"""Build input files for the Qt collection generator."""

from __future__ import annotations

import html
import os
import posixpath
import re
from collections.abc import Iterable
from os import path
from pathlib import Path
from typing import TYPE_CHECKING, Any, cast

from docutils import nodes
from sphinx import addnodes
from sphinx.builders.html import StandaloneHTMLBuilder
from sphinx.environment.adapters.indexentries import IndexEntries
from sphinx.locale import get_translation
from sphinx.util import logging
from sphinx.util.nodes import NodeMatcher
from sphinx.util.osutil import canon_path, make_filename
from sphinx.util.template import SphinxRenderer

if TYPE_CHECKING:
    from docutils.nodes import Node
    from sphinx.application import Sphinx

__version__ = '2.0.0'
__version_info__ = (2, 0, 0)

logger = logging.getLogger(__name__)
package_dir = path.abspath(path.dirname(__file__))

__ = get_translation(__name__, 'console')


_idpattern = re.compile(
    r'(?P<title>.+) (\((class in )?(?P<id>[\w\.]+)( (?P<descr>\w+))?\))$')


section_template = '<section title="%(title)s" ref="%(ref)s"/>'


def render_file(filename: str, **kwargs: Any) -> str:
    pathname = path.join(package_dir, 'templates', filename)
    return SphinxRenderer.render_from_file(pathname, kwargs)


class QtHelpBuilder(StandaloneHTMLBuilder):
    """
    Builder that also outputs Qt help project, contents and index files.
    """
    name = 'qthelp'
    epilog = __('You can now run "qcollectiongenerator" with the .qhcp '
                'project file in %(outdir)s, like this:\n'
                '$ qcollectiongenerator %(outdir)s/%(project)s.qhcp\n'
                'To view the help file:\n'
                '$ assistant -collectionFile %(outdir)s/%(project)s.qhc')

    # don't copy the reST source
    copysource = False
    supported_image_types = ['image/svg+xml', 'image/png', 'image/gif',
                             'image/jpeg']

    # don't add links
    add_permalinks = False

    # don't add sidebar etc.
    embedded = True
    # disable download role
    download_support = False

    # don't generate the search index or include the search page
    search = False

    def init(self) -> None:
        super().init()
        # the output files for HTML help must be .html only
        self.out_suffix = '.html'
        self.link_suffix = '.html'
        # self.config.html_style = 'traditional.css'

    def get_theme_config(self) -> tuple[str, dict[str, str | int | bool]]:
        return self.config.qthelp_theme, self.config.qthelp_theme_options

    def handle_finish(self) -> None:
        self.epilog = self.epilog % {
            'outdir': '%(outdir)s',
            'project': self.config.qthelp_basename,
        }
        self.build_qhp(self.outdir, self.config.qthelp_basename)

    def build_qhp(self, outdir: str | os.PathLike[str], outname: str) -> None:
        logger.info(__('writing project file...'))

        # sections
        tocdoc = self.env.get_and_resolve_doctree(self.config.master_doc, self,
                                                  prune_toctrees=False)

        sections = []
        matcher = NodeMatcher(addnodes.compact_paragraph, toctree=True)
        for node in tocdoc.findall(matcher):
            sections.extend(self.write_toc(node))

        for indexname, indexcls, _content, _collapse in self.domain_indices:
            item = section_template % {'title': indexcls.localname,
                                       'ref': indexname + self.out_suffix}
            sections.append(' ' * 4 * 4 + item)
        sections = '\n'.join(sections)  # type: ignore[assignment]

        # keywords
        keywords = []
        index = IndexEntries(self.env).create_index(self, group_entries=False)
        for (_group_key, group) in index:
            for title, (refs, subitems, _category_key) in group:
                keywords.extend(self.build_keywords(title, refs, subitems))
        keywords = '\n'.join(keywords)  # type: ignore[assignment]

        # it seems that the "namespace" may not contain non-alphanumeric
        # characters, and more than one successive dot, or leading/trailing
        # dots, are also forbidden
        if self.config.qthelp_namespace:
            nspace = self.config.qthelp_namespace
        else:
            nspace = f'org.sphinx.{outname}.{self.config.version}'

        nspace = re.sub(r'[^a-zA-Z0-9.\-]', '', nspace)
        nspace = re.sub(r'\.+', '.', nspace).strip('.')
        nspace = nspace.lower()

        # write the project file
        body = render_file('project.qhp', outname=outname,
                           title=self.config.html_title, version=self.config.version,
                           project=self.config.project, namespace=nspace,
                           master_doc=self.config.master_doc,
                           sections=sections, keywords=keywords,
                           files=self.get_project_files(outdir))
        filename = Path(outdir, f'{outname}.qhp')
        filename.write_text(body, encoding='utf-8')

        homepage = 'qthelp://' + posixpath.join(
            nspace, 'doc', self.get_target_uri(self.config.master_doc))
        startpage = 'qthelp://' + posixpath.join(nspace, 'doc', f'index{self.link_suffix}')

        logger.info(__('writing collection project file...'))
        body = render_file('project.qhcp', outname=outname,
                           title=self.config.html_short_title,
                           homepage=homepage, startpage=startpage)
        filename = Path(outdir, f'{outname}.qhcp')
        filename.write_text(body, encoding='utf-8')

    def isdocnode(self, node: Node) -> bool:
        if not isinstance(node, nodes.list_item):
            return False
        if len(node.children) != 2:
            return False
        if not isinstance(node[0], addnodes.compact_paragraph):
            return False
        if not isinstance(node[0][0], nodes.reference):
            return False
        return isinstance(node[1], nodes.bullet_list)

    def write_toc(self, node: Node, indentlevel: int = 4) -> list[str]:
        parts: list[str] = []
        if isinstance(node, nodes.list_item) and self.isdocnode(node):
            compact_paragraph = cast(addnodes.compact_paragraph, node[0])
            reference = cast(nodes.reference, compact_paragraph[0])
            link = reference['refuri']
            title = html.escape(reference.astext()).replace('"', '&quot;')
            item = f'<section title="{title}" ref="{link}">'
            parts.append(' ' * 4 * indentlevel + item)

            bullet_list = cast(nodes.bullet_list, node[1])
            list_items = cast(Iterable[nodes.list_item], bullet_list)
            for list_item in list_items:
                parts.extend(self.write_toc(list_item, indentlevel + 1))
            parts.append(' ' * 4 * indentlevel + '</section>')
        elif isinstance(node, nodes.list_item):
            for subnode in node:
                parts.extend(self.write_toc(subnode, indentlevel))
        elif isinstance(node, nodes.reference):
            link = node['refuri']
            title = html.escape(node.astext()).replace('"', '&quot;')
            item = section_template % {'title': title, 'ref': link}
            item = ' ' * 4 * indentlevel + item
            parts.append(item.encode('ascii', 'xmlcharrefreplace').decode())
        elif isinstance(node, (nodes.bullet_list, addnodes.compact_paragraph)):
            for subnode in node:
                parts.extend(self.write_toc(subnode, indentlevel))

        return parts

    def keyword_item(self, name: str, ref: Any) -> str:
        matchobj = _idpattern.match(name)
        if matchobj:
            groupdict = matchobj.groupdict()
            shortname = groupdict['title']
            id = groupdict.get('id')
            # descr = groupdict.get('descr')
            if shortname.endswith('()'):
                shortname = shortname[:-2]
            id = html.escape(f'{id}.{shortname}', True)
        else:
            id = None

        nameattr = html.escape(name, quote=True)
        refattr = html.escape(ref[1], quote=True)
        if id:
            item = ' ' * 12 + f'<keyword name="{nameattr}" id="{id}" ref="{refattr}"/>'
        else:
            item = ' ' * 12 + f'<keyword name="{nameattr}" ref="{refattr}"/>'
        item.encode('ascii', 'xmlcharrefreplace')
        return item

    def build_keywords(self, title: str, refs: list[Any], subitems: Any) -> list[str]:
        keywords: list[str] = []

        # if len(refs) == 0: # XXX
        #     write_param('See Also', title)
        if len(refs) == 1:
            keywords.append(self.keyword_item(title, refs[0]))
        elif len(refs) > 1:
            for _i, ref in enumerate(refs):  # XXX  # NoQA: FURB148
                # item = (' '*12 +
                #         '<keyword name="%s [%d]" ref="%s"/>' % (
                #          title, i, ref))
                # item.encode('ascii', 'xmlcharrefreplace')
                # keywords.append(item)
                keywords.append(self.keyword_item(title, ref))

        if subitems:
            for subitem in subitems:
                keywords.extend(self.build_keywords(subitem[0], subitem[1], []))

        return keywords

    def get_project_files(self, outdir: str | os.PathLike[str]) -> list[str]:
        project_files = []
        staticdir = path.join(outdir, '_static')
        imagesdir = path.join(outdir, self.imagedir)
        for root, _dirs, files in os.walk(outdir):
            resourcedir = root.startswith((staticdir, imagesdir))
            for fn in sorted(files):
                if (resourcedir and not fn.endswith('.js')) or fn.endswith('.html'):
                    filename = path.relpath(path.join(root, fn), outdir)
                    project_files.append(canon_path(filename))

        return project_files


def setup(app: Sphinx) -> dict[str, Any]:
    app.require_sphinx('5.0')
    app.setup_extension('sphinx.builders.html')
    app.add_builder(QtHelpBuilder)
    app.add_message_catalog(__name__, path.join(package_dir, 'locales'))

    app.add_config_value('qthelp_basename', lambda self: make_filename(self.project), 'html')
    app.add_config_value('qthelp_namespace', None, 'html', [str])
    app.add_config_value('qthelp_theme', 'nonav', 'html')
    app.add_config_value('qthelp_theme_options', {}, 'html')

    return {
        'version': __version__,
        'parallel_read_safe': True,
        'parallel_write_safe': True,
    }