from DirMetadataExtractor import DirMetadataExtractor
from RDFItemMerger import RDFItemMerger
import RDF, os

"""
Extract metadata from a file called meta.rdf in the current gallery directory
and add it to the channel metadata.
"""
class DirRDFExtractor(DirMetadataExtractor, RDFItemMerger):
    def __init__(self):
        DirMetadataExtractor.__init__(self)
    
    def extract(self, directory, channel):
        name = os.path.join(directory, "meta.rdf")
        if os.path.exists(name):
            for s in RDF.Parser().parse_as_stream("file://" + name): # TODO: base uri
                # TODO: only add statements with the right URI
                self.merge_statement(channel, s)