Attempt graphql backend

Apply upstream feedback

Remove fastapi layer from gql

Process review comments

Rebase

create_type -> create_strawberry_type

pyproject.toml

@@ -18,6 +18,7 @@ dependencies = [
     "pvi~=0.10.0",
     "pytango",
     "softioc>=4.5.0",
+    "strawberry-graphql",
 ]
 dynamic = ["version"]
 license.file = "LICENSE"
@@ -63,7 +64,7 @@ version_file = "src/fastcs/_version.py"
 
 [tool.pyright]
 typeCheckingMode = "standard"
-reportMissingImports = false # Ignore missing stubs in imported modules
+reportMissingImports = false  # Ignore missing stubs in imported modules
 
 [tool.pytest.ini_options]
 # Run pytest with all our checkers, and don't spam us with massive tracebacks on error

src/fastcs/launch.py

@@ -14,11 +14,12 @@
 from .exceptions import LaunchError
 from .transport.adapter import TransportAdapter
 from .transport.epics.options import EpicsOptions
+from .transport.graphQL.options import GraphQLOptions
 from .transport.rest.options import RestOptions
 from .transport.tango.options import TangoOptions
 
 # Define a type alias for transport options
-TransportOptions: TypeAlias = EpicsOptions | TangoOptions | RestOptions
+TransportOptions: TypeAlias = EpicsOptions | TangoOptions | RestOptions | GraphQLOptions
 
 
 class FastCS:
@@ -38,6 +39,13 @@ def __init__(
                     self._backend.dispatcher,
                     transport_options,
                 )
+            case GraphQLOptions():
+                from .transport.graphQL.adapter import GraphQLTransport
+
+                self._transport = GraphQLTransport(
+                    controller,
+                    transport_options,
+                )
             case TangoOptions():
                 from .transport.tango.adapter import TangoTransport
 

src/fastcs/transport/__init__.py

@@ -2,6 +2,8 @@
 from .epics.options import EpicsGUIOptions as EpicsGUIOptions
 from .epics.options import EpicsIOCOptions as EpicsIOCOptions
 from .epics.options import EpicsOptions as EpicsOptions
+from .graphQL.options import GraphQLOptions as GraphQLOptions
+from .graphQL.options import GraphQLServerOptions as GraphQLServerOptions
 from .rest.options import RestOptions as RestOptions
 from .rest.options import RestServerOptions as RestServerOptions
 from .tango.options import TangoDSROptions as TangoDSROptions

src/fastcs/transport/graphQL/adapter.py

@@ -0,0 +1,24 @@
+from fastcs.controller import Controller
+from fastcs.transport.adapter import TransportAdapter
+
+from .graphQL import GraphQLServer
+from .options import GraphQLOptions
+
+
+class GraphQLTransport(TransportAdapter):
+    def __init__(
+        self,
+        controller: Controller,
+        options: GraphQLOptions | None = None,
+    ):
+        self.options = options or GraphQLOptions()
+        self._server = GraphQLServer(controller)
+
+    def create_docs(self) -> None:
+        raise NotImplementedError
+
+    def create_gui(self) -> None:
+        raise NotImplementedError
+
+    def run(self) -> None:
+        self._server.run(self.options.gql)

src/fastcs/transport/graphQL/graphQL.py

@@ -0,0 +1,198 @@
+from collections.abc import Awaitable, Callable, Coroutine
+from typing import Any
+
+import strawberry
+import uvicorn
+from strawberry.asgi import GraphQL
+from strawberry.tools import create_type
+from strawberry.types.field import StrawberryField
+
+from fastcs.attributes import AttrR, AttrRW, AttrW, T
+from fastcs.controller import BaseController, Controller
+
+from .options import GraphQLServerOptions
+
+
+class GraphQLServer:
+    def __init__(self, controller: Controller):
+        self._controller = controller
+        self._fields_tree: FieldTree = FieldTree("")
+        self._app = self._create_app()
+
+    def _create_app(self) -> GraphQL:
+        _add_attribute_operations(self._fields_tree, self._controller)
+        _add_command_mutations(self._fields_tree, self._controller)
+
+        schema_kwargs = {}
+        for key in ["query", "mutation"]:
+            if s_type := self._fields_tree.create_strawberry_type(key):
+                schema_kwargs[key] = s_type
+        schema = strawberry.Schema(**schema_kwargs)  # type: ignore
+        app = GraphQL(schema)
+
+        return app
+
+    def run(self, options: GraphQLServerOptions | None = None) -> None:
+        if options is None:
+            options = GraphQLServerOptions()
+
+        uvicorn.run(
+            self._app,
+            host=options.host,
+            port=options.port,
+            log_level=options.log_level,
+        )
+
+
+def _wrap_attr_set(
+    attr_name: str,
+    attribute: AttrW[T],
+) -> Callable[[T], Coroutine[Any, Any, None]]:
+    async def _dynamic_f(value):
+        await attribute.process(value)
+        return value
+
+    # Add type annotations for validation, schema, conversions
+    _dynamic_f.__name__ = attr_name
+    _dynamic_f.__annotations__["value"] = attribute.datatype.dtype
+    _dynamic_f.__annotations__["return"] = attribute.datatype.dtype
+
+    return _dynamic_f
+
+
+def _wrap_attr_get(
+    attr_name: str,
+    attribute: AttrR[T],
+) -> Callable[[], Coroutine[Any, Any, Any]]:
+    async def _dynamic_f() -> Any:
+        return attribute.get()
+
+    _dynamic_f.__name__ = attr_name
+    _dynamic_f.__annotations__["return"] = attribute.datatype.dtype
+
+    return _dynamic_f
+
+
+def _wrap_as_field(
+    field_name: str,
+    strawberry_type: type,
+) -> StrawberryField:
+    def _dynamic_field():
+        return strawberry_type()
+
+    _dynamic_field.__name__ = field_name
+    _dynamic_field.__annotations__["return"] = strawberry_type
+
+    return strawberry.field(_dynamic_field)
+
+
+class FieldTree:
+    def __init__(self, name: str):
+        self.name = name
+        self.children: dict[str, FieldTree] = {}
+        self.fields: dict[str, list[StrawberryField]] = {
+            "query": [],
+            "mutation": [],
+        }
+
+    def insert(self, path: list[str]) -> "FieldTree":
+        # Create child if not exist
+        name = path.pop(0)
+        if child := self.get_child(name):
+            pass
+        else:
+            child = FieldTree(name)
+            self.children[name] = child
+
+        # Recurse if needed
+        if path:
+            return child.insert(path)
+        else:
+            return child
+
+    def get_child(self, name: str) -> "FieldTree | None":
+        if name in self.children:
+            return self.children[name]
+        else:
+            return None
+
+    def create_strawberry_type(self, strawberry_type: str) -> type | None:
+        for child in self.children.values():
+            if new_type := child.create_strawberry_type(strawberry_type):
+                child_field = _wrap_as_field(
+                    child.name,
+                    new_type,
+                )
+                self.fields[strawberry_type].append(child_field)
+
+        if self.fields[strawberry_type]:
+            return create_type(
+                f"{self.name}{strawberry_type}", self.fields[strawberry_type]
+            )
+        else:
+            return None
+
+
+def _add_attribute_operations(
+    fields_tree: FieldTree,
+    controller: Controller,
+) -> None:
+    for single_mapping in controller.get_controller_mappings():
+        path = single_mapping.controller.path
+        if path:
+            node = fields_tree.insert(path)
+        else:
+            node = fields_tree
+
+        if node is not None:
+            for attr_name, attribute in single_mapping.attributes.items():
+                match attribute:
+                    # mutation for server changes https://graphql.org/learn/queries/
+                    case AttrRW():
+                        node.fields["query"].append(
+                            strawberry.field(_wrap_attr_get(attr_name, attribute))
+                        )
+                        node.fields["mutation"].append(
+                            strawberry.mutation(_wrap_attr_set(attr_name, attribute))
+                        )
+                    case AttrR():
+                        node.fields["query"].append(
+                            strawberry.field(_wrap_attr_get(attr_name, attribute))
+                        )
+                    case AttrW():
+                        node.fields["mutation"].append(
+                            strawberry.mutation(_wrap_attr_set(attr_name, attribute))
+                        )
+
+
+def _wrap_command(
+    method_name: str, method: Callable, controller: BaseController
+) -> Callable[..., Awaitable[bool]]:
+    async def _dynamic_f() -> bool:
+        await getattr(controller, method.__name__)()
+        return True
+
+    _dynamic_f.__name__ = method_name
+
+    return _dynamic_f
+
+
+def _add_command_mutations(fields_tree: FieldTree, controller: Controller) -> None:
+    for single_mapping in controller.get_controller_mappings():
+        path = single_mapping.controller.path
+        if path:
+            node = fields_tree.insert(path)
+        else:
+            node = fields_tree
+
+        if node is not None:
+            for cmd_name, method in single_mapping.command_methods.items():
+                node.fields["mutation"].append(
+                    strawberry.mutation(
+                        _wrap_command(
+                            cmd_name,
+                            method.fn,
+                            single_mapping.controller,
+                        )
+                    )
+                )

src/fastcs/transport/graphQL/options.py

@@ -0,0 +1,13 @@
+from dataclasses import dataclass, field
+
+
+@dataclass
+class GraphQLServerOptions:
+    host: str = "localhost"
+    port: int = 8080
+    log_level: str = "info"
+
+
+@dataclass
+class GraphQLOptions:
+    gql: GraphQLServerOptions = field(default_factory=GraphQLServerOptions)