"""
    sphinx.util
    ~~~~~~~~~~~

    Utility functions for Sphinx.

    :copyright: Copyright 2007-2020 by the Sphinx team, see AUTHORS.
    :license: BSD, see LICENSE for details.
"""

import fnmatch
import functools
import hashlib
import os
import posixpath
import re
import sys
import tempfile
import traceback
import unicodedata
import warnings
from codecs import BOM_UTF8
from collections import deque
from datetime import datetime
from importlib import import_module
from os import path
from time import mktime, strptime
from typing import Any, Callable, Dict, IO, Iterable, Iterator, List, Pattern, Set, Tuple
from urllib.parse import urlsplit, urlunsplit, quote_plus, parse_qsl, urlencode

from sphinx.deprecation import RemovedInSphinx40Warning, RemovedInSphinx50Warning
from sphinx.errors import (
    PycodeError, SphinxParallelError, ExtensionError, FiletypeNotFoundError
)
from sphinx.locale import __
from sphinx.util import logging
from sphinx.util.console import strip_colors, colorize, bold, term_width_line  # type: ignore
from sphinx.util.typing import PathMatcher
from sphinx.util import smartypants  # noqa

# import other utilities; partly for backwards compatibility, so don't
# prune unused ones indiscriminately
from sphinx.util.osutil import (  # noqa
    SEP, os_path, relative_uri, ensuredir, walk, mtimes_of_files, movefile,
    copyfile, copytimes, make_filename)
from sphinx.util.nodes import (   # noqa
    nested_parse_with_titles, split_explicit_title, explicit_title_re,
    caption_ref_re)
from sphinx.util.matching import patfilter  # noqa


if False:
    # For type annotation
    from typing import Type  # for python3.5.1
    from sphinx.application import Sphinx


logger = logging.getLogger(__name__)

# Generally useful regular expressions.
ws_re = re.compile(r'\s+')                      # type: Pattern
url_re = re.compile(r'(?P<schema>.+)://.*')     # type: Pattern


# High-level utility functions.

def docname_join(basedocname: str, docname: str) -> str:
    return posixpath.normpath(
        posixpath.join('/' + basedocname, '..', docname))[1:]


def path_stabilize(filepath: str) -> str:
    "normalize path separater and unicode string"
    newpath = filepath.replace(os.path.sep, SEP)
    return unicodedata.normalize('NFC', newpath)


def get_matching_files(dirname: str,
                       exclude_matchers: Tuple[PathMatcher, ...] = ()) -> Iterable[str]:  # NOQA
    """Get all file names in a directory, recursively.

    Exclude files and dirs matching some matcher in *exclude_matchers*.
    """
    # dirname is a normalized absolute path.
    dirname = path.normpath(path.abspath(dirname))
    dirlen = len(dirname) + 1    # exclude final os.path.sep

    for root, dirs, files in os.walk(dirname, followlinks=True):
        relativeroot = root[dirlen:]

        qdirs = enumerate(path_stabilize(path.join(relativeroot, dn))
                          for dn in dirs)  # type: Iterable[Tuple[int, str]]
        qfiles = enumerate(path_stabilize(path.join(relativeroot, fn))
                           for fn in files)  # type: Iterable[Tuple[int, str]]
        for matcher in exclude_matchers:
            qdirs = [entry for entry in qdirs if not matcher(entry[1])]
            qfiles = [entry for entry in qfiles if not matcher(entry[1])]

        dirs[:] = sorted(dirs[i] for (i, _) in qdirs)

        for i, filename in sorted(qfiles):
            yield filename


def get_matching_docs(dirname: str, suffixes: List[str],
                      exclude_matchers: Tuple[PathMatcher, ...] = ()) -> Iterable[str]:
    """Get all file names (without suffixes) matching a suffix in a directory,
    recursively.

    Exclude files and dirs matching a pattern in *exclude_patterns*.
    """
    warnings.warn('get_matching_docs() is now deprecated. Use get_matching_files() instead.',
                  RemovedInSphinx40Warning, stacklevel=2)
    suffixpatterns = ['*' + s for s in suffixes]
    for filename in get_matching_files(dirname, exclude_matchers):
        for suffixpattern in suffixpatterns:
            if fnmatch.fnmatch(filename, suffixpattern):
                yield filename[:-len(suffixpattern) + 1]
                break


def get_filetype(source_suffix: Dict[str, str], filename: str) -> str:
    for suffix, filetype in source_suffix.items():
        if filename.endswith(suffix):
            # If default filetype (None), considered as restructuredtext.
            return filetype or 'restructuredtext'
    else:
        raise FiletypeNotFoundError


class FilenameUniqDict(dict):
    """
    A dictionary that automatically generates unique names for its keys,
    interpreted as filenames, and keeps track of a set of docnames they
    appear in.  Used for images and downloadable files in the environment.
    """
    def __init__(self) -> None:
        self._existing = set()  # type: Set[str]

    def add_file(self, docname: str, newfile: str) -> str:
        if newfile in self:
            self[newfile][0].add(docname)
            return self[newfile][1]
        uniquename = path.basename(newfile)
        base, ext = path.splitext(uniquename)
        i = 0
        while uniquename in self._existing:
            i += 1
            uniquename = '%s%s%s' % (base, i, ext)
        self[newfile] = ({docname}, uniquename)
        self._existing.add(uniquename)
        return uniquename

    def purge_doc(self, docname: str) -> None:
        for filename, (docs, unique) in list(self.items()):
            docs.discard(docname)
            if not docs:
                del self[filename]
                self._existing.discard(unique)

    def merge_other(self, docnames: Set[str], other: Dict[str, Tuple[Set[str], Any]]) -> None:
        for filename, (docs, unique) in other.items():
            for doc in docs & set(docnames):
                self.add_file(doc, filename)

    def __getstate__(self) -> Set[str]:
        return self._existing

    def __setstate__(self, state: Set[str]) -> None:
        self._existing = state


def md5(data=b'', **kwargs):
    """Wrapper around hashlib.md5

    Attempt call with 'usedforsecurity=False' if we get a ValueError, which happens when
    OpenSSL FIPS mode is enabled:
    ValueError: error:060800A3:digital envelope routines:EVP_DigestInit_ex:disabled for fips

    See: https://github.com/sphinx-doc/sphinx/issues/7611
    """

    try:
        return hashlib.md5(data, **kwargs)  # type: ignore
    except ValueError:
        return hashlib.md5(data, **kwargs, usedforsecurity=False)  # type: ignore


def sha1(data=b'', **kwargs):
    """Wrapper around hashlib.sha1

    Attempt call with 'usedforsecurity=False' if we get a ValueError

    See: https://github.com/sphinx-doc/sphinx/issues/7611
    """

    try:
        return hashlib.sha1(data, **kwargs)  # type: ignore
    except ValueError:
        return hashlib.sha1(data, **kwargs, usedforsecurity=False)  # type: ignore


class DownloadFiles(dict):
    """A special dictionary for download files.

    .. important:: This class would be refactored in nearly future.
                   Hence don't hack this directly.
    """

    def add_file(self, docname: str, filename: str) -> str:
        if filename not in self:
            digest = md5(filename.encode()).hexdigest()
            dest = '%s/%s' % (digest, os.path.basename(filename))
            self[filename] = (set(), dest)

        self[filename][0].add(docname)
        return self[filename][1]

    def purge_doc(self, docname: str) -> None:
        for filename, (docs, dest) in list(self.items()):
            docs.discard(docname)
            if not docs:
                del self[filename]

    def merge_other(self, docnames: Set[str], other: Dict[str, Tuple[Set[str], Any]]) -> None:
        for filename, (docs, dest) in other.items():
            for docname in docs & set(docnames):
                self.add_file(docname, filename)


_DEBUG_HEADER = '''\
# Sphinx version: %s
# Python version: %s (%s)
# Docutils version: %s %s
# Jinja2 version: %s
# Last messages:
%s
# Loaded extensions:
'''


def save_traceback(app: "Sphinx") -> str:
    """Save the current exception's traceback in a temporary file."""
    import sphinx
    import jinja2
    import docutils
    import platform
    exc = sys.exc_info()[1]
    if isinstance(exc, SphinxParallelError):
        exc_format = '(Error in parallel process)\n' + exc.traceback
    else:
        exc_format = traceback.format_exc()
    fd, path = tempfile.mkstemp('.log', 'sphinx-err-')
    last_msgs = ''
    if app is not None:
        last_msgs = '\n'.join(
            '#   %s' % strip_colors(s).strip()
            for s in app.messagelog)
    os.write(fd, (_DEBUG_HEADER %
                  (sphinx.__display_version__,
                   platform.python_version(),
                   platform.python_implementation(),
                   docutils.__version__, docutils.__version_details__,
                   jinja2.__version__,  # type: ignore
                   last_msgs)).encode())
    if app is not None:
        for ext in app.extensions.values():
            modfile = getattr(ext.module, '__file__', 'unknown')
            if ext.version != 'builtin':
                os.write(fd, ('#   %s (%s) from %s\n' %
                              (ext.name, ext.version, modfile)).encode())
    os.write(fd, exc_format.encode())
    os.close(fd)
    return path


def get_module_source(modname: str) -> Tuple[str, str]:
    """Try to find the source code for a module.

    Can return ('file', 'filename') in which case the source is in the given
    file, or ('string', 'source') which which case the source is the string.
    """
    warnings.warn('get_module_source() is deprecated.',
                  RemovedInSphinx40Warning, stacklevel=2)
    try:
        mod = import_module(modname)
    except Exception as err:
        raise PycodeError('error importing %r' % modname, err) from err
    filename = getattr(mod, '__file__', None)
    loader = getattr(mod, '__loader__', None)
    if loader and getattr(loader, 'get_filename', None):
        try:
            filename = loader.get_filename(modname)
        except Exception as err:
            raise PycodeError('error getting filename for %r' % filename, err) from err
    if filename is None and loader:
        try:
            filename = loader.get_source(modname)
            if filename:
                return 'string', filename
        except Exception as err:
            raise PycodeError('error getting source for %r' % modname, err) from err
    if filename is None:
        raise PycodeError('no source found for module %r' % modname)
    filename = path.normpath(path.abspath(filename))
    lfilename = filename.lower()
    if lfilename.endswith('.pyo') or lfilename.endswith('.pyc'):
        filename = filename[:-1]
        if not path.isfile(filename) and path.isfile(filename + 'w'):
            filename += 'w'
    elif not (lfilename.endswith('.py') or lfilename.endswith('.pyw')):
        raise PycodeError('source is not a .py file: %r' % filename)
    elif ('.egg' + os.path.sep) in filename:
        pat = '(?<=\\.egg)' + re.escape(os.path.sep)
        eggpath, _ = re.split(pat, filename, 1)
        if path.isfile(eggpath):
            return 'file', filename

    if not path.isfile(filename):
        raise PycodeError('source file is not present: %r' % filename)
    return 'file', filename


def get_full_modname(modname: str, attribute: str) -> str:
    if modname is None:
        # Prevents a TypeError: if the last getattr() call will return None
        # then it's better to return it directly
        return None
    module = import_module(modname)

    # Allow an attribute to have multiple parts and incidentally allow
    # repeated .s in the attribute.
    value = module
    for attr in attribute.split('.'):
        if attr:
            value = getattr(value, attr)

    return getattr(value, '__module__', None)


# a regex to recognize coding cookies
_coding_re = re.compile(r'coding[:=]\s*([-\w.]+)')


def detect_encoding(readline: Callable[[], bytes]) -> str:
    """Like tokenize.detect_encoding() from Py3k, but a bit simplified."""
    warnings.warn('sphinx.util.detect_encoding() is deprecated',
                  RemovedInSphinx40Warning, stacklevel=2)

    def read_or_stop() -> bytes:
        try:
            return readline()
        except StopIteration:
            return None

    def get_normal_name(orig_enc: str) -> str:
        """Imitates get_normal_name in tokenizer.c."""
        # Only care about the first 12 characters.
        enc = orig_enc[:12].lower().replace('_', '-')
        if enc == 'utf-8' or enc.startswith('utf-8-'):
            return 'utf-8'
        if enc in ('latin-1', 'iso-8859-1', 'iso-latin-1') or \
           enc.startswith(('latin-1-', 'iso-8859-1-', 'iso-latin-1-')):
            return 'iso-8859-1'
        return orig_enc

    def find_cookie(line: bytes) -> str:
        try:
            line_string = line.decode('ascii')
        except UnicodeDecodeError:
            return None

        matches = _coding_re.findall(line_string)
        if not matches:
            return None
        return get_normal_name(matches[0])

    default = sys.getdefaultencoding()
    first = read_or_stop()
    if first and first.startswith(BOM_UTF8):
        first = first[3:]
        default = 'utf-8-sig'
    if not first:
        return default
    encoding = find_cookie(first)
    if encoding:
        return encoding
    second = read_or_stop()
    if not second:
        return default
    encoding = find_cookie(second)
    if encoding:
        return encoding
    return default


class UnicodeDecodeErrorHandler:
    """Custom error handler for open() that warns and replaces."""

    def __init__(self, docname: str) -> None:
        self.docname = docname

    def __call__(self, error: UnicodeDecodeError) -> Tuple[str, int]:
        linestart = error.object.rfind(b'\n', 0, error.start)
        lineend = error.object.find(b'\n', error.start)
        if lineend == -1:
            lineend = len(error.object)
        lineno = error.object.count(b'\n', 0, error.start) + 1
        logger.warning(__('undecodable source characters, replacing with "?": %r'),
                       (error.object[linestart + 1:error.start] + b'>>>' +
                        error.object[error.start:error.end] + b'<<<' +
                        error.object[error.end:lineend]),
                       location=(self.docname, lineno))
        return ('?', error.end)


# Low-level utility functions and classes.

class Tee:
    """
    File-like object writing to two streams.
    """
    def __init__(self, stream1: IO, stream2: IO) -> None:
        self.stream1 = stream1
        self.stream2 = stream2

    def write(self, text: str) -> None:
        self.stream1.write(text)
        self.stream2.write(text)

    def flush(self) -> None:
        if hasattr(self.stream1, 'flush'):
            self.stream1.flush()
        if hasattr(self.stream2, 'flush'):
            self.stream2.flush()


def parselinenos(spec: str, total: int) -> List[int]:
    """Parse a line number spec (such as "1,2,4-6") and return a list of
    wanted line numbers.
    """
    items = list()
    parts = spec.split(',')
    for part in parts:
        try:
            begend = part.strip().split('-')
            if ['', ''] == begend:
                raise ValueError
            elif len(begend) == 1:
                items.append(int(begend[0]) - 1)
            elif len(begend) == 2:
                start = int(begend[0] or 1)  # left half open (cf. -10)
                end = int(begend[1] or max(start, total))  # right half open (cf. 10-)
                if start > end:  # invalid range (cf. 10-1)
                    raise ValueError
                items.extend(range(start - 1, end))
            else:
                raise ValueError
        except Exception as exc:
            raise ValueError('invalid line number spec: %r' % spec) from exc

    return items


def force_decode(string: str, encoding: str) -> str:
    """Forcibly get a unicode string out of a bytestring."""
    warnings.warn('force_decode() is deprecated.',
                  RemovedInSphinx40Warning, stacklevel=2)
    if isinstance(string, bytes):
        try:
            if encoding:
                string = string.decode(encoding)
            else:
                # try decoding with utf-8, should only work for real UTF-8
                string = string.decode()
        except UnicodeError:
            # last resort -- can't fail
            string = string.decode('latin1')
    return string


class attrdict(dict):
    def __init__(self, *args: Any, **kwargs: Any) -> None:
        super().__init__(*args, **kwargs)
        warnings.warn('The attrdict class is deprecated.',
                      RemovedInSphinx40Warning, stacklevel=2)

    def __getattr__(self, key: str) -> str:
        return self[key]

    def __setattr__(self, key: str, val: str) -> None:
        self[key] = val

    def __delattr__(self, key: str) -> None:
        del self[key]


def rpartition(s: str, t: str) -> Tuple[str, str]:
    """Similar to str.rpartition from 2.5, but doesn't return the separator."""
    warnings.warn('rpartition() is now deprecated.', RemovedInSphinx50Warning, stacklevel=2)
    i = s.rfind(t)
    if i != -1:
        return s[:i], s[i + len(t):]
    return '', s


def split_into(n: int, type: str, value: str) -> List[str]:
    """Split an index entry into a given number of parts at semicolons."""
    parts = [x.strip() for x in value.split(';', n - 1)]
    if sum(1 for part in parts if part) < n:
        raise ValueError('invalid %s index entry %r' % (type, value))
    return parts


def split_index_msg(type: str, value: str) -> List[str]:
    # new entry types must be listed in directives/other.py!
    if type == 'single':
        try:
            result = split_into(2, 'single', value)
        except ValueError:
            result = split_into(1, 'single', value)
    elif type == 'pair':
        result = split_into(2, 'pair', value)
    elif type == 'triple':
        result = split_into(3, 'triple', value)
    elif type == 'see':
        result = split_into(2, 'see', value)
    elif type == 'seealso':
        result = split_into(2, 'see', value)
    else:
        raise ValueError('invalid %s index entry %r' % (type, value))

    return result


def format_exception_cut_frames(x: int = 1) -> str:
    """Format an exception with traceback, but only the last x frames."""
    typ, val, tb = sys.exc_info()
    # res = ['Traceback (most recent call last):\n']
    res = []  # type: List[str]
    tbres = traceback.format_tb(tb)
    res += tbres[-x:]
    res += traceback.format_exception_only(typ, val)
    return ''.join(res)


class PeekableIterator:
    """
    An iterator which wraps any iterable and makes it possible to peek to see
    what's the next item.
    """
    def __init__(self, iterable: Iterable) -> None:
        self.remaining = deque()  # type: deque
        self._iterator = iter(iterable)
        warnings.warn('PeekableIterator is deprecated.',
                      RemovedInSphinx40Warning, stacklevel=2)

    def __iter__(self) -> "PeekableIterator":
        return self

    def __next__(self) -> Any:
        """Return the next item from the iterator."""
        if self.remaining:
            return self.remaining.popleft()
        return next(self._iterator)

    next = __next__  # Python 2 compatibility

    def push(self, item: Any) -> None:
        """Push the `item` on the internal stack, it will be returned on the
        next :meth:`next` call.
        """
        self.remaining.append(item)

    def peek(self) -> Any:
        """Return the next item without changing the state of the iterator."""
        item = next(self)
        self.push(item)
        return item


def import_object(objname: str, source: str = None) -> Any:
    """Import python object by qualname."""
    try:
        objpath = objname.split('.')
        modname = objpath.pop(0)
        obj = import_module(modname)
        for name in objpath:
            modname += '.' + name
            try:
                obj = getattr(obj, name)
            except AttributeError:
                obj = import_module(modname)

        return obj
    except (AttributeError, ImportError) as exc:
        if source:
            raise ExtensionError('Could not import %s (needed for %s)' %
                                 (objname, source), exc) from exc
        else:
            raise ExtensionError('Could not import %s' % objname, exc) from exc


def split_full_qualified_name(name: str) -> Tuple[str, str]:
    """Split full qualified name to a pair of modname and qualname.

    A qualname is an abbreviation for "Qualified name" introduced at PEP-3155
    (https://www.python.org/dev/peps/pep-3155/).  It is a dotted path name
    from the module top-level.

    A "full" qualified name means a string containing both module name and
    qualified name.

    .. note:: This function imports module actually to check the exisitence.
              Therefore you need to mock 3rd party modules if needed before
              calling this function.
    """
    parts = name.split('.')
    for i, part in enumerate(parts, 1):
        try:
            modname = ".".join(parts[:i])
            import_module(modname)
        except ImportError:
            if parts[:i - 1]:
                return ".".join(parts[:i - 1]), ".".join(parts[i - 1:])
            else:
                return None, ".".join(parts)
        except IndexError:
            pass

    return name, ""


def encode_uri(uri: str) -> str:
    split = list(urlsplit(uri))
    split[1] = split[1].encode('idna').decode('ascii')
    split[2] = quote_plus(split[2].encode(), '/')
    query = list((q, v.encode()) for (q, v) in parse_qsl(split[3]))
    split[3] = urlencode(query)
    return urlunsplit(split)


def display_chunk(chunk: Any) -> str:
    if isinstance(chunk, (list, tuple)):
        if len(chunk) == 1:
            return str(chunk[0])
        return '%s .. %s' % (chunk[0], chunk[-1])
    return str(chunk)


def old_status_iterator(iterable: Iterable, summary: str, color: str = "darkgreen",
                        stringify_func: Callable[[Any], str] = display_chunk) -> Iterator:
    l = 0
    for item in iterable:
        if l == 0:
            logger.info(bold(summary), nonl=True)
            l = 1
        logger.info(stringify_func(item), color=color, nonl=True)
        logger.info(" ", nonl=True)
        yield item
    if l == 1:
        logger.info('')


# new version with progress info
def status_iterator(iterable: Iterable, summary: str, color: str = "darkgreen",
                    length: int = 0, verbosity: int = 0,
                    stringify_func: Callable[[Any], str] = display_chunk) -> Iterable:
    if length == 0:
        yield from old_status_iterator(iterable, summary, color, stringify_func)
        return
    l = 0
    summary = bold(summary)
    for item in iterable:
        l += 1
        s = '%s[%3d%%] %s' % (summary, 100 * l / length, colorize(color, stringify_func(item)))
        if verbosity:
            s += '\n'
        else:
            s = term_width_line(s)
        logger.info(s, nonl=True)
        yield item
    if l > 0:
        logger.info('')


class SkipProgressMessage(Exception):
    pass


class progress_message:
    def __init__(self, message: str) -> None:
        self.message = message

    def __enter__(self) -> None:
        logger.info(bold(self.message + '... '), nonl=True)

    def __exit__(self, exc_type: "Type[Exception]", exc_value: Exception, traceback: Any) -> bool:  # NOQA
        if isinstance(exc_value, SkipProgressMessage):
            logger.info(__('skipped'))
            if exc_value.args:
                logger.info(*exc_value.args)
            return True
        elif exc_type:
            logger.info(__('failed'))
        else:
            logger.info(__('done'))

        return False

    def __call__(self, f: Callable) -> Callable:
        @functools.wraps(f)
        def wrapper(*args: Any, **kwargs: Any) -> Any:
            with self:
                return f(*args, **kwargs)

        return wrapper


def epoch_to_rfc1123(epoch: float) -> str:
    """Convert datetime format epoch to RFC1123."""
    from babel.dates import format_datetime

    dt = datetime.fromtimestamp(epoch)
    fmt = 'EEE, dd LLL yyyy hh:mm:ss'
    return format_datetime(dt, fmt, locale='en') + ' GMT'


def rfc1123_to_epoch(rfc1123: str) -> float:
    return mktime(strptime(rfc1123, '%a, %d %b %Y %H:%M:%S %Z'))


def xmlname_checker() -> Pattern:
    # https://www.w3.org/TR/REC-xml/#NT-Name
    name_start_chars = [
        ':', ['A', 'Z'], '_', ['a', 'z'], ['\u00C0', '\u00D6'],
        ['\u00D8', '\u00F6'], ['\u00F8', '\u02FF'], ['\u0370', '\u037D'],
        ['\u037F', '\u1FFF'], ['\u200C', '\u200D'], ['\u2070', '\u218F'],
        ['\u2C00', '\u2FEF'], ['\u3001', '\uD7FF'], ['\uF900', '\uFDCF'],
        ['\uFDF0', '\uFFFD'], ['\U00010000', '\U000EFFFF']]

    name_chars = [
        "\\-", "\\.", ['0', '9'], '\u00B7', ['\u0300', '\u036F'],
        ['\u203F', '\u2040']
    ]

    def convert(entries: Any, splitter: str = '|') -> str:
        results = []
        for entry in entries:
            if isinstance(entry, list):
                results.append('[%s]' % convert(entry, '-'))
            else:
                results.append(entry)
        return splitter.join(results)

    start_chars_regex = convert(name_start_chars)
    name_chars_regex = convert(name_chars)
    return re.compile('(%s)(%s|%s)*' % (
        start_chars_regex, start_chars_regex, name_chars_regex))
