""" Tabbed views for Sphinx, with HTML builder """

import base64
import json
import posixpath
import os
from docutils import nodes
from docutils.parsers.rst import Directive, directives
from pkg_resources import resource_filename
from pygments.lexers import get_all_lexers
from sphinx.util.osutil import copyfile
from sphinx.util import logging


FILES = [
    'tabs.js',
    'tabs.css',
    'semantic-ui-2.2.10/segment.min.css',
    'semantic-ui-2.2.10/menu.min.css',
    'semantic-ui-2.2.10/tab.min.css',
    'semantic-ui-2.2.10/tab.min.js',
]


LEXER_MAP = {}
for lexer in get_all_lexers():
    for short_name in lexer[1]:
        LEXER_MAP[short_name] = lexer[0]


def get_compatible_builders(app):
    builders = ['html', 'singlehtml', 'dirhtml',
                'readthedocs', 'readthedocsdirhtml',
                'readthedocssinglehtml', 'readthedocssinglehtmllocalmedia',
                'spelling']
    builders.extend(app.config['sphinx_tabs_valid_builders'])
    return builders


class TabsDirective(Directive):
    """ Top-level tabs directive """

    has_content = True

    def run(self):
        """ Parse a tabs directive """
        self.assert_has_content()
        env = self.state.document.settings.env

        node = nodes.container()
        node['classes'] = ['sphinx-tabs']

        if 'next_tabs_id' not in env.temp_data:
            env.temp_data['next_tabs_id'] = 0
        if 'tabs_stack' not in env.temp_data:
            env.temp_data['tabs_stack'] = []

        tabs_id = env.temp_data['next_tabs_id']
        tabs_key = 'tabs_%d' % tabs_id
        env.temp_data['next_tabs_id'] += 1
        env.temp_data['tabs_stack'].append(tabs_id)

        env.temp_data[tabs_key] = {}
        env.temp_data[tabs_key]['tab_ids'] = []
        env.temp_data[tabs_key]['tab_titles'] = []
        env.temp_data[tabs_key]['is_first_tab'] = True

        self.state.nested_parse(self.content, self.content_offset, node)

        if env.app.builder.name in get_compatible_builders(env.app):
            tabs_node = nodes.container()
            tabs_node.tagname = 'div'

            classes = 'ui top attached tabular menu sphinx-menu'
            tabs_node['classes'] = classes.split(' ')

            tab_titles = env.temp_data[tabs_key]['tab_titles']
            for idx, [data_tab, tab_name] in enumerate(tab_titles):
                tab = nodes.container()
                tab.tagname = 'a'
                tab['classes'] = ['item'] if idx > 0 else ['active', 'item']
                tab['classes'].append(data_tab)
                tab += tab_name
                tabs_node += tab

            node.children.insert(0, tabs_node)

        env.temp_data['tabs_stack'].pop()
        return [node]


class TabDirective(Directive):
    """ Tab directive, for adding a tab to a collection of tabs """

    has_content = True

    def run(self):
        """ Parse a tab directive """
        self.assert_has_content()
        env = self.state.document.settings.env

        tabs_id = env.temp_data['tabs_stack'][-1]
        tabs_key = 'tabs_%d' % tabs_id

        args = self.content[0].strip()
        if args.startswith('{'):
            try:
                args = json.loads(args)
                self.content.trim_start(1)
            except ValueError:
                args = {}
        else:
            args = {}

        tab_name = nodes.container()
        self.state.nested_parse(
            self.content[:1], self.content_offset, tab_name)
        args['tab_name'] = tab_name

        include_tabs_id_in_data_tab = False
        if 'tab_id' not in args:
            args['tab_id'] = env.new_serialno(tabs_key)
            include_tabs_id_in_data_tab = True
        i = 1
        while args['tab_id'] in env.temp_data[tabs_key]['tab_ids']:
            args['tab_id'] = '%s-%d' % (args['tab_id'], i)
            i += 1
        env.temp_data[tabs_key]['tab_ids'].append(args['tab_id'])

        data_tab = str(args['tab_id'])
        if include_tabs_id_in_data_tab:
            data_tab = '%d-%s' % (tabs_id, data_tab)
        data_tab = "sphinx-data-tab-{}".format(data_tab)

        env.temp_data[tabs_key]['tab_titles'].append(
            (data_tab, args['tab_name']))

        text = '\n'.join(self.content)
        node = nodes.container(text)

        classes = 'ui bottom attached sphinx-tab tab segment'
        node['classes'] = classes.split(' ')
        node['classes'].extend(args.get('classes', []))
        node['classes'].append(data_tab)

        if env.temp_data[tabs_key]['is_first_tab']:
            node['classes'].append('active')
            env.temp_data[tabs_key]['is_first_tab'] = False

        self.state.nested_parse(self.content[2:], self.content_offset, node)

        if env.app.builder.name not in get_compatible_builders(env.app):
            outer_node = nodes.container()
            tab = nodes.container()
            tab.tagname = 'a'
            tab['classes'] = ['item']
            tab += tab_name

            outer_node.append(tab)
            outer_node.append(node)
            return [outer_node]

        return [node]


class GroupTabDirective(Directive):
    """ Tab directive that toggles with same tab names across page"""

    has_content = True

    def run(self):
        """ Parse a tab directive """
        self.assert_has_content()

        group_name = self.content[0]
        self.content.trim_start(2)

        for idx, line in enumerate(self.content.data):
            self.content.data[idx] = '   ' + line

        tab_args = {
            'tab_id': base64.b64encode(
                group_name.encode('utf-8')).decode('utf-8'),
            'group_tab': True
        }

        new_content = [
            '.. tab:: {}'.format(json.dumps(tab_args)),
            '   {}'.format(group_name),
            '',
        ]

        for idx, line in enumerate(new_content):
            self.content.data.insert(idx, line)
            self.content.items.insert(idx, (None, idx))

        node = nodes.container()
        self.state.nested_parse(self.content, self.content_offset, node)
        return node.children


class CodeTabDirective(Directive):
    """ Tab directive with a codeblock as its content"""

    has_content = True
    option_spec = {
        'linenos': directives.flag
    }

    def run(self):
        """ Parse a tab directive """
        self.assert_has_content()

        args = self.content[0].strip().split()
        self.content.trim_start(2)

        lang = args[0]
        tab_name = ' '.join(args[1:]) if len(args) > 1 else LEXER_MAP[lang]

        for idx, line in enumerate(self.content.data):
            self.content.data[idx] = '      ' + line

        tab_args = {
            'tab_id': base64.b64encode(
                tab_name.encode('utf-8')).decode('utf-8'),
            'classes': ['code-tab'],
        }

        new_content = [
            '.. tab:: {}'.format(json.dumps(tab_args)),
            '   {}'.format(tab_name),
            '',
            '   .. code-block:: {}'.format(lang),
        ]

        if 'linenos' in self.options:
            new_content.append('      :linenos:')

        new_content.append('')

        for idx, line in enumerate(new_content):
            self.content.data.insert(idx, line)
            self.content.items.insert(idx, (None, idx))

        node = nodes.container()
        self.state.nested_parse(self.content, self.content_offset, node)
        return node.children


class _FindTabsDirectiveVisitor(nodes.NodeVisitor):
    """ Visitor pattern than looks for a sphinx tabs
        directive in a document """
    def __init__(self, document):
        nodes.NodeVisitor.__init__(self, document)
        self._found = False

    def unknown_visit(self, node):
        if not self._found and isinstance(node, nodes.container) and \
           'classes' in node and isinstance(node['classes'], list):
            self._found = 'sphinx-tabs' in node['classes']

    @property
    def found_tabs_directive(self):
        """ Return whether a sphinx tabs directive was found """
        return self._found


# pylint: disable=unused-argument
def update_context(app, pagename, templatename, context, doctree):
    """ Remove sphinx-tabs CSS and JS asset files if not used in a page """
    if doctree is None:
        return
    visitor = _FindTabsDirectiveVisitor(doctree)
    doctree.walk(visitor)
    if not visitor.found_tabs_directive:
        paths = [posixpath.join('_static', 'sphinx_tabs/' + f) for f in FILES]
        if 'css_files' in context:
            context['css_files'] = context['css_files'][:]
            for path in paths:
                if path.endswith('.css'):
                    context['css_files'].remove(path)
        if 'script_files' in context:
            context['script_files'] = context['script_files'][:]
            for path in paths:
                if path.endswith('.js'):
                    context['script_files'].remove(path)
# pylint: enable=unused-argument


def copy_assets(app, exception):
    """ Copy asset files to the output """
    if 'getLogger' in dir(logging):
        log = logging.getLogger(__name__).info  # pylint: disable=no-member
    else:
        log = app.info
    builders = get_compatible_builders(app)
    if exception:
        return
    if app.builder.name not in builders:
        if not app.config['sphinx_tabs_nowarn']:
            app.warn(
                'Not copying tabs assets! Not compatible with %s builder' %
                app.builder.name)
        return

    log('Copying tabs assets')

    installdir = os.path.join(app.builder.outdir, '_static', 'sphinx_tabs')

    for path in FILES:
        source = resource_filename('sphinx_tabs', path)
        dest = os.path.join(installdir, path)

        destdir = os.path.dirname(dest)
        if not os.path.exists(destdir):
            os.makedirs(destdir)

        copyfile(source, dest)


def setup(app):
    """ Set up the plugin """
    app.add_config_value('sphinx_tabs_nowarn', False, '')
    app.add_config_value('sphinx_tabs_valid_builders', [], '')
    app.add_directive('tabs', TabsDirective)
    app.add_directive('tab', TabDirective)
    app.add_directive('group-tab', GroupTabDirective)
    app.add_directive('code-tab', CodeTabDirective)
    for path in ['sphinx_tabs/' + f for f in FILES]:
        if path.endswith('.css'):
            if 'add_css_file' in dir(app):
                app.add_css_file(path)
            else:
                app.add_stylesheet(path)
        if path.endswith('.js'):
            if 'add_script_file' in dir(app):
                app.add_script_file(path)
            else:
                app.add_javascript(path)
    app.connect('html-page-context', update_context)
    app.connect('build-finished', copy_assets)