from FileMetadataExtractor import FileMetadataExtractor
import os
from RSS import ns

class JpegCommentExtractor(FileMetadataExtractor):
    def __init__(self):
        if os.path.exists("/usr/bin/rdjpgcom"):
            self.extract = self.realExtract
        else:
            self.extract = lambda f,item: None
    
    def realExtract(self, f, item):
        # TODO: maybe rewrite with a Python native JPEG parser, and re-use for
        # the RDF/XMP extractor
        if not os.path.splitext(f)[1] in (".jpg", ".jpeg"): return
        p = os.popen("rdjpgcom '%s'" % f, "r")
        l = p.readlines()
        p.close()
        if l: item[(ns.rss10, "title")] = ''.join(l).strip()