Attempt graphql backend

Author: marcelldls

pyproject.toml

@@ -17,6 +17,8 @@ dependencies = [
     "pvi~=0.10.0",
     "pytango",
     "softioc",
+    "fastapi[standard]",
+    "strawberry-graphql[fastapi]",
 ]
 dynamic = ["version"]
 license.file = "LICENSE"
@@ -43,6 +45,7 @@ dev = [
     "types-mock",
     "aioca",
     "p4p",
+    "httpx",
 ]
 
 [project.scripts]
@@ -61,7 +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/backends/graphQL/__init__.py

@@ -0,0 +1,14 @@
+from fastcs.backend import Backend
+from fastcs.controller import Controller
+
+from .graphQL import GraphQLServer
+
+
+class GraphQLBackend(Backend):
+    def __init__(self, controller: Controller):
+        super().__init__(controller)
+
+        self._server = GraphQLServer(self._mapping)
+
+    def _run(self):
+        self._server.run()

src/fastcs/backends/graphQL/backend.py

@@ -0,0 +1,226 @@
+from collections.abc import Awaitable, Callable, Coroutine
+from dataclasses import dataclass
+from typing import Any
+
+import strawberry
+import uvicorn
+from fastapi import FastAPI
+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
+from fastcs.mapping import Mapping
+
+
+@dataclass
+class GraphQLServerOptions:
+    host: str = "localhost"
+    port: int = 8080
+    log_level: str = "info"
+
+
+class GraphQLServer:
+    def __init__(self, mapping: Mapping):
+        self._mapping = mapping
+        self._fields_tree: FieldsTree = FieldsTree("")
+        self._app = self._create_app()
+
+    def _create_app(self) -> FastAPI:
+        _add_dev_attributes(self._fields_tree, self._mapping)
+        _add_dev_commands(self._fields_tree, self._mapping)
+
+        schema_kwargs = {}
+        for key in ["query", "mutation"]:
+            if s_type := self._fields_tree.create_type(key):
+                schema_kwargs[key] = s_type
+        schema = strawberry.Schema(**schema_kwargs)  # type: ignore
+        graphql_app: GraphQL = GraphQL(schema)
+
+        app = FastAPI()
+        app.add_route("/graphql", graphql_app)  # type: ignore
+        app.add_websocket_route("/graphql", graphql_app)  # type: ignore
+
+        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(
+    d_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__ = d_attr_name
+    _dynamic_f.__annotations__["value"] = attribute.datatype.dtype
+    _dynamic_f.__annotations__["return"] = attribute.datatype.dtype
+
+    return _dynamic_f
+
+
+def _wrap_attr_get(
+    d_attr_name: str,
+    attribute: AttrR[T],
+) -> Callable[[], Coroutine[Any, Any, Any]]:
+    async def _dynamic_f() -> Any:
+        return attribute.get()
+
+    _dynamic_f.__name__ = d_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 NodeNotFoundError(Exception):
+    pass
+
+
+class FieldsTree:
+    def __init__(self, name: str):
+        self.name = name
+        self.children: list[FieldsTree] = []
+        self.fields_dict: dict[str, list[StrawberryField]] = {
+            "query": [],
+            "mutation": [],
+        }
+
+    def insert(self, path: list[str]) -> "FieldsTree":
+        # Create child if not exist
+        name = path.pop(0)
+        if self.is_child(name):
+            child = self.get_child(name)
+        else:
+            child = FieldsTree(name)
+            self.children.append(child)
+
+        # Recurse if needed
+        if path:
+            return child.insert(path)  # type: ignore
+        else:
+            return child
+
+    def is_child(self, name: str) -> bool:
+        for child in self.children:
+            if child.name == name:
+                return True
+        return False
+
+    def get_child(self, name: str) -> "FieldsTree":
+        for child in self.children:
+            if child.name == name:
+                return child
+        raise NodeNotFoundError
+
+    def create_type(self, strawberry_type: str) -> type | None:
+        for child in self.children:
+            if new_type := child.create_type(strawberry_type):
+                child_field = _wrap_as_field(
+                    child.name,
+                    new_type,
+                )
+                self.fields_dict[strawberry_type].append(child_field)
+
+        if self.fields_dict[strawberry_type]:
+            return create_type(
+                f"{self.name}{strawberry_type}", self.fields_dict[strawberry_type]
+            )
+        else:
+            return None
+
+
+def _add_dev_attributes(
+    fields_tree: FieldsTree,
+    mapping: Mapping,
+) -> None:
+    for single_mapping in mapping.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():
+                attr_name = attr_name.title().replace("_", "")
+
+                match attribute:
+                    # mutation for server changes https://graphql.org/learn/queries/
+                    case AttrRW():
+                        node.fields_dict["query"].append(
+                            strawberry.field(_wrap_attr_get(attr_name, attribute))
+                        )
+                        node.fields_dict["mutation"].append(
+                            strawberry.mutation(_wrap_attr_set(attr_name, attribute))
+                        )
+                    case AttrR():
+                        node.fields_dict["query"].append(
+                            strawberry.field(_wrap_attr_get(attr_name, attribute))
+                        )
+                    case AttrW():
+                        node.fields_dict["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 method.__get__(controller)()
+        return True
+
+    _dynamic_f.__name__ = method_name
+
+    return _dynamic_f
+
+
+def _add_dev_commands(
+    fields_tree: FieldsTree,
+    mapping: Mapping,
+) -> None:
+    for single_mapping in mapping.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 name, method in single_mapping.command_methods.items():
+                cmd_name = name.title().replace("_", "")
+                node.fields_dict["mutation"].append(
+                    strawberry.mutation(
+                        _wrap_command(
+                            cmd_name,
+                            method.fn,
+                            single_mapping.controller,
+                        )
+                    )
+                )

src/fastcs/backends/graphQL/graphQL.py

@@ -0,0 +1,115 @@
+import copy
+import json
+import re
+from typing import Any
+
+import pytest
+from fastapi.testclient import TestClient
+from pytest_mock import MockerFixture
+from tests.conftest import AssertableController
+
+from fastcs.attributes import AttrR
+from fastcs.backends.graphQL.backend import GraphQLBackend
+from fastcs.datatypes import Bool, Float, Int
+
+
+def pascal_2_snake(input: list[str]) -> list[str]:
+    snake_list = copy.deepcopy(input)
+    snake_list[-1] = re.sub(r"(?<!^)(?=[A-Z])", "_", snake_list[-1]).lower()
+    return snake_list
+
+
+def nest_query(path: list[str]) -> str:
+    queue = copy.deepcopy(path)
+    field = queue.pop(0)
+
+    if queue:
+        nesting = nest_query(queue)
+        return f"{field} {{ {nesting} }} "
+    else:
+        return field
+
+
+def nest_mutation(path: list[str], value: Any) -> str:
+    queue = copy.deepcopy(path)
+    field = queue.pop(0)
+
+    if queue:
+        nesting = nest_query(queue)
+        return f"{field} {{ {nesting} }} "
+    else:
+        return f"{field}(value: {json.dumps(value)})"
+
+
+def nest_responce(path: list[str], value: Any) -> dict:
+    queue = copy.deepcopy(path)
+    field = queue.pop(0)
+
+    if queue:
+        nesting = nest_responce(queue, value)
+        return {field: nesting}
+    else:
+        return {field: value}
+
+
+class TestGraphQLServer:
+    @pytest.fixture(autouse=True)
+    def setup_tests(self, mocker: MockerFixture):
+        self.controller = AssertableController(mocker)
+        app = GraphQLBackend(self.controller)._server._app
+        self.client = TestClient(app)
+
+    def client_read(self, path: list[str], expected: Any):
+        query = f"query {{ {nest_query(path)} }}"
+        with self.controller.assertPerformed(pascal_2_snake(path), "READ"):
+            response = self.client.post("/graphql", json={"query": query})
+        assert response.status_code == 200
+        assert response.json()["data"] == nest_responce(path, expected)
+
+    def client_write(self, path: list[str], value: Any):
+        mutation = f"mutation {{ {nest_mutation(path, value)} }}"
+        with self.controller.assertPerformed(pascal_2_snake(path), "WRITE"):
+            response = self.client.post("/graphql", json={"query": mutation})
+        assert response.status_code == 200
+        assert response.json()["data"] == nest_responce(path, value)
+
+    def client_exec(self, path: list[str]):
+        mutation = f"mutation {{ {nest_query(path)} }}"
+        with self.controller.assertPerformed(pascal_2_snake(path), "EXECUTE"):
+            response = self.client.post("/graphql", json={"query": mutation})
+        assert response.status_code == 200
+        assert response.json()["data"] == {path[-1]: True}
+
+    def test_read_int(self):
+        self.client_read(["ReadInt"], AttrR(Int())._value)
+
+    def test_read_write_int(self):
+        self.client_read(["ReadWriteInt"], AttrR(Int())._value)
+        self.client_write(["ReadWriteInt"], AttrR(Int())._value)
+
+    def test_read_write_float(self):
+        self.client_read(["ReadWriteFloat"], AttrR(Float())._value)
+        self.client_write(["ReadWriteFloat"], AttrR(Float())._value)
+
+    def test_read_bool(self):
+        self.client_read(["ReadBool"], AttrR(Bool())._value)
+
+    def test_write_bool(self):
+        self.client_write(["WriteBool"], AttrR(Bool())._value)
+
+    # # We need to discuss enums
+    # def test_string_enum(self):
+
+    def test_big_enum(self):
+        self.client_read(
+            ["BigEnum"], AttrR(Int(), allowed_values=list(range(1, 18)))._value
+        )
+
+    def test_go(self):
+        self.client_exec(["Go"])
+
+    def test_read_child1(self):
+        self.client_read(["SubController01", "ReadInt"], AttrR(Int())._value)
+
+    def test_read_child2(self):
+        self.client_read(["SubController02", "ReadInt"], AttrR(Int())._value)