modified: netbox_services/engine/__init__.py

modified:   netbox_services/engine/allocators.py
modified:   netbox_services/engine/context.py
new file:   netbox_services/engine/mappers.py
modified:   netbox_services/engine/resolver.py
new file:   netbox_services/engine/templating.py
modified:   netbox_services/forms.py
modified:   netbox_services/models.py
modified:   netbox_services/tests/test_allocators.py
new file:   netbox_services/tests/test_mappers.py
modified:   netbox_services/tests/test_resolver.py
new file:   netbox_services/tests/test_templating.py
Simplify layout to template and service instances

netbox_services/engine/templating.py

@@ -0,0 +1,80 @@
+"""Jinja2-based attribute templating with ``..`` / ``...`` parent access.
+
+Syntax inside ``{{ }}`` expressions:
+  - ``..``       → immediate parent      (alias ``p1``)
+  - ``...``      → parent of parent      (alias ``p2``)
+  - ``....``     → great-grandparent     (alias ``p3``)
+  - ``service``  → the Service instance
+  - ``index``    → 0-based index within a ``quantity`` loop
+
+Example::
+
+    attrs:
+      name: "rtr-{{ service.tenant.slug }}-{{ index + 1 }}"
+      site: "{{ ..site.pk }}"          # parent device's site PK
+      notes: "{{ ...region.slug }}"     # grandparent region slug
+"""
+
+import re
+
+from jinja2.sandbox import SandboxedEnvironment
+
+_DOT_RE = re.compile(r"(?<![.\w])\.{2,}")
+
+_env = SandboxedEnvironment(
+    variable_start_string="{{",
+    variable_end_string="}}",
+    autoescape=False,
+)
+
+
+def preprocess_dots(s):
+    """Replace ``..`` → ``p1.``, ``...`` → ``p2.``, etc.
+
+    Runs of 2+ dots not preceded by a word char or dot are replaced.
+    This preserves single dots (attribute access, IP addresses like
+    ``10.0.0.1``) and literal strings without ``{{ }}``.
+    """
+    def replacer(m):
+        depth = len(m.group(0)) - 1
+        return f"p{depth}."
+
+    return _DOT_RE.sub(replacer, s)
+
+
+def _build_jinja_ctx(service, ancestors, index):
+    ctx = {"service": service, "index": index}
+    for i, obj in enumerate(ancestors):
+        ctx[f"p{i + 1}"] = obj
+    return ctx
+
+
+def render_value(value, service, ancestors, index):
+    """Render a single attribute value.
+
+    Strings are preprocessed (``..`` → ``p1.``) then Jinja2-rendered.
+    Non-strings (int, bool, list, dict) are returned as-is.
+    """
+    if not isinstance(value, str):
+        return value
+
+    if "{{" not in value:
+        return value
+
+    processed = preprocess_dots(value)
+    template = _env.from_string(processed)
+    return template.render(**_build_jinja_ctx(service, ancestors, index))
+
+
+def render_attrs(attrs, service, ancestors, index):
+    """Render all values in an attrs dict.
+
+    *ancestors* is a list where ``ancestors[0]`` is the immediate parent,
+    ``ancestors[1]`` is the grandparent, etc.
+    """
+    if not attrs:
+        return {}
+    return {
+        key: render_value(val, service, ancestors, index)
+        for key, val in attrs.items()
+    }