"""
    sphinx.highlighting
    ~~~~~~~~~~~~~~~~~~~

    Highlight code blocks using Pygments.

    :copyright: Copyright 2007-2019 by the Sphinx team, see AUTHORS.
    :license: BSD, see LICENSE for details.
"""

import html
import warnings
from functools import partial

from pygments import highlight
from pygments.filters import ErrorToken
from pygments.formatters import HtmlFormatter, LatexFormatter
from pygments.lexer import Lexer
from pygments.lexers import get_lexer_by_name, guess_lexer
from pygments.lexers import PythonLexer, Python3Lexer, PythonConsoleLexer, \
    CLexer, TextLexer, RstLexer
from pygments.styles import get_style_by_name
from pygments.util import ClassNotFound

from sphinx.deprecation import RemovedInSphinx30Warning
from sphinx.ext import doctest
from sphinx.locale import __
from sphinx.pygments_styles import SphinxStyle, NoneStyle
from sphinx.util import logging
from sphinx.util.texescape import tex_hl_escape_map_new

if False:
    # For type annotation
    from typing import Any, Dict  # NOQA
    from pygments.formatter import Formatter  # NOQA
    from pygments.style import Style  # NOQA


logger = logging.getLogger(__name__)

lexers = {}  # type: Dict[str, Lexer]
lexer_classes = {
    'none': partial(TextLexer, stripnl=False),
    'python': partial(PythonLexer, stripnl=False),
    'python3': partial(Python3Lexer, stripnl=False),
    'pycon': partial(PythonConsoleLexer, stripnl=False),
    'pycon3': partial(PythonConsoleLexer, python3=True, stripnl=False),
    'rest': partial(RstLexer, stripnl=False),
    'c': partial(CLexer, stripnl=False),
}  # type: Dict[str, Lexer]


escape_hl_chars = {ord('\\'): '\\PYGZbs{}',
                   ord('{'): '\\PYGZob{}',
                   ord('}'): '\\PYGZcb{}'}

# used if Pygments is available
# use textcomp quote to get a true single quote
_LATEX_ADD_STYLES = r'''
\renewcommand\PYGZsq{\textquotesingle}
'''


class PygmentsBridge:
    # Set these attributes if you want to have different Pygments formatters
    # than the default ones.
    html_formatter = HtmlFormatter
    latex_formatter = LatexFormatter

    def __init__(self, dest='html', stylename='sphinx', trim_doctest_flags=None):
        # type: (str, str, bool) -> None
        self.dest = dest

        style = self.get_style(stylename)
        self.formatter_args = {'style': style}  # type: Dict[str, Any]
        if dest == 'html':
            self.formatter = self.html_formatter
        else:
            self.formatter = self.latex_formatter
            self.formatter_args['commandprefix'] = 'PYG'

        self.trim_doctest_flags = trim_doctest_flags
        if trim_doctest_flags is not None:
            warnings.warn('trim_doctest_flags option for PygmentsBridge is now deprecated.',
                          RemovedInSphinx30Warning, stacklevel=2)

    def get_style(self, stylename):
        # type: (str) -> Style
        if stylename is None or stylename == 'sphinx':
            return SphinxStyle
        elif stylename == 'none':
            return NoneStyle
        elif '.' in stylename:
            module, stylename = stylename.rsplit('.', 1)
            return getattr(__import__(module, None, None, ['__name__']), stylename)
        else:
            return get_style_by_name(stylename)

    def get_formatter(self, **kwargs):
        # type: (Any) -> Formatter
        kwargs.update(self.formatter_args)
        return self.formatter(**kwargs)

    def unhighlighted(self, source):
        # type: (str) -> str
        warnings.warn('PygmentsBridge.unhighlighted() is now deprecated.',
                      RemovedInSphinx30Warning, stacklevel=2)
        if self.dest == 'html':
            return '<pre>' + html.escape(source) + '</pre>\n'
        else:
            # first, escape highlighting characters like Pygments does
            source = source.translate(escape_hl_chars)
            # then, escape all characters nonrepresentable in LaTeX
            source = source.translate(tex_hl_escape_map_new)
            return '\\begin{Verbatim}[commandchars=\\\\\\{\\}]\n' + \
                   source + '\\end{Verbatim}\n'

    def get_lexer(self, source, lang, opts=None, force=False, location=None):
        # type: (str, str, Dict, bool, Any) -> Lexer
        if not opts:
            opts = {}

        # find out which lexer to use
        if lang in ('py', 'python'):
            if source.startswith('>>>'):
                # interactive session
                lang = 'pycon'
            else:
                lang = 'python'
        elif lang in ('py3', 'python3', 'default'):
            if source.startswith('>>>'):
                lang = 'pycon3'
            else:
                lang = 'python3'
        elif lang == 'guess':
            try:
                lexer = guess_lexer(source)
            except Exception:
                lexer = lexers['none']

        if lang in lexers:
            lexer = lexers[lang]
        elif lang in lexer_classes:
            lexer = lexer_classes[lang](**opts)
        else:
            try:
                if lang == 'guess':
                    lexer = guess_lexer(lang, **opts)
                else:
                    lexer = get_lexer_by_name(lang, **opts)
            except ClassNotFound:
                logger.warning(__('Pygments lexer name %r is not known'), lang,
                               location=location)
                lexer = lexer_classes['none'](**opts)

        if not force:
            lexer.add_filter('raiseonerror')

        return lexer

    def highlight_block(self, source, lang, opts=None, force=False, location=None, **kwargs):
        # type: (str, str, Dict, bool, Any, Any) -> str
        if not isinstance(source, str):
            source = source.decode()

        lexer = self.get_lexer(source, lang, opts, force, location)

        # trim doctest options if wanted
        if isinstance(lexer, PythonConsoleLexer) and self.trim_doctest_flags:
            source = doctest.blankline_re.sub('', source)
            source = doctest.doctestopt_re.sub('', source)

        # highlight via Pygments
        formatter = self.get_formatter(**kwargs)
        try:
            hlsource = highlight(source, lexer, formatter)
        except ErrorToken:
            # this is most probably not the selected language,
            # so let it pass unhighlighted
            if lang == 'default':
                pass  # automatic highlighting failed.
            else:
                logger.warning(__('Could not lex literal_block as "%s". '
                                  'Highlighting skipped.'), lang,
                               type='misc', subtype='highlighting_failure',
                               location=location)
            lexer = self.get_lexer(source, 'none', opts, force, location)
            hlsource = highlight(source, lexer, formatter)

        if self.dest == 'html':
            return hlsource
        else:
            return hlsource.translate(tex_hl_escape_map_new)

    def get_stylesheet(self):
        # type: () -> str
        formatter = self.get_formatter()
        if self.dest == 'html':
            return formatter.get_style_defs('.highlight')
        else:
            return formatter.get_style_defs() + _LATEX_ADD_STYLES
