#!/usr/bin/python
# -*- coding: iso-8859-15 -*-

"""
New latex formatter using dvipng and tempfile

Author: JohannesBerg <johannes@sipsolutions.net>

This parser (and the corresponding macro) was tested with Python 2.3.4 and
 * Debian Linux with out-of-the-box tetex-bin and dvipng packages installed
 * Windows XP with cygwin and a self-compiled dvipng
   (you need tetex-devel, libpng14-devel and the usual make/gcc stuff to compile)
 * Windows NT 4.0 with miktex (comes with dvipng even in the 'small' install!)
 
In the parser, you can add stuff to the prologue by writing 
%%end-prologue%%
somewhere in the document, before that write stuff like \\usepackage and after it put
the actual latex display code.
"""

# this plugin only works with cmd.exe
import os
class ShellNotSupported:
    '''due to deficiencies of the command shell Win9x has this plugin cannot work on those systems.'''

# COMSPEC is only set on windows systems, so if it is
# unset we assume all is fine (default value "cmd.exe")
if (os.path.basename(os.environ.get("COMSPEC", "cmd.exe")).lower() != "cmd.exe"):
    raise ShellNotSupported
# end of cmd.exe check

Dependencies = []

import sha, tempfile, shutil, re
from MoinMoin.action import AttachFile
from MoinMoin.Page import Page

latex_template = r'''
\documentclass[12pt]{article}
\pagestyle{empty}
%(prologue)s
\begin{document}
%(raw)s
\end{document}
'''

max_pages = 10

latex = "latex"
dvipng = "dvipng"

# stdin must be connected to /dev/null or, on windows, NUL,
# otherwise latex may block reading stuff from stdin!
# stdout is now read by the parser in order to be able to
# report latex errors to the wiki user.
if os.name == 'nt':
    null = 'NUL'
else:
    null = '/dev/null'

latex_line = "%(latex)s %%s.tex < %(null)s" % {
  'latex': latex,
  'null': null,
  }

dvipng_line = "%(dvipng)s -T tight -l %(max_pages)s %%s.dvi < %(null)s" % {
  'dvipng': dvipng,
  'max_pages': max_pages,
  'null': null,
  }

# this is formatted with hexdigest(texcode),
# page number and extension are appended by
# the tools
latex_name_template = "latex2_%s_p"

# keep this up-to-date, also with max_pages!!
latex_attachment = re.compile((latex_name_template+'%s%s') % (r'[0-9a-fA-F]{40}', r'[0-9]{1,2}', r'\.png'))

anchor = re.compile(r'^%%anchor:[ ]*([a-zA-Z0-9_-]+)$', re.MULTILINE | re.IGNORECASE)
# the anchor re must start with a % sign to be ignored by latex as a comment!
end_prologue = '%%end-prologue%%'

def call_command_in_dir(cmd, targetdir):
    # well. the windows shell has separate current working directories
    # for each drive! so if it happens that the tmpdir is on another drive
    # we need to fix that up...
    cdcmd = ''
    if os.name == 'nt':
        if targetdir[1] == ':':
            cdcmd += targetdir[0:2] + " && "
    cdcmd += 'cd %s' % targetdir
    stdouterr = os.popen("%s && %s" % (cdcmd, cmd), 'r')
    output = ''.join(stdouterr.readlines())
    err = stdouterr.close()
    if not err is None:
        return ' error! exitcode was %d, transscript follows:\n\n%s' % (err,output)
    return None

class Parser:
    extensions = ['.tex']
    def __init__ (self, raw, request, **kw):
        self.raw = raw
        if len(self.raw)>0 and self.raw[0] == '#':
            self.raw[0] = '%'
        self.request = request
        self.exclude = []
        if not hasattr(request, "latex2_cleanup_done"):
            request.latex2_cleanup_done = {}

    def cleanup(self, pagename):
        attachdir = AttachFile.getAttachDir(self.request, pagename, create=1)
        for f in os.listdir(attachdir):
            if not latex_attachment.match(f) is None:
                os.remove("%s/%s" % (attachdir, f))

    def format(self, formatter):
        tmp = self.raw.split(end_prologue, 1)
        if len(tmp) == 2:
            prologue,tex=tmp
        else:
            prologue = ''
            tex = tmp[0]
        self.request.write(self.get(formatter, tex, prologue));

    def get(self, formatter, inputtex, prologue):
        if not self.request.latex2_cleanup_done.has_key(formatter.page.page_name):
            self.request.latex2_cleanup_done[formatter.page.page_name] = True
            self.cleanup(formatter.page.page_name)

        if len(inputtex) == 0: return ''

        tex = latex_template % { 'raw': inputtex, 'prologue': prologue }
        fn = latex_name_template % sha.new(tex).hexdigest()

        attachdir = AttachFile.getAttachDir(self.request, formatter.page.page_name, create=1)
        dst = "%s/%s%%d.png" % (attachdir, fn)
        if not os.access(dst % 1, os.R_OK):
          tmpdir = tempfile.mkdtemp()
          try:
              data = open ("%s/%s.tex" % (tmpdir, fn), "w")
              data.write(tex)
              data.close()
              res = call_command_in_dir(latex_line % fn, tmpdir)
              if not res is None:
                  return formatter.preformatted(1)+formatter.text('latex'+res)+formatter.preformatted(0)
              res = call_command_in_dir(dvipng_line % fn, tmpdir)
              if not res is None:
                  return formatter.preformatted(1)+formatter.text('dvipng'+res)+formatter.preformatted(0)

              page = 1
              while os.access("%s/%s%d.png" % (tmpdir, fn, page), os.R_OK):
                  shutil.copyfile ("%s/%s%d.png" % (tmpdir, fn, page), dst % page)
                  page += 1

          finally:
              for root,dirs,files in os.walk(tmpdir, topdown=False):
                  for name in files:
                      os.remove(os.path.join(root,name))
                  for name in dirs:
                      os.rmdir(os.path.join(root,name))
              os.rmdir(tmpdir)

        result = ""
        page = 1
        loop = False
        for match in anchor.finditer(inputtex):
            result += formatter.anchordef(match.group(1))
        for match in anchor.finditer(prologue):
            result += formatter.anchordef(match.group(1))
        while os.access(dst % page, os.R_OK):
            url = AttachFile.getAttachUrl(formatter.page.page_name, fn+"%d.png" % page, self.request)
            if loop:
                result += formatter.linebreak(0)+formatter.linebreak(0)
            result += formatter.image(src="%s" % url, alt=inputtex, title=inputtex, align="absmiddle")
            page += 1
            loop = True
        return result