Checkpoint

Author: marcelldls

pyproject.toml

@@ -43,6 +43,7 @@ dev = [
     "types-mock",
     "aioca",
     "p4p",
+    "strawberry-graphql[fastapi]",
 ]
 
 [project.scripts]
@@ -61,7 +62,7 @@ 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/backend.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/graphQL.py

@@ -0,0 +1,175 @@
+from collections.abc import Awaitable, Callable, Coroutine
+from dataclasses import dataclass
+from types import MethodType
+from typing import Any
+
+import strawberry
+import uvicorn
+from fastapi import FastAPI
+from pydantic import create_model
+from strawberry.asgi import GraphQL
+from strawberry.tools import create_type
+
+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"
+
+
+@strawberry.type
+class User:
+    name: str
+    age: int
+
+
+@strawberry.type
+class Query:
+    @strawberry.field
+    def user(self) -> User:
+        return User(name="Patrick", age=100)
+
+
+schema = strawberry.Schema(query=Query)
+
+
+class GraphQLServer:
+    def __init__(self, mapping: Mapping):
+        self._mapping = mapping
+        self._app = self._create_app()
+
+    def _create_app(self):
+        Query = self._create_query(self._mapping)
+        Mutation = self._create_mutation()
+        # https://docs.github.com/en/graphql/guides/forming-calls-with-graphql
+        schema = strawberry.Schema(query=Query, mutation=Mutation)
+        graphql_app = GraphQL(schema)
+
+        app = FastAPI()
+        app.add_route("/graphql", graphql_app)
+        app.add_websocket_route("/graphql", graphql_app)
+        # _add_dev_attributes(app, self._mapping)
+        # _add_dev_commands(app, self._mapping)
+
+        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 _put_request_body(attribute: AttrW[T]):
+    return create_model(
+        f"Put{str(attribute.datatype.dtype)}Value",
+        **{"value": (attribute.datatype.dtype, ...)},  # type: ignore
+    )
+
+
+def _wrap_attr_put(
+    attribute: AttrW[T],
+) -> Callable[[T], Coroutine[Any, Any, None]]:
+    async def attr_set(request):
+        await attribute.process_without_display_update(request.value)
+
+    # Fast api uses type annotations for validation, schema, conversions
+    attr_set.__annotations__["request"] = _put_request_body(attribute)
+
+    return attr_set
+
+
+def _get_response_body(attribute: AttrR[T]):
+    return create_model(
+        f"Get{str(attribute.datatype.dtype)}Value",
+        **{"value": (attribute.datatype.dtype, ...)},  # type: ignore
+    )
+
+
+def _wrap_attr_get(
+    attribute: AttrR[T],
+) -> Callable[[], Coroutine[Any, Any, Any]]:
+    async def attr_get() -> Any:  # Must be any as response_model is set
+        value = attribute.get()  # type: ignore
+        return {"value": value}
+
+    return attr_get
+
+
+def _add_dev_attributes(app: FastAPI, mapping: Mapping) -> None:
+    for single_mapping in mapping.get_controller_mappings():
+        path = single_mapping.controller.path
+
+        for attr_name, attribute in single_mapping.attributes.items():
+            attr_name = attr_name.title().replace("_", "")
+            d_attr_name = f"{'/'.join(path)}/{attr_name}" if path else attr_name
+
+            match attribute:
+                # https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods
+                case AttrRW():
+                    strawberry.type
+                    app.add_api_route(
+                        f"/{d_attr_name}",
+                        _wrap_attr_get(attribute),
+                        methods=["GET"],  # Idemponent and safe data retrieval,
+                        status_code=200,  # https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/GET
+                        response_model=_get_response_body(attribute),
+                    )
+                    app.add_api_route(
+                        f"/{d_attr_name}",
+                        _wrap_attr_put(attribute),
+                        methods=["PUT"],  # Idempotent state change
+                        status_code=204,  # https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/PUT
+                    )
+                case AttrR():
+                    app.add_api_route(
+                        f"/{d_attr_name}",
+                        _wrap_attr_get(attribute),
+                        methods=["GET"],
+                        status_code=200,
+                        response_model=_get_response_body(attribute),
+                    )
+                case AttrW():
+                    app.add_api_route(
+                        f"/{d_attr_name}",
+                        _wrap_attr_put(attribute),
+                        methods=["PUT"],
+                        status_code=204,
+                    )
+
+
+def _wrap_command(
+    method: Callable, controller: BaseController
+) -> Callable[..., Awaitable[None]]:
+    async def command() -> None:
+        await MethodType(method, controller)()
+
+    return command
+
+
+def _add_dev_commands(app: FastAPI, mapping: Mapping) -> None:
+    for single_mapping in mapping.get_controller_mappings():
+        path = single_mapping.controller.path
+
+        for name, method in single_mapping.command_methods.items():
+            cmd_name = name.title().replace("_", "")
+            d_cmd_name = f"{'/'.join(path)}/{cmd_name}" if path else cmd_name
+            app.add_api_route(
+                f"/{d_cmd_name}",
+                _wrap_command(
+                    method.fn,
+                    single_mapping.controller,
+                ),
+                methods=["PUT"],
+                status_code=204,
+            )