Add governed View surface runtime

src/govoplan_core/core/modules.py

@@ -4,6 +4,8 @@ from collections.abc import Callable, Iterable, Mapping, Sequence
 from dataclasses import dataclass, field
 from typing import Any, Literal, Protocol, TYPE_CHECKING
 
+from govoplan_core.core.views import ViewSurface
+
 if TYPE_CHECKING:
     from fastapi import APIRouter
 
@@ -57,6 +59,7 @@ class NavItem:
     required_all: tuple[str, ...] = ()
     required_any: tuple[str, ...] = ()
     order: int = 100
+    surface_id: str | None = None
 
 
 
@@ -68,6 +71,7 @@ class FrontendRoute:
     required_all: tuple[str, ...] = ()
     required_any: tuple[str, ...] = ()
     order: int = 100
+    surface_id: str | None = None
 
 
 @dataclass(frozen=True, slots=True)
@@ -92,6 +96,7 @@ class FrontendModule:
     public_routes: tuple[PublicFrontendRoute, ...] = ()
     nav_items: tuple[NavItem, ...] = ()
     settings_routes: tuple[FrontendRoute, ...] = ()
+    view_surfaces: tuple[ViewSurface, ...] = ()
 
 
 @dataclass(frozen=True, slots=True)

src/govoplan_core/core/registry.py

@@ -25,6 +25,13 @@ from govoplan_core.core.modules import (
     user_workflow_scope_condition_issues,
 )
 from govoplan_core.core.versioning import format_version_range, version_range_is_valid, version_satisfies_range
+from govoplan_core.core.views import (
+    ViewSurface,
+    module_view_surface_id,
+    navigation_view_surface_id,
+    route_view_surface_id,
+    validate_view_surface_id,
+)
 
 _MODULE_ID_RE = re.compile(r"^[a-z][a-z0-9_]*$")
 _NPM_PACKAGE_RE = re.compile(r"^(?:@[a-z0-9][a-z0-9_.-]*/)?[a-z0-9][a-z0-9_.-]*$")
@@ -113,6 +120,13 @@ class PlatformRegistry:
     def nav_items(self) -> tuple[NavItem, ...]:
         return tuple(sorted((item for manifest in self.manifests() for item in manifest.nav_items), key=lambda item: item.order))
 
+    def view_surfaces(self) -> tuple[ViewSurface, ...]:
+        return tuple(
+            surface
+            for manifest in self.manifests()
+            for surface in manifest_view_surfaces(manifest)
+        )
+
     def resource_acl_providers(self) -> tuple[ResourceAclProvider, ...]:
         return tuple(provider for manifest in self.manifests() for provider in manifest.resource_acl_providers)
 
@@ -230,6 +244,53 @@ class PlatformRegistry:
         return (self._manifests[module_id] for module_id in ordered)
 
 
+def manifest_view_surfaces(manifest: ModuleManifest) -> tuple[ViewSurface, ...]:
+    frontend = manifest.frontend
+    if frontend is None:
+        return ()
+    root_id = module_view_surface_id(manifest.id)
+    surfaces = [
+        ViewSurface(
+            id=root_id,
+            module_id=manifest.id,
+            kind="module",
+            label=manifest.name,
+            order=min((item.order for item in frontend.nav_items), default=100),
+        )
+    ]
+    surfaces.extend(
+        ViewSurface(
+            id=item.surface_id or navigation_view_surface_id(manifest.id, item.path),
+            module_id=manifest.id,
+            kind="navigation",
+            label=item.label,
+            parent_id=root_id,
+            order=item.order,
+        )
+        for item in frontend.nav_items
+    )
+    surfaces.extend(
+        ViewSurface(
+            id=route.surface_id or route_view_surface_id(manifest.id, route.path),
+            module_id=manifest.id,
+            kind="route",
+            label=route.component,
+            parent_id=root_id,
+            description=route.path,
+            order=route.order,
+        )
+        for route in (*frontend.routes, *frontend.settings_routes)
+    )
+    surfaces.extend(
+        replace(
+            surface,
+            parent_id=surface.parent_id or root_id,
+        )
+        for surface in frontend.view_surfaces
+    )
+    return tuple(surfaces)
+
+
 def _normalize_delete_veto_result(
     result: object,
     *,
@@ -438,8 +499,90 @@ def _validate_manifest_frontend(manifest: ModuleManifest) -> None:
         raise RegistryError(f"Module {manifest.id!r} has invalid frontend package name {frontend.package_name!r}")
     for route in (*frontend.routes, *frontend.settings_routes, *frontend.public_routes):
         _validate_frontend_route(manifest.id, route.path, route.component)
+    for route in (*frontend.routes, *frontend.settings_routes):
+        if route.surface_id is not None:
+            _validate_view_surface_id(manifest.id, route.surface_id)
     for item in frontend.nav_items:
         _validate_nav_item(manifest.id, item)
+        if item.surface_id is not None:
+            _validate_view_surface_id(manifest.id, item.surface_id)
+    _validate_view_surfaces(manifest)
+
+
+def _validate_view_surfaces(manifest: ModuleManifest) -> None:
+    frontend = manifest.frontend
+    if frontend is None:
+        return
+    root_id = module_view_surface_id(manifest.id)
+    _validate_view_surface_id(manifest.id, root_id)
+    known_ids = {root_id}
+    for item in frontend.nav_items:
+        surface_id = item.surface_id or navigation_view_surface_id(manifest.id, item.path)
+        _validate_view_surface_id(manifest.id, surface_id)
+        if surface_id in known_ids:
+            raise RegistryError(
+                f"Duplicate view surface id {surface_id!r} in module {manifest.id!r}"
+            )
+        known_ids.add(surface_id)
+    for route in (*frontend.routes, *frontend.settings_routes):
+        surface_id = route.surface_id or route_view_surface_id(manifest.id, route.path)
+        _validate_view_surface_id(manifest.id, surface_id)
+        if surface_id in known_ids:
+            raise RegistryError(
+                f"Duplicate view surface id {surface_id!r} in module {manifest.id!r}"
+            )
+        known_ids.add(surface_id)
+    for surface in frontend.view_surfaces:
+        if surface.module_id != manifest.id:
+            raise RegistryError(
+                f"View surface {surface.id!r} belongs to {surface.module_id!r}, "
+                f"not module {manifest.id!r}"
+            )
+        _validate_view_surface_id(manifest.id, surface.id)
+        if surface.id in known_ids:
+            raise RegistryError(
+                f"Duplicate view surface id {surface.id!r} in module {manifest.id!r}"
+            )
+        known_ids.add(surface.id)
+    for surface in frontend.view_surfaces:
+        parent_id = surface.parent_id or root_id
+        if parent_id not in known_ids:
+            raise RegistryError(
+                f"View surface {surface.id!r} in module {manifest.id!r} "
+                f"references unknown parent {parent_id!r}"
+            )
+        if surface.required and not surface.default_visible:
+            raise RegistryError(
+                f"Required view surface {surface.id!r} in module {manifest.id!r} "
+                "must be visible by default"
+            )
+    parent_by_id = {
+        surface.id: surface.parent_id or root_id
+        for surface in frontend.view_surfaces
+    }
+    for surface_id in parent_by_id:
+        path: set[str] = set()
+        current_id: str | None = surface_id
+        while current_id in parent_by_id:
+            if current_id in path:
+                raise RegistryError(
+                    f"View surface hierarchy in module {manifest.id!r} "
+                    f"contains a cycle at {current_id!r}"
+                )
+            path.add(current_id)
+            current_id = parent_by_id[current_id]
+
+
+def _validate_view_surface_id(module_id: str, surface_id: str) -> None:
+    if not validate_view_surface_id(surface_id):
+        raise RegistryError(
+            f"View surface id for module {module_id!r} is invalid: {surface_id!r}"
+        )
+    if not surface_id.startswith(f"{module_id}."):
+        raise RegistryError(
+            f"View surface id for module {module_id!r} must start with "
+            f"{module_id!r} followed by '.': {surface_id!r}"
+        )
 
 
 def _validate_frontend_route(module_id: str, path: str, component: str) -> None:

src/govoplan_core/core/views.py

@@ -0,0 +1,94 @@
+from __future__ import annotations
+
+import re
+from collections.abc import Iterable
+from dataclasses import dataclass
+from typing import Literal, Protocol, runtime_checkable
+
+
+VIEWS_MODULE_ID = "views"
+CAPABILITY_VIEWS_RESOLVER = "views.resolver"
+VIEW_SURFACE_CONTRACT_VERSION = "1"
+
+ViewSurfaceKind = Literal[
+    "module",
+    "navigation",
+    "route",
+    "section",
+    "action",
+    "selector",
+]
+
+_SURFACE_ID_RE = re.compile(r"^[a-z][a-z0-9_.-]{2,159}$")
+_SURFACE_SLUG_RE = re.compile(r"[^a-z0-9]+")
+
+
+@dataclass(frozen=True, slots=True)
+class ViewSurface:
+    id: str
+    module_id: str
+    kind: ViewSurfaceKind
+    label: str
+    parent_id: str | None = None
+    description: str | None = None
+    order: int = 100
+    default_visible: bool = True
+    required: bool = False
+
+
+@dataclass(frozen=True, slots=True)
+class EffectiveView:
+    view_id: str | None
+    revision_id: str | None
+    name: str | None
+    visible_surface_ids: frozenset[str]
+    locked: bool = False
+    provenance: tuple[dict[str, object], ...] = ()
+
+
+@runtime_checkable
+class ViewResolver(Protocol):
+    def resolve_effective_view(
+        self,
+        session: object,
+        *,
+        tenant_id: str,
+        account_id: str,
+        group_ids: Iterable[str] = (),
+    ) -> EffectiveView: ...
+
+
+def module_view_surface_id(module_id: str) -> str:
+    return f"{module_id}.module"
+
+
+def navigation_view_surface_id(module_id: str, path: str) -> str:
+    return f"{module_id}.nav.{_surface_slug(path)}"
+
+
+def route_view_surface_id(module_id: str, path: str) -> str:
+    return f"{module_id}.route.{_surface_slug(path)}"
+
+
+def validate_view_surface_id(value: str) -> bool:
+    return bool(_SURFACE_ID_RE.fullmatch(value))
+
+
+def _surface_slug(value: str) -> str:
+    normalized = _SURFACE_SLUG_RE.sub(".", value.strip().lower()).strip(".")
+    return normalized or "root"
+
+
+__all__ = [
+    "CAPABILITY_VIEWS_RESOLVER",
+    "EffectiveView",
+    "VIEWS_MODULE_ID",
+    "VIEW_SURFACE_CONTRACT_VERSION",
+    "ViewResolver",
+    "ViewSurface",
+    "ViewSurfaceKind",
+    "module_view_surface_id",
+    "navigation_view_surface_id",
+    "route_view_surface_id",
+    "validate_view_surface_id",
+]