"""
display SVN URLs in trac's respository browser
"""

from genshi.builder import tag 
from genshi.filters.transform import StreamBuffer
from genshi.filters.transform import Transformer
from genshi.input import TEXT

from trac.core import *
from trac.config import Option
from trac.web import ITemplateStreamFilter

class SVNURLs(Component):
    implements(ITemplateStreamFilter)

    ### class data
    
    svn_base_url = Option('svnurls', 'svn_base_url',
                          doc="base URL of svn repository")
    link_text = Option('svnurls', 'link_text', default='[svn]',
                         doc="text display for svn url links")
    link_title = "URL of SVN location"
    
    def url(self, path):
        return u'/'.join((self.svn_base_url.rstrip(u'/'), path.lstrip(u'/')))

    ### methods for handling different views
    ### these should return the stream

    def browser(self, stream, data):

        if not data.has_key('path')
            # this probably means that there is an upstream error
            return stream

        # mark up the title
        # XXX disabled due to a bug in Transformer.substitute
        # - see http://genshi.edgewall.org/ticket/226
        # stream |= Transformer('//title/text()').substitute('/', data['svn_base_url']   '/')

        # provide a link to the svn repository
        stream |= Transformer("//div[@id='content']/h1").after(tag.a(self.link_text, href=self.url(data['path']), title=self.link_title))

        # if a directory, provide links to the children files
        if data['dir']:
            pos = 1
            offset = 2 # table header, index of 0 (python) versus 1 (xpath)
            if data['path'] != '/':                
                offset  = 1 # parent directory row

            # add the table header
            stream |= Transformer("//table[@id='dirlist']//th[%s]" % pos).after(tag.th('URL'))

            # add table cells
            for idx, entry in enumerate(data['dir']['entries']):
                contents = "%s of %s" % (idx, len(data['dir']['entries']))
                stream |= Transformer("//table[@id='dirlist']//tr[%s]/td[%s]" % (offset   idx, pos)).after(tag.td(tag.a(self.link_text, href=self.url(entry.path), title=self.link_title)))

        return stream

    def svnlog(self, stream, data):
        return stream


    # method for ITemplateStreamFilter

    def filter_stream(self, req, method, filename, stream, data):
        """Return a filtered Genshi event stream, or the original unfiltered
        stream if no match.

        `req` is the current request object, `method` is the Genshi render
        method (xml, xhtml or text), `filename` is the filename of the template
        to be rendered, `stream` is the event stream and `data` is the data for
        the current template.

        See the Genshi documentation for more information.
        """

        svn_base_url = self.svn_base_url.rstrip('/')

        handlers = { '/browser': self.browser,
                     '/log': self.svnlog,
                    }

        path = req.environ.get('PATH_INFO')
        if svn_base_url:
            for handler in handlers:
                if path.startswith(handler):
                    import pdb;  pdb.set_trace()
                    return handlers[handler](stream, data)
    
        return stream