text.py

"""
    sphinx.writers.text
    ~~~~~~~~~~~~~~~~~~~

    Custom docutils writer for plain text.

    :copyright: Copyright 2007-2020 by the Sphinx team, see AUTHORS.
    :license: BSD, see LICENSE for details.
"""
import math
import os
import re
import textwrap
from itertools import groupby, chain
from typing import Any, Dict, Generator, List, Iterable, Optional, Set, Tuple, Union
from typing import cast

from docutils import nodes, writers
from docutils.nodes import Element, Node, Text
from docutils.utils import column_width

from sphinx import addnodes
from sphinx.locale import admonitionlabels, _
from sphinx.util.docutils import SphinxTranslator

if False:
    # For type annotation
    from sphinx.builders.text import TextBuilder


class Cell:
    """Represents a cell in a table.
    It can span on multiple columns or on multiple lines.
    """
    def __init__(self, text: str = "", rowspan: int = 1, colspan: int = 1) -> None:
        self.text = text
        self.wrapped = []  # type: List[str]
        self.rowspan = rowspan
        self.colspan = colspan
        self.col = None  # type: Optional[int]
        self.row = None  # type: Optional[int]

    def __repr__(self) -> str:
        return "<Cell {!r} {}v{}/{}>{}>".format(
            self.text, self.row, self.rowspan, self.col, self.colspan
        )

    def __hash__(self) -> int:
        return hash((self.col, self.row))

    def wrap(self, width: int) -> None:
        self.wrapped = my_wrap(self.text, width)


class Table:
    """Represents a table, handling cells that can span on multiple lines
    or rows, like::

       +-----------+-----+
       | AAA       | BBB |
       +-----+-----+     |
       |     | XXX |     |
       |     +-----+-----+
       | DDD | CCC       |
       +-----+-----------+

    This class can be used in two ways:

    - Either with absolute positions: call ``table[line, col] = Cell(...)``,
      this overwrite an existing cell if any.

    - Either with relative positions: call the ``add_row()`` and
      ``add_cell(Cell(...))`` as needed.

    Cell spanning on multiple rows or multiple columns (having a
    colspan or rowspan greater than one) are automatically referenced
    by all the table cells they covers. This is a useful
    representation as we can simply check ``if self[x, y] is self[x,
    y+1]`` to recognize a rowspan.

    Colwidth is not automatically computed, it has to be given, either
    at construction time, either during the table construction.

    Example usage::

       table = Table([6, 6])
       table.add_cell(Cell("foo"))
       table.add_cell(Cell("bar"))
       table.set_separator()
       table.add_row()
       table.add_cell(Cell("FOO"))
       table.add_cell(Cell("BAR"))
       print(table)
       +--------+--------+
       | foo    | bar    |
       |========|========|
       | FOO    | BAR    |
       +--------+--------+

    """
    def __init__(self, colwidth: List[int] = None) -> None:
        self.lines = []  # type: List[List[Cell]]
        self.separator = 0
        self.colwidth = (colwidth if colwidth is not None
                         else [])  # type: List[int]
        self.current_line = 0
        self.current_col = 0

    def add_row(self) -> None:
        """Add a row to the table, to use with ``add_cell()``.  It is not needed
        to call ``add_row()`` before the first ``add_cell()``.
        """
        self.current_line += 1
        self.current_col = 0

    def set_separator(self) -> None:
        """Sets the separator below the current line.
        """
        self.separator = len(self.lines)

    def add_cell(self, cell: Cell) -> None:
        """Add a cell to the current line, to use with ``add_row()``.  To add
        a cell spanning on multiple lines or rows, simply set the
        ``cell.colspan`` or ``cell.rowspan`` BEFORE inserting it to
        the table.
        """
        while self[self.current_line, self.current_col]:
            self.current_col += 1
        self[self.current_line, self.current_col] = cell
        self.current_col += cell.colspan

    def __getitem__(self, pos: Tuple[int, int]) -> Cell:
        line, col = pos
        self._ensure_has_line(line + 1)
        self._ensure_has_column(col + 1)
        return self.lines[line][col]

    def __setitem__(self, pos: Tuple[int, int], cell: Cell) -> None:
        line, col = pos
        self._ensure_has_line(line + cell.rowspan)
        self._ensure_has_column(col + cell.colspan)
        for dline in range(cell.rowspan):
            for dcol in range(cell.colspan):
                self.lines[line + dline][col + dcol] = cell
                cell.row = line
                cell.col = col

    def _ensure_has_line(self, line: int) -> None:
        while len(self.lines) < line:
            self.lines.append([])

    def _ensure_has_column(self, col: int) -> None:
        for line in self.lines:
            while len(line) < col:
                line.append(None)

    def __repr__(self) -> str:
        return "\n".join(repr(line) for line in self.lines)

    def cell_width(self, cell: Cell, source: List[int]) -> int:
        """Give the cell width, according to the given source (either
        ``self.colwidth`` or ``self.measured_widths``).
        This take into account cells spanning on multiple columns.
        """
        width = 0
        for i in range(self[cell.row, cell.col].colspan):
            width += source[cell.col + i]
        return width + (cell.colspan - 1) * 3

    @property
    def cells(self) -> Generator[Cell, None, None]:
        seen = set()  # type: Set[Cell]
        for lineno, line in enumerate(self.lines):
            for colno, cell in enumerate(line):
                if cell and cell not in seen:
                    yield cell
                    seen.add(cell)

    def rewrap(self) -> None:
        """Call ``cell.wrap()`` on all cells, and measure each column width
        after wrapping (result written in ``self.measured_widths``).
        """
        self.measured_widths = self.colwidth[:]
        for cell in self.cells:
            cell.wrap(width=self.cell_width(cell, self.colwidth))
            if not cell.wrapped:
                continue
            width = math.ceil(max(column_width(x) for x in cell.wrapped) / cell.colspan)
            for col in range(cell.col, cell.col + cell.colspan):
                self.measured_widths[col] = max(self.measured_widths[col], width)

    def physical_lines_for_line(self, line: List[Cell]) -> int:
        """From a given line, compute the number of physical lines it spans
        due to text wrapping.
        """
        physical_lines = 1
        for cell in line:
            physical_lines = max(physical_lines, len(cell.wrapped))
        return physical_lines

    def __str__(self) -> str:
        out = []
        self.rewrap()

        def writesep(char: str = "-", lineno: Optional[int] = None) -> str:
            """Called on the line *before* lineno.
            Called with no *lineno* for the last sep.
            """
            out = []  # type: List[str]
            for colno, width in enumerate(self.measured_widths):
                if (
                    lineno is not None and
                    lineno > 0 and
                    self[lineno, colno] is self[lineno - 1, colno]
                ):
                    out.append(" " * (width + 2))
                else:
                    out.append(char * (width + 2))
            head = "+" if out[0][0] == "-" else "|"
            tail = "+" if out[-1][0] == "-" else "|"
            glue = [
                "+" if left[0] == "-" or right[0] == "-" else "|"
                for left, right in zip(out, out[1:])
            ]
            glue.append(tail)
            return head + "".join(chain.from_iterable(zip(out, glue)))

        for lineno, line in enumerate(self.lines):
            if self.separator and lineno == self.separator:
                out.append(writesep("=", lineno))
            else:
                out.append(writesep("-", lineno))
            for physical_line in range(self.physical_lines_for_line(line)):
                linestr = ["|"]
                for colno, cell in enumerate(line):
                    if cell.col != colno:
                        continue
                    if lineno != cell.row:
                        physical_text = ""
                    elif physical_line >= len(cell.wrapped):
                        physical_text = ""
                    else:
                        physical_text = cell.wrapped[physical_line]
                    adjust_len = len(physical_text) - column_width(physical_text)
                    linestr.append(
                        " " +
                        physical_text.ljust(
                            self.cell_width(cell, self.measured_widths) + 1 + adjust_len
                        ) + "|"
                    )
                out.append("".join(linestr))
        out.append(writesep("-"))
        return "\n".join(out)


class TextWrapper(textwrap.TextWrapper):
    """Custom subclass that uses a different word separator regex."""

    wordsep_re = re.compile(
        r'(\s+|'                                  # any whitespace
        r'(?<=\s)(?::[a-z-]+:)?`\S+|'             # interpreted text start
        r'[^\s\w]*\w+[a-zA-Z]-(?=\w+[a-zA-Z])|'   # hyphenated words
        r'(?<=[\w\!\"\'\&\.\,\?])-{2,}(?=\w))')   # em-dash

    def _wrap_chunks(self, chunks: List[str]) -> List[str]:
        """_wrap_chunks(chunks : [string]) -> [string]

        The original _wrap_chunks uses len() to calculate width.
        This method respects wide/fullwidth characters for width adjustment.
        """
        lines = []  # type: List[str]
        if self.width <= 0:
            raise ValueError("invalid width %r (must be > 0)" % self.width)

        chunks.reverse()

        while chunks:
            cur_line = []
            cur_len = 0

            if lines:
                indent = self.subsequent_indent
            else:
                indent = self.initial_indent

            width = self.width - column_width(indent)

            if self.drop_whitespace and chunks[-1].strip() == '' and lines:
                del chunks[-1]

            while chunks:
                l = column_width(chunks[-1])

                if cur_len + l <= width:
                    cur_line.append(chunks.pop())
                    cur_len += l

                else:
                    break

            if chunks and column_width(chunks[-1]) > width:
                self._handle_long_word(chunks, cur_line, cur_len, width)

            if self.drop_whitespace and cur_line and cur_line[-1].strip() == '':
                del cur_line[-1]

            if cur_line:
                lines.append(indent + ''.join(cur_line))

        return lines

    def _break_word(self, word: str, space_left: int) -> Tuple[str, str]:
        """_break_word(word : string, space_left : int) -> (string, string)

        Break line by unicode width instead of len(word).
        """
        total = 0
        for i, c in enumerate(word):
            total += column_width(c)
            if total > space_left:
                return word[:i - 1], word[i - 1:]
        return word, ''

    def _split(self, text: str) -> List[str]:
        """_split(text : string) -> [string]

        Override original method that only split by 'wordsep_re'.
        This '_split' split wide-characters into chunk by one character.
        """
        def split(t: str) -> List[str]:
            return super(TextWrapper, self)._split(t)
        chunks = []  # type: List[str]
        for chunk in split(text):
            for w, g in groupby(chunk, column_width):
                if w == 1:
                    chunks.extend(split(''.join(g)))
                else:
                    chunks.extend(list(g))
        return chunks

    def _handle_long_word(self, reversed_chunks: List[str], cur_line: List[str],
                          cur_len: int, width: int) -> None:
        """_handle_long_word(chunks : [string],
                             cur_line : [string],
                             cur_len : int, width : int)

        Override original method for using self._break_word() instead of slice.
        """
        space_left = max(width - cur_len, 1)
        if self.break_long_words:
            l, r = self._break_word(reversed_chunks[-1], space_left)
            cur_line.append(l)
            reversed_chunks[-1] = r

        elif not cur_line:
            cur_line.append(reversed_chunks.pop())


MAXWIDTH = 70
STDINDENT = 3


def my_wrap(text: str, width: int = MAXWIDTH, **kwargs: Any) -> List[str]:
    w = TextWrapper(width=width, **kwargs)
    return w.wrap(text)


class TextWriter(writers.Writer):
    supported = ('text',)
    settings_spec = ('No options here.', '', ())
    settings_defaults = {}  # type: Dict

    output = None  # type: str

    def __init__(self, builder: "TextBuilder") -> None:
        super().__init__()
        self.builder = builder

    def translate(self) -> None:
        visitor = self.builder.create_translator(self.document, self.builder)
        self.document.walkabout(visitor)
        self.output = cast(TextTranslator, visitor).body


class TextTranslator(SphinxTranslator):
    builder = None  # type: TextBuilder

    def __init__(self, document: nodes.document, builder: "TextBuilder") -> None:
        super().__init__(document, builder)

        newlines = self.config.text_newlines
        if newlines == 'windows':
            self.nl = '\r\n'
        elif newlines == 'native':
            self.nl = os.linesep
        else:
            self.nl = '\n'
        self.sectionchars = self.config.text_sectionchars
        self.add_secnumbers = self.config.text_add_secnumbers
        self.secnumber_suffix = self.config.text_secnumber_suffix
        self.states = [[]]      # type: List[List[Tuple[int, Union[str, List[str]]]]]
        self.stateindent = [0]
        self.list_counter = []  # type: List[int]
        self.sectionlevel = 0
        self.lineblocklevel = 0
        self.table = None       # type: Table

    def add_text(self, text: str) -> None:
        self.states[-1].append((-1, text))

    def new_state(self, indent: int = STDINDENT) -> None:
        self.states.append([])
        self.stateindent.append(indent)

    def end_state(self, wrap: bool = True, end: List[str] = [''], first: str = None) -> None:
        content = self.states.pop()
        maxindent = sum(self.stateindent)
        indent = self.stateindent.pop()
        result = []     # type: List[Tuple[int, List[str]]]
        toformat = []   # type: List[str]

        def do_format() -> None:
            if not toformat:
                return
            if wrap:
                res = my_wrap(''.join(toformat), width=MAXWIDTH - maxindent)
            else:
                res = ''.join(toformat).splitlines()
            if end:
                res += end
            result.append((indent, res))
        for itemindent, item in content:
            if itemindent == -1:
                toformat.append(item)  # type: ignore
            else:
                do_format()
                result.append((indent + itemindent, item))  # type: ignore
                toformat = []
        do_format()
        if first is not None and result:
            # insert prefix into first line (ex. *, [1], See also, etc.)
            newindent = result[0][0] - indent
            if result[0][1] == ['']:
                result.insert(0, (newindent, [first]))
            else:
                text = first + result[0][1].pop(0)
                result.insert(0, (newindent, [text]))

        self.states[-1].extend(result)

    def visit_document(self, node: Element) -> None:
        self.new_state(0)

    def depart_document(self, node: Element) -> None:
        self.end_state()
        self.body = self.nl.join(line and (' ' * indent + line)
                                 for indent, lines in self.states[0]
                                 for line in lines)
        # XXX header/footer?

    def visit_section(self, node: Element) -> None:
        self._title_char = self.sectionchars[self.sectionlevel]
        self.sectionlevel += 1

    def depart_section(self, node: Element) -> None:
        self.sectionlevel -= 1

    def visit_topic(self, node: Element) -> None:
        self.new_state(0)

    def depart_topic(self, node: Element) -> None:
        self.end_state()

    visit_sidebar = visit_topic
    depart_sidebar = depart_topic

    def visit_rubric(self, node: Element) -> None:
        self.new_state(0)
        self.add_text('-[ ')

    def depart_rubric(self, node: Element) -> None:
        self.add_text(' ]-')
        self.end_state()

    def visit_compound(self, node: Element) -> None:
        pass

    def depart_compound(self, node: Element) -> None:
        pass

    def visit_glossary(self, node: Element) -> None:
        pass

    def depart_glossary(self, node: Element) -> None:
        pass

    def visit_title(self, node: Element) -> None:
        if isinstance(node.parent, nodes.Admonition):
            self.add_text(node.astext() + ': ')
            raise nodes.SkipNode
        self.new_state(0)

    def get_section_number_string(self, node: Element) -> str:
        if isinstance(node.parent, nodes.section):
            anchorname = '#' + node.parent['ids'][0]
            numbers = self.builder.secnumbers.get(anchorname)
            if numbers is None:
                numbers = self.builder.secnumbers.get('')
            if numbers is not None:
                return '.'.join(map(str, numbers)) + self.secnumber_suffix
        return ''

    def depart_title(self, node: Element) -> None:
        if isinstance(node.parent, nodes.section):
            char = self._title_char
        else:
            char = '^'
        text = ''
        text = ''.join(x[1] for x in self.states.pop() if x[0] == -1)  # type: ignore
        if self.add_secnumbers:
            text = self.get_section_number_string(node) + text
        self.stateindent.pop()
        title = ['', text, '%s' % (char * column_width(text)), '']
        if len(self.states) == 2 and len(self.states[-1]) == 0:
            # remove an empty line before title if it is first section title in the document
            title.pop(0)
        self.states[-1].append((0, title))

    def visit_subtitle(self, node: Element) -> None:
        pass

    def depart_subtitle(self, node: Element) -> None:
        pass

    def visit_attribution(self, node: Element) -> None:
        self.add_text('-- ')

    def depart_attribution(self, node: Element) -> None:
        pass

    def visit_desc(self, node: Element) -> None:
        pass

    def depart_desc(self, node: Element) -> None:
        pass

    def visit_desc_signature(self, node: Element) -> None:
        self.new_state(0)

    def depart_desc_signature(self, node: Element) -> None:
        # XXX: wrap signatures in a way that makes sense
        self.end_state(wrap=False, end=None)

    def visit_desc_signature_line(self, node: Element) -> None:
        pass

    def depart_desc_signature_line(self, node: Element) -> None:
        self.add_text('\n')

    def visit_desc_name(self, node: Element) -> None:
        pass

    def depart_desc_name(self, node: Element) -> None:
        pass

    def visit_desc_addname(self, node: Element) -> None:
        pass

    def depart_desc_addname(self, node: Element) -> None:
        pass

    def visit_desc_type(self, node: Element) -> None:
        pass

    def depart_desc_type(self, node: Element) -> None:
        pass

    def visit_desc_returns(self, node: Element) -> None:
        self.add_text(' -> ')

    def depart_desc_returns(self, node: Element) -> None:
        pass

    def visit_desc_parameterlist(self, node: Element) -> None:
        self.add_text('(')
        self.first_param = 1

    def depart_desc_parameterlist(self, node: Element) -> None:
        self.add_text(')')

    def visit_desc_parameter(self, node: Element) -> None:
        if not self.first_param:
            self.add_text(', ')
        else:
            self.first_param = 0
        self.add_text(node.astext())
        raise nodes.SkipNode

    def visit_desc_optional(self, node: Element) -> None:
        self.add_text('[')

    def depart_desc_optional(self, node: Element) -> None:
        self.add_text(']')

    def visit_desc_annotation(self, node: Element) -> None:
        pass

    def depart_desc_annotation(self, node: Element) -> None:
        pass

    def visit_desc_content(self, node: Element) -> None:
        self.new_state()
        self.add_text(self.nl)

    def depart_desc_content(self, node: Element) -> None:
        self.end_state()

    def visit_figure(self, node: Element) -> None:
        self.new_state()

    def depart_figure(self, node: Element) -> None:
        self.end_state()

    def visit_caption(self, node: Element) -> None:
        pass

    def depart_caption(self, node: Element) -> None:
        pass

    def visit_productionlist(self, node: Element) -> None:
        self.new_state()
        names = []
        productionlist = cast(Iterable[addnodes.production], node)
        for production in productionlist:
            names.append(production['tokenname'])
        maxlen = max(len(name) for name in names)
        lastname = None
        for production in productionlist:
            if production['tokenname']:
                self.add_text(production['tokenname'].ljust(maxlen) + ' ::=')
                lastname = production['tokenname']
            elif lastname is not None:
                self.add_text('%s    ' % (' ' * len(lastname)))
            self.add_text(production.astext() + self.nl)
        self.end_state(wrap=False)
        raise nodes.SkipNode

    def visit_footnote(self, node: Element) -> None:
        label = cast(nodes.label, node[0])
        self._footnote = label.astext().strip()
        self.new_state(len(self._footnote) + 3)

    def depart_footnote(self, node: Element) -> None:
        self.end_state(first='[%s] ' % self._footnote)

    def visit_citation(self, node: Element) -> None:
        if len(node) and isinstance(node[0], nodes.label):
            self._citlabel = node[0].astext()
        else:
            self._citlabel = ''
        self.new_state(len(self._citlabel) + 3)

    def depart_citation(self, node: Element) -> None:
        self.end_state(first='[%s] ' % self._citlabel)

    def visit_label(self, node: Element) -> None:
        raise nodes.SkipNode

    def visit_legend(self, node: Element) -> None:
        pass

    def depart_legend(self, node: Element) -> None:
        pass

    # XXX: option list could use some better styling

    def visit_option_list(self, node: Element) -> None:
        pass

    def depart_option_list(self, node: Element) -> None:
        pass

    def visit_option_list_item(self, node: Element) -> None:
        self.new_state(0)

    def depart_option_list_item(self, node: Element) -> None:
        self.end_state()

    def visit_option_group(self, node: Element) -> None:
        self._firstoption = True

    def depart_option_group(self, node: Element) -> None:
        self.add_text('     ')

    def visit_option(self, node: Element) -> None:
        if self._firstoption:
            self._firstoption = False
        else:
            self.add_text(', ')

    def depart_option(self, node: Element) -> None:
        pass

    def visit_option_string(self, node: Element) -> None:
        pass

    def depart_option_string(self, node: Element) -> None:
        pass

    def visit_option_argument(self, node: Element) -> None:
        self.add_text(node['delimiter'])

    def depart_option_argument(self, node: Element) -> None:
        pass

    def visit_description(self, node: Element) -> None:
        pass

    def depart_description(self, node: Element) -> None:
        pass

    def visit_tabular_col_spec(self, node: Element) -> None:
        raise nodes.SkipNode

    def visit_colspec(self, node: Element) -> None:
        self.table.colwidth.append(node["colwidth"])
        raise nodes.SkipNode

    def visit_tgroup(self, node: Element) -> None:
        pass

    def depart_tgroup(self, node: Element) -> None:
        pass

    def visit_thead(self, node: Element) -> None:
        pass

    def depart_thead(self, node: Element) -> None:
        pass

    def visit_tbody(self, node: Element) -> None:
        self.table.set_separator()

    def depart_tbody(self, node: Element) -> None:
        pass

    def visit_row(self, node: Element) -> None:
        if self.table.lines:
            self.table.add_row()

    def depart_row(self, node: Element) -> None:
        pass

    def visit_entry(self, node: Element) -> None:
        self.entry = Cell(
            rowspan=node.get("morerows", 0) + 1, colspan=node.get("morecols", 0) + 1
        )
        self.new_state(0)

    def depart_entry(self, node: Element) -> None:
        text = self.nl.join(self.nl.join(x[1]) for x in self.states.pop())
        self.stateindent.pop()
        self.entry.text = text
        self.table.add_cell(self.entry)
        self.entry = None

    def visit_table(self, node: Element) -> None:
        if self.table:
            raise NotImplementedError('Nested tables are not supported.')
        self.new_state(0)
        self.table = Table()

    def depart_table(self, node: Element) -> None:
        self.add_text(str(self.table))
        self.table = None
        self.end_state(wrap=False)

    def visit_acks(self, node: Element) -> None:
        bullet_list = cast(nodes.bullet_list, node[0])
        list_items = cast(Iterable[nodes.list_item], bullet_list)
        self.new_state(0)
        self.add_text(', '.join(n.astext() for n in list_items) + '.')
        self.end_state()
        raise nodes.SkipNode

    def visit_image(self, node: Element) -> None:
        if 'alt' in node.attributes:
            self.add_text(_('[image: %s]') % node['alt'])
        self.add_text(_('[image]'))
        raise nodes.SkipNode

    def visit_transition(self, node: Element) -> None:
        indent = sum(self.stateindent)
        self.new_state(0)
        self.add_text('=' * (MAXWIDTH - indent))
        self.end_state()
        raise nodes.SkipNode

    def visit_bullet_list(self, node: Element) -> None:
        self.list_counter.append(-1)

    def depart_bullet_list(self, node: Element) -> None:
        self.list_counter.pop()

    def visit_enumerated_list(self, node: Element) -> None:
        self.list_counter.append(node.get('start', 1) - 1)

    def depart_enumerated_list(self, node: Element) -> None:
        self.list_counter.pop()

    def visit_definition_list(self, node: Element) -> None:
        self.list_counter.append(-2)

    def depart_definition_list(self, node: Element) -> None:
        self.list_counter.pop()

    def visit_list_item(self, node: Element) -> None:
        if self.list_counter[-1] == -1:
            # bullet list
            self.new_state(2)
        elif self.list_counter[-1] == -2:
            # definition list
            pass
        else:
            # enumerated list
            self.list_counter[-1] += 1
            self.new_state(len(str(self.list_counter[-1])) + 2)

    def depart_list_item(self, node: Element) -> None:
        if self.list_counter[-1] == -1:
            self.end_state(first='* ')
        elif self.list_counter[-1] == -2:
            pass
        else:
            self.end_state(first='%s. ' % self.list_counter[-1])

    def visit_definition_list_item(self, node: Element) -> None:
        self._classifier_count_in_li = len(node.traverse(nodes.classifier))

    def depart_definition_list_item(self, node: Element) -> None:
        pass

    def visit_term(self, node: Element) -> None:
        self.new_state(0)

    def depart_term(self, node: Element) -> None:
        if not self._classifier_count_in_li:
            self.end_state(end=None)

    def visit_classifier(self, node: Element) -> None:
        self.add_text(' : ')

    def depart_classifier(self, node: Element) -> None:
        self._classifier_count_in_li -= 1
        if not self._classifier_count_in_li:
            self.end_state(end=None)

    def visit_definition(self, node: Element) -> None:
        self.new_state()

    def depart_definition(self, node: Element) -> None:
        self.end_state()

    def visit_field_list(self, node: Element) -> None:
        pass

    def depart_field_list(self, node: Element) -> None:
        pass

    def visit_field(self, node: Element) -> None:
        pass

    def depart_field(self, node: Element) -> None:
        pass

    def visit_field_name(self, node: Element) -> None:
        self.new_state(0)

    def depart_field_name(self, node: Element) -> None:
        self.add_text(':')
        self.end_state(end=None)

    def visit_field_body(self, node: Element) -> None:
        self.new_state()

    def depart_field_body(self, node: Element) -> None:
        self.end_state()

    def visit_centered(self, node: Element) -> None:
        pass

    def depart_centered(self, node: Element) -> None:
        pass

    def visit_hlist(self, node: Element) -> None:
        pass

    def depart_hlist(self, node: Element) -> None:
        pass

    def visit_hlistcol(self, node: Element) -> None:
        pass

    def depart_hlistcol(self, node: Element) -> None:
        pass

    def visit_admonition(self, node: Element) -> None:
        self.new_state(0)

    def depart_admonition(self, node: Element) -> None:
        self.end_state()

    def _visit_admonition(self, node: Element) -> None:
        self.new_state(2)

    def _depart_admonition(self, node: Element) -> None:
        label = admonitionlabels[node.tagname]
        indent = sum(self.stateindent) + len(label)
        if (len(self.states[-1]) == 1 and
                self.states[-1][0][0] == 0 and
                MAXWIDTH - indent >= sum(len(s) for s in self.states[-1][0][1])):
            # short text: append text after admonition label
            self.stateindent[-1] += len(label)
            self.end_state(first=label + ': ')
        else:
            # long text: append label before the block
            self.states[-1].insert(0, (0, [self.nl]))
            self.end_state(first=label + ':')

    visit_attention = _visit_admonition
    depart_attention = _depart_admonition
    visit_caution = _visit_admonition
    depart_caution = _depart_admonition
    visit_danger = _visit_admonition
    depart_danger = _depart_admonition
    visit_error = _visit_admonition
    depart_error = _depart_admonition
    visit_hint = _visit_admonition
    depart_hint = _depart_admonition
    visit_important = _visit_admonition
    depart_important = _depart_admonition
    visit_note = _visit_admonition
    depart_note = _depart_admonition
    visit_tip = _visit_admonition
    depart_tip = _depart_admonition
    visit_warning = _visit_admonition
    depart_warning = _depart_admonition
    visit_seealso = _visit_admonition
    depart_seealso = _depart_admonition

    def visit_versionmodified(self, node: Element) -> None:
        self.new_state(0)

    def depart_versionmodified(self, node: Element) -> None:
        self.end_state()

    def visit_literal_block(self, node: Element) -> None:
        self.new_state()

    def depart_literal_block(self, node: Element) -> None:
        self.end_state(wrap=False)

    def visit_doctest_block(self, node: Element) -> None:
        self.new_state(0)

    def depart_doctest_block(self, node: Element) -> None:
        self.end_state(wrap=False)

    def visit_line_block(self, node: Element) -> None:
        self.new_state()
        self.lineblocklevel += 1

    def depart_line_block(self, node: Element) -> None:
        self.lineblocklevel -= 1
        self.end_state(wrap=False, end=None)
        if not self.lineblocklevel:
            self.add_text('\n')

    def visit_line(self, node: Element) -> None:
        pass

    def depart_line(self, node: Element) -> None:
        self.add_text('\n')

    def visit_block_quote(self, node: Element) -> None:
        self.new_state()

    def depart_block_quote(self, node: Element) -> None:
        self.end_state()

    def visit_compact_paragraph(self, node: Element) -> None:
        pass

    def depart_compact_paragraph(self, node: Element) -> None:
        pass

    def visit_paragraph(self, node: Element) -> None:
        if not isinstance(node.parent, nodes.Admonition) or \
           isinstance(node.parent, addnodes.seealso):
            self.new_state(0)

    def depart_paragraph(self, node: Element) -> None:
        if not isinstance(node.parent, nodes.Admonition) or \
           isinstance(node.parent, addnodes.seealso):
            self.end_state()

    def visit_target(self, node: Element) -> None:
        raise nodes.SkipNode

    def visit_index(self, node: Element) -> None:
        raise nodes.SkipNode

    def visit_toctree(self, node: Element) -> None:
        raise nodes.SkipNode

    def visit_substitution_definition(self, node: Element) -> None:
        raise nodes.SkipNode

    def visit_pending_xref(self, node: Element) -> None:
        pass

    def depart_pending_xref(self, node: Element) -> None:
        pass

    def visit_reference(self, node: Element) -> None:
        if self.add_secnumbers:
            numbers = node.get("secnumber")
            if numbers is not None:
                self.add_text('.'.join(map(str, numbers)) + self.secnumber_suffix)

    def depart_reference(self, node: Element) -> None:
        pass

    def visit_number_reference(self, node: Element) -> None:
        text = nodes.Text(node.get('title', '#'))
        self.visit_Text(text)
        raise nodes.SkipNode

    def visit_download_reference(self, node: Element) -> None:
        pass

    def depart_download_reference(self, node: Element) -> None:
        pass

    def visit_emphasis(self, node: Element) -> None:
        self.add_text('*')

    def depart_emphasis(self, node: Element) -> None:
        self.add_text('*')

    def visit_literal_emphasis(self, node: Element) -> None:
        self.add_text('*')

    def depart_literal_emphasis(self, node: Element) -> None:
        self.add_text('*')

    def visit_strong(self, node: Element) -> None:
        self.add_text('**')

    def depart_strong(self, node: Element) -> None:
        self.add_text('**')

    def visit_literal_strong(self, node: Element) -> None:
        self.add_text('**')

    def depart_literal_strong(self, node: Element) -> None:
        self.add_text('**')

    def visit_abbreviation(self, node: Element) -> None:
        self.add_text('')

    def depart_abbreviation(self, node: Element) -> None:
        if node.hasattr('explanation'):
            self.add_text(' (%s)' % node['explanation'])

    def visit_manpage(self, node: Element) -> None:
        return self.visit_literal_emphasis(node)

    def depart_manpage(self, node: Element) -> None:
        return self.depart_literal_emphasis(node)

    def visit_title_reference(self, node: Element) -> None:
        self.add_text('*')

    def depart_title_reference(self, node: Element) -> None:
        self.add_text('*')

    def visit_literal(self, node: Element) -> None:
        self.add_text('"')

    def depart_literal(self, node: Element) -> None:
        self.add_text('"')

    def visit_subscript(self, node: Element) -> None:
        self.add_text('_')

    def depart_subscript(self, node: Element) -> None:
        pass

    def visit_superscript(self, node: Element) -> None:
        self.add_text('^')

    def depart_superscript(self, node: Element) -> None:
        pass

    def visit_footnote_reference(self, node: Element) -> None:
        self.add_text('[%s]' % node.astext())
        raise nodes.SkipNode

    def visit_citation_reference(self, node: Element) -> None:
        self.add_text('[%s]' % node.astext())
        raise nodes.SkipNode

    def visit_Text(self, node: Text) -> None:
        self.add_text(node.astext())

    def depart_Text(self, node: Text) -> None:
        pass

    def visit_generated(self, node: Element) -> None:
        pass

    def depart_generated(self, node: Element) -> None:
        pass

    def visit_inline(self, node: Element) -> None:
        if 'xref' in node['classes'] or 'term' in node['classes']:
            self.add_text('*')

    def depart_inline(self, node: Element) -> None:
        if 'xref' in node['classes'] or 'term' in node['classes']:
            self.add_text('*')

    def visit_container(self, node: Element) -> None:
        pass

    def depart_container(self, node: Element) -> None:
        pass

    def visit_problematic(self, node: Element) -> None:
        self.add_text('>>')

    def depart_problematic(self, node: Element) -> None:
        self.add_text('<<')

    def visit_system_message(self, node: Element) -> None:
        self.new_state(0)
        self.add_text('<SYSTEM MESSAGE: %s>' % node.astext())
        self.end_state()
        raise nodes.SkipNode

    def visit_comment(self, node: Element) -> None:
        raise nodes.SkipNode

    def visit_meta(self, node: Element) -> None:
        # only valid for HTML
        raise nodes.SkipNode

    def visit_raw(self, node: Element) -> None:
        if 'text' in node.get('format', '').split():
            self.new_state(0)
            self.add_text(node.astext())
            self.end_state(wrap = False)
        raise nodes.SkipNode

    def visit_math(self, node: Element) -> None:
        pass

    def depart_math(self, node: Element) -> None:
        pass

    def visit_math_block(self, node: Element) -> None:
        self.new_state()

    def depart_math_block(self, node: Element) -> None:
        self.end_state()

    def unknown_visit(self, node: Node) -> None:
        raise NotImplementedError('Unknown node: ' + node.__class__.__name__)