"""
    sphinx.builders.latex
    ~~~~~~~~~~~~~~~~~~~~~

    LaTeX builder.

    :copyright: Copyright 2007-2020 by the Sphinx team, see AUTHORS.
    :license: BSD, see LICENSE for details.
"""

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

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

import sphinx.builders.latex.nodes  # NOQA  # Workaround: import this before writer to avoid ImportError
from sphinx import package_dir, addnodes, highlighting
from sphinx.application import Sphinx
from sphinx.builders import Builder
from sphinx.builders.latex.util import ExtBabel
from sphinx.config import Config, ENUM
from sphinx.deprecation import RemovedInSphinx40Warning
from sphinx.environment.adapters.asset import ImageAdapter
from sphinx.errors import NoUri, SphinxError
from sphinx.locale import _, __
from sphinx.util import texescape, logging, progress_message, status_iterator
from sphinx.util.console import bold, darkgreen  # type: ignore
from sphinx.util.docutils import SphinxFileOutput, new_document
from sphinx.util.fileutil import copy_asset_file
from sphinx.util.i18n import format_date
from sphinx.util.nodes import inline_all_toctrees
from sphinx.util.osutil import SEP, make_filename_from_project
from sphinx.util.template import LaTeXRenderer
from sphinx.writers.latex import (
    ADDITIONAL_SETTINGS, DEFAULT_SETTINGS, LaTeXWriter, LaTeXTranslator
)

# load docutils.nodes after loading sphinx.builders.latex.nodes
from docutils import nodes  # NOQA


XINDY_LANG_OPTIONS = {
    # language codes from docutils.writers.latex2e.Babel
    # ! xindy language names may differ from those in use by LaTeX/babel
    # ! xindy does not support all Latin scripts as recognized by LaTeX/babel
    # ! not all xindy-supported languages appear in Babel.language_codes
    # cd /usr/local/texlive/2018/texmf-dist/xindy/modules/lang
    # find . -name '*utf8.xdy'
    # LATIN
    'sq': '-L albanian -C utf8 ',
    'hr': '-L croatian -C utf8 ',
    'cs': '-L czech -C utf8 ',
    'da': '-L danish -C utf8 ',
    'nl': '-L dutch -C ij-as-ij-utf8 ',
    'en': '-L english -C utf8 ',
    'eo': '-L esperanto -C utf8 ',
    'et': '-L estonian -C utf8 ',
    'fi': '-L finnish -C utf8 ',
    'fr': '-L french -C utf8 ',
    'de': '-L german -C din5007-utf8 ',
    'is': '-L icelandic -C utf8 ',
    'it': '-L italian -C utf8 ',
    'la': '-L latin -C utf8 ',
    'lv': '-L latvian -C utf8 ',
    'lt': '-L lithuanian -C utf8 ',
    'dsb': '-L lower-sorbian -C utf8 ',
    'ds': '-L lower-sorbian -C utf8 ',   # trick, no conflict
    'nb': '-L norwegian -C utf8 ',
    'no': '-L norwegian -C utf8 ',       # and what about nynorsk?
    'pl': '-L polish -C utf8 ',
    'pt': '-L portuguese -C utf8 ',
    'ro': '-L romanian -C utf8 ',
    'sk': '-L slovak -C small-utf8 ',    # there is also slovak-large
    'sl': '-L slovenian -C utf8 ',
    'es': '-L spanish -C modern-utf8 ',  # there is also spanish-traditional
    'sv': '-L swedish -C utf8 ',
    'tr': '-L turkish -C utf8 ',
    'hsb': '-L upper-sorbian -C utf8 ',
    'hs': '-L upper-sorbian -C utf8 ',   # trick, no conflict
    'vi': '-L vietnamese -C utf8 ',
    # CYRILLIC
    # for usage with pdflatex, needs also cyrLICRutf8.xdy module
    'be': '-L belarusian -C utf8 ',
    'bg': '-L bulgarian -C utf8 ',
    'mk': '-L macedonian -C utf8 ',
    'mn': '-L mongolian -C cyrillic-utf8 ',
    'ru': '-L russian -C utf8 ',
    'sr': '-L serbian -C utf8 ',
    'sh-cyrl': '-L serbian -C utf8 ',
    'sh': '-L serbian -C utf8 ',         # trick, no conflict
    'uk': '-L ukrainian -C utf8 ',
    # GREEK
    # can work only with xelatex/lualatex, not supported by texindy+pdflatex
    'el': '-L greek -C utf8 ',
    # FIXME, not compatible with [:2] slice but does Sphinx support Greek ?
    'el-polyton': '-L greek -C polytonic-utf8 ',
}

XINDY_CYRILLIC_SCRIPTS = [
    'be', 'bg', 'mk', 'mn', 'ru', 'sr', 'sh', 'uk',
]

logger = logging.getLogger(__name__)


class LaTeXBuilder(Builder):
    """
    Builds LaTeX output to create PDF.
    """
    name = 'latex'
    format = 'latex'
    epilog = __('The LaTeX files are in %(outdir)s.')
    if os.name == 'posix':
        epilog += __("\nRun 'make' in that directory to run these through "
                     "(pdf)latex\n"
                     "(use `make latexpdf' here to do that automatically).")

    supported_image_types = ['application/pdf', 'image/png', 'image/jpeg']
    supported_remote_images = False
    default_translator_class = LaTeXTranslator

    def init(self) -> None:
        self.babel = None           # type: ExtBabel
        self.context = {}           # type: Dict[str, Any]
        self.docnames = []          # type: Iterable[str]
        self.document_data = []     # type: List[Tuple[str, str, str, str, str, bool]]
        self.usepackages = self.app.registry.latex_packages
        texescape.init()

        self.init_context()
        self.init_babel()

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

    def get_target_uri(self, docname: str, typ: 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: 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.latex_documents]
        if not preliminary_document_data:
            logger.warning(__('no "latex_documents" config value found; no documents '
                              'will be written'))
            return
        # assign subdirs to titles
        self.titles = []  # type: List[Tuple[str, str]]
        for entry in preliminary_document_data:
            docname = entry[0]
            if docname not in self.env.all_docs:
                logger.warning(__('"latex_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 init_context(self) -> None:
        self.context = DEFAULT_SETTINGS.copy()

        # Add special settings for latex_engine
        self.context.update(ADDITIONAL_SETTINGS.get(self.config.latex_engine, {}))

        # Add special settings for (latex_engine, language_code)
        if self.config.language:
            key = (self.config.latex_engine, self.config.language[:2])
            self.context.update(ADDITIONAL_SETTINGS.get(key, {}))

        # Apply extension settings to context
        self.context['packages'] = self.usepackages

        # Apply user settings to context
        self.context.update(self.config.latex_elements)
        self.context['release'] = self.config.release
        self.context['use_xindy'] = self.config.latex_use_xindy

        if self.config.today:
            self.context['date'] = self.config.today
        else:
            self.context['date'] = format_date(self.config.today_fmt or _('%b %d, %Y'),
                                               language=self.config.language)

        if self.config.latex_logo:
            self.context['logofilename'] = path.basename(self.config.latex_logo)

        # for compatibilities
        self.context['indexname'] = _('Index')
        if self.config.release:
            # Show the release label only if release value exists
            self.context.setdefault('releasename', _('Release'))

    def init_babel(self) -> None:
        self.babel = ExtBabel(self.config.language, not self.context['babel'])
        if self.config.language and not self.babel.is_supported_language():
            # emit warning if specified language is invalid
            # (only emitting, nothing changed to processing)
            logger.warning(__('no Babel option known for language %r'),
                           self.config.language)

    def write_stylesheet(self) -> None:
        highlighter = highlighting.PygmentsBridge('latex', self.config.pygments_style)
        stylesheet = path.join(self.outdir, 'sphinxhighlight.sty')
        with open(stylesheet, 'w') as f:
            f.write('\\NeedsTeXFormat{LaTeX2e}[1995/12/01]\n')
            f.write('\\ProvidesPackage{sphinxhighlight}'
                    '[2016/05/29 stylesheet for highlighting with pygments]\n\n')
            f.write(highlighter.get_stylesheet())

    def write(self, *ignored: Any) -> None:
        docwriter = LaTeXWriter(self)
        docsettings = OptionParser(
            defaults=self.env.settings,
            components=(docwriter,),
            read_config_files=True).get_default_values()  # type: Any

        self.init_document_data()
        self.write_stylesheet()

        for entry in self.document_data:
            docname, targetname, title, author, docclass = entry[:5]
            toctree_only = False
            if len(entry) > 5:
                toctree_only = entry[5]
            destination = SphinxFileOutput(destination_path=path.join(self.outdir, targetname),
                                           encoding='utf-8', overwrite_if_changed=True)
            with progress_message(__("processing %s") % targetname):
                doctree = self.env.get_doctree(docname)
                toctree = next(iter(doctree.traverse(addnodes.toctree)), None)
                if toctree and toctree.get('maxdepth') > 0:
                    tocdepth = toctree.get('maxdepth')
                else:
                    tocdepth = None

                doctree = self.assemble_doctree(
                    docname, toctree_only,
                    appendices=(self.config.latex_appendices if docclass != 'howto' else []))
                doctree['tocdepth'] = tocdepth
                self.post_process_images(doctree)
                self.update_doc_context(title, author)

            with progress_message(__("writing")):
                docsettings.author = author
                docsettings.title = title
                docsettings.contentsname = self.get_contentsname(docname)
                docsettings.docname = docname
                docsettings.docclass = docclass

                doctree.settings = docsettings
                docwriter.write(doctree, destination)

    def get_contentsname(self, indexfile: str) -> str:
        tree = self.env.get_doctree(indexfile)
        contentsname = None
        for toctree in tree.traverse(addnodes.toctree):
            if 'caption' in toctree:
                contentsname = toctree['caption']
                break

        return contentsname

    def update_doc_context(self, title: str, author: str) -> None:
        self.context['title'] = title
        self.context['author'] = author

    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('<latex 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.traverse(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)
        # resolve :ref:s to distant tex files -- we can't add a cross-reference,
        # but append the document name
        for pendingnode in largetree.traverse(addnodes.pending_xref):
            docname = pendingnode['refdocname']
            sectname = pendingnode['refsectname']
            newnodes = [nodes.emphasis(sectname, sectname)]  # type: List[Node]
            for subdir, title in self.titles:
                if docname.startswith(subdir):
                    newnodes.append(nodes.Text(_(' (in '), _(' (in ')))
                    newnodes.append(nodes.emphasis(title, title))
                    newnodes.append(nodes.Text(')', ')'))
                    break
            else:
                pass
            pendingnode.replace_self(newnodes)
        return largetree

    def apply_transforms(self, doctree: nodes.document) -> None:
        warnings.warn('LaTeXBuilder.apply_transforms() is deprecated.',
                      RemovedInSphinx40Warning)

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

        if self.config.latex_additional_files:
            self.copy_latex_additional_files()

    @progress_message(__('copying TeX support files'))
    def copy_support_files(self) -> None:
        """copy TeX support files from texinputs."""
        # configure usage of xindy (impacts Makefile and latexmkrc)
        # FIXME: convert this rather to a confval with suitable default
        #        according to language ? but would require extra documentation
        if self.config.language:
            xindy_lang_option = \
                XINDY_LANG_OPTIONS.get(self.config.language[:2],
                                       '-L general -C utf8 ')
            xindy_cyrillic = self.config.language[:2] in XINDY_CYRILLIC_SCRIPTS
        else:
            xindy_lang_option = '-L english -C utf8 '
            xindy_cyrillic = False
        context = {
            'latex_engine':      self.config.latex_engine,
            'xindy_use':         self.config.latex_use_xindy,
            'xindy_lang_option': xindy_lang_option,
            'xindy_cyrillic':    xindy_cyrillic,
        }
        logger.info(bold(__('copying TeX support files...')))
        staticdirname = path.join(package_dir, 'texinputs')
        for filename in os.listdir(staticdirname):
            if not filename.startswith('.'):
                copy_asset_file(path.join(staticdirname, filename),
                                self.outdir, context=context)

        # use pre-1.6.x Makefile for make latexpdf on Windows
        if os.name == 'nt':
            staticdirname = path.join(package_dir, 'texinputs_win')
            copy_asset_file(path.join(staticdirname, 'Makefile_t'),
                            self.outdir, context=context)

    @progress_message(__('copying additional files'))
    def copy_latex_additional_files(self) -> None:
        for filename in self.config.latex_additional_files:
            logger.info(' ' + filename, nonl=True)
            copy_asset_file(path.join(self.confdir, filename), self.outdir)

    def copy_image_files(self) -> 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:
                    copy_asset_file(path.join(self.srcdir, src),
                                    path.join(self.outdir, dest))
                except Exception as err:
                    logger.warning(__('cannot copy image file %r: %s'),
                                   path.join(self.srcdir, src), err)
        if self.config.latex_logo:
            if not path.isfile(path.join(self.confdir, self.config.latex_logo)):
                raise SphinxError(__('logo file %r does not exist') % self.config.latex_logo)
            else:
                copy_asset_file(path.join(self.confdir, self.config.latex_logo), self.outdir)

    def write_message_catalog(self) -> None:
        formats = self.config.numfig_format
        context = {
            'addtocaptions': r'\@iden',
            'figurename': formats.get('figure', '').split('%s', 1),
            'tablename': formats.get('table', '').split('%s', 1),
            'literalblockname': formats.get('code-block', '').split('%s', 1)
        }

        if self.context['babel'] or self.context['polyglossia']:
            context['addtocaptions'] = r'\addto\captions%s' % self.babel.get_language()

        filename = path.join(package_dir, 'templates', 'latex', 'sphinxmessages.sty_t')
        copy_asset_file(filename, self.outdir, context=context, renderer=LaTeXRenderer())


def validate_config_values(app: Sphinx, config: Config) -> None:
    for key in list(config.latex_elements):
        if key not in DEFAULT_SETTINGS:
            msg = __("Unknown configure key: latex_elements[%r]. ignored.")
            logger.warning(msg % (key,))
            config.latex_elements.pop(key)


def default_latex_engine(config: Config) -> str:
    """ Better default latex_engine settings for specific languages. """
    if config.language == 'ja':
        return 'platex'
    elif (config.language or '').startswith('zh'):
        return 'xelatex'
    elif config.language == 'el':
        return 'xelatex'
    else:
        return 'pdflatex'


def default_latex_docclass(config: Config) -> Dict[str, str]:
    """ Better default latex_docclass settings for specific languages. """
    if config.language == 'ja':
        if config.latex_engine == 'uplatex':
            return {'manual': 'ujbook',
                    'howto': 'ujreport'}
        else:
            return {'manual': 'jsbook',
                    'howto': 'jreport'}
    else:
        return {}


def default_latex_use_xindy(config: Config) -> bool:
    """ Better default latex_use_xindy settings for specific engines. """
    return config.latex_engine in {'xelatex', 'lualatex'}


def default_latex_documents(config: Config) -> List[Tuple[str, str, str, str, str]]:
    """ Better default latex_documents settings. """
    project = texescape.escape(config.project, config.latex_engine)
    author = texescape.escape(config.author, config.latex_engine)
    return [(config.master_doc,
             make_filename_from_project(config.project) + '.tex',
             texescape.escape_abbr(project),
             texescape.escape_abbr(author),
             'manual')]


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

    app.add_builder(LaTeXBuilder)
    app.connect('config-inited', validate_config_values)

    app.add_config_value('latex_engine', default_latex_engine, None,
                         ENUM('pdflatex', 'xelatex', 'lualatex', 'platex', 'uplatex'))
    app.add_config_value('latex_documents', default_latex_documents, None)
    app.add_config_value('latex_logo', None, None, [str])
    app.add_config_value('latex_appendices', [], None)
    app.add_config_value('latex_use_latex_multicolumn', False, None)
    app.add_config_value('latex_use_xindy', default_latex_use_xindy, None, [bool])
    app.add_config_value('latex_toplevel_sectioning', None, None,
                         ENUM(None, 'part', 'chapter', 'section'))
    app.add_config_value('latex_domain_indices', True, None, [list])
    app.add_config_value('latex_show_urls', 'no', None)
    app.add_config_value('latex_show_pagerefs', False, None)
    app.add_config_value('latex_elements', {}, None)
    app.add_config_value('latex_additional_files', [], None)

    app.add_config_value('latex_docclass', default_latex_docclass, None)

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