"""Texinfo builder."""

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

from docutils import nodes
from docutils.frontend import OptionParser
from docutils.io import FileOutput
from docutils.nodes import Node

from sphinx import addnodes, package_dir
from sphinx.application import Sphinx
from sphinx.builders import Builder
from sphinx.config import Config
from sphinx.environment.adapters.asset import ImageAdapter
from sphinx.errors import NoUri
from sphinx.locale import _, __
from sphinx.util import logging, progress_message, status_iterator
from sphinx.util.console import darkgreen  # type: ignore
from sphinx.util.docutils import new_document
from sphinx.util.fileutil import copy_asset_file
from sphinx.util.nodes import inline_all_toctrees
from sphinx.util.osutil import SEP, ensuredir, make_filename_from_project
from sphinx.writers.texinfo import TexinfoTranslator, TexinfoWriter

logger = logging.getLogger(__name__)
template_dir = os.path.join(package_dir, 'templates', 'texinfo')


class TexinfoBuilder(Builder):
    """
    Builds Texinfo output to create Info documentation.
    """
    name = 'texinfo'
    format = 'texinfo'
    epilog = __('The Texinfo files are in %(outdir)s.')
    if os.name == 'posix':
        epilog += __("\nRun 'make' in that directory to run these through "
                     "makeinfo\n"
                     "(use 'make info' here to do that automatically).")

    supported_image_types = ['image/png', 'image/jpeg',
                             'image/gif']
    default_translator_class = TexinfoTranslator

    def init(self) -> None:
        self.docnames: Iterable[str] = []
        self.document_data: List[Tuple[str, str, str, str, str, str, str, bool]] = []

    def get_outdated_docs(self) -> Union[str, List[str]]:
        return 'all documents'  # for now

    def get_target_uri(self, docname: str, typ: Optional[str] = None) -> str:
        if docname not in self.docnames:
            raise NoUri(docname, typ)
        else:
            return '%' + docname

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

    def init_document_data(self) -> None:
        preliminary_document_data = [list(x) for x in self.config.texinfo_documents]
        if not preliminary_document_data:
            logger.warning(__('no "texinfo_documents" config value found; no documents '
                              'will be written'))
            return
        # assign subdirs to titles
        self.titles: List[Tuple[str, str]] = []
        for entry in preliminary_document_data:
            docname = entry[0]
            if docname not in self.env.all_docs:
                logger.warning(__('"texinfo_documents" config value references unknown '
                                  'document %s'), docname)
                continue
            self.document_data.append(entry)  # type: ignore
            if docname.endswith(SEP + 'index'):
                docname = docname[:-5]
            self.titles.append((docname, entry[2]))

    def write(self, *ignored: Any) -> None:
        self.init_document_data()
        for entry in self.document_data:
            docname, targetname, title, author = entry[:4]
            targetname += '.texi'
            direntry = description = category = ''
            if len(entry) > 6:
                direntry, description, category = entry[4:7]
            toctree_only = False
            if len(entry) > 7:
                toctree_only = entry[7]
            destination = FileOutput(
                destination_path=path.join(self.outdir, targetname),
                encoding='utf-8')
            with progress_message(__("processing %s") % targetname):
                appendices = self.config.texinfo_appendices or []
                doctree = self.assemble_doctree(docname, toctree_only, appendices=appendices)

            with progress_message(__("writing")):
                self.post_process_images(doctree)
                docwriter = TexinfoWriter(self)
                with warnings.catch_warnings():
                    warnings.filterwarnings('ignore', category=DeprecationWarning)
                    # DeprecationWarning: The frontend.OptionParser class will be replaced
                    # by a subclass of argparse.ArgumentParser in Docutils 0.21 or later.
                    settings: Any = OptionParser(
                        defaults=self.env.settings,
                        components=(docwriter,),
                        read_config_files=True).get_default_values()
                settings.author = author
                settings.title = title
                settings.texinfo_filename = targetname[:-5] + '.info'
                settings.texinfo_elements = self.config.texinfo_elements
                settings.texinfo_dir_entry = direntry or ''
                settings.texinfo_dir_category = category or ''
                settings.texinfo_dir_description = description or ''
                settings.docname = docname
                doctree.settings = settings
                docwriter.write(doctree, destination)
                self.copy_image_files(targetname[:-5])

    def assemble_doctree(self, indexfile: str, toctree_only: bool, appendices: List[str]) -> nodes.document:  # NOQA
        self.docnames = set([indexfile] + appendices)
        logger.info(darkgreen(indexfile) + " ", nonl=True)
        tree = self.env.get_doctree(indexfile)
        tree['docname'] = indexfile
        if toctree_only:
            # extract toctree nodes from the tree and put them in a
            # fresh document
            new_tree = new_document('<texinfo output>')
            new_sect = nodes.section()
            new_sect += nodes.title('<Set title in conf.py>',
                                    '<Set title in conf.py>')
            new_tree += new_sect
            for node in tree.findall(addnodes.toctree):
                new_sect += node
            tree = new_tree
        largetree = inline_all_toctrees(self, self.docnames, indexfile, tree,
                                        darkgreen, [indexfile])
        largetree['docname'] = indexfile
        for docname in appendices:
            appendix = self.env.get_doctree(docname)
            appendix['docname'] = docname
            largetree.append(appendix)
        logger.info('')
        logger.info(__("resolving references..."))
        self.env.resolve_references(largetree, indexfile, self)
        # TODO: add support for external :ref:s
        for pendingnode in largetree.findall(addnodes.pending_xref):
            docname = pendingnode['refdocname']
            sectname = pendingnode['refsectname']
            newnodes: List[Node] = [nodes.emphasis(sectname, sectname)]
            for subdir, title in self.titles:
                if docname.startswith(subdir):
                    newnodes.append(nodes.Text(_(' (in ')))
                    newnodes.append(nodes.emphasis(title, title))
                    newnodes.append(nodes.Text(')'))
                    break
            else:
                pass
            pendingnode.replace_self(newnodes)
        return largetree

    def finish(self) -> None:
        self.copy_support_files()

    def copy_image_files(self, targetname: str) -> None:
        if self.images:
            stringify_func = ImageAdapter(self.app.env).get_original_image_uri
            for src in status_iterator(self.images, __('copying images... '), "brown",
                                       len(self.images), self.app.verbosity,
                                       stringify_func=stringify_func):
                dest = self.images[src]
                try:
                    imagedir = path.join(self.outdir, targetname + '-figures')
                    ensuredir(imagedir)
                    copy_asset_file(path.join(self.srcdir, src),
                                    path.join(imagedir, dest))
                except Exception as err:
                    logger.warning(__('cannot copy image file %r: %s'),
                                   path.join(self.srcdir, src), err)

    def copy_support_files(self) -> None:
        try:
            with progress_message(__('copying Texinfo support files')):
                logger.info('Makefile ', nonl=True)
                copy_asset_file(os.path.join(template_dir, 'Makefile'), self.outdir)
        except OSError as err:
            logger.warning(__("error writing file Makefile: %s"), err)


def default_texinfo_documents(config: Config) -> List[Tuple[str, str, str, str, str, str, str]]:  # NOQA
    """ Better default texinfo_documents settings. """
    filename = make_filename_from_project(config.project)
    return [(config.root_doc, filename, config.project, config.author, filename,
             'One line description of project', 'Miscellaneous')]


def setup(app: Sphinx) -> Dict[str, Any]:
    app.add_builder(TexinfoBuilder)

    app.add_config_value('texinfo_documents', default_texinfo_documents, False)
    app.add_config_value('texinfo_appendices', [], False)
    app.add_config_value('texinfo_elements', {}, False)
    app.add_config_value('texinfo_domain_indices', True, False, [list])
    app.add_config_value('texinfo_show_urls', 'footnote', False)
    app.add_config_value('texinfo_no_detailmenu', False, False)
    app.add_config_value('texinfo_cross_references', True, False)

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