Files
clan-core/pkgs/classgen/main.py
2025-05-20 16:10:32 +02:00

438 lines
14 KiB
Python

# ruff: noqa: RUF001
import argparse
import json
import logging
import sys
from collections.abc import Callable
from functools import partial
from pathlib import Path
from typing import Any
logger = logging.getLogger(__name__)
class Error(Exception):
pass
# Function to map JSON schemas and types to Python types
def map_json_type(
json_type: Any, nested_types: set[str] | None = None, parent: Any = None
) -> set[str]:
if nested_types is None:
nested_types = {"Any"}
if isinstance(json_type, list):
res = set()
for t in json_type:
res |= map_json_type(t)
return res
if isinstance(json_type, dict):
items = json_type.get("items")
if items:
nested_types = map_json_type(items)
return map_json_type(json_type.get("type"), nested_types)
if json_type == "string":
return {"str"}
if json_type == "integer":
return {"int"}
if json_type == "number":
return {"float"}
if json_type == "boolean":
return {"bool"}
# In Python, "number" is analogous to the float type.
# https://json-schema.org/understanding-json-schema/reference/numeric#number
if json_type == "number":
return {"float"}
if json_type == "array":
assert nested_types, f"Array type not found for {parent}"
return {f"""list[{" | ".join(nested_types)}]"""}
if json_type == "object":
assert nested_types, f"dict type not found for {parent}"
return {f"""dict[str, {" | ".join(nested_types)}]"""}
if json_type == "null":
return {"None"}
msg = f"Python type not found for {json_type}"
raise Error(msg)
known_classes = set()
root_class = "Inventory"
# TODO: make this configurable
# For now this only includes static top-level attributes of the inventory.
attrs = ["machines", "meta", "services"]
static: dict[str, str] = {"Service": "dict[str, Any]"}
def field_def_from_default_type(
field_name: str,
field_types: set[str],
class_name: str,
finalize_field: Callable[..., tuple[str, str]],
) -> tuple[str, str] | None:
if "dict" in str(field_types):
return finalize_field(
field_types=field_types,
default_factory="dict",
)
if "list" in str(field_types):
return finalize_field(
field_types=field_types,
default_factory="list",
)
if "None" in str(field_types):
return finalize_field(
field_types=field_types,
default="None",
)
if class_name.endswith("Config"):
# SingleDiskConfig
# PackagesConfig
# ...
# Config classes MUST always be optional
msg = f"""
#################################################
Clan module '{class_name}' specifies a top-level option '{field_name}' without a default value.
To fix this:
- Add a default value to the option
lib.mkOption {{
type = lib.types.nullOr lib.types.str;
default = null; # <- Add a default value here
}};
# Other options
- make the field nullable
lib.mkOption {{
# ╔══════════════╗ <- Nullable type
type = lib.types.nullOr lib.types.str;
}};
- Use lib.types.attrsOf if suitable
- Use lib.types.listOf if suitable
Or report this problem to the clan team. So the class generator can be improved.
#################################################
"""
raise Error(msg)
return None
def field_def_from_default_value(
default_value: Any,
field_name: str,
field_types: set[str],
nested_class_name: str,
finalize_field: Callable[..., tuple[str, str]],
) -> tuple[str, str] | None:
# default_value = prop_info.get("default")
if "Unknown" in field_types:
# Unknown type, doesnt matter what the default value is
# type Unknown | a -> Unknown
return finalize_field(
field_types=field_types,
)
if default_value is None:
return finalize_field(
field_types=field_types | {"None"},
default="None",
)
if isinstance(default_value, list):
return finalize_field(
field_types=field_types,
default_factory="list",
)
if isinstance(default_value, dict):
serialised_types = " | ".join(field_types)
if serialised_types == nested_class_name:
return finalize_field(
field_types=field_types,
default_factory=nested_class_name,
)
if "dict[str," in serialised_types:
return finalize_field(
field_types=field_types,
default_factory="dict",
)
return finalize_field(
field_types=field_types,
default_factory="dict",
type_appendix=" | dict[str,Any]",
)
# Primitive types
if isinstance(default_value, str):
return finalize_field(
field_types=field_types,
default=f"'{default_value}'",
)
if isinstance(default_value, bool | int | float):
# Bool must be checked before int
return finalize_field(
field_types=field_types,
default=f"{default_value}",
)
# Other default values unhandled yet.
msg = f"Unhandled default value for field '{field_name}' - default value: {default_value}. ( In {nested_class_name} )"
raise Error(msg)
def get_field_def(
field_name: str,
field_meta: str | None,
field_types: set[str],
default: str | None = None,
default_factory: str | None = None,
type_appendix: str = "",
) -> tuple[str, str]:
if "None" in field_types or default or default_factory:
if "None" in field_types:
field_types.remove("None")
serialised_types = " | ".join(field_types) + type_appendix
serialised_types = f"{serialised_types}"
else:
serialised_types = " | ".join(field_types) + type_appendix
return (field_name, serialised_types)
# Recursive function to generate dataclasses from JSON schema
def generate_dataclass(
schema: dict[str, Any],
attr_path: list[str],
class_name: str = root_class,
) -> str:
properties = schema.get("properties", {})
required_fields: list[tuple[str, str]] = []
fields_with_default: list[tuple[str, str]] = []
nested_classes: list[str] = []
# if We are at the top level, and the attribute name is in shallow
# return f"{class_name} = dict[str, Any]"
if class_name in static:
return f"{class_name} = {static[class_name]}"
for prop, prop_info in properties.items():
# If we are at the top level, and the attribute name is not explicitly included we only do shallow
field_name = prop.replace("-", "_")
if len(attr_path) == 0 and prop not in attrs:
field_def = field_name, "dict[str, Any]"
fields_with_default.append(field_def)
# breakpoint()
continue
prop_type = prop_info.get("type", None)
union_variants = prop_info.get("oneOf", [])
enum_variants = prop_info.get("enum", [])
# Collect all types
field_types = set()
title = prop_info.get("title", prop.removesuffix("s"))
title_sanitized = "".join([p.capitalize() for p in title.split("-")])
nested_class_name = f"""{class_name if class_name != root_class and not prop_info.get("title") else ""}{title_sanitized}"""
if not prop_type and not union_variants and not enum_variants:
msg = f"Type not found for property {prop} {prop_info}.\nConverting to unknown type.\n"
logger.warning(msg)
prop_type = "Unknown"
if union_variants:
field_types = map_json_type(union_variants)
elif prop_type == "array":
item_schema = prop_info.get("items")
if isinstance(item_schema, dict):
field_types = map_json_type(
prop_type, map_json_type(item_schema), field_name
)
elif enum := prop_info.get("enum"):
literals = ", ".join([f'"{string}"' for string in enum])
field_types = {f"""Literal[{literals}]"""}
elif prop_type == "object":
inner_type = prop_info.get("additionalProperties")
if inner_type and inner_type.get("type") == "object":
# Inner type is a class
field_types = map_json_type(prop_type, {nested_class_name}, field_name)
if nested_class_name not in known_classes:
nested_classes.append(
generate_dataclass(
inner_type, [*attr_path, prop], nested_class_name
)
)
known_classes.add(nested_class_name)
elif inner_type and inner_type.get("type") != "object":
# Trivial type:
# dict[str, inner_type]
field_types = {
f"""dict[str, {" | ".join(map_json_type(inner_type))}]"""
}
elif not inner_type:
# The type is a class
field_types = {nested_class_name}
if nested_class_name not in known_classes:
nested_classes.append(
generate_dataclass(
prop_info, [*attr_path, prop], nested_class_name
)
)
known_classes.add(nested_class_name)
elif prop_type == "Unknown":
field_types = {"Unknown"}
else:
field_types = map_json_type(
prop_type,
nested_types=set(),
parent=field_name,
)
assert field_types, f"Python type not found for {prop} {prop_info}"
field_meta = None
if field_name != prop:
field_meta = f"""{{"alias": "{prop}"}}"""
finalize_field = partial(get_field_def, field_name, field_meta)
if "default" in prop_info or field_name not in prop_info.get("required", []):
if prop_info.get("type") == "object":
prop_info.update({"default": {}})
if "default" in prop_info:
default_value = prop_info.get("default")
field_def = field_def_from_default_value(
default_value=default_value,
field_name=field_name,
field_types=field_types,
nested_class_name=nested_class_name,
finalize_field=finalize_field,
)
if field_def:
fields_with_default.append(field_def)
if not field_def:
# Finalize without the default value
field_def = finalize_field(
field_types=field_types,
)
required_fields.append(field_def)
if "default" not in prop_info:
# Field is not required and but also specifies no default value
# Trying to infer default value from type
field_def = field_def_from_default_type(
field_name=field_name,
field_types=field_types,
class_name=class_name,
finalize_field=finalize_field,
)
if field_def:
fields_with_default.append(field_def)
if not field_def:
field_def = finalize_field(
field_types=field_types,
)
required_fields.append(field_def)
else:
field_def = finalize_field(
field_types=field_types,
)
required_fields.append(field_def)
# Join field name with type to form a complete field declaration
# e.g. "name: str"
all_field_declarations = [f"{n}: {t}" for n, t in (required_fields)] + [
f"{n}: NotRequired[{class_name}{n.capitalize()}Type]"
for n, t in (fields_with_default)
]
hoisted_types: str = "\n".join(
[
f"{class_name}{n.capitalize()}Type = {x}"
for n, x in (required_fields + fields_with_default)
]
)
fields_str = "\n ".join(all_field_declarations)
nested_classes_str = "\n\n".join(nested_classes)
class_def = f"\n\n{hoisted_types}\n"
class_def += f"\nclass {class_name}(TypedDict):\n"
if not required_fields + fields_with_default:
class_def += " pass"
else:
class_def += f" {fields_str}"
return f"{nested_classes_str}\n\n{class_def}" if nested_classes_str else class_def
def run_gen(args: argparse.Namespace) -> None:
print(f"Converting {args.input} to {args.output}")
dataclass_code = ""
with args.input.open() as f:
schema = json.load(f)
dataclass_code = generate_dataclass(schema, [])
with args.output.open("w") as f:
f.write(
"""# DO NOT EDIT THIS FILE MANUALLY. IT IS GENERATED.
# This file was generated by running `pkgs/clan-cli/clan_cli/inventory/update.sh`
#
# ruff: noqa: N815
# ruff: noqa: N806
# ruff: noqa: F401
# fmt: off
from typing import Any, Literal, NotRequired, TypedDict\n
# Mimic "unknown".
# 'Any' is unsafe because it allows any operations
# This forces the user to use type-narrowing or casting in the code
class Unknown:
pass
"""
)
f.write(dataclass_code)
f.write("\n")
def main() -> None:
parser = argparse.ArgumentParser()
parser.add_argument("input", help="Input JSON schema file", type=Path)
parser.add_argument("output", help="Output Python file", type=Path)
parser.add_argument(
"--stop-at",
type=str,
help="Property name to stop generating classes for. Other classes below that property will be generated",
default=None,
)
parser.set_defaults(func=run_gen)
args = parser.parse_args()
try:
args.func(args)
except Error as e:
print(e)
sys.exit(1)
if __name__ == "__main__":
main()