generate_dev_docs.py

# Script for generating some of documents in `dev-docs` from Misago's code
import ast
from dataclasses import dataclass
from importlib import import_module
from pathlib import Path
from textwrap import dedent, indent

HOOKS_MODULES = (
    "misago.categories.hooks",
    "misago.oauth2.hooks",
    "misago.parser.hooks",
    "misago.permissions.hooks",
    "misago.threads.hooks",
    "misago.users.hooks",
)
PLUGIN_MANIFEST = "misago.plugins.manifest.MisagoPlugin"
OUTLETS_ENUM = "misago.plugins.enums.PluginOutlet"

BASE_PATH = Path(__file__).parent
DOCS_PATH = BASE_PATH / "dev-docs"
PLUGINS_PATH = DOCS_PATH / "plugins"
PLUGINS_HOOKS_PATH = PLUGINS_PATH / "hooks"


def main():
    generate_plugin_manifest_reference()
    generate_hooks_reference()
    generate_outlets_reference()


def generate_plugin_manifest_reference():
    manifest_path, manifest_attr = PLUGIN_MANIFEST.rsplit(".", 1)
    manifest_type = getattr(import_module(manifest_path), manifest_attr)

    with open(PLUGINS_PATH / "plugin-manifest-reference.md", "w") as fp:
        fp.write("# Plugin manifest reference")
        fp.write("\n\n")
        fp.write(indent_docstring_headers(dedent(manifest_type.__doc__)).strip())


def generate_hooks_reference():
    hooks_data: dict[str, dict[str, ast.Module]] = {}
    for hooks_module in HOOKS_MODULES:
        init_path = module_path_to_init_path(hooks_module)
        hooks_data[hooks_module] = get_all_modules(init_path)

    generate_hooks_reference_index(hooks_data)

    for import_from, module_hooks in hooks_data.items():
        for hook_name, hook_module in module_hooks.items():
            generate_hook_reference(import_from, hook_name, hook_module)


def generate_hooks_reference_index(hooks_data: dict[str, dict[str, ast.Module]]):
    with open(PLUGINS_HOOKS_PATH / "reference.md", "w") as fp:
        fp.write("# Built-in hooks reference")
        fp.write("\n\n")
        fp.write(
            "This document contains a list of all standard plugin hooks existing in Misago."
        )
        fp.write("\n\n")
        fp.write("Hooks instances are importable from the following Python modules:")

        fp.write("\n")
        for module_name in sorted(hooks_data):
            fp.write(f"\n- [`{module_name}`](#{slugify_name(module_name)})")

        for module_name, module_hooks in hooks_data.items():
            fp.write("\n\n\n")
            fp.write(f"## `{module_name}`")
            fp.write("\n\n")
            fp.write(f"`{module_name}` defines the following hooks:")
            fp.write("\n")

            for module_hook in sorted(module_hooks):
                fp.write(f"\n- [`{module_hook}`](./{slugify_name(module_hook)}.md)")


def generate_hook_reference(import_from: str, hook_name: str, hook_module: ast.Module):
    hook_filename = f"{slugify_name(hook_name)}.md"

    module_classes = {}
    for item in hook_module.body:
        if isinstance(item, ast.ClassDef):
            module_classes[item.name] = item

        if (
            isinstance(item, ast.Expr)
            and item.value
            and isinstance(item.value, ast.Constant)
            and isinstance(item.value.value, str)
        ):
            if module_docstring is not None:
                raise ValueError(
                    f"'{hook_name}': module with hook defines multiple docstrings."
                )
            module_docstring = parse_hook_docstring(item.value.value)

    hook_type: str | None = None
    hook_ast: ast.ClassDef | None = None
    hook_action_ast: ast.ClassDef | None = None
    hook_filter_ast: ast.ClassDef | None = None
    for class_name, class_ast in module_classes.items():
        class_hook_type = is_class_base_hook(class_ast)
        if class_hook_type:
            hook_ast = class_ast
            hook_type = class_hook_type
        elif is_class_protocol(class_ast):
            if class_name.endswith("HookAction"):
                hook_action_ast = class_ast
            elif class_name.endswith("HookFilter"):
                hook_filter_ast = class_ast

    hook_docstring: HookDocstring | None = None
    hook_ast_docstring = get_class_docstring(hook_ast)
    if hook_ast_docstring:
        hook_docstring = parse_hook_docstring(hook_ast_docstring)

    with open(PLUGINS_HOOKS_PATH / hook_filename, "w") as fp:
        fp.write(f"# `{hook_name}`")
        fp.write("\n\n")

        if hook_docstring and hook_docstring.description:
            fp.write(hook_docstring.description)
        elif hook_type == "ACTION":
            fp.write(f"`{hook_name}` is an **action** hook.")
        elif hook_type == "FILTER":
            fp.write(f"`{hook_name}` is a **filter** hook.")

        fp.write("\n\n\n")
        fp.write("## Location")
        fp.write("\n\n")
        fp.write(f"This hook can be imported from `{import_from}`:")
        fp.write("\n\n")
        fp.write("```python")
        fp.write("\n")
        fp.write(f"from {import_from} import {hook_name}")
        fp.write("\n")
        fp.write("```")

        if hook_type == "ACTION":
            fp.write("\n\n\n")
            fp.write("## Action")

            if hook_action_ast:
                hook_cropped = hook_name
                if hook_cropped.endswith("_hook"):
                    hook_cropped = hook_cropped[:-5]

                hook_action_signature = get_callable_class_signature(hook_action_ast)
                if hook_action_signature:
                    hook_action_args, hook_action_returns = hook_action_signature
                else:
                    hook_action_args = ""
                    hook_action_returns = "Unknown"

                fp.write("\n\n")
                fp.write("```python")
                fp.write("\n")
                fp.write(
                    f"def custom_{hook_cropped}_filter({hook_action_args}){hook_action_returns}:"
                )
                fp.write("\n")
                fp.write("    ...")
                fp.write("\n")
                fp.write("```")

                hook_action_docstring = get_class_docstring(hook_action_ast)
                if hook_action_docstring:
                    fp.write("\n\n")
                    fp.write(indent_docstring_headers(hook_action_docstring, level=2))
            else:
                fp.write("_This section is empty._")

        if hook_type == "FILTER":
            fp.write("\n\n\n")
            fp.write("## Filter")

            if hook_filter_ast:
                hook_cropped = hook_name
                if hook_cropped.startswith("filter_"):
                    hook_cropped = hook_cropped[7:]
                if hook_cropped.endswith("_hook"):
                    hook_cropped = hook_cropped[:-5]

                hook_filter_signature = get_callable_class_signature(hook_filter_ast)
                if hook_filter_signature:
                    hook_filter_args, hook_filter_returns = hook_filter_signature
                else:
                    hook_filter_args = ""
                    hook_filter_returns = "Unknown"

                fp.write("\n\n")
                fp.write("```python")
                fp.write("\n")
                fp.write(
                    f"def custom_{hook_cropped}_filter({hook_filter_args}){hook_filter_returns}:"
                )
                fp.write("\n")
                fp.write("    ...")
                fp.write("\n")
                fp.write("```")

                hook_filter_docstring = get_class_docstring(hook_filter_ast)
                if hook_filter_docstring:
                    fp.write("\n\n")
                    fp.write(indent_docstring_headers(hook_filter_docstring, level=2))
            else:
                fp.write("_This section is empty._")

            fp.write("\n\n\n")
            fp.write("## Action")

            if hook_action_ast:
                hook_cropped = hook_name
                if hook_cropped.endswith("_hook"):
                    hook_cropped = hook_cropped[:-5]

                hook_action_signature = get_callable_class_signature(hook_action_ast)
                if hook_action_signature:
                    hook_action_args, hook_action_returns = hook_action_signature
                else:
                    hook_action_args = ""
                    hook_action_returns = "Unknown"

                fp.write("\n\n")
                fp.write("```python")
                fp.write("\n")
                fp.write(
                    f"def {hook_cropped}_action({hook_action_args}){hook_action_returns}:"
                )
                fp.write("\n")
                fp.write("    ...")
                fp.write("\n")
                fp.write("```")

                hook_action_docstring = get_class_docstring(hook_action_ast)
                if hook_action_docstring:
                    fp.write("\n\n")
                    fp.write(indent_docstring_headers(hook_action_docstring, level=2))

            else:
                fp.write("_This section is empty._")

        if hook_docstring and hook_docstring.examples:
            for example_title, example_text in hook_docstring.examples.items():
                fp.write("\n\n\n")
                fp.write(f"## {example_title}")
                fp.write("\n\n")
                fp.write(example_text)


def is_class_base_hook(class_def: ast.ClassDef) -> str | None:
    if not class_def.bases:
        return None

    for base in class_def.bases:
        if (
            isinstance(base, ast.Subscript)
            and isinstance(base.value, ast.Name)
            and isinstance(base.value.id, str)
        ):
            if base.value.id == "ActionHook":
                return "ACTION"
            if base.value.id == "FilterHook":
                return "FILTER"

    return None


def is_class_protocol(class_def: ast.ClassDef) -> bool:
    if not class_def.bases or len(class_def.bases) != 1:
        return False

    return (
        isinstance(class_def.bases[0], ast.Name)
        and isinstance(class_def.bases[0].id, str)
        and class_def.bases[0].id == "Protocol"
    )


@dataclass
class HookDocstring:
    description: str | None
    examples: dict[str, str] | None


def parse_hook_docstring(docstring: str) -> HookDocstring:
    description: str | None = None
    examples: dict[str, str] = {}

    for block in split_docstring(docstring):
        if block[:5].strip().startswith("# ") and block.lstrip("# ").lower().startswith(
            "example"
        ):
            example_name = block[: block.index("\n")].strip("# ")
            example_block = block[block.index("\n") :].strip()
            examples[example_name] = example_block
        elif not block[:5].strip().startswith("# "):
            description = block

    return HookDocstring(description=description, examples=examples or None)


def generate_outlets_reference():
    outlets_path, outlets_attr = OUTLETS_ENUM.rsplit(".", 1)
    outlets_enum = getattr(import_module(outlets_path), outlets_attr)
    outlets_dict = {outlet.name: outlet.value for outlet in outlets_enum}

    with open(PLUGINS_PATH / "template-outlets-reference.md", "w") as fp:
        fp.write("# Built-in template outlets reference")
        fp.write("\n\n")
        fp.write(
            "This document contains a list of all built-in template outlets in Misago."
        )
        for outlet_name in sorted(outlets_dict):
            fp.write("\n\n\n")
            fp.write(f"## `{outlet_name}`")
            fp.write("\n\n")
            fp.write(outlets_dict[outlet_name])


def get_callable_class_signature(class_def: ast.ClassDef) -> tuple[str, str | None]:
    for item in class_def.body:
        if not isinstance(item, ast.FunctionDef):
            continue
        if item.name != "__call__":
            continue

        item_args = ast.unparse(item.args)
        if item_args.startswith("self, "):
            item_args = item_args[6:]

        if len(item_args) > 70:
            item_args = item_args.replace(", ", ",\n")
            # Hack to fix invalid linebreaks in `[T1, T2]`...
            offset = 0
            for _ in range(item_args.count("[")):
                position = item_args.find("[", offset)
                end_position = item_args.find("]", position)
                if ",\n" in item_args[position:end_position]:
                    item_args_copy = item_args
                    item_args = item_args_copy[:position]
                    item_args += item_args_copy[position:end_position].replace(
                        ",\n", ", "
                    )
                    item_args += item_args_copy[end_position:]
                offset = position + 1
            item_args = "\n" + indent(item_args, "    ") + ",\n"

        elif len(item_args) > 50:
            item_args = f"\n    {item_args}\n"

        if item.returns:
            item_returns = " -> " + ast.unparse(item.returns)
        else:
            item_returns = ""

        return item_args, item_returns

    return None


def get_class_docstring(class_def: ast.ClassDef) -> str | None:
    for item in class_def.body:
        if (
            isinstance(item, ast.Expr)
            and isinstance(item.value, ast.Constant)
            and isinstance(item.value.value, str)
        ):
            return dedent(item.value.value).strip()

    return None


def split_docstring(docstring: str) -> list[str]:
    blocks: list[str] = []
    block: str = ""
    in_code = False
    for line in docstring.strip().splitlines():
        if in_code:
            if line == "```":
                in_code = False
            block += line
        else:
            if line.startswith("```"):
                in_code = True
                block += line

            elif line.startswith("# "):
                if block:
                    blocks.append(wrap_docstring_lines(block.strip()))
                block = line

            else:
                block += line

        block += "\n"

    if block:
        blocks.append(wrap_docstring_lines(block))

    return blocks


def indent_docstring_headers(docstring: str, level: int = 1) -> str:
    in_code = False
    prefix = "#" * level

    new_docstring = ""
    for line in docstring.splitlines():
        if in_code:
            if line == "```":
                in_code = False
            new_docstring += line
        else:
            if line.startswith("```"):
                in_code = True
            if not in_code and line.startswith("#"):
                new_docstring += prefix
            new_docstring += line

        new_docstring += "\n"

    return wrap_docstring_lines(new_docstring.strip())


def wrap_docstring_lines(docstring: str) -> str:
    in_code = False
    new_docstring = ""
    previous_line = ""

    for line in docstring.splitlines():
        if in_code:
            new_docstring += line
            new_docstring += "\n"

            if line == "```":
                in_code = False
        else:
            if line.startswith("```"):
                in_code = True
                new_docstring += line
                new_docstring += "\n"
            elif line.startswith("#"):
                if new_docstring and not previous_line.startswith("#"):
                    new_docstring += "\n"
                new_docstring += line
                new_docstring += "\n\n"
            elif line:
                if new_docstring and not new_docstring.endswith("\n"):
                    new_docstring += " "
                new_docstring += line
            elif not previous_line.startswith("#"):
                while not new_docstring.endswith("\n\n"):
                    new_docstring += "\n"

            if line:
                previous_line = line

    return new_docstring.strip()


def get_all_modules(file_path: str) -> dict[str, ast.Module]:
    all_names: list[str] = []
    all_imports: dict[str, ast.Module] = {}

    file_ast: ast.Module = parse_python_file(file_path)
    for item in file_ast.body:
        if not isinstance(item, ast.Assign):
            continue  # Skip non-value assignment

        if not item.targets or not item.value:
            continue  # Skip value assignment without targets

        if item.targets[0].id != "__all__":
            continue  # Skip variables that aren't __all__

        if not isinstance(item.value, (ast.List, ast.Tuple)):
            continue  # Skip non-list or tuple

        for item_value in item.value.elts:
            if not isinstance(item_value, ast.Constant):
                raise ValueError(f"'{file_path}': '__all__' items must be constants.")
            if not isinstance(item_value.value, str):
                raise ValueError(f"'{file_path}': '__all__' items must be strings.")

            all_names.append(item_value.value)

    for item in file_ast.body:
        if not isinstance(item, ast.ImportFrom):
            continue  # Skip non-value assignment

        if len(item.names) != 1:
            continue

        import_name = item.names[0].name
        if import_name not in all_names:
            continue

        import_path = Path(file_path).parent / f"{item.module}.py"
        if not import_path.is_file():
            raise ValueError(f"'{file_path}': '{item.module}' could not be imported.")

        all_imports[import_name] = parse_python_file(import_path)

    for name in all_names:
        if name not in all_imports:
            raise ValueError(f"'{file_path}': import for '{name}' could not be found.")

    return {name: all_imports[name] for name in sorted(all_names)}


def parse_python_file(file_path: Path) -> ast.Module:
    with open(file_path, "r") as fp:
        return ast.parse(fp.read())


def module_path_to_init_path(module_path: str) -> Path:
    base_path = Path(BASE_PATH, *module_path.split("."), "__init__.py")
    if not base_path.is_file():
        raise ValueError(f"'{base_path}' doesn't exist or is not a file.")
    return base_path


def slugify_name(py_name: str) -> str:
    return py_name.replace(".", "-").replace("_", "-")


if __name__ == "__main__":
    main()