add telegram bot

internal/memos/client.go

@@ -67,6 +67,43 @@ func (c *Client) ListMemos(ctx context.Context, filter string, pageSize int, pag
 	return &result, nil
 }
 
+// DownloadAttachment downloads the attachment data as bytes.
+func (c *Client) DownloadAttachment(ctx context.Context, att Attachment) ([]byte, error) {
+	var reqURL string
+	var needsAuth bool
+
+	if att.ExternalLink != "" {
+		reqURL = att.ExternalLink
+	} else {
+		reqURL = fmt.Sprintf("%s/file/%s/%s", c.baseURL, att.Name, att.Filename)
+		needsAuth = true
+	}
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, reqURL, nil)
+	if err != nil {
+		return nil, fmt.Errorf("create request: %w", err)
+	}
+	if needsAuth {
+		req.Header.Set("Authorization", "Bearer "+c.token)
+	}
+
+	resp, err := c.httpClient.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("do request: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("download attachment %s: status %d", att.Name, resp.StatusCode)
+	}
+
+	data, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, fmt.Errorf("read body: %w", err)
+	}
+	return data, nil
+}
+
 // GetRandomMemo fetches a single memo without any filter (for full fallback).
 func (c *Client) GetRandomMemo(ctx context.Context) (*Memo, error) {
 	resp, err := c.ListMemos(ctx, "", 1, "")