> = {}) {
     this.config = {
@@ -64,6 +89,12 @@ export class TelegramNotifier implements NotificationSender {
       accountLabel: config.accountLabel,
     };
     this.baseUrl = `https://api.telegram.org/bot${this.config.botToken}`;
+    console.info(`${LOG_PREFIX} Notifier config`, {
+      enabled: this.config.enabled,
+      botToken: maskSecret(this.config.botToken),
+      chatId: maskChatId(this.config.chatId),
+      accountLabel: this.config.accountLabel ?? "none",
+    });
   }
 
   isEnabled(): boolean {
@@ -72,9 +103,22 @@ export class TelegramNotifier implements NotificationSender {
 
   async send(notification: TradeNotification): Promise<void> {
     if (!this.isEnabled()) {
+      if (!this.disabledLogged) {
+        console.warn(`${LOG_PREFIX} Skipping send (missing bot token or chat id).`, {
+          botToken: maskSecret(this.config.botToken),
+          chatId: maskChatId(this.config.chatId),
+        });
+        this.disabledLogged = true;
+      }
       return;
     }
 
+    console.info(`${LOG_PREFIX} Queueing notification`, {
+      type: notification.type,
+      level: notification.level,
+      title: notification.title,
+      chatId: maskChatId(this.config.chatId),
+    });
     this.sendQueue = this.sendQueue
       .then(() => this.doSend(notification))
       .catch(() => {});
@@ -85,6 +129,11 @@ export class TelegramNotifier implements NotificationSender {
     const url = `${this.baseUrl}/sendMessage`;
 
     try {
+      console.info(`${LOG_PREFIX} Sending notification`, {
+        chatId: maskChatId(this.config.chatId),
+        textLength: text.length,
+        textPreview: previewText(text),
+      });
       const response = await fetch(url, {
         method: "POST",
         headers: { "Content-Type": "application/json" },
@@ -94,12 +143,17 @@ export class TelegramNotifier implements NotificationSender {
         }),
       });
 
+      const responseText = await response.text().catch(() => "unknown response");
+      console.info(`${LOG_PREFIX} Response`, {
+        ok: response.ok,
+        status: response.status,
+        body: responseText,
+      });
       if (!response.ok) {
-        const errorText = await response.text().catch(() => "unknown error");
-        console.error(`[Telegram] Failed to send notification: ${response.status} ${errorText}`);
+        console.error(`${LOG_PREFIX} Failed to send notification: ${response.status} ${responseText}`);
       }
     } catch (error) {
-      console.error(`[Telegram] Failed to send notification: ${error instanceof Error ? error.message : String(error)}`);
+      console.error(`${LOG_PREFIX} Failed to send notification: ${error instanceof Error ? error.message : String(error)}`);
     }
   }
 }