"""Single HTML builders."""

from os import path
from typing import Any, Dict, List, Optional, Tuple, Union

from docutils import nodes
from docutils.nodes import Node

from sphinx.application import Sphinx
from sphinx.builders.html import StandaloneHTMLBuilder
from sphinx.environment.adapters.toctree import TocTree
from sphinx.locale import __
from sphinx.util import logging, progress_message
from sphinx.util.console import darkgreen  # type: ignore
from sphinx.util.nodes import inline_all_toctrees

logger = logging.getLogger(__name__)


class SingleFileHTMLBuilder(StandaloneHTMLBuilder):
    """
    A StandaloneHTMLBuilder subclass that puts the whole document tree on one
    HTML page.
    """
    name = 'singlehtml'
    epilog = __('The HTML page is in %(outdir)s.')

    copysource = False

    def get_outdated_docs(self) -> Union[str, List[str]]:  # type: ignore[override]
        return 'all documents'

    def get_target_uri(self, docname: str, typ: Optional[str] = None) -> str:
        if docname in self.env.all_docs:
            # all references are on the same page...
            return self.config.root_doc + self.out_suffix + \
                '#document-' + docname
        else:
            # chances are this is a html_additional_page
            return docname + self.out_suffix

    def get_relative_uri(self, from_: str, to: str, typ: Optional[str] = None) -> str:
        # ignore source
        return self.get_target_uri(to, typ)

    def fix_refuris(self, tree: Node) -> None:
        # fix refuris with double anchor
        fname = self.config.root_doc + self.out_suffix
        for refnode in tree.findall(nodes.reference):
            if 'refuri' not in refnode:
                continue
            refuri = refnode['refuri']
            hashindex = refuri.find('#')
            if hashindex < 0:
                continue
            hashindex = refuri.find('#', hashindex + 1)
            if hashindex >= 0:
                refnode['refuri'] = fname + refuri[hashindex:]

    def _get_local_toctree(self, docname: str, collapse: bool = True, **kwargs: Any) -> str:
        if 'includehidden' not in kwargs:
            kwargs['includehidden'] = False
        toctree = TocTree(self.env).get_toctree_for(docname, self, collapse, **kwargs)
        if toctree is not None:
            self.fix_refuris(toctree)
        return self.render_partial(toctree)['fragment']

    def assemble_doctree(self) -> nodes.document:
        master = self.config.root_doc
        tree = self.env.get_doctree(master)
        tree = inline_all_toctrees(self, set(), master, tree, darkgreen, [master])
        tree['docname'] = master
        self.env.resolve_references(tree, master, self)
        self.fix_refuris(tree)
        return tree

    def assemble_toc_secnumbers(self) -> Dict[str, Dict[str, Tuple[int, ...]]]:
        # Assemble toc_secnumbers to resolve section numbers on SingleHTML.
        # Merge all secnumbers to single secnumber.
        #
        # Note: current Sphinx has refid confliction in singlehtml mode.
        #       To avoid the problem, it replaces key of secnumbers to
        #       tuple of docname and refid.
        #
        #       There are related codes in inline_all_toctres() and
        #       HTMLTranslter#add_secnumber().
        new_secnumbers: Dict[str, Tuple[int, ...]] = {}
        for docname, secnums in self.env.toc_secnumbers.items():
            for id, secnum in secnums.items():
                alias = "%s/%s" % (docname, id)
                new_secnumbers[alias] = secnum

        return {self.config.root_doc: new_secnumbers}

    def assemble_toc_fignumbers(self) -> Dict[str, Dict[str, Dict[str, Tuple[int, ...]]]]:
        # Assemble toc_fignumbers to resolve figure numbers on SingleHTML.
        # Merge all fignumbers to single fignumber.
        #
        # Note: current Sphinx has refid confliction in singlehtml mode.
        #       To avoid the problem, it replaces key of secnumbers to
        #       tuple of docname and refid.
        #
        #       There are related codes in inline_all_toctres() and
        #       HTMLTranslter#add_fignumber().
        new_fignumbers: Dict[str, Dict[str, Tuple[int, ...]]] = {}
        # {'foo': {'figure': {'id2': (2,), 'id1': (1,)}}, 'bar': {'figure': {'id1': (3,)}}}
        for docname, fignumlist in self.env.toc_fignumbers.items():
            for figtype, fignums in fignumlist.items():
                alias = "%s/%s" % (docname, figtype)
                new_fignumbers.setdefault(alias, {})
                for id, fignum in fignums.items():
                    new_fignumbers[alias][id] = fignum

        return {self.config.root_doc: new_fignumbers}

    def get_doc_context(self, docname: str, body: str, metatags: str) -> Dict[str, Any]:
        # no relation links...
        toctree = TocTree(self.env).get_toctree_for(self.config.root_doc, self, False)
        # if there is no toctree, toc is None
        if toctree:
            self.fix_refuris(toctree)
            toc = self.render_partial(toctree)['fragment']
            display_toc = True
        else:
            toc = ''
            display_toc = False
        return {
            'parents': [],
            'prev': None,
            'next': None,
            'docstitle': None,
            'title': self.config.html_title,
            'meta': None,
            'body': body,
            'metatags': metatags,
            'rellinks': [],
            'sourcename': '',
            'toc': toc,
            'display_toc': display_toc,
        }

    def write(self, *ignored: Any) -> None:
        docnames = self.env.all_docs

        with progress_message(__('preparing documents')):
            self.prepare_writing(docnames)  # type: ignore

        with progress_message(__('assembling single document')):
            doctree = self.assemble_doctree()
            self.env.toc_secnumbers = self.assemble_toc_secnumbers()
            self.env.toc_fignumbers = self.assemble_toc_fignumbers()

        with progress_message(__('writing')):
            self.write_doc_serialized(self.config.root_doc, doctree)
            self.write_doc(self.config.root_doc, doctree)

    def finish(self) -> None:
        self.write_additional_files()
        self.copy_image_files()
        self.copy_download_files()
        self.copy_static_files()
        self.copy_extra_files()
        self.write_buildinfo()
        self.dump_inventory()

    @progress_message(__('writing additional files'))
    def write_additional_files(self) -> None:
        # no indices or search pages are supported

        # additional pages from conf.py
        for pagename, template in self.config.html_additional_pages.items():
            logger.info(' ' + pagename, nonl=True)
            self.handle_page(pagename, {}, template)

        if self.config.html_use_opensearch:
            logger.info(' opensearch', nonl=True)
            fn = path.join(self.outdir, '_static', 'opensearch.xml')
            self.handle_page('opensearch', {}, 'opensearch.xml', outfilename=fn)


def setup(app: Sphinx) -> Dict[str, Any]:
    app.setup_extension('sphinx.builders.html')

    app.add_builder(SingleFileHTMLBuilder)
    app.add_config_value('singlehtml_sidebars', lambda self: self.html_sidebars, 'html')

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