"""
    sphinx.ext.graphviz
    ~~~~~~~~~~~~~~~~~~~

    Allow graphviz-formatted graphs to be included in Sphinx-generated
    documents inline.

    :copyright: Copyright 2007-2019 by the Sphinx team, see AUTHORS.
    :license: BSD, see LICENSE for details.
"""

import posixpath
import re
import subprocess
from hashlib import sha1
from os import path
from subprocess import CalledProcessError, PIPE

from docutils import nodes
from docutils.parsers.rst import directives

import sphinx
from sphinx.errors import SphinxError
from sphinx.locale import _, __
from sphinx.util import logging
from sphinx.util.docutils import SphinxDirective
from sphinx.util.fileutil import copy_asset
from sphinx.util.i18n import search_image_for_language
from sphinx.util.nodes import set_source_info
from sphinx.util.osutil import ensuredir

if False:
    # For type annotation
    from docutils.parsers.rst import Directive  # NOQA
    from typing import Any, Dict, List, Tuple  # NOQA
    from sphinx.application import Sphinx  # NOQA
    from sphinx.util.docutils import SphinxTranslator  # NOQA
    from sphinx.writers.html import HTMLTranslator  # NOQA
    from sphinx.writers.latex import LaTeXTranslator  # NOQA
    from sphinx.writers.manpage import ManualPageTranslator  # NOQA
    from sphinx.writers.texinfo import TexinfoTranslator  # NOQA
    from sphinx.writers.text import TextTranslator  # NOQA

logger = logging.getLogger(__name__)


class GraphvizError(SphinxError):
    category = 'Graphviz error'


class ClickableMapDefinition:
    """A manipulator for clickable map file of graphviz."""
    maptag_re = re.compile('<map id="(.*?)"')
    href_re = re.compile('href=".*?"')

    def __init__(self, filename, content, dot=''):
        # type: (str, str, str) -> None
        self.id = None  # type: str
        self.filename = filename
        self.content = content.splitlines()
        self.clickable = []  # type: List[str]

        self.parse(dot=dot)

    def parse(self, dot=None):
        # type: (str) -> None
        matched = self.maptag_re.match(self.content[0])
        if not matched:
            raise GraphvizError('Invalid clickable map file found: %s' % self.filename)

        self.id = matched.group(1)
        if self.id == '%3':
            # graphviz generates wrong ID if graph name not specified
            # https://gitlab.com/graphviz/graphviz/issues/1327
            hashed = sha1(dot.encode()).hexdigest()
            self.id = 'grapviz%s' % hashed[-10:]
            self.content[0] = self.content[0].replace('%3', self.id)

        for line in self.content:
            if self.href_re.search(line):
                self.clickable.append(line)

    def generate_clickable_map(self):
        # type: () -> str
        """Generate clickable map tags if clickable item exists.

        If not exists, this only returns empty string.
        """
        if self.clickable:
            return '\n'.join([self.content[0]] + self.clickable + [self.content[-1]])
        else:
            return ''


class graphviz(nodes.General, nodes.Inline, nodes.Element):
    pass


def figure_wrapper(directive, node, caption):
    # type: (Directive, graphviz, str) -> nodes.figure
    figure_node = nodes.figure('', node)
    if 'align' in node:
        figure_node['align'] = node.attributes.pop('align')

    inodes, messages = directive.state.inline_text(caption, directive.lineno)
    caption_node = nodes.caption(caption, '', *inodes)
    caption_node.extend(messages)
    set_source_info(directive, caption_node)
    figure_node += caption_node
    return figure_node


def align_spec(argument):
    # type: (Any) -> str
    return directives.choice(argument, ('left', 'center', 'right'))


class Graphviz(SphinxDirective):
    """
    Directive to insert arbitrary dot markup.
    """
    has_content = True
    required_arguments = 0
    optional_arguments = 1
    final_argument_whitespace = False
    option_spec = {
        'alt': directives.unchanged,
        'align': align_spec,
        'caption': directives.unchanged,
        'graphviz_dot': directives.unchanged,
        'name': directives.unchanged,
    }

    def run(self):
        # type: () -> List[nodes.Node]
        if self.arguments:
            document = self.state.document
            if self.content:
                return [document.reporter.warning(
                    __('Graphviz directive cannot have both content and '
                       'a filename argument'), line=self.lineno)]
            argument = search_image_for_language(self.arguments[0], self.env)
            rel_filename, filename = self.env.relfn2path(argument)
            self.env.note_dependency(rel_filename)
            try:
                with open(filename, encoding='utf-8') as fp:
                    dotcode = fp.read()
            except OSError:
                return [document.reporter.warning(
                    __('External Graphviz file %r not found or reading '
                       'it failed') % filename, line=self.lineno)]
        else:
            dotcode = '\n'.join(self.content)
            if not dotcode.strip():
                return [self.state_machine.reporter.warning(
                    __('Ignoring "graphviz" directive without content.'),
                    line=self.lineno)]
        node = graphviz()
        node['code'] = dotcode
        node['options'] = {'docname': self.env.docname}

        if 'graphviz_dot' in self.options:
            node['options']['graphviz_dot'] = self.options['graphviz_dot']
        if 'alt' in self.options:
            node['alt'] = self.options['alt']
        if 'align' in self.options:
            node['align'] = self.options['align']

        if 'caption' not in self.options:
            self.add_name(node)
            return [node]
        else:
            figure = figure_wrapper(self, node, self.options['caption'])
            self.add_name(figure)
            return [figure]


class GraphvizSimple(SphinxDirective):
    """
    Directive to insert arbitrary dot markup.
    """
    has_content = True
    required_arguments = 1
    optional_arguments = 0
    final_argument_whitespace = False
    option_spec = {
        'alt': directives.unchanged,
        'align': align_spec,
        'caption': directives.unchanged,
        'graphviz_dot': directives.unchanged,
        'name': directives.unchanged,
    }

    def run(self):
        # type: () -> List[nodes.Node]
        node = graphviz()
        node['code'] = '%s %s {\n%s\n}\n' % \
                       (self.name, self.arguments[0], '\n'.join(self.content))
        node['options'] = {'docname': self.env.docname}
        if 'graphviz_dot' in self.options:
            node['options']['graphviz_dot'] = self.options['graphviz_dot']
        if 'alt' in self.options:
            node['alt'] = self.options['alt']
        if 'align' in self.options:
            node['align'] = self.options['align']

        if 'caption' not in self.options:
            self.add_name(node)
            return [node]
        else:
            figure = figure_wrapper(self, node, self.options['caption'])
            self.add_name(figure)
            return [figure]


def render_dot(self, code, options, format, prefix='graphviz'):
    # type: (SphinxTranslator, str, Dict, str, str) -> Tuple[str, str]
    """Render graphviz code into a PNG or PDF output file."""
    graphviz_dot = options.get('graphviz_dot', self.builder.config.graphviz_dot)
    hashkey = (code + str(options) + str(graphviz_dot) +
               str(self.builder.config.graphviz_dot_args)).encode()

    fname = '%s-%s.%s' % (prefix, sha1(hashkey).hexdigest(), format)
    relfn = posixpath.join(self.builder.imgpath, fname)
    outfn = path.join(self.builder.outdir, self.builder.imagedir, fname)

    if path.isfile(outfn):
        return relfn, outfn

    if (hasattr(self.builder, '_graphviz_warned_dot') and
       self.builder._graphviz_warned_dot.get(graphviz_dot)):  # type: ignore  # NOQA
        return None, None

    ensuredir(path.dirname(outfn))

    dot_args = [graphviz_dot]
    dot_args.extend(self.builder.config.graphviz_dot_args)
    dot_args.extend(['-T' + format, '-o' + outfn])

    docname = options.get('docname', 'index')
    cwd = path.dirname(path.join(self.builder.srcdir, docname))

    if format == 'png':
        dot_args.extend(['-Tcmapx', '-o%s.map' % outfn])

    try:
        ret = subprocess.run(dot_args, input=code.encode(), stdout=PIPE, stderr=PIPE,
                             cwd=cwd, check=True)
        if not path.isfile(outfn):
            raise GraphvizError(__('dot did not produce an output file:\n[stderr]\n%r\n'
                                   '[stdout]\n%r') % (ret.stderr, ret.stdout))
        return relfn, outfn
    except OSError:
        logger.warning(__('dot command %r cannot be run (needed for graphviz '
                          'output), check the graphviz_dot setting'), graphviz_dot)
        if not hasattr(self.builder, '_graphviz_warned_dot'):
            self.builder._graphviz_warned_dot = {}  # type: ignore
        self.builder._graphviz_warned_dot[graphviz_dot] = True  # type: ignore
        return None, None
    except CalledProcessError as exc:
        raise GraphvizError(__('dot exited with error:\n[stderr]\n%r\n'
                               '[stdout]\n%r') % (exc.stderr, exc.stdout))


def render_dot_html(self, node, code, options, prefix='graphviz',
                    imgcls=None, alt=None):
    # type: (HTMLTranslator, graphviz, str, Dict, str, str, str) -> Tuple[str, str]
    format = self.builder.config.graphviz_output_format
    try:
        if format not in ('png', 'svg'):
            raise GraphvizError(__("graphviz_output_format must be one of 'png', "
                                   "'svg', but is %r") % format)
        fname, outfn = render_dot(self, code, options, format, prefix)
    except GraphvizError as exc:
        logger.warning(__('dot code %r: %s'), code, exc)
        raise nodes.SkipNode

    if imgcls:
        imgcls += " graphviz"
    else:
        imgcls = "graphviz"

    if fname is None:
        self.body.append(self.encode(code))
    else:
        if alt is None:
            alt = node.get('alt', self.encode(code).strip())
        if 'align' in node:
            self.body.append('<div align="%s" class="align-%s">' %
                             (node['align'], node['align']))
        if format == 'svg':
            self.body.append('<div class="graphviz">')
            self.body.append('<object data="%s" type="image/svg+xml" class="%s">\n' %
                             (fname, imgcls))
            self.body.append('<p class="warning">%s</p>' % alt)
            self.body.append('</object></div>\n')
        else:
            with open(outfn + '.map', encoding='utf-8') as mapfile:
                imgmap = ClickableMapDefinition(outfn + '.map', mapfile.read(), dot=code)
                if imgmap.clickable:
                    # has a map
                    self.body.append('<div class="graphviz">')
                    self.body.append('<img src="%s" alt="%s" usemap="#%s" class="%s" />' %
                                     (fname, alt, imgmap.id, imgcls))
                    self.body.append('</div>\n')
                    self.body.append(imgmap.generate_clickable_map())
                else:
                    # nothing in image map
                    self.body.append('<div class="graphviz">')
                    self.body.append('<img src="%s" alt="%s" class="%s" />' %
                                     (fname, alt, imgcls))
                    self.body.append('</div>\n')
        if 'align' in node:
            self.body.append('</div>\n')

    raise nodes.SkipNode


def html_visit_graphviz(self, node):
    # type: (HTMLTranslator, graphviz) -> None
    render_dot_html(self, node, node['code'], node['options'])


def render_dot_latex(self, node, code, options, prefix='graphviz'):
    # type: (LaTeXTranslator, graphviz, str, Dict, str) -> None
    try:
        fname, outfn = render_dot(self, code, options, 'pdf', prefix)
    except GraphvizError as exc:
        logger.warning(__('dot code %r: %s'), code, exc)
        raise nodes.SkipNode

    is_inline = self.is_inline(node)

    if not is_inline:
        pre = ''
        post = ''
        if 'align' in node:
            if node['align'] == 'left':
                pre = '{'
                post = r'\hspace*{\fill}}'
            elif node['align'] == 'right':
                pre = r'{\hspace*{\fill}'
                post = '}'
            elif node['align'] == 'center':
                pre = r'{\hfill'
                post = r'\hspace*{\fill}}'
        self.body.append('\n%s' % pre)

    self.body.append(r'\sphinxincludegraphics[]{%s}' % fname)

    if not is_inline:
        self.body.append('%s\n' % post)

    raise nodes.SkipNode


def latex_visit_graphviz(self, node):
    # type: (LaTeXTranslator, graphviz) -> None
    render_dot_latex(self, node, node['code'], node['options'])


def render_dot_texinfo(self, node, code, options, prefix='graphviz'):
    # type: (TexinfoTranslator, graphviz, str, Dict, str) -> None
    try:
        fname, outfn = render_dot(self, code, options, 'png', prefix)
    except GraphvizError as exc:
        logger.warning(__('dot code %r: %s'), code, exc)
        raise nodes.SkipNode
    if fname is not None:
        self.body.append('@image{%s,,,[graphviz],png}\n' % fname[:-4])
    raise nodes.SkipNode


def texinfo_visit_graphviz(self, node):
    # type: (TexinfoTranslator, graphviz) -> None
    render_dot_texinfo(self, node, node['code'], node['options'])


def text_visit_graphviz(self, node):
    # type: (TextTranslator, graphviz) -> None
    if 'alt' in node.attributes:
        self.add_text(_('[graph: %s]') % node['alt'])
    else:
        self.add_text(_('[graph]'))
    raise nodes.SkipNode


def man_visit_graphviz(self, node):
    # type: (ManualPageTranslator, graphviz) -> None
    if 'alt' in node.attributes:
        self.body.append(_('[graph: %s]') % node['alt'])
    else:
        self.body.append(_('[graph]'))
    raise nodes.SkipNode


def on_build_finished(app, exc):
    # type: (Sphinx, Exception) -> None
    if exc is None:
        src = path.join(sphinx.package_dir, 'templates', 'graphviz', 'graphviz.css')
        dst = path.join(app.outdir, '_static')
        copy_asset(src, dst)


def setup(app):
    # type: (Sphinx) -> Dict[str, Any]
    app.add_node(graphviz,
                 html=(html_visit_graphviz, None),
                 latex=(latex_visit_graphviz, None),
                 texinfo=(texinfo_visit_graphviz, None),
                 text=(text_visit_graphviz, None),
                 man=(man_visit_graphviz, None))
    app.add_directive('graphviz', Graphviz)
    app.add_directive('graph', GraphvizSimple)
    app.add_directive('digraph', GraphvizSimple)
    app.add_config_value('graphviz_dot', 'dot', 'html')
    app.add_config_value('graphviz_dot_args', [], 'html')
    app.add_config_value('graphviz_output_format', 'png', 'html')
    app.add_css_file('graphviz.css')
    app.connect('build-finished', on_build_finished)
    return {'version': sphinx.__display_version__, 'parallel_read_safe': True}
