#
# Gramps - a GTK+/GNOME based genealogy program
#
# Copyright (C) 2009 Benny Malengier
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#

# $Id: docbackend.py 14091 2010-01-18 04:42:17Z pez4brian $

"""File and File format management for the different reports
"""

#------------------------------------------------------------------------
#
# Python modules
#
#------------------------------------------------------------------------
from gen.ggettext import gettext as _

#-------------------------------------------------------------------------
#
# GTK modules
#
#-------------------------------------------------------------------------

#------------------------------------------------------------------------
#
# Gramps modules
#
#------------------------------------------------------------------------

#------------------------------------------------------------------------
#
# Set up logging
#
#------------------------------------------------------------------------
import logging
LOG = logging.getLogger(".docbackend.py")

#------------------------------------------------------------------------
#
# Functions
#
#------------------------------------------------------------------------

def noescape(text):
    """
    Function that does not escape the text passed. Default for backends
    """
    return text

#-------------------------------------------------------------------------
#
# DocBackend exception
#
#-------------------------------------------------------------------------
class DocBackendError(Exception):
    """Error used to report docbackend errors."""
    def __init__(self, value=""):
        Exception.__init__(self)
        self.value = value

    def __str__(self):
        return self.value
    
#------------------------------------------------------------------------
#
# Document Backend class
#
#------------------------------------------------------------------------

class DocBackend(object):
    """
    Base class for text document backends. 
    The DocBackend manages a file to which it writes. It further knowns 
    enough of the file format to be able to translate between the BaseDoc API 
    and the file format. 
    Specifically for text reports a translation of styled notes to the file
    format usage is done.
    """
    BOLD = 0
    ITALIC = 1
    UNDERLINE = 2
    FONTFACE = 3
    FONTSIZE = 4
    FONTCOLOR = 5
    HIGHLIGHT = 6
    SUPERSCRIPT = 7
    
    SUPPORTED_MARKUP = []

    ESCAPE_FUNC = lambda x: noescape
    #Map between styletypes and internally used values. This map is needed
    # to make TextDoc officially independant of gen.lib.styledtexttag
    STYLETYPE_MAP = {
        }
    CLASSMAP = None
    
    #STYLETAGTABLE to store markup for write_markup associated with style tags
    STYLETAG_MARKUP = {
        BOLD        : ("", ""),
        ITALIC      : ("", ""),
        UNDERLINE   : ("", ""),
        SUPERSCRIPT : ("", ""),
        }

    def __init__(self, filename=None):
        """
        @param filename: path name of the file the backend works on
        """
        self.__file = None
        self._filename = filename
    
    def getf(self):
        """
        Obtain the filename on which backend writes
        """
        return self._filename
    
    def setf(self, value):
        """
        Set the filename on which the backend writes, changing the value 
        passed on initialization
        Can only be done if the previous filename is not open
        """
        if self.__file is not None:
            raise ValueError, _('Close file first')
        self._filename = value

    filename = property(getf, setf, None, "The filename the backend works on")

    def open(self):
        """
        Opens the document.
        """
        if self.filename is None:
            raise DocBackendError(_('No filename given'))
        if self.__file is not None :
            raise DocBackendError(_('File %s already open, close it first.')
                                            % self.filename)
        self._checkfilename()
        try:
            self.__file = open(self.filename, "w")
        except IOError, msg:
            errmsg = "%s\n%s" % (_("Could not create %s") % self.filename, msg)
            raise DocBackendError(errmsg)
        except:
            raise DocBackendError(_("Could not create %s") % self.filename)

    def _checkfilename(self):
        """
        Check to make sure filename satisfies the standards for this filetype
        """
        pass
    
    def close(self):
        """
        Closes the file that is written on.
        """
        if self.__file is None:
            raise IOError, 'No file open'
        self.__file.close()
        self.__file = None        

    def write(self, string):
        """Write a string to the file. There is no return value. 
            Due to buffering, the string may not actually show up untill the 
            close() method is called.
        """
        self.__file.write(string)

    def writelines(self, sequence):
        """Write a sequence of strings to the file. The sequence can be any 
            iterable object producing strings, typically a list of strings. 
        """
        self.__file.writelines(sequence)
    
    def escape(self, preformatted=False):
        """
        The escape func on text for this file format.
        @param preformatted: bool: some formats can have different escape 
                function for normal text and preformatted text
        
        """
        return self.ESCAPE_FUNC()
        
    
    def find_tag_by_stag(self, s_tag):
        """
        @param s_tag: object: assumed styledtexttag
        @param s_tagvalue: None/int/str: value associated with the tag
        
        A styled tag is type with a value. 
        Every styled tag must be converted to the tags used in the corresponding
            markup for the backend, eg <b>text</b> for bold in html.
        These markups are stored in STYLETAG_MARKUP. They are tuples for begin
            and end tag
        If a markup is not present yet, it is created, using the 
            _create_xmltag method you can overwrite
        """
        tagtype = s_tag.name
        
        if not self.STYLETYPE_MAP or \
        self.CLASSMAP != tagtype.__class__.__name__ :
            self.CLASSMAP == tagtype.__class__.__name__
            self.STYLETYPE_MAP[tagtype.__class__.BOLD]        = self.BOLD
            self.STYLETYPE_MAP[tagtype.ITALIC]      = self.ITALIC
            self.STYLETYPE_MAP[tagtype.UNDERLINE]   = self.UNDERLINE
            self.STYLETYPE_MAP[tagtype.FONTFACE]    = self.FONTFACE
            self.STYLETYPE_MAP[tagtype.FONTSIZE]    = self.FONTSIZE
            self.STYLETYPE_MAP[tagtype.FONTCOLOR]   = self.FONTCOLOR
            self.STYLETYPE_MAP[tagtype.HIGHLIGHT]   = self.HIGHLIGHT
            self.STYLETYPE_MAP[tagtype.SUPERSCRIPT] = self.SUPERSCRIPT

        typeval = int(s_tag.name)
        s_tagvalue = s_tag.value
        tag_name = None
        if tagtype.STYLE_TYPE[typeval] == bool:
            return self.STYLETAG_MARKUP[self.STYLETYPE_MAP[typeval]]
        elif tagtype.STYLE_TYPE[typeval] == str:
            tag_name = "%d %s" % (typeval, s_tagvalue)
        elif tagtype.STYLE_TYPE[typeval] == int:
            tag_name = "%d %d" % (typeval, s_tagvalue)
        if not tag_name:
            return None
        
        tags = self.STYLETAG_MARKUP.get(tag_name)
        if tags is not None:
            return tags
        #no tag known yet, create the markup, add to lookup, and return
        tags = self._create_xmltag(self.STYLETYPE_MAP[typeval], s_tagvalue)
        self.STYLETAG_MARKUP[tag_name] = tags
        return tags

    def _create_xmltag(self, tagtype, value):
        """
        Create the xmltags for the backend.
        Overwrite this method to create functionality with a backend
        """
        if tagtype not in self.SUPPORTED_MARKUP:
            return None
        return ('', '')
    
    def add_markup_from_styled(self, text, s_tags, split=''):
        """
        Input is plain text, output is text with markup added according to the
        s_tags which are assumed to be styledtexttags.
        When split is given the text will be split over the value given, and 
        tags applied in such a way that it the text can be safely splitted in
        pieces along split
        
        @param text   : str, a piece of text
        @param s_tags : styledtexttags that must be applied to the text
        @param split  : str, optional. A string along which the output can 
                    be safely split without breaking the styling.
        As adding markup means original text must be escaped, ESCAPE_FUNC is 
            used
        This can be used to convert the text of a styledtext to the format 
            needed for a document backend
        Do not call this method in a report, use the write_markup method
            
        @note: the algorithm is complex as it assumes mixing of tags is not
                allowed: eg <b>text<i> here</b> not</i> is assumed invalid
                as markup. If the s_tags require such a setup, what is returned
                is <b>text</b><i><b> here</b> not</i>
               overwrite this method if this complexity is not needed. 
        """
        #unicode text must be sliced correctly
        text = unicode(text)
        FIRST = 0
        LAST = 1
        tagspos = {}
        for s_tag in s_tags:
            tag = self.find_tag_by_stag(s_tag)
            if tag is not None:
                for (start, end) in s_tag.ranges:
                    if start in tagspos:
                        tagspos[start] += [(tag, FIRST)]
                    else:
                        tagspos[start] = [(tag, FIRST)]
                    if end in tagspos:
                        tagspos[end] = [(tag, LAST)] + tagspos[end]
                    else:
                        tagspos[end] = [(tag, LAST)]
        start = 0
        end = len(text)
        keylist = tagspos.keys()
        keylist.sort()
        keylist = [x for x in keylist if x <= len(text)]
        opentags = []
        otext = u""  #the output, text with markup
        lensplit = len(split)
        for pos in keylist:
            #write text up to tag
            if pos > start:
                if split:
                    #make sure text can split
                    splitpos = text[start:pos].find(split)
                    while splitpos != -1:
                        otext += self.ESCAPE_FUNC()(text[start:start+splitpos])
                        #close open tags
                        for opentag in reversed(opentags):
                            otext += opentag[1]
                        #add split text
                        otext += self.ESCAPE_FUNC()(split)
                        #open the tags again
                        for opentag in opentags:
                            otext += opentag[0]
                        #obtain new values
                        start = start + splitpos + lensplit
                        splitpos = text[start:pos].find(split)
                    
                otext += self.ESCAPE_FUNC()(text[start:pos])
            #write out tags
            for tag in tagspos[pos]:
                #close open tags starting from last open
                for opentag in reversed(opentags):
                    otext += opentag[1]
                #if start, add to opentag in beginning as first to open
                if tag[1] == FIRST:
                    opentags = [tag[0]] + opentags
                else:
                    #end tag, is closed already, remove from opentag
                    opentags = [x for x in opentags if not x == tag[0] ]
                #now all tags are closed, open the ones that should open
                for opentag in opentags:
                    otext += opentag[0]
            start = pos
        #add remainder of text, no markup present there
        otext += self.ESCAPE_FUNC()(text[start:end])

        #opentags should be empty. If not, user gave tags on positions that 
        # are over the end of the text. Just close the tags still open
        if opentags:
            print 'WARNING: DocBackend : More style tags in text than length '\
                    'of text allows.\n', opentags
            for opentag in reversed(opentags):
                otext += opentag[1]
        
        return otext
