General optimations and refactorings in preparation for simpleicon role implementation

module_utils/domain_utils.py

@@ -0,0 +1,52 @@
+# filter_plugins/domain_utils.py
+from ansible.errors import AnsibleFilterError
+
+def get_domain(domains, application_id):
+    """
+    Return the domain for application_id from the domains mapping:
+      - If value is a string, return it.
+      - If value is a dict, return its first value.
+      - If value is a list, return its first element.
+      - Otherwise, raise an error.
+    """
+    if not isinstance(domains, dict):
+        raise AnsibleFilterError(f"'domains' must be a dict, got {type(domains).__name__}")
+
+    if application_id not in domains:
+        raise AnsibleFilterError(f"application_id '{application_id}' not found in domains mapping")
+
+    val = domains[application_id]
+
+    # String case
+    if isinstance(val, str):
+        if not val:
+            raise AnsibleFilterError(f"domains['{application_id}'] is an empty string")
+        return val
+
+    # Dict case
+    if isinstance(val, dict):
+        try:
+            first_val = next(iter(val.values()))
+        except StopIteration:
+            raise AnsibleFilterError(f"domains['{application_id}'] dict is empty")
+        if not isinstance(first_val, str) or not first_val:
+            raise AnsibleFilterError(
+                f"first value of domains['{application_id}'] must be a non-empty string, got {first_val!r}"
+            )
+        return first_val
+
+    # List case
+    if isinstance(val, list):
+        if not val:
+            raise AnsibleFilterError(f"domains['{application_id}'] list is empty")
+        first = val[0]
+        if not isinstance(first, str) or not first:
+            raise AnsibleFilterError(
+                f"first element of domains['{application_id}'] must be a non-empty string, got {first!r}"
+            )
+        return first
+
+    # Unsupported type
+    raise AnsibleFilterError(
+        f"domains['{application_id}'] has unsupported type {type(val).__name__}, must be str, dict or list"
+    )