"""Importer utilities for autodoc
"""

import importlib
import traceback
import warnings
from typing import Any, Callable, Dict, List, NamedTuple, Optional, Tuple

from sphinx.deprecation import RemovedInSphinx50Warning
from sphinx.ext.autodoc.mock import ismock, undecorate
from sphinx.pycode import ModuleAnalyzer, PycodeError
from sphinx.util import logging
from sphinx.util.inspect import (getannotations, getmro, getslots, isclass, isenumclass,
                                 safe_getattr)

if False:
    # For type annotation
    from typing import Type  # NOQA

    from sphinx.ext.autodoc import ObjectMember

logger = logging.getLogger(__name__)


def mangle(subject: Any, name: str) -> str:
    """Mangle the given name."""
    try:
        if isclass(subject) and name.startswith('__') and not name.endswith('__'):
            return "_%s%s" % (subject.__name__, name)
    except AttributeError:
        pass

    return name


def unmangle(subject: Any, name: str) -> Optional[str]:
    """Unmangle the given name."""
    try:
        if isclass(subject) and not name.endswith('__'):
            prefix = "_%s__" % subject.__name__
            if name.startswith(prefix):
                return name.replace(prefix, "__", 1)
            else:
                for cls in subject.__mro__:
                    prefix = "_%s__" % cls.__name__
                    if name.startswith(prefix):
                        # mangled attribute defined in parent class
                        return None
    except AttributeError:
        pass

    return name


def import_module(modname: str, warningiserror: bool = False) -> Any:
    """
    Call importlib.import_module(modname), convert exceptions to ImportError
    """
    try:
        with warnings.catch_warnings():
            warnings.filterwarnings("ignore", category=ImportWarning)
            with logging.skip_warningiserror(not warningiserror):
                return importlib.import_module(modname)
    except BaseException as exc:
        # Importing modules may cause any side effects, including
        # SystemExit, so we need to catch all errors.
        raise ImportError(exc, traceback.format_exc()) from exc


def import_object(modname: str, objpath: List[str], objtype: str = '',
                  attrgetter: Callable[[Any, str], Any] = safe_getattr,
                  warningiserror: bool = False) -> Any:
    if objpath:
        logger.debug('[autodoc] from %s import %s', modname, '.'.join(objpath))
    else:
        logger.debug('[autodoc] import %s', modname)

    try:
        module = None
        exc_on_importing = None
        objpath = list(objpath)
        while module is None:
            try:
                module = import_module(modname, warningiserror=warningiserror)
                logger.debug('[autodoc] import %s => %r', modname, module)
            except ImportError as exc:
                logger.debug('[autodoc] import %s => failed', modname)
                exc_on_importing = exc
                if '.' in modname:
                    # retry with parent module
                    modname, name = modname.rsplit('.', 1)
                    objpath.insert(0, name)
                else:
                    raise

        obj = module
        parent = None
        object_name = None
        for attrname in objpath:
            parent = obj
            logger.debug('[autodoc] getattr(_, %r)', attrname)
            mangled_name = mangle(obj, attrname)
            obj = attrgetter(obj, mangled_name)

            try:
                logger.debug('[autodoc] => %r', obj)
            except TypeError:
                # fallback of failure on logging for broken object
                # refs: https://github.com/sphinx-doc/sphinx/issues/9095
                logger.debug('[autodoc] => %r', (obj,))

            object_name = attrname
        return [module, parent, object_name, obj]
    except (AttributeError, ImportError) as exc:
        if isinstance(exc, AttributeError) and exc_on_importing:
            # restore ImportError
            exc = exc_on_importing

        if objpath:
            errmsg = ('autodoc: failed to import %s %r from module %r' %
                      (objtype, '.'.join(objpath), modname))
        else:
            errmsg = 'autodoc: failed to import %s %r' % (objtype, modname)

        if isinstance(exc, ImportError):
            # import_module() raises ImportError having real exception obj and
            # traceback
            real_exc, traceback_msg = exc.args
            if isinstance(real_exc, SystemExit):
                errmsg += ('; the module executes module level statement '
                           'and it might call sys.exit().')
            elif isinstance(real_exc, ImportError) and real_exc.args:
                errmsg += '; the following exception was raised:\n%s' % real_exc.args[0]
            else:
                errmsg += '; the following exception was raised:\n%s' % traceback_msg
        else:
            errmsg += '; the following exception was raised:\n%s' % traceback.format_exc()

        logger.debug(errmsg)
        raise ImportError(errmsg) from exc


def get_module_members(module: Any) -> List[Tuple[str, Any]]:
    """Get members of target module."""
    from sphinx.ext.autodoc import INSTANCEATTR

    warnings.warn('sphinx.ext.autodoc.importer.get_module_members() is deprecated.',
                  RemovedInSphinx50Warning)

    members: Dict[str, Tuple[str, Any]] = {}
    for name in dir(module):
        try:
            value = safe_getattr(module, name, None)
            members[name] = (name, value)
        except AttributeError:
            continue

    # annotation only member (ex. attr: int)
    for name in getannotations(module):
        if name not in members:
            members[name] = (name, INSTANCEATTR)

    return sorted(list(members.values()))


class Attribute(NamedTuple):
    name: str
    directly_defined: bool
    value: Any


def get_object_members(subject: Any, objpath: List[str], attrgetter: Callable,
                       analyzer: ModuleAnalyzer = None) -> Dict[str, Attribute]:
    """Get members and attributes of target object."""
    from sphinx.ext.autodoc import INSTANCEATTR

    # the members directly defined in the class
    obj_dict = attrgetter(subject, '__dict__', {})

    members: Dict[str, Attribute] = {}

    # enum members
    if isenumclass(subject):
        for name, value in subject.__members__.items():
            if name not in members:
                members[name] = Attribute(name, True, value)

        superclass = subject.__mro__[1]
        for name in obj_dict:
            if name not in superclass.__dict__:
                value = safe_getattr(subject, name)
                members[name] = Attribute(name, True, value)

    # members in __slots__
    try:
        __slots__ = getslots(subject)
        if __slots__:
            from sphinx.ext.autodoc import SLOTSATTR

            for name in __slots__:
                members[name] = Attribute(name, True, SLOTSATTR)
    except (TypeError, ValueError):
        pass

    # other members
    for name in dir(subject):
        try:
            value = attrgetter(subject, name)
            directly_defined = name in obj_dict
            name = unmangle(subject, name)
            if name and name not in members:
                members[name] = Attribute(name, directly_defined, value)
        except AttributeError:
            continue

    # annotation only member (ex. attr: int)
    for i, cls in enumerate(getmro(subject)):
        for name in getannotations(cls):
            name = unmangle(cls, name)
            if name and name not in members:
                members[name] = Attribute(name, i == 0, INSTANCEATTR)

    if analyzer:
        # append instance attributes (cf. self.attr1) if analyzer knows
        namespace = '.'.join(objpath)
        for (ns, name) in analyzer.find_attr_docs():
            if namespace == ns and name not in members:
                members[name] = Attribute(name, True, INSTANCEATTR)

    return members


def get_class_members(subject: Any, objpath: List[str], attrgetter: Callable
                      ) -> Dict[str, "ObjectMember"]:
    """Get members and attributes of target class."""
    from sphinx.ext.autodoc import INSTANCEATTR, ObjectMember

    # the members directly defined in the class
    obj_dict = attrgetter(subject, '__dict__', {})

    members: Dict[str, ObjectMember] = {}

    # enum members
    if isenumclass(subject):
        for name, value in subject.__members__.items():
            if name not in members:
                members[name] = ObjectMember(name, value, class_=subject)

        superclass = subject.__mro__[1]
        for name in obj_dict:
            if name not in superclass.__dict__:
                value = safe_getattr(subject, name)
                members[name] = ObjectMember(name, value, class_=subject)

    # members in __slots__
    try:
        __slots__ = getslots(subject)
        if __slots__:
            from sphinx.ext.autodoc import SLOTSATTR

            for name, docstring in __slots__.items():
                members[name] = ObjectMember(name, SLOTSATTR, class_=subject,
                                             docstring=docstring)
    except (TypeError, ValueError):
        pass

    # other members
    for name in dir(subject):
        try:
            value = attrgetter(subject, name)
            if ismock(value):
                value = undecorate(value)

            unmangled = unmangle(subject, name)
            if unmangled and unmangled not in members:
                if name in obj_dict:
                    members[unmangled] = ObjectMember(unmangled, value, class_=subject)
                else:
                    members[unmangled] = ObjectMember(unmangled, value)
        except AttributeError:
            continue

    try:
        for cls in getmro(subject):
            try:
                modname = safe_getattr(cls, '__module__')
                qualname = safe_getattr(cls, '__qualname__')
                analyzer = ModuleAnalyzer.for_module(modname)
                analyzer.analyze()
            except AttributeError:
                qualname = None
                analyzer = None
            except PycodeError:
                analyzer = None

            # annotation only member (ex. attr: int)
            for name in getannotations(cls):
                name = unmangle(cls, name)
                if name and name not in members:
                    if analyzer and (qualname, name) in analyzer.attr_docs:
                        docstring = '\n'.join(analyzer.attr_docs[qualname, name])
                    else:
                        docstring = None

                    members[name] = ObjectMember(name, INSTANCEATTR, class_=cls,
                                                 docstring=docstring)

            # append instance attributes (cf. self.attr1) if analyzer knows
            if analyzer:
                for (ns, name), docstring in analyzer.attr_docs.items():
                    if ns == qualname and name not in members:
                        members[name] = ObjectMember(name, INSTANCEATTR, class_=cls,
                                                     docstring='\n'.join(docstring))
    except AttributeError:
        pass

    return members