# -*- coding: utf-8 -*-
"""
    sphinx.util.docutils
    ~~~~~~~~~~~~~~~~~~~~

    Utility functions for docutils.

    :copyright: Copyright 2007-2018 by the Sphinx team, see AUTHORS.
    :license: BSD, see LICENSE for details.
"""
from __future__ import absolute_import

import re
import types
import warnings
from contextlib import contextmanager
from copy import copy
from distutils.version import LooseVersion

import docutils
from docutils import nodes
from docutils.languages import get_language
from docutils.parsers.rst import Directive, directives, roles, convert_directive_function
from docutils.statemachine import StateMachine
from docutils.utils import Reporter

from sphinx.deprecation import RemovedInSphinx30Warning
from sphinx.errors import ExtensionError
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 False:
    # For type annotation
    from typing import Any, Callable, Generator, Iterator, List, Set, Tuple  # NOQA
    from docutils.statemachine import State, ViewList  # NOQA
    from sphinx.config import Config  # NOQA
    from sphinx.environment import BuildEnvironment  # NOQA
    from sphinx.io import SphinxFileInput  # NOQA


__version_info__ = tuple(LooseVersion(docutils.__version__).version)
additional_nodes = set()  # type: Set[nodes.Node]


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

        yield
    finally:
        directives._directives = _directives
        roles._roles = _roles

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


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


def register_node(node):
    # type: (nodes.Node) -> 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__])
        additional_nodes.add(node)


def unregister_node(node):
    # type: (nodes.Node) -> 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__)


def patched_get_language(language_code, reporter=None):
    # type: (unicode, Reporter) -> Any
    """A wrapper for docutils.languages.get_language().

    This ignores the second argument ``reporter`` to suppress warnings.
    refs: https://github.com/sphinx-doc/sphinx/issues/3788
    """
    return get_language(language_code)


@contextmanager
def patch_docutils():
    # type: () -> Iterator[None]
    """Patch to docutils temporarily."""
    try:
        docutils.languages.get_language = patched_get_language

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


class ElementLookupError(Exception):
    pass


class sphinx_domains(object):
    """Monkey-patch directive and role dispatch, so that domain-specific
    markup takes precedence.
    """
    def __init__(self, env):
        # type: (BuildEnvironment) -> None
        self.env = env
        self.directive_func = None  # type: Callable
        self.roles_func = None  # type: Callable

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

    def __exit__(self, type, value, traceback):
        # type: (unicode, unicode, unicode) -> None
        self.disable()

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

        directives.directive = self.lookup_directive
        roles.role = self.lookup_role

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

    def lookup_domain_element(self, type, name):
        # type: (unicode, unicode) -> Tuple[Any, List]
        """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 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 lookup_directive(self, name, lang_module, document):
        # type: (unicode, unicode, nodes.document) -> Tuple[Any, List]
        try:
            return self.lookup_domain_element('directive', name)
        except ElementLookupError:
            return self.directive_func(name, lang_module, document)

    def lookup_role(self, name, lang_module, lineno, reporter):
        # type: (unicode, unicode, int, Any) -> Tuple[Any, List]
        try:
            return self.lookup_domain_element('role', name)
        except ElementLookupError:
            return self.role_func(name, lang_module, lineno, reporter)


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


class LoggingReporter(Reporter):
    @classmethod
    def from_reporter(cls, reporter):
        # type: (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, report_level, halt_level,
                 debug=False, error_handler='backslashreplace'):
        # type: (unicode, int, int, bool, unicode) -> None
        stream = WarningStream()
        Reporter.__init__(self, source, report_level, halt_level,
                          stream, debug, error_handler=error_handler)


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

    def __init__(self):
        # type: () -> None
        Reporter.__init__(self, '', 999, 4)


def is_html5_writer_available():
    # type: () -> bool
    return __version_info__ > (0, 13, 0)


def directive_helper(obj, has_content=None, argument_spec=None, **option_spec):
    # type: (Any, bool, Tuple[int, int, bool], Any) -> Any
    warnings.warn('function based directive support is now deprecated. '
                  'Use class based directive instead.',
                  RemovedInSphinx30Warning)

    if isinstance(obj, (types.FunctionType, types.MethodType)):
        obj.content = has_content                       # type: ignore
        obj.arguments = argument_spec or (0, 0, False)  # type: ignore
        obj.options = option_spec                       # type: ignore
        return convert_directive_function(obj)
    else:
        if has_content or argument_spec or option_spec:
            raise ExtensionError(__('when adding directive classes, no '
                                    'additional arguments may be given'))
        return obj


@contextmanager
def switch_source_input(state, content):
    # type: (State, ViewList) -> Generator
    """Switch current source input of state temporarily."""
    try:
        # remember the original ``get_source_and_line()`` method
        get_source_and_line = state.memo.reporter.get_source_and_line

        # replace it by new one
        state_machine = StateMachine([], None)
        state_machine.input_lines = content
        state.memo.reporter.get_source_and_line = state_machine.get_source_and_line

        yield
    finally:
        # restore the method
        state.memo.reporter.get_source_and_line = get_source_and_line


class SphinxDirective(Directive):
    """A base class for Directives.

    Compared with ``docutils.parsers.rst.Directive``, this class improves
    accessibility to Sphinx APIs.
    """

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

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


# cache a vanilla instance of nodes.document
# Used in new_document() function
__document_cache__ = None  # type: nodes.document


def new_document(source_path, settings=None):
    # type: (unicode, Any) -> 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 instanciation.
    This makes an instantiation of document nodes much faster.
    """
    global __document_cache__
    if __document_cache__ is None:
        __document_cache__ = docutils.utils.new_document(source_path)

    if settings is None:
        # Make a copy of ``settings`` from cache to accelerate instansiation
        settings = copy(__document_cache__.settings)

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