1 files changed, 32 insertions, 0 deletions
diff --git a/app/backends/common.py b/app/backends/common.py
index 42faa7e..d5e1b6b 100644
--- a/app/backends/common.py
+++ b/app/backends/common.py
@@ -150,6 +150,38 @@ def url_with_port(url: str, port: int) -> str:
         (parts.scheme or "http", f"{host}:{port}", parts.path, "", ""))
 
 
+def normalize_remote_url(value: str) -> str:
+    """Normalize a user-supplied remote server URL, or '' for "disabled".
+
+    Accepts a bare ``host[:port]`` (a scheme of ``http`` is assumed), a full
+    ``http(s)://host[:port][/path]`` URL, or the empty string (no remote
+    server configured). Returns the normalized URL (bare host:port becomes
+    ``http://host:port``). Raises ValueError for anything else — a missing
+    host, a host containing whitespace, or a non-numeric port.
+    """
+    cleaned = value.strip()
+    if not cleaned:
+        return ""
+    parts = urllib.parse.urlsplit(cleaned)
+    if not parts.scheme:
+        # Bare host[:port] — add the default scheme so netloc/host/port
+        # parse cleanly. An explicit scheme is kept as-is (so "http://"
+        # with no host fails the host check below).
+        parts = urllib.parse.urlsplit(f"http://{cleaned}")
+    host = parts.hostname
+    if not host or any(ch.isspace() for ch in host):
+        raise ValueError(
+            "Enter a host:port (e.g. 10.20.30.40:8000) or a full URL "
+            f"(e.g. http://10.20.30.40:8000); got {value!r}")
+    try:
+        parts.port  # raises ValueError for a non-numeric port
+    except ValueError as exc:
+        raise ValueError(
+            f"Invalid port in remote URL {value!r}: {exc}") from exc
+    return urllib.parse.urlunsplit(
+        (parts.scheme or "http", parts.netloc, parts.path, "", ""))
+
+
 def server_running(url: str, timeout: float = 0.3) -> bool:
     """True when something accepts TCP connections at URL's host:port.