WIP: class based api

hiku/classes/node.py

@@ -0,0 +1,160 @@
+import dataclasses as dc
+import typing
+from collections.abc import Hashable
+from functools import partial
+
+import hiku.types
+from hiku.classes.strings import to_snake_case
+from hiku.directives import SchemaDirective
+
+"""
+@node(...)
+class Human:
+    id: int = field(...)
+    droid: ref[Droid] = field_link(...)
+"""
+
+_T = typing.TypeVar("_T", bound=Hashable)
+
+
+class NodeProto(typing.Protocol[_T]):
+    __key__: _T
+
+
+_TNode = typing.TypeVar("_TNode", bound=NodeProto)
+
+
+@dc.dataclass
+class HikuNode:
+    name: str
+    fields: "list[_HikuField] | list[_HikuFieldLink] | list[_HikuField | _HikuFieldLink]"
+    description: str | None
+    directives: list[SchemaDirective] | None
+    implements: list[str] | None
+
+
+def node(
+    cls: type[_TNode] | None = None,
+    *,
+    name: str | None = None,
+    description: str | None = None,
+    directives: list[SchemaDirective] | None = None,
+    # TODO(s.kovbasa): handle interfaces from mro
+    implements: list[str] | None = None,
+) -> typing.Callable[[type[_TNode]], type[_TNode]] | type[_TNode]:
+    # TODO(s.kovbasa): add validation and stuff
+
+    def _wrap_cls(
+        cls: type[_TNode],
+        name: str | None,
+        description: str | None,
+        directives: list[SchemaDirective] | None,
+        implements: list[str] | None,
+    ) -> type[_TNode]:
+        setattr(
+            cls,
+            "__hiku_node__",
+            HikuNode(
+                name=name or cls.__name__,
+                fields=_get_fields(cls),
+                description=description,
+                directives=directives,
+                implements=implements,
+            ),
+        )
+        return cls
+
+    _do_wrap = partial(
+        _wrap_cls,
+        name=name,
+        description=description,
+        directives=directives,
+        implements=implements,
+    )
+
+    if cls is None:
+        return _do_wrap
+
+    return _do_wrap(cls)
+
+
+def _get_fields(
+    cls: type[_TNode],
+) -> "list[_HikuField] | list[_HikuFieldLink] | list[_HikuField | _HikuFieldLink]":
+    # TODO(s.kovbasa): handle name and type from annotations
+    # TODO(s.kovbasa): first process fields, then links; resolve link requires
+    return []
+
+
+@dc.dataclass
+class _HikuField:
+    func: typing.Callable
+    name: str | None
+    typ: type
+    options: object | None
+    description: str | None
+    deprecated: str | None
+    directives: typing.Sequence[SchemaDirective] | None
+
+
+def field(
+    func: typing.Callable | None = None,
+    *,
+    options: object | None = None,
+    name: str | None = None,
+    description: str | None = None,
+    deprecated: str | None = None,
+    directives: list | None = None,
+) -> typing.Any:
+    return _HikuField(
+        func=func or resolve_getattr,
+        name=name,
+        typ=None,  # type: ignore
+        options=options,
+        description=description,
+        deprecated=deprecated,
+        directives=directives,
+    )
+
+
+@dc.dataclass
+class _HikuFieldLink:
+    func: typing.Callable
+    name: str | None
+    typ: type
+    requires_func: typing.Callable[[], tuple] | None
+    options: object | None
+    description: str | None
+    deprecated: str | None
+    directives: typing.Sequence[SchemaDirective] | None
+
+
+def field_link(
+    func: typing.Callable | None = None,
+    *,
+    options: object | None = None,
+    requires: typing.Callable[[], tuple[typing.Any, ...]] | None,
+    name: str | None = None,
+    description: str | None = None,
+    deprecated: str | None = None,
+    directives: list | None = None,
+) -> typing.Any:
+    return _HikuFieldLink(
+        func=func or direct_link,
+        name=name,
+        typ=None,  # type: ignore
+        requires_func=requires,
+        options=options,
+        description=description,
+        deprecated=deprecated,
+        directives=directives,
+    )
+
+
+def resolve_getattr(fields, tuples) -> list[list]:
+    field_names = [to_snake_case(f.name) for f in fields]
+    return [[getattr(t, f_name) for f_name in field_names] for t in tuples]
+
+
+def direct_link(ids):
+    return ids

hiku/classes/strings.py

@@ -0,0 +1,10 @@
+import re
+
+UPPER_CAMEL_CASE_BOUNDS_RE = re.compile(r"(.)([A-Z][a-z]+)")
+LOWER_CAMEL_CASE_BOUNDS_RE = re.compile(r"([a-z0-9])([A-Z])")
+
+
+# http://stackoverflow.com/a/1176023/1072990
+def to_snake_case(name: str) -> str:
+    s1 = UPPER_CAMEL_CASE_BOUNDS_RE.sub(r"\1_\2", name)
+    return LOWER_CAMEL_CASE_BOUNDS_RE.sub(r"\1_\2", s1).lower()

hiku/classes/types.py

@@ -0,0 +1,202 @@
+import dataclasses as dc
+import importlib
+import inspect
+import types
+import typing
+from collections.abc import Hashable
+
+import hiku.graph
+import hiku.types
+
+_T = typing.TypeVar("_T", bound=Hashable)
+
+
+class NodeProto(typing.Protocol[_T]):
+    __key__: _T
+
+
+_TNode = typing.TypeVar("_TNode", bound=NodeProto)
+
+
+@dc.dataclass
+class raw_type:
+    """
+    Helps to update hiku types gradually. E.g.
+
+    id: typing.Annotated[str, hiku.raw_type(hiku.types.ID)]
+    some_field: typing.Annotated[None, hiku.raw_type(TypeRef["Product"])]
+    """
+
+    typ: hiku.types.GenericMeta
+
+    def apply(
+        self,
+        container: hiku.types.OptionalMeta | hiku.types.SequenceMeta,
+    ) -> typing.Self:
+        return dc.replace(self, typ=container[self.typ])
+
+    def __hash__(self) -> int:
+        return hash(self.typ)
+
+
+class lazy:
+    """
+    Allows for a lazy type resolve when circular imports are encountered.
+    Lazy resolvers are processed during Graph.__init__
+    """
+
+    module: str
+    package: str | None
+
+    def __init__(self, module: str):
+        self.module = module
+        self.package = None
+
+        if module.startswith("."):
+            current_frame = inspect.currentframe()
+            assert current_frame is not None
+            assert current_frame.f_back is not None
+
+            self.package = current_frame.f_back.f_globals["__package__"]
+
+
+class ref(typing.Generic[_TNode]):
+    """Represents a reference to another object type.
+
+    Is needed in case we someday plan to implement proper mypy checks - this way
+    we can make use of ref object as a thin wrapper around type's __key__
+    """
+
+
+_BUILTINS_TO_HIKU = {
+    int: hiku.types.Integer,
+    float: hiku.types.Float,
+    str: hiku.types.String,
+    bool: hiku.types.Boolean,
+}
+
+
+@dc.dataclass
+class _LazyTypeRef:
+    """strawberry-like impl for lazy type refs"""
+
+    classname: str
+    module: str
+    package: str | None
+    containers: (
+        list[hiku.types.OptionalMeta | hiku.types.SequenceMeta] | None
+    ) = None
+
+    @property
+    def typ(self) -> hiku.types.GenericMeta:
+        module = importlib.import_module(self.module, self.package)
+        cls = module.__dict__[self.classname]
+
+        type_ref = hiku.types.TypeRef[cls.__hiku_node__.name]
+
+        containers = reversed(self.containers or [])
+        for c in containers:
+            type_ref = c[type_ref]
+
+        return type_ref
+
+    def apply(
+        self,
+        container: hiku.types.OptionalMeta | hiku.types.SequenceMeta,
+    ) -> typing.Self:
+        return dc.replace(
+            self,
+            containers=[container] + (self.containers or []),
+        )
+
+
+class _HikuTypeWrapperProto(typing.Protocol):
+
+    @property
+    def typ(self) -> hiku.types.GenericMeta: ...
+
+    def apply(
+        self, container: hiku.types.OptionalMeta | hiku.types.SequenceMeta
+    ) -> typing.Self: ...
+
+
+def to_hiku_type(typ: type, lazy_: lazy | None = None) -> _HikuTypeWrapperProto:
+    if typ in _BUILTINS_TO_HIKU:
+        return raw_type(_BUILTINS_TO_HIKU[typ])
+
+    origin = typing.get_origin(typ)
+    args = typing.get_args(typ)
+
+    if origin is typing.Annotated:
+        metadata = typ.__metadata__
+
+        raw_types = []
+        lazy_refs = []
+        for val in metadata:
+            if isinstance(val, raw_type):
+                raw_types.append(val)
+            elif isinstance(val, lazy):
+                lazy_refs.append(val)
+
+        if lazy_refs and raw_types:
+            raise ValueError("lazy and raw_type are not composable")
+
+        if len(raw_types) > 1:
+            raise ValueError("more than 1 raw_type")
+
+        if len(raw_types) == 1:
+            return raw_types[0]
+
+        if len(lazy_refs) > 1:
+            raise ValueError("more than 1 lazy reference")
+
+        if len(lazy_refs) == 1:
+            lazy_typeref = to_hiku_type(typ.__origin__, lazy_refs[0])
+            if not isinstance(lazy_typeref, _LazyTypeRef):
+                raise ValueError("lazy can only be used with ref types")
+
+            return lazy_typeref
+
+        return to_hiku_type(args[0])
+
+    # new optionals
+    if origin in (typing.Union, types.UnionType):
+        if len(args) != 2 or types.NoneType not in args:
+            raise ValueError("unions are allowed only as optional types")
+
+        next_type = [a for a in args if a is not types.NoneType][0]
+        arg = to_hiku_type(next_type, lazy_)
+        return arg.apply(hiku.types.Optional)
+
+    # old optionals
+    if origin is typing.Optional:
+        arg = to_hiku_type(args[0], lazy_)
+        return arg.apply(hiku.types.Optional)
+
+    # lists
+    if origin in (list, typing.List):
+        if len(args) == 0:
+            raise ValueError("naked lists not allowed")
+
+        next_type = args[0]
+        arg = to_hiku_type(next_type, lazy_)
+        return arg.apply(hiku.types.Sequence)
+
+    if origin is ref:
+        ref_ = args[0]
+        if isinstance(ref_, typing.ForwardRef):
+            if lazy_ is None:
+                raise ValueError("need to use hiku.lazy for lazy imports")
+
+            return _LazyTypeRef(
+                classname=ref_.__forward_arg__,
+                module=lazy_.module,
+                package=lazy_.package,
+            )
+
+        if not hasattr(ref_, "__hiku_node__"):
+            raise ValueError("expected ref arg to be a @node")
+
+        return raw_type(hiku.types.TypeRef[ref_.__hiku_node__.name])
+
+    raise ValueError("invalid hiku type")