# -*- coding: utf-8 -*-
# Copyright (C) 2006-2010 Søren Roug, European Environment Agency
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
#
# Contributor(s):
#
# Copyright (C) 2014 Georges Khaznadar <georgesk@debian.org>
#     migration to Python3, JavaDOC comments and automatic
#      build of documentation
#

__doc__="""Use OpenDocument to generate your documents."""

import zipfile, time, sys, mimetypes, copy, os.path

# to allow Python3 to access modules in the same path
sys.path.append(os.path.dirname(__file__))

# using BytesIO provides a cleaner interface than StringIO
# with both Python2 and Python3: the programmer must care to
# convert strings or unicode to bytes, which is valid for Python 2 and 3.
from io import StringIO, BytesIO

from namespaces import *
import manifest
import meta
from office import *
import element
from attrconverters import make_NCName
from xml.sax.xmlreader import InputSource
from odfmanifest import manifestlist

if sys.version_info[0] == 3:
    unicode=str # unicode function does not exist

__version__= TOOLSVERSION

_XMLPROLOGUE = u"<?xml version='1.0' encoding='UTF-8'?>\n"

#####
# file permission as an integer value.
# The following syntax would be invalid for Python3:
# UNIXPERMS = 0100644 << 16L  # -rw-r--r--
#
# So it has been precomputed:
# 2175008768 is the same value as 0100644 << 16L == -rw-r--r--
####
UNIXPERMS = 2175008768

IS_FILENAME = 0
IS_IMAGE = 1
# We need at least Python 2.2
assert sys.version_info[0]>=2 and sys.version_info[1] >= 2

#sys.setrecursionlimit(100)
#The recursion limit is set conservative so mistakes like
# s=content() s.addElement(s) won't eat up too much processor time.

###############
# mime-types => file extensions
###############
odmimetypes = {
 u'application/vnd.oasis.opendocument.text':                  u'.odt',
 u'application/vnd.oasis.opendocument.text-template':         u'.ott',
 u'application/vnd.oasis.opendocument.graphics':              u'.odg',
 u'application/vnd.oasis.opendocument.graphics-template':     u'.otg',
 u'application/vnd.oasis.opendocument.presentation':          u'.odp',
 u'application/vnd.oasis.opendocument.presentation-template': u'.otp',
 u'application/vnd.oasis.opendocument.spreadsheet':           u'.ods',
 u'application/vnd.oasis.opendocument.spreadsheet-template':  u'.ots',
 u'application/vnd.oasis.opendocument.chart':                 u'.odc',
 u'application/vnd.oasis.opendocument.chart-template':        u'.otc',
 u'application/vnd.oasis.opendocument.image':                 u'.odi',
 u'application/vnd.oasis.opendocument.image-template':        u'.oti',
 u'application/vnd.oasis.opendocument.formula':               u'.odf',
 u'application/vnd.oasis.opendocument.formula-template':      u'.otf',
 u'application/vnd.oasis.opendocument.text-master':           u'.odm',
 u'application/vnd.oasis.opendocument.text-web':              u'.oth',
}

class OpaqueObject:
    """
    just a record to bear a filename, a mediatype and a bytes content
    """
    def __init__(self, filename, mediatype, content=None):
        """
        the constructor
        @param filename a unicode string
        @param mediatype a unicode string
        @param content a byte string or None
        """
        assert(type(filename)==type(u""))
        assert(type(mediatype)==type(u""))
        assert(type(content)==type(b"") or content == None)

        self.mediatype = mediatype
        self.filename = filename
        self.content = content

class OpenDocument:
    """
    A class to hold the content of an OpenDocument document
    Use the xml method to write the XML
    source to the screen or to a file.
    Example of use: d = OpenDocument(mimetype); fd.write(d.xml())
    """
    thumbnail = None

    def __init__(self, mimetype, add_generator=True):
        """
        the constructor
        @param mimetype a unicode string
        @param add_generator a boolean
        """
        assert(type(mimetype)==type(u""))
        assert(isinstance(add_generator,True.__class__))

        self.mimetype = mimetype
        self.childobjects = []
        self._extra = []
        self.folder = u"" # Always empty for toplevel documents
        self.topnode = Document(mimetype=self.mimetype)
        self.topnode.ownerDocument = self

        self.clear_caches()

        self.Pictures = {}
        self.meta = Meta()
        self.topnode.addElement(self.meta)
        if add_generator:
            self.meta.addElement(meta.Generator(text=TOOLSVERSION))
        self.scripts = Scripts()
        self.topnode.addElement(self.scripts)
        self.fontfacedecls = FontFaceDecls()
        self.topnode.addElement(self.fontfacedecls)
        self.settings = Settings()
        self.topnode.addElement(self.settings)
        self.styles = Styles()
        self.topnode.addElement(self.styles)
        self.automaticstyles = AutomaticStyles()
        self.topnode.addElement(self.automaticstyles)
        self.masterstyles = MasterStyles()
        self.topnode.addElement(self.masterstyles)
        self.body = Body()
        self.topnode.addElement(self.body)

    def rebuild_caches(self, node=None):
        if node is None: node = self.topnode
        self.build_caches(node)
        for e in node.childNodes:
            if e.nodeType == element.Node.ELEMENT_NODE:
                self.rebuild_caches(e)

    def clear_caches(self):
        """
        Clears internal caches
        """
        self.element_dict = {}
        self._styles_dict = {}
        self._styles_ooo_fix = {}

    def build_caches(self, elt):
        """
        Builds internal caches; called from element.py
        @param elt an element.Element instance
        """
        # assert(isinstance(elt, element.Element))
        # why do I need this more intricated assertion?
        # with Python3, the type of elt pops out as odf.element.Element
        # in one test ???
        import odf.element
        assert(isinstance(elt, element.Element) or isinstance(elt, odf.element.Element) )

        if elt.qname not in self.element_dict:
            self.element_dict[elt.qname] = []
        self.element_dict[elt.qname].append(elt)
        if elt.qname == (STYLENS, u'style'):
            self.__register_stylename(elt) # Add to style dictionary
        styleref = elt.getAttrNS(TEXTNS,u'style-name')
        if styleref is not None and styleref in self._styles_ooo_fix:
            elt.setAttrNS(TEXTNS,u'style-name', self._styles_ooo_fix[styleref])

    def __register_stylename(self, elt):
        '''
        Register a style. But there are three style dictionaries:
        office:styles, office:automatic-styles and office:master-styles
        Chapter 14.
        @param elt an element.Element instance
        '''
        assert(isinstance(elt, element.Element))

        name = elt.getAttrNS(STYLENS, u'name')
        if name is None:
            return
        if elt.parentNode.qname in ((OFFICENS,u'styles'), (OFFICENS,u'automatic-styles')):
            if name in self._styles_dict:
                newname = u'M'+name # Rename style
                self._styles_ooo_fix[name] = newname
                # From here on all references to the old name will refer to the new one
                name = newname
                elt.setAttrNS(STYLENS, u'name', name)
            self._styles_dict[name] = elt

    def toXml(self, filename=u''):
        """
        converts the document to a valid Xml format.
        @param filename unicode string: the name of a file, defaults to
        an empty string.
        @return if filename is not empty, the XML code will be written into it
        and the method returns None; otherwise the method returns a StringIO
        containing valid XML.
        Then a ".getvalue()" should return a unicode string.
        """
        assert(type(filename)==type(u""))

        result=None
        xml=StringIO()
        if sys.version_info[0]==2:
            xml.write(_XMLPROLOGUE)
        else:
            xml.write(_XMLPROLOGUE)
        self.body.toXml(0, xml)
        if not filename:
            result=xml.getvalue()
        else:
            f=codecs.open(filename,'w', encoding='utf-8')
            f.write(xml.getvalue())
            f.close()
        return result

    def xml(self):
        """
        Generates the full document as an XML "file"
        @return a bytestream in UTF-8 encoding
        """
        self.__replaceGenerator()
        xml=StringIO()
        if sys.version_info[0]==2:
            xml.write(_XMLPROLOGUE)
        else:
            xml.write(_XMLPROLOGUE)
        self.topnode.toXml(0, xml)
        return xml.getvalue().encode("utf-8")


    def contentxml(self):
        """
        Generates the content.xml file
        @return a bytestream in UTF-8 encoding
        """
        xml=StringIO()
        xml.write(_XMLPROLOGUE)
        x = DocumentContent()
        x.write_open_tag(0, xml)
        if self.scripts.hasChildNodes():
            self.scripts.toXml(1, xml)
        if self.fontfacedecls.hasChildNodes():
            self.fontfacedecls.toXml(1, xml)
        a = AutomaticStyles()
        stylelist = self._used_auto_styles([self.styles, self.automaticstyles, self.body])
        if len(stylelist) > 0:
            a.write_open_tag(1, xml)
            for s in stylelist:
                s.toXml(2, xml)
            a.write_close_tag(1, xml)
        else:
            a.toXml(1, xml)
        self.body.toXml(1, xml)
        x.write_close_tag(0, xml)
        return xml.getvalue().encode("utf-8")

    def __manifestxml(self):
        """
        Generates the manifest.xml file;
        The self.manifest isn't avaible unless the document is being saved
        @return a unicode string
        """
        xml=StringIO()
        xml.write(_XMLPROLOGUE)
        self.manifest.toXml(0,xml)
        result=xml.getvalue()
        assert(type(result)==type(u""))
        return result

    def metaxml(self):
        """
        Generates the meta.xml file
        @return a unicode string
        """
        self.__replaceGenerator()
        x = DocumentMeta()
        x.addElement(self.meta)
        xml=StringIO()
        xml.write(_XMLPROLOGUE)
        x.toXml(0,xml)
        result=xml.getvalue()
        assert(type(result)==type(u""))
        return result

    def settingsxml(self):
        """
        Generates the settings.xml file
        @return a unicode string
        """
        x = DocumentSettings()
        x.addElement(self.settings)
        xml=StringIO()
        if sys.version_info[0]==2:
            xml.write(_XMLPROLOGUE)
        else:
            xml.write(_XMLPROLOGUE)
        x.toXml(0,xml)
        result=xml.getvalue()
        assert(type(result)==type(u""))
        return result

    def _parseoneelement(self, top, stylenamelist):
        """
        Finds references to style objects in master-styles
        and add the style name to the style list if not already there.
        Recursive
        @return the list of style names as unicode strings
        """
        for e in top.childNodes:
            if e.nodeType == element.Node.ELEMENT_NODE:
                for styleref in (
                        (CHARTNS,u'style-name'),
                        (DRAWNS,u'style-name'),
                        (DRAWNS,u'text-style-name'),
                        (PRESENTATIONNS,u'style-name'),
                        (STYLENS,u'data-style-name'),
                        (STYLENS,u'list-style-name'),
                        (STYLENS,u'page-layout-name'),
                        (STYLENS,u'style-name'),
                        (TABLENS,u'default-cell-style-name'),
                        (TABLENS,u'style-name'),
                        (TEXTNS,u'style-name') ):
                    if e.getAttrNS(styleref[0],styleref[1]):
                        stylename = e.getAttrNS(styleref[0],styleref[1])
                        if stylename not in stylenamelist:
                            # due to the polymorphism of e.getAttrNS(),
                            # a unicode type is enforced for elements
                            stylenamelist.append(unicode(stylename))
                stylenamelist = self._parseoneelement(e, stylenamelist)
        return stylenamelist

    def _used_auto_styles(self, segments):
        """
        Loop through the masterstyles elements, and find the automatic
        styles that are used. These will be added to the automatic-styles
        element in styles.xml
        @return a list of element.Element instances
        """
        stylenamelist = []
        for top in segments:
            stylenamelist = self._parseoneelement(top, stylenamelist)
        stylelist = []
        for e in self.automaticstyles.childNodes:
            if e.getAttrNS(STYLENS,u'name') in stylenamelist:
                stylelist.append(e)

        # check the type of the returned data
        ok=True
        for e in stylelist: ok = ok and isinstance(e, element.Element)
        assert(ok)

        return stylelist

    def stylesxml(self):
        """
        Generates the styles.xml file
        @return valid XML code as a unicode string
        """
        xml=StringIO()
        xml.write(_XMLPROLOGUE)
        x = DocumentStyles()
        x.write_open_tag(0, xml)
        if self.fontfacedecls.hasChildNodes():
            self.fontfacedecls.toXml(1, xml)
        self.styles.toXml(1, xml)
        a = AutomaticStyles()
        a.write_open_tag(1, xml)
        for s in self._used_auto_styles([self.masterstyles]):
            s.toXml(2, xml)
        a.write_close_tag(1, xml)
        if self.masterstyles.hasChildNodes():
            self.masterstyles.toXml(1, xml)
        x.write_close_tag(0, xml)
        result = xml.getvalue()

        assert(type(result)==type(u""))

        return result

    def addPicture(self, filename, mediatype=None, content=None):
        """
        Add a picture
        It uses the same convention as OOo, in that it saves the picture in
        the zipfile in the subdirectory 'Pictures'
        If passed a file ptr, mediatype must be set
        @param filename unicode string: name of a file for Pictures
        @param mediatype unicode string: name of a media, None by default
        @param content bytes: content of media, None by default
        @return a unicode string: the file name of the media, eventually
        created on the fly
        """
        if content is None:
            if mediatype is None:
                mediatype, encoding = mimetypes.guess_type(filename)
            if mediatype is None:
                mediatype = u''
                try: ext = filename[filename.rindex(u'.'):]
                except: ext=u''
            else:
                ext = mimetypes.guess_extension(mediatype)
            manifestfn = u"Pictures/%0.0f%s" % ((time.time()*10000000000), ext)
            self.Pictures[manifestfn] = (IS_FILENAME, filename, mediatype)
            content=b""  # this value is only use by the assert further
            filename=u"" # this value is only use by the assert further
        else:
            manifestfn = filename
            self.Pictures[manifestfn] = (IS_IMAGE, content, mediatype)

        assert(type(filename)==type(u""))
        assert(type(mediatype)==type(u""))
        assert(type(content) == type(b""))

        return manifestfn

    def addPictureFromFile(self, filename, mediatype=None):
        """
        Add a picture
        It uses the same convention as OOo, in that it saves the picture in
        the zipfile in the subdirectory 'Pictures'.
        If mediatype is not given, it will be guessed from the filename
        extension.
        @param filesname unicode string: name of an image file
        @param mediatype unicode string: type of media, dfaults to None
        @return a unicode string, the name of the created file
        """
        if mediatype is None:
            mediatype, encoding = mimetypes.guess_type(filename)
        if mediatype is None:
            mediatype = u''
            try: ext = filename[filename.rindex(u'.'):]
            except ValueError: ext=u''
        else:
            ext = mimetypes.guess_extension(mediatype)
        manifestfn = u"Pictures/%0.0f%s" % ((time.time()*10000000000), ext)
        self.Pictures[manifestfn] = (IS_FILENAME, filename, mediatype)

        assert(type(filename)==type(u""))
        assert(type(mediatype)==type(u""))

        return manifestfn

    def addPictureFromString(self, content, mediatype):
        """
        Add a picture from contents given as a Byte string.
        It uses the same convention as OOo, in that it saves the picture in
        the zipfile in the subdirectory 'Pictures'. The content variable
        is a string that contains the binary image data. The mediatype
        indicates the image format.
        @param content bytes: content of media
        @param mediatype unicode string: name of a media
        @return a unicode string, the name of the created file
        """
        assert(type(content)==type(b""))
        assert(type(mediatype)==type(u""))

        ext = mimetypes.guess_extension(mediatype)
        manifestfn = u"Pictures/%0.0f%s" % ((time.time()*10000000000), ext)
        self.Pictures[manifestfn] = (IS_IMAGE, content, mediatype)
        return manifestfn

    def addThumbnail(self, filecontent=None):
        """
        Add a fixed thumbnail
        The thumbnail in the library is big, so this is pretty useless.
        @param filecontent bytes: the content of a file; defaults to None
        """
        assert(type(filecontent)==type(b""))

        if filecontent is None:
            import thumbnail
            self.thumbnail = thumbnail.thumbnail()
        else:
            self.thumbnail = filecontent

    def addObject(self, document, objectname=None):
        """
        Adds an object (subdocument). The object must be an OpenDocument class
        @param document OpenDocument instance
        @param objectname unicode string: the name of an object to add
        @return a unicode string: the folder name in the zipfile the object is
        stored in.
        """
        assert(isinstance(document, OpenDocument))
        assert(type(objectname)==type(u"") or objectname == None)

        self.childobjects.append(document)
        if objectname is None:
            document.folder = u"%s/Object %d" % (self.folder, len(self.childobjects))
        else:
            document.folder = objectname
        return u".%s" % document.folder

    def _savePictures(self, anObject, folder):
        """
        saves pictures contained in an object
        @param anObject instance of OpenDocument containing pictures
        @param folder unicode string: place to save pictures
        """
        assert(isinstance(anObject, OpenDocument))
        assert(type(folder)==type(u""))

        hasPictures = False
        for arcname, picturerec in anObject.Pictures.items():
            what_it_is, fileobj, mediatype = picturerec
            self.manifest.addElement(manifest.FileEntry(fullpath=u"%s%s" % ( folder ,arcname), mediatype=mediatype))
            hasPictures = True
            if what_it_is == IS_FILENAME:
                self._z.write(fileobj, arcname, zipfile.ZIP_STORED)
            else:
                zi = zipfile.ZipInfo(str(arcname), self._now)
                zi.compress_type = zipfile.ZIP_STORED
                zi.external_attr = UNIXPERMS
                self._z.writestr(zi, fileobj)
        # According to section 17.7.3 in ODF 1.1, the pictures folder should not have a manifest entry
#       if hasPictures:
#           self.manifest.addElement(manifest.FileEntry(fullpath="%sPictures/" % folder, mediatype=""))
        # Look in subobjects
        subobjectnum = 1
        for subobject in anObject.childobjects:
            self._savePictures(subobject, u'%sObject %d/' % (folder, subobjectnum))
            subobjectnum += 1

    def __replaceGenerator(self):
        """
        Removes a previous 'generator' stance and declares TOOLSVERSION
        as the new generator.
        Section 3.1.1: The application MUST NOT export the original identifier
        belonging to the application that created the document.
        """
        for m in self.meta.childNodes[:]:
            if m.qname == (METANS, u'generator'):
                self.meta.removeChild(m)
        self.meta.addElement(meta.Generator(text=TOOLSVERSION))

    def save(self, outputfile, addsuffix=False):
        """
        Save the document under the filename.
        If the filename is '-' then save to stdout
        @param outputfile unicode string: the special name '-' is for stdout;
        as an alternative, it can be an io.ByteIO instance which contains
        the ZIP content.
        @param addsuffix boolean: whether to add a suffix or not; defaults to False
        """
        assert(type(outputfile)==type(u"") or 'wb' in repr(outputfile) or 'BufferedWriter' in repr(outputfile)  or 'BytesIO' in repr(outputfile))
        assert(type(addsuffix)==type(True))

        if outputfile == u'-':
            outputfp = zipfile.ZipFile(sys.stdout,"w")
        else:
            if addsuffix:
                outputfile = outputfile + odmimetypes.get(self.mimetype,u'.xxx')
            outputfp = zipfile.ZipFile(outputfile, "w")
        self.__zipwrite(outputfp)
        outputfp.close()

    def write(self, outputfp):
        """
        User API to write the ODF file to an open file descriptor
        Writes the ZIP format
        @param outputfp open file descriptor
        """
        assert('wb' in repr(outputfp) or 'BufferedWriter' in repr(outputfp)  or 'BytesIO' in repr(outputfp))

        zipoutputfp = zipfile.ZipFile(outputfp,"w")
        self.__zipwrite(zipoutputfp)

    def __zipwrite(self, outputfp):
        """
        Write the document to an open file pointer
        This is where the real work is done
        @param outputfp instance of zipfile.ZipFile
        """
        assert(isinstance(outputfp, zipfile.ZipFile))

        self._z = outputfp
        self._now = time.localtime()[:6]
        self.manifest = manifest.Manifest()

        # Write mimetype
        zi = zipfile.ZipInfo('mimetype', self._now)
        zi.compress_type = zipfile.ZIP_STORED
        zi.external_attr = UNIXPERMS
        self._z.writestr(zi, self.mimetype.encode("utf-8"))

        self._saveXmlObjects(self,u"")

        # Write pictures
        self._savePictures(self,u"")

        # Write the thumbnail
        if self.thumbnail is not None:
            self.manifest.addElement(manifest.FileEntry(fullpath=u"Thumbnails/", mediatype=u''))
            self.manifest.addElement(manifest.FileEntry(fullpath=u"Thumbnails/thumbnail.png", mediatype=u''))
            zi = zipfile.ZipInfo(u"Thumbnails/thumbnail.png", self._now)
            zi.compress_type = zipfile.ZIP_DEFLATED
            zi.external_attr = UNIXPERMS
            self._z.writestr(zi, self.thumbnail)

        # Write any extra files
        for op in self._extra:
            if op.filename == u"META-INF/documentsignatures.xml": continue # Don't save signatures
            self.manifest.addElement(manifest.FileEntry(fullpath=op.filename, mediatype=op.mediatype))
            if sys.version_info[0]==3:
                zi = zipfile.ZipInfo(op.filename, self._now)
            else:
                zi = zipfile.ZipInfo(op.filename.encode('utf-8'), self._now)
            zi.compress_type = zipfile.ZIP_DEFLATED
            zi.external_attr = UNIXPERMS
            if op.content is not None:
                self._z.writestr(zi, op.content)
        # Write manifest
        zi = zipfile.ZipInfo(u"META-INF/manifest.xml", self._now)
        zi.compress_type = zipfile.ZIP_DEFLATED
        zi.external_attr = UNIXPERMS
        self._z.writestr(zi, self.__manifestxml() )
        del self._z
        del self._now
        del self.manifest


    def _saveXmlObjects(self, anObject, folder):
        """
        save xml objects of an opendocument to some folder
        @param anObject instance of OpenDocument
        @param folder unicode string place to save xml objects
        """
        assert(isinstance(anObject, OpenDocument))
        assert(type(folder)==type(u""))

        if self == anObject:
            self.manifest.addElement(manifest.FileEntry(fullpath=u"/", mediatype=anObject.mimetype))
        else:
            self.manifest.addElement(manifest.FileEntry(fullpath=folder, mediatype=anObject.mimetype))
        # Write styles
        self.manifest.addElement(manifest.FileEntry(fullpath=u"%sstyles.xml" % folder, mediatype=u"text/xml"))
        zi = zipfile.ZipInfo(u"%sstyles.xml" % folder, self._now)
        zi.compress_type = zipfile.ZIP_DEFLATED
        zi.external_attr = UNIXPERMS
        self._z.writestr(zi, anObject.stylesxml().encode("utf-8") )

        # Write content
        self.manifest.addElement(manifest.FileEntry(fullpath=u"%scontent.xml" % folder, mediatype=u"text/xml"))
        zi = zipfile.ZipInfo(u"%scontent.xml" % folder, self._now)
        zi.compress_type = zipfile.ZIP_DEFLATED
        zi.external_attr = UNIXPERMS
        self._z.writestr(zi, anObject.contentxml() )

        # Write settings
        if anObject.settings.hasChildNodes():
            self.manifest.addElement(manifest.FileEntry(fullpath=u"%ssettings.xml" % folder, mediatype=u"text/xml"))
            zi = zipfile.ZipInfo(u"%ssettings.xml" % folder, self._now)
            zi.compress_type = zipfile.ZIP_DEFLATED
            zi.external_attr = UNIXPERMS
            self._z.writestr(zi, anObject.settingsxml() )

        # Write meta
        if self == anObject:
            self.manifest.addElement(manifest.FileEntry(fullpath=u"meta.xml", mediatype=u"text/xml"))
            zi = zipfile.ZipInfo(u"meta.xml", self._now)
            zi.compress_type = zipfile.ZIP_DEFLATED
            zi.external_attr = UNIXPERMS
            self._z.writestr(zi, anObject.metaxml() )

        # Write subobjects
        subobjectnum = 1
        for subobject in anObject.childobjects:
            self._saveXmlObjects(subobject, u'%sObject %d/' % (folder, subobjectnum))
            subobjectnum += 1

# Document's DOM methods
    def createElement(self, elt):
        """
        Inconvenient interface to create an element, but follows XML-DOM.
        Does not allow attributes as argument, therefore can't check grammar.
        @param elt element.Element instance
        @return an element.Element instance whose grammar is not checked
        """
        assert(isinstance(elt, element.Element))

        # this old code is ambiguous: is 'element' the module or is it the
        # local variable? To disambiguate this, the local variable has been
        # renamed to 'elt'
        #return element(check_grammar=False)
        return elt(check_grammar=False)

    def createTextNode(self, data):
        """
        Method to create a text node
        @param data unicode string to include in the Text element
        @return an instance of element.Text
        """
        assert(type(data)==type(u""))

        return element.Text(data)

    def createCDATASection(self, data):
        """
        Method to create a CDATA section
        @param data unicode string to include in the CDATA element
        @return an instance of element.CDATASection
        """
        assert(type(data)==type(u""))

        return element.CDATASection(cdata)

    def getMediaType(self):
        """
        Returns the media type
        @result a unicode string
        """
        assert (type(self.mimetype)==type(u""))

        return self.mimetype

    def getStyleByName(self, name):
        """
        Finds a style object based on the name
        @param name unicode string the name of style to search
        @return a syle as an element.Element instance
        """
        assert(type(name)==type(u""))

        ncname = make_NCName(name)
        if self._styles_dict == {}:
            self.rebuild_caches()
        result=self._styles_dict.get(ncname, None)

        assert(isinstance(result, element.Element))
        return result

    def getElementsByType(self, elt):
        """
        Gets elements based on the type, which is function from
        text.py, draw.py etc.
        @param elt instance of a function which returns an element.Element
        @return a list of istances of element.Element
        """
        import types
        assert(isinstance (elt, types.FunctionType))

        obj = elt(check_grammar=False)
        assert (isinstance(obj, element.Element))

        if self.element_dict == {}:
            self.rebuild_caches()

        # This previous code was ambiguous
        # was "element" the module name or the local variable?
        # the local variable is renamed to "elt" to disambiguate the code
        #return self.element_dict.get(obj.qname, [])

        result=self.element_dict.get(obj.qname, [])

        ok=True
        for e in result: ok = ok and isinstance(e, element.Element)
        assert(ok)

        return result

# Convenience functions
def OpenDocumentChart():
    """
    Creates a chart document
    @return an OpenDocument instance with chart mimetype
    """
    doc = OpenDocument(u'application/vnd.oasis.opendocument.chart')
    doc.chart = Chart()
    doc.body.addElement(doc.chart)
    return doc

def OpenDocumentDrawing():
    """
    Creates a drawing document
    @return an OpenDocument instance with drawing mimetype
    """
    doc = OpenDocument(u'application/vnd.oasis.opendocument.graphics')
    doc.drawing = Drawing()
    doc.body.addElement(doc.drawing)
    return doc

def OpenDocumentImage():
    """
    Creates an image document
    @return an OpenDocument instance with image mimetype
    """
    doc = OpenDocument(u'application/vnd.oasis.opendocument.image')
    doc.image = Image()
    doc.body.addElement(doc.image)
    return doc

def OpenDocumentPresentation():
    """
    Creates a presentation document
    @return an OpenDocument instance with presentation mimetype
    """
    doc = OpenDocument(u'application/vnd.oasis.opendocument.presentation')
    doc.presentation = Presentation()
    doc.body.addElement(doc.presentation)
    return doc

def OpenDocumentSpreadsheet():
    """
    Creates a spreadsheet document
    @return an OpenDocument instance with spreadsheet mimetype
    """
    doc = OpenDocument(u'application/vnd.oasis.opendocument.spreadsheet')
    doc.spreadsheet = Spreadsheet()
    doc.body.addElement(doc.spreadsheet)
    return doc

def OpenDocumentText():
    """
    Creates a text document
    @return an OpenDocument instance with text mimetype
    """
    doc = OpenDocument(u'application/vnd.oasis.opendocument.text')
    doc.text = Text()
    doc.body.addElement(doc.text)
    return doc

def OpenDocumentTextMaster():
    """
    Creates a text master document
    @return an OpenDocument instance with master mimetype
    """
    doc = OpenDocument(u'application/vnd.oasis.opendocument.text-master')
    doc.text = Text()
    doc.body.addElement(doc.text)
    return doc

def __loadxmlparts(z, manifest, doc, objectpath):
    """
    Parses a document from its zipfile
    @param z an instance of zipfile.ZipFile
    @param manifest Manifest data structured in a dictionary
    @param doc instance of OpenDocument to feed in
    @param objectpath unicode string: path to an object
    """
    assert(isinstance(z, zipfile.ZipFile))
    assert(type(manifest)==type(dict()))
    assert(isinstance(doc, OpenDocument))
    assert(type(objectpath)==type(u""))

    from load import LoadParser
    from xml.sax import make_parser, handler

    for xmlfile in (objectpath+u'settings.xml', objectpath+u'meta.xml', objectpath+u'content.xml', objectpath+u'styles.xml'):
        if xmlfile not in manifest:
            continue
        ##########################################################
        # this one is added to debug the bad behavior with Python2
        # which raises exceptions of type SAXParseException
        from xml.sax._exceptions import SAXParseException
        ##########################################################
        try:
            xmlpart = z.read(xmlfile).decode("utf-8")
            doc._parsing = xmlfile

            parser = make_parser()
            parser.setFeature(handler.feature_namespaces, 1)
            parser.setContentHandler(LoadParser(doc))
            parser.setErrorHandler(handler.ErrorHandler())

            inpsrc = InputSource()
            #################
            # There may be a SAXParseException triggered because of
            # a missing xmlns prefix like meta, config, etc.
            # So i add such declarations when needed (GK, 2014/10/21).
            # Is there any option to prevent xmlns checks by SAX?
            xmlpart=__fixXmlPart(xmlpart)

            inpsrc.setByteStream(BytesIO(xmlpart.encode("utf-8")))
            parser.parse(inpsrc)
            del doc._parsing
        except KeyError as v: pass
        except SAXParseException:
            print (u"====== SAX FAILED TO PARSE ==========\n", xmlpart)

def __fixXmlPart(xmlpart):
    """
    fixes an xml code when it does not contain a set of requested
    "xmlns:whatever" declarations.
    added by G.K. on 2014/10/21
    @param xmlpart unicode string: some XML code
    @return fixed XML code
    """
    result=xmlpart
    requestedPrefixes = (u'meta', u'config', u'dc', u'style',
                         u'svg', u'fo',u'draw', u'table',u'form')
    for prefix in requestedPrefixes:
        if u' xmlns:{prefix}'.format(prefix=prefix) not in xmlpart:
            pos=result.index(u" xmlns:")
            toInsert=u' xmlns:{prefix}="urn:oasis:names:tc:opendocument:xmlns:{prefix}:1.0"'.format(prefix=prefix)
            result=result[:pos]+toInsert+result[pos:]
    return result


def __detectmimetype(zipfd, odffile):
    """
    detects the mime-type of an ODF file
    @param zipfd an open zipfile.ZipFile instance
    @param odffile this parameter is not used
    @return a mime-type as a unicode string
    """
    assert(isinstance(zipfd, zipfile.ZipFile))
    assert(type(odffile)==type(u"") or 'rb' in repr(odffile) \
               or 'BufferedReader' in repr(odffile)  or 'BytesIO' in repr(odffile))

    try:
        mimetype = zipfd.read('mimetype').decode("utf-8")
        return mimetype
    except:
        pass
    # Fall-through to next mechanism
    manifestpart = zipfd.read('META-INF/manifest.xml')
    manifest =  manifestlist(manifestpart)
    for mentry,mvalue in manifest.items():
        if mentry == "/":
            assert(type(mvalue['media-type'])==type(u""))
            return mvalue['media-type']

    # Fall-through to last mechanism
    return u'application/vnd.oasis.opendocument.text'

def load(odffile):
    """
    Load an ODF file into memory
    @param odffile unicode string: name of a file, or as an alternative,
    an open readable stream
    @return a reference to the structure (an OpenDocument instance)
    """
    assert(type(odffile)==type(u"") or 'rb' in repr(odffile) \
               or 'BufferedReader' in repr(odffile)  or 'BytesIO' in repr(odffile))

    z = zipfile.ZipFile(odffile)
    mimetype = __detectmimetype(z, odffile)
    doc = OpenDocument(mimetype, add_generator=False)

    # Look in the manifest file to see if which of the four files there are
    manifestpart = z.read('META-INF/manifest.xml')
    manifest =  manifestlist(manifestpart)
    __loadxmlparts(z, manifest, doc, u'')
    for mentry,mvalue in manifest.items():
        if mentry[:9] == u"Pictures/" and len(mentry) > 9:
            doc.addPicture(mvalue['full-path'], mvalue['media-type'], z.read(mentry))
        elif mentry == u"Thumbnails/thumbnail.png":
            doc.addThumbnail(z.read(mentry))
        elif mentry in (u'settings.xml', u'meta.xml', u'content.xml', u'styles.xml'):
            pass
        # Load subobjects into structure
        elif mentry[:7] == u"Object " and len(mentry) < 11 and mentry[-1] == u"/":
            subdoc = OpenDocument(mvalue['media-type'], add_generator=False)
            doc.addObject(subdoc, u"/" + mentry[:-1])
            __loadxmlparts(z, manifest, subdoc, mentry)
        elif mentry[:7] == u"Object ":
            pass # Don't load subobjects as opaque objects
        else:
            if mvalue['full-path'][-1] == u'/':
                doc._extra.append(OpaqueObject(mvalue['full-path'], mvalue['media-type'], None))
            else:
                doc._extra.append(OpaqueObject(mvalue['full-path'], mvalue['media-type'], z.read(mentry)))
            # Add the SUN junk here to the struct somewhere
            # It is cached data, so it can be out-of-date
    z.close()
    b = doc.getElementsByType(Body)
    if mimetype[:39] == u'application/vnd.oasis.opendocument.text':
        doc.text = b[0].firstChild
    elif mimetype[:43] == u'application/vnd.oasis.opendocument.graphics':
        doc.graphics = b[0].firstChild
    elif mimetype[:47] == u'application/vnd.oasis.opendocument.presentation':
        doc.presentation = b[0].firstChild
    elif mimetype[:46] == u'application/vnd.oasis.opendocument.spreadsheet':
        doc.spreadsheet = b[0].firstChild
    elif mimetype[:40] == u'application/vnd.oasis.opendocument.chart':
        doc.chart = b[0].firstChild
    elif mimetype[:40] == u'application/vnd.oasis.opendocument.image':
        doc.image = b[0].firstChild
    elif mimetype[:42] == u'application/vnd.oasis.opendocument.formula':
        doc.formula = b[0].firstChild

    return doc

# vim: set expandtab sw=4 :