#!/usr/bin/env python
#
# Simple script to export a file from the datastore
# Reinier Heeres, <reinier@heeres.eu>, 2007-12-24
# Phil Bordelon <phil@thenexusproject.org>

import sys
import os
import shutil
import optparse
import dbus

if os.path.exists("/tmp/olpc-session-bus"):
    os.environ["DBUS_SESSION_BUS_ADDRESS"] = "unix:path=/tmp/olpc-session-bus"

from sugar.datastore import datastore
import sugar.mime

# Limit the number of objects returned on an ambiguous query to this number,
# for quicker operation.
RETURN_LIMIT = 2

def build_option_parser():

    usage = "Usage: %prog [-o OBJECT_ID] [-q SEARCH_STR] [-m] OUTFILE"
    parser = optparse.OptionParser(usage=usage)

    parser.add_option("-o", "--object_id", action="store", dest="object_id",
                      help="Retrieve object with explicit ID OBJECT_ID", 
                      metavar="OBJECT_ID", default=None)

    parser.add_option("-q", "--query", action="store", dest="query",
                      help="Full-text-search the metadata for SEARCH_STR", 
                      metavar="SEARCH_STR", default=None)

    parser.add_option("-m", "--metadata", action="store_true", dest="show_meta",
                      help="Show all non-preview metadata [default: hide]", 
                      default=False)

    return parser

if __name__ == "__main__":

    parser = build_option_parser()
    options, args = parser.parse_args()
    if len(args) < 1:
        parser.print_help()
        exit(0)

    try:
        dsentry = None
    
        # Get object directly if we were given an explicit object ID.
        if options.object_id is not None:
            dsentry = datastore.get(options.object_id)
    
        # Compose the query based on the options provided.
        if dsentry is None:
            query = {}
    
            if options.query is not None:
                query['query'] = options.query
    
            # We only want a single file at a time; limit the number of objects
            # returned to two, as anything more than one means the criteria were
            # not limited enough.
            objects, count = datastore.find(query, limit=RETURN_LIMIT, sorting='-mtime')
            if count > 1:
                print 'WARNING: %d objects found; retrieving most recent.' % (count)
                for i in xrange(1, RETURN_LIMIT):
                    objects[i].destroy()
    
            if count > 0:
                dsentry = objects[0]
    
        # If neither an explicit object ID nor a query gave us data, fail.
        if dsentry is None:
            print 'ERROR: unable to determine journal object to copy.'
            parser.print_help()
            exit(0)
    
        # Print metadata if that is what the user asked for.
        if options.show_meta:
            print 'Metadata:'
            for key, val in dsentry.metadata.get_dictionary().iteritems():
                if key != 'preview':
                    print '%20s -> %s' % (key, val)
    
        # If no file is associated with this object, we can't save it out.
        if dsentry.get_file_path() == "":
            print 'ERROR: no file associated with object, just metadata.'
            dsentry.destroy()
            exit(0)
    
        outname = args[0]
        outroot, outext = os.path.splitext(outname)
    
        # Do our best to determine the output file extension, based on Sugar's
        # MIME-type-to-extension mappings.
        if outext == "":
            mimetype = dsentry.metadata['mime_type']
            outext = sugar.mime.get_primary_extension(mimetype)
            if outext == None:
                outext = "dsobject"
            outext = '.' + outext    
    
        # Lastly, actually copy the file out of the datastore and onto the
        # filesystem.
        shutil.copyfile(dsentry.get_file_path(), outroot + outext)
        print '%s -> %s' % (dsentry.get_file_path(), outroot + outext)
    
        # Cleanup.
        dsentry.destroy()

    except dbus.DBusException:
        print 'ERROR: Unable to connect to the datastore.\n'\
              'Check that you are running in the same environment as the '\
              'datastore service.'

    except Exception, e:
        print 'ERROR: %s' % (e)