import ast
import importlib
import inspect
import itertools
import logging
import os
import re
import sys
import warnings
from argparse import ArgumentParser
from typing import Any, Callable, Dict, List, Optional, Set

logger = logging.getLogger(__name__)

_visited_objects = []

# A list of function docstring pre-processing hooks
function_docstring_preprocessing_hooks: List[Callable[[str], str]] = []


def _find_str_end(s, start):
    for i in range(start + 1, len(s)):
        c = s[i]
        if c == "\\":  # skip escaped chars
            continue
        if c == s[start]:
            return i
    return -1


def _is_balanced(s):
    closing = {"(": ")", "{": "}", "[": "]"}

    stack = []
    i = 0
    while i < len(s):
        c = s[i]
        if c in "\"'":
            # TODO: handle triple-quoted strings too
            i = _find_str_end(s, i)
            if i < 0:
                return False
        if c in closing:
            stack.append(closing[c])
        elif stack and stack[-1] == c:
            stack.pop()
        i += 1

    return len(stack) == 0


class DirectoryWalkerGuard(object):
    def __init__(self, dirname):
        self.dirname = dirname
        self.origin = os.getcwd()

    def __enter__(self):
        if not os.path.exists(self.dirname):
            os.makedirs(self.dirname)

        assert os.path.isdir(self.dirname)
        os.chdir(self.dirname)

    def __exit__(self, exc_type, exc_val, exc_tb):
        os.chdir(self.origin)


_default_pybind11_repr_re = re.compile(
    r"(<(?P<class>\w+(\.\w+)*) object at 0x[0-9a-fA-F]+>)|"
    r"(<(?P<enum>\w+(.\w+)*): -?\d+>)"
)


def replace_default_pybind11_repr(line):
    default_reprs = []

    def replacement(m):
        if m.group("class"):
            default_reprs.append(m.group(0))
            return "..."
        return m.group("enum")

    return default_reprs, _default_pybind11_repr_re.sub(replacement, line)


class FunctionSignature(object):
    # When True don't raise an error when invalid signatures/defaultargs are
    # encountered (yes, global variables, blame me)
    ignore_invalid_signature = False
    ignore_invalid_defaultarg = False

    signature_downgrade = True

    # Number of invalid default values found so far
    n_invalid_default_values = 0

    # Number of invalid signatures found so far
    n_invalid_signatures = 0

    @classmethod
    def n_fatal_errors(cls):
        return (
            0 if cls.ignore_invalid_defaultarg else cls.n_invalid_default_values
        ) + (0 if cls.ignore_invalid_signature else cls.n_invalid_signatures)

    def __init__(self, name, args="*args, **kwargs", rtype="None", validate=True):
        self.name = name
        self.args = args
        self.rtype = rtype

        if validate:
            invalid_defaults, self.args = replace_default_pybind11_repr(self.args)
            if invalid_defaults:
                FunctionSignature.n_invalid_default_values += 1
                lvl = (
                    logging.WARNING
                    if FunctionSignature.ignore_invalid_defaultarg
                    else logging.ERROR
                )
                logger.log(
                    lvl, "Default argument value(s) replaced with ellipses (...):"
                )
                for invalid_default in invalid_defaults:
                    logger.log(lvl, "    {}".format(invalid_default))

            function_def_str = "def {sig.name}({sig.args}) -> {sig.rtype}: ...".format(
                sig=self
            )
            try:
                ast.parse(function_def_str)
            except SyntaxError as e:
                FunctionSignature.n_invalid_signatures += 1
                if FunctionSignature.signature_downgrade:
                    self.name = name
                    self.args = "*args, **kwargs"
                    self.rtype = "typing.Any"
                    lvl = (
                        logging.WARNING
                        if FunctionSignature.ignore_invalid_signature
                        else logging.ERROR
                    )
                    logger.log(
                        lvl,
                        "Generated stubs signature is degraded to `(*args, **kwargs) -> typing.Any` for",
                    )
                else:
                    lvl = logging.WARNING
                    logger.warning("Ignoring invalid signature:")
                logger.log(lvl, function_def_str)
                logger.log(lvl, " " * (e.offset - 1) + "^-- Invalid syntax")

    def __eq__(self, other):
        return isinstance(other, FunctionSignature) and (
            self.name,
            self.args,
            self.rtype,
        ) == (other.name, other.args, other.rtype)

    def __hash__(self):
        return hash((self.name, self.args, self.rtype))

    def split_arguments(self):
        if len(self.args.strip()) == 0:
            return []

        prev_stop = 0
        brackets = 0
        splitted_args = []

        for i, c in enumerate(self.args):
            if c == "[":
                brackets += 1
            elif c == "]":
                brackets -= 1
                assert brackets >= 0
            elif c == "," and brackets == 0:
                splitted_args.append(self.args[prev_stop:i])
                prev_stop = i + 1

        splitted_args.append(self.args[prev_stop:])
        assert brackets == 0
        return splitted_args

    @staticmethod
    def argument_type(arg):
        return arg.split(":")[-1].strip()

    def get_all_involved_types(self):
        types = []
        for t in [self.rtype] + self.split_arguments():
            types.extend(
                [
                    m[0]
                    for m in re.findall(
                        r"([a-zA-Z_][a-zA-Z0-9_]*(\.[a-zA-Z_][a-zA-Z0-9_]*)*)",
                        self.argument_type(t),
                    )
                ]
            )
        return types


class PropertySignature(object):
    NONE = 0
    READ_ONLY = 1
    WRITE_ONLY = 2
    READ_WRITE = READ_ONLY | WRITE_ONLY

    def __init__(self, rtype, setter_args, access_type):
        self.rtype = rtype
        self.setter_args = setter_args
        self.access_type = access_type

    @property
    def setter_arg_type(self):
        return FunctionSignature.argument_type(
            FunctionSignature("name", self.setter_args).split_arguments()[1]
        )


# If true numpy.ndarray[int32[3,3]] will be reduced to numpy.ndarray
BARE_NUPMY_NDARRAY = False


def replace_numpy_array(match_obj):
    if BARE_NUPMY_NDARRAY:
        return "numpy.ndarray"
    numpy_type = match_obj.group("type")
    # pybind always append size of data type
    if numpy_type in [
        "int8",
        "int16",
        "int32",
        "int64",
        "float16",
        "float32",
        "float64",
        "complex32",
        "complex64",
        "longcomplex",
    ]:
        numpy_type = "numpy." + numpy_type

    shape = match_obj.group("shape")
    if shape:
        shape = ", _Shape[{}]".format(shape)
    else:
        shape = ""
    result = r"numpy.ndarray[{type}{shape}]".format(type=numpy_type, shape=shape)
    return result


def replace_typing_types(match):
    # pybind used to have iterator/iterable in place of Iterator/Iterable
    name = match.group("type")
    capitalized = name[0].capitalize() + name[1:]
    return "typing." + capitalized


class StubsGenerator(object):
    INDENT = " " * 4

    GLOBAL_CLASSNAME_REPLACEMENTS = {
        re.compile(
            r"numpy.ndarray\[(?P<type>[^\[\]]+)(\[(?P<shape>[^\[\]]+)\])?(?P<extra>[^][]*)\]"
        ): replace_numpy_array,
        re.compile(
            r"(?<!\w)(?P<type>Callable|Dict|[Ii]terator|[Ii]terable|List"
            r"|Optional|Set|Tuple|Union|ItemsView|KeysView|ValuesView)(?!\w)"
        ): replace_typing_types,
    }

    def parse(self):
        raise NotImplementedError

    def to_lines(self):  # type: () -> List[str]
        raise NotImplementedError

    @staticmethod
    def _indent(line):  # type: (str) -> str
        return StubsGenerator.INDENT + line

    @staticmethod
    def indent(lines):  # type: (str) -> str
        lines = lines.split("\n")
        lines = [StubsGenerator._indent(l) if l else l for l in lines]
        return "\n".join(lines)

    @staticmethod
    def is_valid_module(module_name):  # type: (str) -> bool
        import importlib.util

        try:
            return importlib.import_module(module_name) is not None
        except ModuleNotFoundError:
            return False

    @staticmethod
    def fully_qualified_name(klass):
        module_name = klass.__module__ if hasattr(klass, "__module__") else None
        class_name = getattr(klass, "__qualname__", klass.__name__)

        if module_name == "builtins":
            return class_name
        else:
            return "{module}.{klass}".format(module=module_name, klass=class_name)

    @staticmethod
    def apply_classname_replacements(s):  # type: (str) -> Any
        for k, v in StubsGenerator.GLOBAL_CLASSNAME_REPLACEMENTS.items():
            s = k.sub(v, s)
        return s

    @staticmethod
    def function_signatures_from_docstring(
        name, func, module_name
    ):  # type: (str, Any, str) -> List[FunctionSignature]
        try:
            signature_regex = (
                r"(\s*(?P<overload_number>\d+).)"
                r"?\s*{name}\s*\((?P<args>{balanced_parentheses})\)"
                r"\s*->\s*"
                r"(?P<rtype>[^\(\)]+)\s*".format(name=name, balanced_parentheses=".*")
            )
            docstring = func.__doc__

            for hook in function_docstring_preprocessing_hooks:
                docstring = hook(docstring)

            signatures = []
            for line in docstring.split("\n"):
                m = re.match(signature_regex, line)
                if m:
                    args = m.group("args")
                    rtype = m.group("rtype")
                    if _is_balanced(args):
                        signatures.append(FunctionSignature(name, args, rtype))

            # strip module name if provided
            if module_name:
                for sig in signatures:
                    regex = r"{}\.(\w+)".format(module_name.replace(".", r"\."))
                    sig.args = re.sub(regex, r"\g<1>", sig.args)
                    sig.rtype = re.sub(regex, r"\g<1>", sig.rtype)

            for sig in signatures:
                sig.args = StubsGenerator.apply_classname_replacements(sig.args)
                sig.rtype = StubsGenerator.apply_classname_replacements(sig.rtype)

            return sorted(list(set(signatures)), key=lambda fs: fs.args)
        except AttributeError:
            return []

    @staticmethod
    def property_signature_from_docstring(
        prop, module_name
    ):  # type:  (Any, str)-> PropertySignature

        getter_rtype = "None"
        setter_args = "None"
        access_type = PropertySignature.NONE

        strip_module_name = module_name is not None

        if hasattr(prop, "fget") and prop.fget is not None:
            access_type |= PropertySignature.READ_ONLY
            if hasattr(prop.fget, "__doc__") and prop.fget.__doc__ is not None:
                for line in prop.fget.__doc__.split("\n"):
                    if strip_module_name:
                        line = line.replace(module_name + ".", "")
                    m = re.match(
                        r"\s*(\w*)\((?P<args>[^()]*)\)\s*->\s*(?P<rtype>[^()]+)\s*",
                        line,
                    )
                    if m:
                        getter_rtype = m.group("rtype")
                        break

        if hasattr(prop, "fset") and prop.fset is not None:
            access_type |= PropertySignature.WRITE_ONLY
            if hasattr(prop.fset, "__doc__") and prop.fset.__doc__ is not None:
                for line in prop.fset.__doc__.split("\n"):
                    if strip_module_name:
                        line = line.replace(module_name + ".", "")
                    m = re.match(
                        r"\s*(\w*)\((?P<args>[^()]*)\)\s*->\s*(?P<rtype>[^()]+)\s*",
                        line,
                    )
                    if m:
                        args = m.group("args")
                        # replace first argument with self
                        setter_args = ",".join(["self"] + args.split(",")[1:])
                        break
        getter_rtype = StubsGenerator.apply_classname_replacements(getter_rtype)
        setter_args = StubsGenerator.apply_classname_replacements(setter_args)
        return PropertySignature(getter_rtype, setter_args, access_type)

    @staticmethod
    def remove_signatures(docstring):  # type: (str) ->str

        if docstring is None:
            return ""

        for hook in function_docstring_preprocessing_hooks:
            docstring = hook(docstring)

        signature_regex = (
            r"(\s*(?P<overload_number>\d+).\s*)"
            r"?{name}\s*\((?P<args>.*)\)\s*(->\s*(?P<rtype>[^\(\)]+)\s*)?".format(
                name=r"\w+"
            )
        )

        lines = docstring.split("\n\n")
        lines = filter(lambda line: line != "Overloaded function.", lines)

        return "\n\n".join(
            filter(lambda line: not re.match(signature_regex, line), lines)
        )

    @staticmethod
    def sanitize_docstring(docstring):  # type: (str) ->str
        docstring = StubsGenerator.remove_signatures(docstring)
        docstring = docstring.rstrip("\n")

        if docstring and re.match(r"^\s*$", docstring):
            docstring = ""

        return docstring

    @staticmethod
    def format_docstring(docstring):
        docstring = inspect.cleandoc("\n" + docstring)
        return StubsGenerator.indent('"""\n{}\n"""'.format(docstring.strip("\n")))


class AttributeStubsGenerator(StubsGenerator):
    def __init__(self, name, attribute):  # type: (str, Any)-> None
        self.name = name
        self.attr = attribute

    def parse(self):
        if self in _visited_objects:
            return
        _visited_objects.append(self)

    def is_safe_to_use_repr(self, value):
        if value is None or isinstance(value, (int, str)):
            return True
        if isinstance(value, (float, complex)):
            try:
                eval(repr(value))
                return True
            except (SyntaxError, NameError):
                return False
        if isinstance(value, (list, tuple, set)):
            for x in value:
                if not self.is_safe_to_use_repr(x):
                    return False
            return True
        if isinstance(value, dict):
            for k, v in value.items():
                if not self.is_safe_to_use_repr(k) or not self.is_safe_to_use_repr(v):
                    return False
            return True
        return False

    def to_lines(self):  # type: () -> List[str]
        if self.is_safe_to_use_repr(self.attr):
            return ["{name} = {repr}".format(name=self.name, repr=repr(self.attr))]

        # special case for modules
        # https://github.com/sizmailov/pybind11-stubgen/issues/43
        if type(self.attr) is type(os) and hasattr(self.attr, "__name__"):
            return ["{name} = {repr}".format(name=self.name, repr=self.attr.__name__)]

        # special case for PyCapsule
        # https://github.com/sizmailov/pybind11-stubgen/issues/86
        attr_type = type(self.attr)
        if attr_type.__name__ == "PyCapsule" and attr_type.__module__ == "builtins":
            return ["{name}: typing.Any  # PyCapsule()".format(name=self.name)]

        value_lines = repr(self.attr).split("\n")
        typename = self.fully_qualified_name(type(self.attr))

        if len(value_lines) == 1:
            value = value_lines[0]
            # remove random address from <foo.Foo object at 0x1234>
            value = re.sub(r" at 0x[0-9a-fA-F]+>", ">", value)
            if value == "<{typename} object>".format(typename=typename):
                value_comment = ""
            else:
                value_comment = " # value = {value}".format(value=value)
            return [
                "{name}: {typename}{value_comment}".format(
                    name=self.name, typename=typename, value_comment=value_comment
                )
            ]
        else:
            return (
                [
                    "{name}: {typename} # value = ".format(
                        name=self.name, typename=typename
                    )
                ]
                + ['"""']
                + [l.replace('"""', r"\"\"\"") for l in value_lines]
                + ['"""']
            )

    def get_involved_modules_names(self):  # type: () -> Set[str]
        attr_type = type(self.attr)
        if attr_type is type(os):
            return {self.attr.__name__}
        if attr_type.__name__ == "PyCapsule" and attr_type.__module__ == "builtins":
            # PyCapsule rendered as typing.Any
            return {"typing"}
        return {self.attr.__class__.__module__}


class FreeFunctionStubsGenerator(StubsGenerator):
    def __init__(self, name, free_function, module_name):
        self.name = name
        self.member = free_function
        self.module_name = module_name
        self.signatures = []  # type:  List[FunctionSignature]

    def parse(self):
        self.signatures = self.function_signatures_from_docstring(
            self.name, self.member, self.module_name
        )

    def to_lines(self):  # type: () -> List[str]
        result = []
        docstring = self.sanitize_docstring(self.member.__doc__)
        if not docstring and not (
            self.name.startswith("__") and self.name.endswith("__")
        ):
            logger.debug(
                "Docstring is empty for '%s'" % self.fully_qualified_name(self.member)
            )
        for sig in self.signatures:
            if len(self.signatures) > 1:
                result.append("@typing.overload")
            result.append(
                "def {name}({args}) -> {rtype}:".format(
                    name=sig.name, args=sig.args, rtype=sig.rtype
                )
            )
            if docstring:
                result.append(self.format_docstring(docstring))
                docstring = None  # don't print docstring for other overloads
            else:
                result.append(self.indent("pass"))

        return result

    def get_involved_modules_names(self):  # type: () -> Set[str]
        involved_modules_names = set()
        for s in self.signatures:  # type: FunctionSignature
            for t in s.get_all_involved_types():  # type: str
                try:
                    module_name = t[: t.rindex(".")]
                    if self.is_valid_module(module_name):
                        involved_modules_names.add(module_name)
                except ValueError:
                    pass
        return involved_modules_names


class ClassMemberStubsGenerator(FreeFunctionStubsGenerator):
    def __init__(self, name, free_function, module_name):
        super(ClassMemberStubsGenerator, self).__init__(
            name, free_function, module_name
        )

    def to_lines(self):  # type: () -> List[str]
        result = []
        docstring = self.sanitize_docstring(self.member.__doc__)
        if not docstring and not (
            self.name.startswith("__") and self.name.endswith("__")
        ):
            logger.debug(
                "Docstring is empty for '%s'" % self.fully_qualified_name(self.member)
            )
        for sig in self.signatures:
            args = sig.args
            sargs = args.strip()
            if not sargs.startswith("self"):
                if sargs.startswith("cls"):
                    result.append("@classmethod")
                    # remove type of cls
                    args = ",".join(["cls"] + sig.split_arguments()[1:])
                else:
                    result.append("@staticmethod")
            else:
                # remove type of self
                args = ",".join(["self"] + sig.split_arguments()[1:])
            if len(self.signatures) > 1:
                result.append("@typing.overload")

            result.append(
                "def {name}({args}) -> {rtype}: {ellipsis}".format(
                    name=sig.name,
                    args=args,
                    rtype=sig.rtype,
                    ellipsis="" if docstring else "...",
                )
            )
            if docstring:
                result.append(self.format_docstring(docstring))
                docstring = None  # don't print docstring for other overloads
        return result


class PropertyStubsGenerator(StubsGenerator):
    def __init__(self, name, prop, module_name):
        self.name = name
        self.prop = prop
        self.module_name = module_name
        self.signature = None  # type: PropertySignature

    def parse(self):
        self.signature = self.property_signature_from_docstring(
            self.prop, self.module_name
        )

    def to_lines(self):  # type: () -> List[str]

        docstring = self.sanitize_docstring(self.prop.__doc__)
        docstring_prop = "\n\n".join(
            [docstring, ":type: {rtype}".format(rtype=self.signature.rtype)]
        )

        result = [
            "@property",
            "def {field_name}(self) -> {rtype}:".format(
                field_name=self.name, rtype=self.signature.rtype
            ),
            self.format_docstring(docstring_prop),
        ]

        if self.signature.setter_args != "None":
            result.append("@{field_name}.setter".format(field_name=self.name))
            result.append(
                "def {field_name}({args}) -> None:".format(
                    field_name=self.name, args=self.signature.setter_args
                )
            )
            if docstring:
                result.append(self.format_docstring(docstring))
            else:
                result.append(self.indent("pass"))

        return result


class ClassStubsGenerator(StubsGenerator):
    ATTRIBUTES_BLACKLIST = (
        "__class__",
        "__module__",
        "__qualname__",
        "__dict__",
        "__weakref__",
        "__annotations__",
    )
    PYBIND11_ATTRIBUTES_BLACKLIST = ("__entries",)
    METHODS_BLACKLIST = ("__dir__", "__sizeof__")
    BASE_CLASS_BLACKLIST = ("pybind11_object", "object")
    CLASS_NAME_BLACKLIST = ("pybind11_type",)

    def __init__(
        self,
        klass,
        attributes_blacklist=ATTRIBUTES_BLACKLIST,
        pybind11_attributes_blacklist=PYBIND11_ATTRIBUTES_BLACKLIST,
        base_class_blacklist=BASE_CLASS_BLACKLIST,
        methods_blacklist=METHODS_BLACKLIST,
        class_name_blacklist=CLASS_NAME_BLACKLIST,
    ):
        self.klass = klass
        assert inspect.isclass(klass)
        assert klass.__name__.isidentifier()

        self.doc_string = None  # type: Optional[str]

        self.classes = []  # type: List[ClassStubsGenerator]
        self.fields = []  # type: List[AttributeStubsGenerator]
        self.properties = []  # type: List[PropertyStubsGenerator]
        self.methods = []  # type: List[ClassMemberStubsGenerator]

        self.base_classes = []
        self.involved_modules_names = set()  # Set[str]

        self.attributes_blacklist = attributes_blacklist
        self.pybind11_attributes_blacklist = pybind11_attributes_blacklist
        self.base_class_blacklist = base_class_blacklist
        self.methods_blacklist = methods_blacklist
        self.class_name_blacklist = class_name_blacklist

    def get_involved_modules_names(self):
        return self.involved_modules_names

    def parse(self):
        if self.klass in _visited_objects:
            return
        _visited_objects.append(self.klass)

        bases = inspect.getmro(self.klass)[1:]

        def is_base_member(name, member):
            for base in bases:
                if hasattr(base, name) and getattr(base, name) is member:
                    return True
            return False

        is_pybind11 = any(base.__name__ == "pybind11_object" for base in bases)

        for name, member in inspect.getmembers(self.klass):
            # check if attribute is in __dict__ (fast path) before slower search in base classes
            if name not in self.klass.__dict__ and is_base_member(name, member):
                continue
            if name.startswith("__pybind11_module"):
                continue
            if inspect.isroutine(member):
                self.methods.append(
                    ClassMemberStubsGenerator(name, member, self.klass.__module__)
                )
            elif name != "__class__" and inspect.isclass(member):
                if (
                    member.__name__ not in self.class_name_blacklist
                    and member.__name__.isidentifier()
                ):
                    self.classes.append(ClassStubsGenerator(member))
            elif isinstance(member, property):
                self.properties.append(
                    PropertyStubsGenerator(name, member, self.klass.__module__)
                )
            elif name == "__doc__":
                self.doc_string = member
            elif not (
                name in self.attributes_blacklist
                or (is_pybind11 and name in self.pybind11_attributes_blacklist)
            ):
                self.fields.append(AttributeStubsGenerator(name, member))
                # logger.warning("Unknown member %s type : `%s` " % (name, str(type(member))))

        for x in itertools.chain(
            self.classes, self.methods, self.properties, self.fields
        ):
            x.parse()

        for B in bases:
            if (
                B.__name__ != self.klass.__name__
                and B.__name__ not in self.base_class_blacklist
            ):
                self.base_classes.append(B)
                self.involved_modules_names.add(B.__module__)

        for f in self.methods:  # type: ClassMemberStubsGenerator
            self.involved_modules_names |= f.get_involved_modules_names()

        for attr in self.fields:
            self.involved_modules_names |= attr.get_involved_modules_names()

    def to_lines(self):  # type: () -> List[str]
        def strip_current_module_name(obj, module_name):
            regex = r"{}\.(\w+)".format(module_name.replace(".", r"\."))
            return re.sub(regex, r"\g<1>", obj)

        base_classes_list = [
            strip_current_module_name(
                self.fully_qualified_name(b), self.klass.__module__
            )
            for b in self.base_classes
        ]
        result = [
            "class {class_name}({base_classes_list}):{doc_string}".format(
                class_name=self.klass.__name__,
                base_classes_list=", ".join(base_classes_list),
                doc_string="\n" + self.format_docstring(self.doc_string)
                if self.doc_string
                else "",
            ),
        ]
        for cl in self.classes:
            result.extend(map(self.indent, cl.to_lines()))

        for f in self.methods:
            if f.name not in self.methods_blacklist:
                result.extend(map(self.indent, f.to_lines()))

        for p in self.properties:
            result.extend(map(self.indent, p.to_lines()))

        for p in self.fields:
            result.extend(map(self.indent, p.to_lines()))

        result.append(self.indent("pass"))
        return result


class ModuleStubsGenerator(StubsGenerator):
    CLASS_NAME_BLACKLIST = ClassStubsGenerator.CLASS_NAME_BLACKLIST
    ATTRIBUTES_BLACKLIST = (
        "__file__",
        "__loader__",
        "__name__",
        "__package__",
        "__spec__",
        "__path__",
        "__cached__",
        "__builtins__",
    )

    def __init__(
        self,
        module_or_module_name,
        attributes_blacklist=ATTRIBUTES_BLACKLIST,
        class_name_blacklist=CLASS_NAME_BLACKLIST,
    ):
        if isinstance(module_or_module_name, str):
            self.module = importlib.import_module(module_or_module_name)
        else:
            self.module = module_or_module_name
            assert inspect.ismodule(self.module)

        self.doc_string = None  # type: Optional[str]
        self.classes = []  # type: List[ClassStubsGenerator]
        self.free_functions = []  # type: List[FreeFunctionStubsGenerator]
        self.submodules = []  # type: List[ModuleStubsGenerator]
        self.imported_modules = []  # type: List[str]
        self.imported_classes = {}  # type: Dict[str, type]
        self.attributes = []  # type: List[AttributeStubsGenerator]
        self.stub_suffix = ""
        self.write_setup_py = False

        self.attributes_blacklist = attributes_blacklist
        self.class_name_blacklist = class_name_blacklist

    def parse(self):
        if self.module in _visited_objects:
            return
        _visited_objects.append(self.module)
        logger.debug("Parsing '%s' module" % self.module.__name__)
        for name, member in inspect.getmembers(self.module):
            if inspect.ismodule(member):
                m = ModuleStubsGenerator(member)
                if m.module.__name__.split(".")[:-1] == self.module.__name__.split("."):
                    self.submodules.append(m)
                else:
                    self.imported_modules += [m.module.__name__]
                    logger.debug(
                        "Skip '%s' module while parsing '%s' "
                        % (m.module.__name__, self.module.__name__)
                    )
            elif inspect.isbuiltin(member) or inspect.isfunction(member):
                self.free_functions.append(
                    FreeFunctionStubsGenerator(name, member, self.module.__name__)
                )
            elif inspect.isclass(member):
                if member.__module__ == self.module.__name__:
                    if (
                        member.__name__ not in self.class_name_blacklist
                        and member.__name__.isidentifier()
                    ):
                        self.classes.append(ClassStubsGenerator(member))
                else:
                    self.imported_classes[name] = member
            elif name == "__doc__":
                self.doc_string = member
            elif name not in self.attributes_blacklist:
                self.attributes.append(AttributeStubsGenerator(name, member))

        for x in itertools.chain(
            self.submodules, self.classes, self.free_functions, self.attributes
        ):
            x.parse()

        def class_ordering(
            a, b
        ):  # type: (ClassStubsGenerator, ClassStubsGenerator) -> int
            if a.klass is b.klass:
                return 0
            if issubclass(a.klass, b.klass):
                return -1
            if issubclass(b.klass, a.klass):
                return 1
            return 0

        # reorder classes so base classes would be printed before derived
        # print([ k.klass.__name__ for k in self.classes ])
        for i in range(len(self.classes)):
            for j in range(i + 1, len(self.classes)):
                if class_ordering(self.classes[i], self.classes[j]) < 0:
                    t = self.classes[i]
                    self.classes[i] = self.classes[j]
                    self.classes[j] = t
        # print( [ k.klass.__name__ for k in self.classes ] )

    def get_involved_modules_names(self):
        result = set(self.imported_modules)

        for attr in self.attributes:
            result |= attr.get_involved_modules_names()

        for C in self.classes:  # type: ClassStubsGenerator
            result |= C.get_involved_modules_names()

        for f in self.free_functions:  # type: FreeFunctionStubsGenerator
            result |= f.get_involved_modules_names()

        return set(result) - {"builtins", "typing", self.module.__name__}

    def to_lines(self):  # type: () -> List[str]

        result = []

        if self.doc_string:
            result += ['"""' + self.doc_string.replace('"""', r"\"\"\"") + '"""']

        if sys.version_info[:2] >= (3, 7):
            result += ["from __future__ import annotations"]

        result += ["import {}".format(self.module.__name__)]

        # import everything from typing
        result += ["import typing"]

        for name, class_ in self.imported_classes.items():
            class_name = getattr(class_, "__qualname__", class_.__name__)
            if name == class_name:
                suffix = ""
            else:
                suffix = " as {}".format(name)
            result += [
                "from {} import {}{}".format(class_.__module__, class_name, suffix)
            ]

        # import used packages
        used_modules = sorted(self.get_involved_modules_names())
        if used_modules:
            # result.append("if TYPE_CHECKING:")
            # result.extend(map(self.indent, map(lambda m: "import {}".format(m), used_modules)))
            result.extend(map(lambda mod: "import {}".format(mod), used_modules))

        if "numpy" in used_modules and not BARE_NUPMY_NDARRAY:
            result += ["_Shape = typing.Tuple[int, ...]"]

        # add space between imports and rest of module
        result += [""]

        globals_ = {}
        exec("from {} import *".format(self.module.__name__), globals_)
        all_ = set(member for member in globals_.keys() if member.isidentifier()) - {
            "__builtins__"
        }
        result.append(
            "__all__ = [\n    "
            + ",\n    ".join(map(lambda s: '"%s"' % s, sorted(all_)))
            + "\n]\n\n"
        )

        for x in itertools.chain(self.classes, self.free_functions, self.attributes):
            result.extend(x.to_lines())
        result.append("")  # Newline at EOF
        return result

    @property
    def short_name(self):
        return self.module.__name__.split(".")[-1]

    def write(self):
        with DirectoryWalkerGuard(self.short_name + self.stub_suffix):
            with open("__init__.pyi", "w", encoding="utf-8") as init_pyi:
                init_pyi.write("\n".join(self.to_lines()))
            for m in self.submodules:
                m.write()

            if self.write_setup_py:
                with open("setup.py", "w", encoding="utf-8") as setuppy:
                    setuppy.write(
                        """from setuptools import setup
import os


def find_stubs(package):
    stubs = []
    for root, dirs, files in os.walk(package):
        for file in files:
            path = os.path.join(root, file).replace(package + os.sep, '', 1)
            stubs.append(path)
    return dict(package=stubs)


setup(
    name='{package_name}-stubs',
    maintainer="{package_name} Developers",
    maintainer_email="example@python.org",
    description="PEP 561 type stubs for {package_name}",
    version='1.0',
    packages=['{package_name}-stubs'],
    # PEP 561 requires these
    install_requires=['{package_name}'],
    package_data=find_stubs('{package_name}-stubs'),
)""".format(
                            package_name=self.short_name
                        )
                    )


def main(args=None):
    parser = ArgumentParser(
        prog="pybind11-stubgen", description="Generates stubs for specified modules"
    )
    parser.add_argument(
        "-o",
        "--output-dir",
        help="the root directory for output stubs",
        default="./stubs",
    )
    parser.add_argument(
        "--root-module-suffix",
        type=str,
        default="-stubs",
        dest="root_module_suffix",
        help="optional suffix to disambiguate from the original package",
    )
    parser.add_argument(
        "--root_module_suffix",
        type=str,
        default=None,
        dest="root_module_suffix_deprecated",
        help="Deprecated.  Use `--root-module-suffix`",
    )
    parser.add_argument("--no-setup-py", action="store_true")
    parser.add_argument(
        "--non-stop", action="store_true", help="Deprecated. Use `--ignore-invalid=all`"
    )
    parser.add_argument(
        "--ignore-invalid",
        nargs="+",
        choices=["signature", "defaultarg", "all"],
        default=[],
        help="Ignore invalid specified python expressions in docstrings",
    )
    parser.add_argument(
        "--skip-signature-downgrade",
        action="store_true",
        help="Do not downgrade invalid function signatures to func(*args, **kwargs)",
    )
    parser.add_argument(
        "--bare-numpy-ndarray",
        action="store_true",
        default=False,
        help="Render `numpy.ndarray` without (non-standardized) bracket-enclosed type and shape info",
    )
    parser.add_argument(
        "module_names", nargs="+", metavar="MODULE_NAME", type=str, help="modules names"
    )
    parser.add_argument("--log-level", default="INFO", help="Set output log level")

    sys_args = parser.parse_args(args or sys.argv[1:])

    if sys_args.non_stop:
        sys_args.ignore_invalid = ["all"]
        warnings.warn(
            "`--non-stop` is deprecated in favor of `--ignore-invalid=all`",
            FutureWarning,
        )

    if sys_args.bare_numpy_ndarray:
        global BARE_NUPMY_NDARRAY
        BARE_NUPMY_NDARRAY = True

    if "all" in sys_args.ignore_invalid:
        FunctionSignature.ignore_invalid_signature = True
        FunctionSignature.ignore_invalid_defaultarg = True
    else:
        if "signature" in sys_args.ignore_invalid:
            FunctionSignature.ignore_invalid_signature = True
        if "defaultarg" in sys_args.ignore_invalid:
            FunctionSignature.ignore_invalid_defaultarg = True

    if sys_args.skip_signature_downgrade:
        FunctionSignature.signature_downgrade = False

    if sys_args.root_module_suffix_deprecated is not None:
        sys_args.root_module_suffix = sys_args.root_module_suffix_deprecated
        warnings.warn(
            "`--root_module_suffix` is deprecated in favor of `--root-module-suffix`",
            FutureWarning,
        )

    stderr_handler = logging.StreamHandler(sys.stderr)
    handlers = [stderr_handler]

    logging.basicConfig(
        level=logging.getLevelName(sys_args.log_level),
        format="[%(asctime)s] {%(filename)s:%(lineno)d} %(levelname)s - %(message)s",
        handlers=handlers,
    )

    with DirectoryWalkerGuard(sys_args.output_dir):
        for _module_name in sys_args.module_names:
            _module = ModuleStubsGenerator(_module_name)
            _module.parse()
            if FunctionSignature.n_fatal_errors() == 0:
                _module.stub_suffix = sys_args.root_module_suffix
                _module.write_setup_py = not sys_args.no_setup_py
                _dir = _module_name.split(".")[:-1] or ["."]
                _dir = os.path.join(*_dir)
                with DirectoryWalkerGuard(_dir):
                    _module.write()

        if FunctionSignature.n_invalid_signatures > 0:
            logger.info("Useful link: Avoiding C++ types in docstrings:")
            logger.info(
                "      https://pybind11.readthedocs.io/en/latest/advanced/misc.html"
                "#avoiding-cpp-types-in-docstrings"
            )

        if FunctionSignature.n_invalid_default_values > 0:
            logger.info("Useful link: Default argument representation:")
            logger.info(
                "      https://pybind11.readthedocs.io/en/latest/advanced/functions.html"
                "#default-arguments-revisited"
            )

        if FunctionSignature.n_fatal_errors() > 0:
            exit(1)


if __name__ == "__main__":
    main()
