"""Manual page writer, extended for Sphinx custom nodes."""

from typing import Any, Dict, Iterable, cast

from docutils import nodes
from docutils.nodes import Element, TextElement
from docutils.writers.manpage import Translator as BaseTranslator
from docutils.writers.manpage import Writer

from sphinx import addnodes
from sphinx.builders import Builder
from sphinx.locale import _, admonitionlabels
from sphinx.util import logging
from sphinx.util.docutils import SphinxTranslator
from sphinx.util.i18n import format_date
from sphinx.util.nodes import NodeMatcher

logger = logging.getLogger(__name__)


class ManualPageWriter(Writer):
    def __init__(self, builder: Builder) -> None:
        super().__init__()
        self.builder = builder

    def translate(self) -> None:
        transform = NestedInlineTransform(self.document)
        transform.apply()
        visitor = self.builder.create_translator(self.document, self.builder)
        self.visitor = cast(ManualPageTranslator, visitor)
        self.document.walkabout(visitor)
        self.output = self.visitor.astext()


class NestedInlineTransform:
    """
    Flatten nested inline nodes:

    Before:
        <strong>foo=<emphasis>1</emphasis>
        &bar=<emphasis>2</emphasis></strong>
    After:
        <strong>foo=</strong><emphasis>var</emphasis>
        <strong>&bar=</strong><emphasis>2</emphasis>
    """
    def __init__(self, document: nodes.document) -> None:
        self.document = document

    def apply(self, **kwargs: Any) -> None:
        matcher = NodeMatcher(nodes.literal, nodes.emphasis, nodes.strong)
        for node in list(self.document.findall(matcher)):  # type: TextElement
            if any(matcher(subnode) for subnode in node):
                pos = node.parent.index(node)
                for subnode in reversed(list(node)):
                    node.remove(subnode)
                    if matcher(subnode):
                        node.parent.insert(pos + 1, subnode)
                    else:
                        newnode = node.__class__('', '', subnode, **node.attributes)
                        node.parent.insert(pos + 1, newnode)
                # move node if all children became siblings of the node
                if not len(node):
                    node.parent.remove(node)


class ManualPageTranslator(SphinxTranslator, BaseTranslator):
    """
    Custom man page translator.
    """

    _docinfo: Dict[str, Any] = {}

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

        self.in_productionlist = 0

        # first title is the manpage title
        self.section_level = -1

        # docinfo set by man_pages config value
        self._docinfo['title'] = self.settings.title
        self._docinfo['subtitle'] = self.settings.subtitle
        if self.settings.authors:
            # don't set it if no author given
            self._docinfo['author'] = self.settings.authors
        self._docinfo['manual_section'] = self.settings.section

        # docinfo set by other config values
        self._docinfo['title_upper'] = self._docinfo['title'].upper()
        if self.config.today:
            self._docinfo['date'] = self.config.today
        else:
            self._docinfo['date'] = format_date(self.config.today_fmt or _('%b %d, %Y'),
                                                language=self.config.language)
        self._docinfo['copyright'] = self.config.copyright
        self._docinfo['version'] = self.config.version
        self._docinfo['manual_group'] = self.config.project

        # Overwrite admonition label translations with our own
        for label, translation in admonitionlabels.items():
            self.language.labels[label] = self.deunicode(translation)

    # overwritten -- added quotes around all .TH arguments
    def header(self) -> str:
        tmpl = (".TH \"%(title_upper)s\" \"%(manual_section)s\""
                " \"%(date)s\" \"%(version)s\" \"%(manual_group)s\"\n")
        if self._docinfo['subtitle']:
            tmpl += (".SH NAME\n"
                     "%(title)s \\- %(subtitle)s\n")
        return tmpl % self._docinfo

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

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

    #############################################################
    # Domain-specific object descriptions
    #############################################################

    # Top-level nodes for descriptions
    ##################################

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

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

    def visit_desc_signature(self, node: Element) -> None:
        self.visit_definition_list_item(node)
        self.visit_term(node)

    def depart_desc_signature(self, node: Element) -> None:
        self.depart_term(node)

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

    def depart_desc_signature_line(self, node: Element) -> None:
        self.body.append(' ')

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

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

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

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

    # Nodes for high-level structure in signatures
    ##############################################

    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.body.append(' -> ')

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

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

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

    def visit_desc_parameter(self, node: Element) -> None:
        if not self.first_param:
            self.body.append(', ')
        else:
            self.first_param = 0

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

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

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

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

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

    ##############################################

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

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

    # overwritten -- don't make whole of term bold if it includes strong node
    def visit_term(self, node: Element) -> None:
        if any(node.findall(nodes.strong)):
            self.body.append('\n')
        else:
            super().visit_term(node)

    # overwritten -- we don't want source comments to show up
    def visit_comment(self, node: Element) -> None:  # type: ignore
        raise nodes.SkipNode

    # overwritten -- added ensure_eol()
    def visit_footnote(self, node: Element) -> None:
        self.ensure_eol()
        super().visit_footnote(node)

    # overwritten -- handle footnotes rubric
    def visit_rubric(self, node: Element) -> None:
        self.ensure_eol()
        if len(node) == 1 and node.astext() in ('Footnotes', _('Footnotes')):
            self.body.append('.SH ' + self.deunicode(node.astext()).upper() + '\n')
            raise nodes.SkipNode
        else:
            self.body.append('.sp\n')

    def depart_rubric(self, node: Element) -> None:
        self.body.append('\n')

    def visit_seealso(self, node: Element) -> None:
        self.visit_admonition(node, 'seealso')

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

    def visit_productionlist(self, node: Element) -> None:
        self.ensure_eol()
        names = []
        self.in_productionlist += 1
        self.body.append('.sp\n.nf\n')
        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']:
                lastname = production['tokenname'].ljust(maxlen)
                self.body.append(self.defs['strong'][0])
                self.body.append(self.deunicode(lastname))
                self.body.append(self.defs['strong'][1])
                self.body.append(' ::= ')
            elif lastname is not None:
                self.body.append('%s     ' % (' ' * len(lastname)))
            production.walkabout(self)
            self.body.append('\n')
        self.body.append('\n.fi\n')
        self.in_productionlist -= 1
        raise nodes.SkipNode

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

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

    # overwritten -- don't emit a warning for images
    def visit_image(self, node: Element) -> None:
        if 'alt' in node.attributes:
            self.body.append(_('[image: %s]') % node['alt'] + '\n')
        self.body.append(_('[image]') + '\n')
        raise nodes.SkipNode

    # overwritten -- don't visit inner marked up nodes
    def visit_reference(self, node: Element) -> None:
        self.body.append(self.defs['reference'][0])
        # avoid repeating escaping code... fine since
        # visit_Text calls astext() and only works on that afterwards
        self.visit_Text(node)  # type: ignore
        self.body.append(self.defs['reference'][1])

        uri = node.get('refuri', '')
        if uri.startswith('mailto:') or uri.startswith('http:') or \
           uri.startswith('https:') or uri.startswith('ftp:'):
            # if configured, put the URL after the link
            if self.config.man_show_urls and node.astext() != uri:
                if uri.startswith('mailto:'):
                    uri = uri[7:]
                self.body.extend([
                    ' <',
                    self.defs['strong'][0], uri, self.defs['strong'][1],
                    '>'])
        raise nodes.SkipNode

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

    def visit_centered(self, node: Element) -> None:
        self.ensure_eol()
        self.body.append('.sp\n.ce\n')

    def depart_centered(self, node: Element) -> None:
        self.body.append('\n.ce 0\n')

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

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

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

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

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

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

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

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

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

    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.ensure_eol()
        bullet_list = cast(nodes.bullet_list, node[0])
        list_items = cast(Iterable[nodes.list_item], bullet_list)
        self.body.append(', '.join(n.astext() for n in list_items) + '.')
        self.body.append('\n')
        raise nodes.SkipNode

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

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

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

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

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

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

    def visit_literal_strong(self, node: Element) -> None:
        return self.visit_strong(node)

    def depart_literal_strong(self, node: Element) -> None:
        return self.depart_strong(node)

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

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

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

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

    # overwritten: handle section titles better than in 0.6 release
    def visit_caption(self, node: Element) -> None:
        if isinstance(node.parent, nodes.container) and node.parent.get('literal_block'):
            self.body.append('.sp\n')
        else:
            super().visit_caption(node)

    def depart_caption(self, node: Element) -> None:
        if isinstance(node.parent, nodes.container) and node.parent.get('literal_block'):
            self.body.append('\n')
        else:
            super().depart_caption(node)

    # overwritten: handle section titles better than in 0.6 release
    def visit_title(self, node: Element) -> None:
        if isinstance(node.parent, addnodes.seealso):
            self.body.append('.IP "')
            return
        elif isinstance(node.parent, nodes.section):
            if self.section_level == 0:
                # skip the document title
                raise nodes.SkipNode
            elif self.section_level == 1:
                self.body.append('.SH %s\n' %
                                 self.deunicode(node.astext().upper()))
                raise nodes.SkipNode
        return super().visit_title(node)

    def depart_title(self, node: Element) -> None:
        if isinstance(node.parent, addnodes.seealso):
            self.body.append('"\n')
            return
        return super().depart_title(node)

    def visit_raw(self, node: Element) -> None:
        if 'manpage' in node.get('format', '').split():
            self.body.append(node.astext())
        raise nodes.SkipNode

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

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

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

    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.visit_centered(node)

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