"""Utility functions for docutils."""

from __future__ import annotations

import os
import re
from collections.abc import Sequence  # NoQA: TCH003
from contextlib import contextmanager
from copy import copy
from os import path
from typing import IO, TYPE_CHECKING, Any, Callable, cast

import docutils
from docutils import nodes
from docutils.io import FileOutput
from docutils.parsers.rst import Directive, directives, roles
from docutils.parsers.rst.states import Inliner  # NoQA: TCH002
from docutils.statemachine import State, StateMachine, StringList
from docutils.utils import Reporter, unescape
from docutils.writers._html_base import HTMLTranslator

from sphinx.errors import SphinxError
from sphinx.locale import _, __
from sphinx.util import logging

logger = logging.getLogger(__name__)
report_re = re.compile('^(.+?:(?:\\d+)?): \\((DEBUG|INFO|WARNING|ERROR|SEVERE)/(\\d+)?\\) ')

if TYPE_CHECKING:
    from collections.abc import Generator
    from types import ModuleType

    from docutils.frontend import Values
    from docutils.nodes import Element, Node, system_message

    from sphinx.builders import Builder
    from sphinx.config import Config
    from sphinx.environment import BuildEnvironment
    from sphinx.util.typing import RoleFunction

# deprecated name -> (object to return, canonical path or empty string)
_DEPRECATED_OBJECTS = {
    '__version_info__': (docutils.__version_info__, 'docutils.__version_info__'),
}


def __getattr__(name):
    if name not in _DEPRECATED_OBJECTS:
        msg = f'module {__name__!r} has no attribute {name!r}'
        raise AttributeError(msg)

    from sphinx.deprecation import _deprecation_warning

    deprecated_object, canonical_name = _DEPRECATED_OBJECTS[name]
    _deprecation_warning(__name__, name, canonical_name, remove=(7, 0))
    return deprecated_object


additional_nodes: set[type[Element]] = set()


@contextmanager
def docutils_namespace() -> Generator[None, None, None]:
    """Create namespace for reST parsers."""
    try:
        _directives = copy(directives._directives)  # type: ignore[attr-defined]
        _roles = copy(roles._roles)  # type: ignore[attr-defined]

        yield
    finally:
        directives._directives = _directives  # type: ignore[attr-defined]
        roles._roles = _roles  # type: ignore[attr-defined]

        for node in list(additional_nodes):
            unregister_node(node)
            additional_nodes.discard(node)


def is_directive_registered(name: str) -> bool:
    """Check the *name* directive is already registered."""
    return name in directives._directives  # type: ignore[attr-defined]


def register_directive(name: str, directive: type[Directive]) -> None:
    """Register a directive to docutils.

    This modifies global state of docutils.  So it is better to use this
    inside ``docutils_namespace()`` to prevent side-effects.
    """
    directives.register_directive(name, directive)


def is_role_registered(name: str) -> bool:
    """Check the *name* role is already registered."""
    return name in roles._roles  # type: ignore[attr-defined]


def register_role(name: str, role: RoleFunction) -> None:
    """Register a role to docutils.

    This modifies global state of docutils.  So it is better to use this
    inside ``docutils_namespace()`` to prevent side-effects.
    """
    roles.register_local_role(name, role)


def unregister_role(name: str) -> None:
    """Unregister a role from docutils."""
    roles._roles.pop(name, None)  # type: ignore[attr-defined]


def is_node_registered(node: type[Element]) -> bool:
    """Check the *node* is already registered."""
    return hasattr(nodes.GenericNodeVisitor, 'visit_' + node.__name__)


def register_node(node: type[Element]) -> None:
    """Register a node to docutils.

    This modifies global state of some visitors.  So it is better to use this
    inside ``docutils_namespace()`` to prevent side-effects.
    """
    if not hasattr(nodes.GenericNodeVisitor, 'visit_' + node.__name__):
        nodes._add_node_class_names([node.__name__])  # type: ignore[attr-defined]
        additional_nodes.add(node)


def unregister_node(node: type[Element]) -> None:
    """Unregister a node from docutils.

    This is inverse of ``nodes._add_nodes_class_names()``.
    """
    if hasattr(nodes.GenericNodeVisitor, 'visit_' + node.__name__):
        delattr(nodes.GenericNodeVisitor, "visit_" + node.__name__)
        delattr(nodes.GenericNodeVisitor, "depart_" + node.__name__)
        delattr(nodes.SparseNodeVisitor, 'visit_' + node.__name__)
        delattr(nodes.SparseNodeVisitor, 'depart_' + node.__name__)


@contextmanager
def patched_get_language() -> Generator[None, None, None]:
    """Patch docutils.languages.get_language() temporarily.

    This ignores the second argument ``reporter`` to suppress warnings.
    refs: https://github.com/sphinx-doc/sphinx/issues/3788
    """
    from docutils.languages import get_language

    def patched_get_language(language_code: str, reporter: Reporter | None = None) -> Any:
        return get_language(language_code)

    try:
        docutils.languages.get_language = patched_get_language
        yield
    finally:
        # restore original implementations
        docutils.languages.get_language = get_language


@contextmanager
def patched_rst_get_language() -> Generator[None, None, None]:
    """Patch docutils.parsers.rst.languages.get_language().
    Starting from docutils 0.17, get_language() in ``rst.languages``
    also has a reporter, which needs to be disabled temporarily.

    This should also work for old versions of docutils,
    because reporter is none by default.

    refs: https://github.com/sphinx-doc/sphinx/issues/10179
    """
    from docutils.parsers.rst.languages import get_language

    def patched_get_language(language_code: str, reporter: Reporter | None = None) -> Any:
        return get_language(language_code)

    try:
        docutils.parsers.rst.languages.get_language = patched_get_language
        yield
    finally:
        # restore original implementations
        docutils.parsers.rst.languages.get_language = get_language


@contextmanager
def using_user_docutils_conf(confdir: str | None) -> Generator[None, None, None]:
    """Let docutils know the location of ``docutils.conf`` for Sphinx."""
    try:
        docutilsconfig = os.environ.get('DOCUTILSCONFIG', None)
        if confdir:
            os.environ['DOCUTILSCONFIG'] = path.join(path.abspath(confdir), 'docutils.conf')

        yield
    finally:
        if docutilsconfig is None:
            os.environ.pop('DOCUTILSCONFIG', None)
        else:
            os.environ['DOCUTILSCONFIG'] = docutilsconfig


@contextmanager
def du19_footnotes() -> Generator[None, None, None]:
    def visit_footnote(self, node):
        label_style = self.settings.footnote_references
        if not isinstance(node.previous_sibling(), type(node)):
            self.body.append(f'<aside class="footnote-list {label_style}">\n')
        self.body.append(self.starttag(node, 'aside',
                                       classes=[node.tagname, label_style],
                                       role="note"))

    def depart_footnote(self, node):
        self.body.append('</aside>\n')
        if not isinstance(node.next_node(descend=False, siblings=True),
                          type(node)):
            self.body.append('</aside>\n')

    old_visit_footnote = HTMLTranslator.visit_footnote
    old_depart_footnote = HTMLTranslator.depart_footnote

    # Only apply on Docutils 0.18 or 0.18.1, as 0.17 and earlier used a <dl> based
    # approach, and 0.19 and later use the fixed approach by default.
    if docutils.__version_info__[:2] == (0, 18):
        HTMLTranslator.visit_footnote = visit_footnote  # type: ignore[method-assign]
        HTMLTranslator.depart_footnote = depart_footnote  # type: ignore[method-assign]

    try:
        yield
    finally:
        if docutils.__version_info__[:2] == (0, 18):
            HTMLTranslator.visit_footnote = old_visit_footnote  # type: ignore[method-assign]
            HTMLTranslator.depart_footnote = old_depart_footnote  # type: ignore[method-assign]


@contextmanager
def patch_docutils(confdir: str | None = None) -> Generator[None, None, None]:
    """Patch to docutils temporarily."""
    with patched_get_language(), \
         patched_rst_get_language(), \
         using_user_docutils_conf(confdir), \
         du19_footnotes():
        yield


class CustomReSTDispatcher:
    """Custom reST's mark-up dispatcher.

    This replaces docutils's directives and roles dispatch mechanism for reST parser
    by original one temporarily.
    """

    def __init__(self) -> None:
        self.directive_func: Callable = lambda *args: (None, [])
        self.roles_func: Callable = lambda *args: (None, [])

    def __enter__(self) -> None:
        self.enable()

    def __exit__(
        self, exc_type: type[Exception], exc_value: Exception, traceback: Any,
    ) -> None:
        self.disable()

    def enable(self) -> None:
        self.directive_func = directives.directive
        self.role_func = roles.role

        directives.directive = self.directive
        roles.role = self.role

    def disable(self) -> None:
        directives.directive = self.directive_func
        roles.role = self.role_func

    def directive(self,
                  directive_name: str, language_module: ModuleType, document: nodes.document,
                  ) -> tuple[type[Directive] | None, list[system_message]]:
        return self.directive_func(directive_name, language_module, document)

    def role(
        self, role_name: str, language_module: ModuleType, lineno: int, reporter: Reporter,
    ) -> tuple[RoleFunction, list[system_message]]:
        return self.role_func(role_name, language_module,  # type: ignore[return-value]
                              lineno, reporter)


class ElementLookupError(Exception):
    pass


class sphinx_domains(CustomReSTDispatcher):
    """Monkey-patch directive and role dispatch, so that domain-specific
    markup takes precedence.
    """
    def __init__(self, env: BuildEnvironment) -> None:
        self.env = env
        super().__init__()

    def lookup_domain_element(self, type: str, name: str) -> Any:
        """Lookup a markup element (directive or role), given its name which can
        be a full name (with domain).
        """
        name = name.lower()
        # explicit domain given?
        if ':' in name:
            domain_name, name = name.split(':', 1)
            if domain_name in self.env.domains:
                domain = self.env.get_domain(domain_name)
                element = getattr(domain, type)(name)
                if element is not None:
                    return element, []
            else:
                logger.warning(_('unknown directive or role name: %s:%s'), domain_name, name)
        # else look in the default domain
        else:
            def_domain = self.env.temp_data.get('default_domain')
            if def_domain is not None:
                element = getattr(def_domain, type)(name)
                if element is not None:
                    return element, []

        # always look in the std domain
        element = getattr(self.env.get_domain('std'), type)(name)
        if element is not None:
            return element, []

        raise ElementLookupError

    def directive(self,
                  directive_name: str, language_module: ModuleType, document: nodes.document,
                  ) -> tuple[type[Directive] | None, list[system_message]]:
        try:
            return self.lookup_domain_element('directive', directive_name)
        except ElementLookupError:
            return super().directive(directive_name, language_module, document)

    def role(
        self, role_name: str, language_module: ModuleType, lineno: int, reporter: Reporter,
    ) -> tuple[RoleFunction, list[system_message]]:
        try:
            return self.lookup_domain_element('role', role_name)
        except ElementLookupError:
            return super().role(role_name, language_module, lineno, reporter)


class WarningStream:
    def write(self, text: str) -> None:
        matched = report_re.search(text)
        if not matched:
            logger.warning(text.rstrip("\r\n"))
        else:
            location, type, level = matched.groups()
            message = report_re.sub('', text).rstrip()
            logger.log(type, message, location=location)


class LoggingReporter(Reporter):
    @classmethod
    def from_reporter(cls, reporter: Reporter) -> LoggingReporter:
        """Create an instance of LoggingReporter from other reporter object."""
        return cls(reporter.source, reporter.report_level, reporter.halt_level,
                   reporter.debug_flag, reporter.error_handler)

    def __init__(self, source: str, report_level: int = Reporter.WARNING_LEVEL,
                 halt_level: int = Reporter.SEVERE_LEVEL, debug: bool = False,
                 error_handler: str = 'backslashreplace') -> None:
        stream = cast(IO, WarningStream())
        super().__init__(source, report_level, halt_level,
                         stream, debug, error_handler=error_handler)


class NullReporter(Reporter):
    """A dummy reporter; write nothing."""

    def __init__(self) -> None:
        super().__init__('', 999, 4)


@contextmanager
def switch_source_input(state: State, content: StringList) -> Generator[None, None, None]:
    """Switch current source input of state temporarily."""
    try:
        # remember the original ``get_source_and_line()`` method
        gsal = state.memo.reporter.get_source_and_line  # type: ignore[attr-defined]

        # replace it by new one
        state_machine = StateMachine([], None)  # type: ignore[arg-type]
        state_machine.input_lines = content
        state.memo.reporter.get_source_and_line = state_machine.get_source_and_line  # type: ignore[attr-defined]  # noqa: E501

        yield
    finally:
        # restore the method
        state.memo.reporter.get_source_and_line = gsal  # type: ignore[attr-defined]


class SphinxFileOutput(FileOutput):
    """Better FileOutput class for Sphinx."""

    def __init__(self, **kwargs: Any) -> None:
        self.overwrite_if_changed = kwargs.pop('overwrite_if_changed', False)
        kwargs.setdefault('encoding', 'utf-8')
        super().__init__(**kwargs)

    def write(self, data: str) -> str:
        if (self.destination_path and self.autoclose and 'b' not in self.mode and
                self.overwrite_if_changed and os.path.exists(self.destination_path)):
            with open(self.destination_path, encoding=self.encoding) as f:
                # skip writing: content not changed
                if f.read() == data:
                    return data

        return super().write(data)


class SphinxDirective(Directive):
    """A base class for Sphinx directives.

    This class provides helper methods for Sphinx directives.

    .. note:: The subclasses of this class might not work with docutils.
              This class is strongly coupled with Sphinx.
    """

    @property
    def env(self) -> BuildEnvironment:
        """Reference to the :class:`.BuildEnvironment` object."""
        return self.state.document.settings.env

    @property
    def config(self) -> Config:
        """Reference to the :class:`.Config` object."""
        return self.env.config

    def get_source_info(self) -> tuple[str, int]:
        """Get source and line number."""
        return self.state_machine.get_source_and_line(self.lineno)

    def set_source_info(self, node: Node) -> None:
        """Set source and line number to the node."""
        node.source, node.line = self.get_source_info()

    def get_location(self) -> str:
        """Get current location info for logging."""
        return ':'.join(str(s) for s in self.get_source_info())


class SphinxRole:
    """A base class for Sphinx roles.

    This class provides helper methods for Sphinx roles.

    .. note:: The subclasses of this class might not work with docutils.
              This class is strongly coupled with Sphinx.
    """
    name: str         #: The role name actually used in the document.
    rawtext: str      #: A string containing the entire interpreted text input.
    text: str         #: The interpreted text content.
    lineno: int       #: The line number where the interpreted text begins.
    inliner: Inliner  #: The ``docutils.parsers.rst.states.Inliner`` object.
    #: A dictionary of directive options for customisation
    #: (from the "role" directive).
    options: dict[str, Any]
    #: A list of strings, the directive content for customisation
    #: (from the "role" directive).
    content: Sequence[str]

    def __call__(self, name: str, rawtext: str, text: str, lineno: int,
                 inliner: Inliner, options: dict | None = None, content: Sequence[str] = (),
                 ) -> tuple[list[Node], list[system_message]]:
        self.rawtext = rawtext
        self.text = unescape(text)
        self.lineno = lineno
        self.inliner = inliner
        self.options = options if options is not None else {}
        self.content = content

        # guess role type
        if name:
            self.name = name.lower()
        else:
            self.name = self.env.temp_data.get('default_role', '')
            if not self.name:
                self.name = self.env.config.default_role
            if not self.name:
                msg = 'cannot determine default role!'
                raise SphinxError(msg)

        return self.run()

    def run(self) -> tuple[list[Node], list[system_message]]:
        raise NotImplementedError

    @property
    def env(self) -> BuildEnvironment:
        """Reference to the :class:`.BuildEnvironment` object."""
        return self.inliner.document.settings.env

    @property
    def config(self) -> Config:
        """Reference to the :class:`.Config` object."""
        return self.env.config

    def get_source_info(self, lineno: int | None = None) -> tuple[str, int]:
        if lineno is None:
            lineno = self.lineno
        return self.inliner.reporter.get_source_and_line(lineno)  # type: ignore[attr-defined]

    def set_source_info(self, node: Node, lineno: int | None = None) -> None:
        node.source, node.line = self.get_source_info(lineno)

    def get_location(self) -> str:
        """Get current location info for logging."""
        return ':'.join(str(s) for s in self.get_source_info())


class ReferenceRole(SphinxRole):
    """A base class for reference roles.

    The reference roles can accept ``link title <target>`` style as a text for
    the role.  The parsed result; link title and target will be stored to
    ``self.title`` and ``self.target``.
    """
    has_explicit_title: bool    #: A boolean indicates the role has explicit title or not.
    disabled: bool              #: A boolean indicates the reference is disabled.
    title: str                  #: The link title for the interpreted text.
    target: str                 #: The link target for the interpreted text.

    # \x00 means the "<" was backslash-escaped
    explicit_title_re = re.compile(r'^(.+?)\s*(?<!\x00)<(.*?)>$', re.DOTALL)

    def __call__(self, name: str, rawtext: str, text: str, lineno: int,
                 inliner: Inliner, options: dict | None = None, content: Sequence[str] = (),
                 ) -> tuple[list[Node], list[system_message]]:
        if options is None:
            options = {}

        # if the first character is a bang, don't cross-reference at all
        self.disabled = text.startswith('!')

        matched = self.explicit_title_re.match(text)
        if matched:
            self.has_explicit_title = True
            self.title = unescape(matched.group(1))
            self.target = unescape(matched.group(2))
        else:
            self.has_explicit_title = False
            self.title = unescape(text)
            self.target = unescape(text)

        return super().__call__(name, rawtext, text, lineno, inliner, options, content)


class SphinxTranslator(nodes.NodeVisitor):
    """A base class for Sphinx translators.

    This class adds a support for visitor/departure method for super node class
    if visitor/departure method for node class is not found.

    It also provides helper methods for Sphinx translators.

    .. note:: The subclasses of this class might not work with docutils.
              This class is strongly coupled with Sphinx.
    """

    def __init__(self, document: nodes.document, builder: Builder) -> None:
        super().__init__(document)
        self.builder = builder
        self.config = builder.config
        self.settings = document.settings

    def dispatch_visit(self, node: Node) -> None:
        """
        Dispatch node to appropriate visitor method.
        The priority of visitor method is:

        1. ``self.visit_{node_class}()``
        2. ``self.visit_{super_node_class}()``
        3. ``self.unknown_visit()``
        """
        for node_class in node.__class__.__mro__:
            method = getattr(self, 'visit_%s' % (node_class.__name__), None)
            if method:
                method(node)
                break
        else:
            super().dispatch_visit(node)

    def dispatch_departure(self, node: Node) -> None:
        """
        Dispatch node to appropriate departure method.
        The priority of departure method is:

        1. ``self.depart_{node_class}()``
        2. ``self.depart_{super_node_class}()``
        3. ``self.unknown_departure()``
        """
        for node_class in node.__class__.__mro__:
            method = getattr(self, 'depart_%s' % (node_class.__name__), None)
            if method:
                method(node)
                break
        else:
            super().dispatch_departure(node)

    def unknown_visit(self, node: Node) -> None:
        logger.warning(__('unknown node type: %r'), node, location=node)


# cache a vanilla instance of nodes.document
# Used in new_document() function
__document_cache__: tuple[Values, Reporter]


def new_document(source_path: str, settings: Any = None) -> nodes.document:
    """Return a new empty document object.  This is an alternative of docutils'.

    This is a simple wrapper for ``docutils.utils.new_document()``.  It
    caches the result of docutils' and use it on second call for instantiation.
    This makes an instantiation of document nodes much faster.
    """
    global __document_cache__
    try:
        cached_settings, reporter = __document_cache__
    except NameError:
        doc = docutils.utils.new_document(source_path)
        __document_cache__ = cached_settings, reporter = doc.settings, doc.reporter

    if settings is None:
        # Make a copy of the cached settings to accelerate instantiation
        settings = copy(cached_settings)

    # Create a new instance of nodes.document using cached reporter
    from sphinx import addnodes
    document = addnodes.document(settings, reporter, source=source_path)
    document.note_source(source_path, -1)
    return document