text: # -*- coding: utf-8 -*-
  """
  Math Render Plugin for Pelican
  ==============================
  This plugin allows your site to render Math. It uses
  the MathJax JavaScript engine.
  
  For markdown, the plugin works by creating a Markdown
  extension which is used during the markdown compilation
  stage.  Math therefore gets treated like a "first class
  citizen" in Pelican
  
  For reStructuredText, the plugin instructs the rst engine
  to output Mathjax for all math.
  
  The mathjax script is by default automatically inserted
  into the HTML.
  
  Typogrify Compatibility
  -----------------------
  This plugin now plays nicely with Typogrify, but it
  requires Typogrify version 2.07 or above.
  
  User Settings
  -------------
  Users are also able to pass a dictionary of settings
  in the settings file which will control how the MathJax
  library renders things. This could be very useful for
  template builders that want to adjust the look and feel of
  the math.  See README for more details.
  """
  
  import os
  import sys
  
  from pelican import signals, generators
  
  try:
      from bs4 import BeautifulSoup
  except ImportError as e:
      BeautifulSoup = None
  
  try:
      from . pelican_mathjax_markdown_extension import PelicanMathJaxExtension
  except ImportError as e:
      PelicanMathJaxExtension = None
  
  def process_settings(pelicanobj):
      """Sets user specified MathJax settings (see README for more details)"""
  
      mathjax_settings = {}
  
      # NOTE TO FUTURE DEVELOPERS: Look at the README and what is happening in
      # this function if any additional changes to the mathjax settings need to
      # be incorporated. Also, please inline comment what the variables
      # will be used for
  
      # Default settings
      mathjax_settings['auto_insert'] = True  # if set to true, it will insert mathjax script automatically into content without needing to alter the template.
      mathjax_settings['align'] = 'center'  # controls alignment of of displayed equations (values can be: left, right, center)
      mathjax_settings['indent'] = '0em'  # if above is not set to 'center', then this setting acts as an indent
      mathjax_settings['show_menu'] = 'true'  # controls whether to attach mathjax contextual menu
      mathjax_settings['process_escapes'] = 'true'  # controls whether escapes are processed
      mathjax_settings['latex_preview'] = 'TeX'  # controls what user sees while waiting for LaTex to render
      mathjax_settings['color'] = 'inherit'  # controls color math is rendered in
      mathjax_settings['linebreak_automatic'] = 'false'  # Set to false by default for performance reasons (see http://docs.mathjax.org/en/latest/output.html#automatic-line-breaking)
      mathjax_settings['tex_extensions'] = ''  # latex extensions that can be embedded inside mathjax (see http://docs.mathjax.org/en/latest/tex.html#tex-and-latex-extensions)
      mathjax_settings['responsive'] = 'false'  # Tries to make displayed math responsive
      mathjax_settings['responsive_break'] = '768'  # The break point at which it math is responsively aligned (in pixels)
      mathjax_settings['mathjax_font'] = 'default'  # forces mathjax to use the specified font.
      mathjax_settings['process_summary'] = BeautifulSoup is not None  # will fix up summaries if math is cut off. Requires beautiful soup
      mathjax_settings['message_style'] = 'normal'  # This value controls the verbosity of the messages in the lower left-hand corner. Set it to "none" to eliminate all messages
  
      # Source for MathJax
      mathjax_settings['source'] = "'https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.0/MathJax.js?config=TeX-AMS-MML_HTMLorMML'"
  
      # Get the user specified settings
      try:
          settings = pelicanobj.settings['MATH_JAX']
      except:
          settings = None
  
      # If no settings have been specified, then return the defaults
      if not isinstance(settings, dict):
          return mathjax_settings
  
      # The following mathjax settings can be set via the settings dictionary
      for key, value in ((key, settings[key]) for key in settings):
          # Iterate over dictionary in a way that is compatible with both version 2
          # and 3 of python
  
          if key == 'align':
              try:
                  typeVal = isinstance(value, basestring)
              except NameError:
                  typeVal = isinstance(value, str)
  
              if not typeVal:
                  continue
  
              if value == 'left' or value == 'right' or value == 'center':
                  mathjax_settings[key] = value
              else:
                  mathjax_settings[key] = 'center'
  
          if key == 'indent':
              mathjax_settings[key] = value
  
          if key == 'source':
              mathjax_settings[key] = value
  
          if key == 'show_menu' and isinstance(value, bool):
              mathjax_settings[key] = 'true' if value else 'false'
  
          if key == 'message_style':
              mathjax_settings[key] = value if value is not None else 'none'
  
          if key == 'auto_insert' and isinstance(value, bool):
              mathjax_settings[key] = value
  
          if key == 'process_escapes' and isinstance(value, bool):
              mathjax_settings[key] = 'true' if value else 'false'
  
          if key == 'latex_preview':
              try:
                  typeVal = isinstance(value, basestring)
              except NameError:
                  typeVal = isinstance(value, str)
  
              if not typeVal:
                  continue
  
              mathjax_settings[key] = value
  
          if key == 'color':
              try:
                  typeVal = isinstance(value, basestring)
              except NameError:
                  typeVal = isinstance(value, str)
  
              if not typeVal:
                  continue
  
              mathjax_settings[key] = value
  
          if key == 'linebreak_automatic' and isinstance(value, bool):
              mathjax_settings[key] = 'true' if value else 'false'
  
          if key == 'process_summary' and isinstance(value, bool):
              if value and BeautifulSoup is None:
                  print("BeautifulSoup4 is needed for summaries to be processed by render_math\nPlease install it")
                  value = False
  
              mathjax_settings[key] = value
  
          if key == 'responsive' and isinstance(value, bool):
              mathjax_settings[key] = 'true' if value else 'false'
  
          if key == 'responsive_break' and isinstance(value, int):
              mathjax_settings[key] = str(value)
  
          if key == 'tex_extensions' and isinstance(value, list):
              # filter string values, then add '' to them
              try:
                  value = filter(lambda string: isinstance(string, basestring), value)
              except NameError:
                  value = filter(lambda string: isinstance(string, str), value)
  
              value = map(lambda string: "'%s'" % string, value)
              mathjax_settings[key] = ',' + ','.join(value)
  
          if key == 'mathjax_font':
              try:
                  typeVal = isinstance(value, basestring)
              except NameError:
                  typeVal = isinstance(value, str)
  
              if not typeVal:
                  continue
  
              value = value.lower()
  
              if value == 'sanserif':
                  value = 'SansSerif'
              elif value == 'fraktur':
                  value = 'Fraktur'
              elif value == 'typewriter':
                  value = 'Typewriter'
              else:
                  value = 'default'
  
              mathjax_settings[key] = value
  
      return mathjax_settings
  
  def process_summary(article):
      """Ensures summaries are not cut off. Also inserts
      mathjax script so that math will be rendered"""
  
      summary = article._get_summary()
      summary_parsed = BeautifulSoup(summary, 'html.parser')
      math = summary_parsed.find_all(class_='math')
  
      if len(math) > 0:
          last_math_text = math[-1].get_text()
          if len(last_math_text) > 3 and last_math_text[-3:] == '...':
              content_parsed = BeautifulSoup(article._content, 'html.parser')
              full_text = content_parsed.find_all(class_='math')[len(math)-1].get_text()
              math[-1].string = "%s ..." % full_text
              summary = summary_parsed.decode()
  
          article._summary = "%s<script type='text/javascript'>%s</script>" % (summary, process_summary.mathjax_script)
  
  def configure_typogrify(pelicanobj, mathjax_settings):
      """Instructs Typogrify to ignore math tags - which allows Typogrify
      to play nicely with math related content"""
  
      # If Typogrify is not being used, then just exit
      if not pelicanobj.settings.get('TYPOGRIFY', False):
          return
  
      try:
          import typogrify
          from distutils.version import LooseVersion
  
          if LooseVersion(typogrify.__version__) < LooseVersion('2.0.7'):
              raise TypeError('Incorrect version of Typogrify')
  
          from typogrify.filters import typogrify
  
          # At this point, we are happy to use Typogrify, meaning
          # it is installed and it is a recent enough version
          # that can be used to ignore all math
          # Instantiate markdown extension and append it to the current extensions
          pelicanobj.settings['TYPOGRIFY_IGNORE_TAGS'].extend(['.math', 'script'])  # ignore math class and script
  
      except (ImportError, TypeError) as e:
          pelicanobj.settings['TYPOGRIFY'] = False  # disable Typogrify
  
          if isinstance(e, ImportError):
              print("\nTypogrify is not installed, so it is being ignored.\nIf you want to use it, please install via: pip install typogrify\n")
  
          if isinstance(e, TypeError):
              print("\nA more recent version of Typogrify is needed for the render_math module.\nPlease upgrade Typogrify to the latest version (anything equal or above version 2.0.7 is okay).\nTypogrify will be turned off due to this reason.\n")
  
  def process_mathjax_script(mathjax_settings):
      """Load the mathjax script template from file, and render with the settings"""
  
      # Read the mathjax javascript template from file
      with open (os.path.dirname(os.path.realpath(__file__))
              + '/mathjax_script_template', 'r') as mathjax_script_template:
          mathjax_template = mathjax_script_template.read()
  
      return mathjax_template.format(**mathjax_settings)
  
  def mathjax_for_markdown(pelicanobj, mathjax_script, mathjax_settings):
      """Instantiates a customized markdown extension for handling mathjax
      related content"""
  
      # Create the configuration for the markdown template
      config = {}
      config['mathjax_script'] = mathjax_script
      config['math_tag_class'] = 'math'
      config['auto_insert'] = mathjax_settings['auto_insert']
  
      # Instantiate markdown extension and append it to the current extensions
      try:
          if isinstance(pelicanobj.settings.get('MD_EXTENSIONS'), list): # pelican 3.6.3 and earlier
              pelicanobj.settings['MD_EXTENSIONS'].append(PelicanMathJaxExtension(config))
          else:
              pelicanobj.settings['MARKDOWN'].setdefault('extensions', []).append(PelicanMathJaxExtension(config))
      except:
          sys.excepthook(*sys.exc_info())
          sys.stderr.write("\nError - the pelican mathjax markdown extension failed to configure. MathJax is non-functional.\n")
          sys.stderr.flush()
  
  def mathjax_for_rst(pelicanobj, mathjax_script):
      """Setup math for RST"""
      docutils_settings = pelicanobj.settings.get('DOCUTILS_SETTINGS', {})
      docutils_settings['math_output'] = 'MathJax'
      pelicanobj.settings['DOCUTILS_SETTINGS'] = docutils_settings
      rst_add_mathjax.mathjax_script = mathjax_script
  
  def pelican_init(pelicanobj):
      """
      Loads the mathjax script according to the settings.
      Instantiate the Python markdown extension, passing in the mathjax
      script as config parameter.
      """
  
      # Process settings, and set global var
      mathjax_settings = process_settings(pelicanobj)
  
      # Generate mathjax script
      mathjax_script = process_mathjax_script(mathjax_settings)
  
      # Configure Typogrify
      configure_typogrify(pelicanobj, mathjax_settings)
  
      # Configure Mathjax For Markdown
      if PelicanMathJaxExtension:
          mathjax_for_markdown(pelicanobj, mathjax_script, mathjax_settings)
  
      # Configure Mathjax For RST
      mathjax_for_rst(pelicanobj, mathjax_script)
  
      # Set process_summary's mathjax_script variable
      process_summary.mathjax_script = None
      if mathjax_settings['process_summary']:
          process_summary.mathjax_script = mathjax_script
  
  def rst_add_mathjax(content):
      """Adds mathjax script for reStructuredText"""
  
      # .rst is the only valid extension for reStructuredText files
      _, ext = os.path.splitext(os.path.basename(content.source_path))
      if ext != '.rst':
          return
  
      # If math class is present in text, add the javascript
      # note that RST hardwires mathjax to be class "math"
      if 'class="math"' in content._content:
          content._content += "<script type='text/javascript'>%s</script>" % rst_add_mathjax.mathjax_script
  
  def process_rst_and_summaries(content_generators):
      """
      Ensure mathjax script is applied to RST and summaries are
      corrected if specified in user settings.
  
      Handles content attached to ArticleGenerator and PageGenerator objects,
      since the plugin doesn't know how to handle other Generator types.
  
      For reStructuredText content, examine both articles and pages.
      If article or page is reStructuredText and there is math present,
      append the mathjax script.
  
      Also process summaries if present (only applies to articles)
      and user wants summaries processed (via user settings)
      """
  
      for generator in content_generators:
          if isinstance(generator, generators.ArticlesGenerator):
              for article in (
                      generator.articles +
                      generator.translations +
                      generator.drafts):
                  rst_add_mathjax(article)
                  #optionally fix truncated formulae in summaries.
                  if process_summary.mathjax_script is not None:
                      process_summary(article)
          elif isinstance(generator, generators.PagesGenerator):
              for page in generator.pages:
                  rst_add_mathjax(page)
  
  def register():
      """Plugin registration"""
      signals.initialized.connect(pelican_init)
      signals.all_generators_finalized.connect(process_rst_and_summaries)
  