# -*- coding: utf-8 -*-
 
 ## Amazon S3 manager
 ## Author: Michal Ludvig <michal@logix.cz>
 ##         http://www.logix.cz/michal
 ## License: GPL Version 2
 ## Copyright: TGRMN Software and contributors
 
 from __future__ import absolute_import
 
 import logging
 from .SortedDict import SortedDict
 from . import Utils
 from . import Config
 
 zero_length_md5 = "d41d8cd98f00b204e9800998ecf8427e"
 cfg = Config.Config()
 
 class FileDict(SortedDict):
     def __init__(self, mapping = None, ignore_case = True, **kwargs):
         SortedDict.__init__(self, mapping = mapping or {}, ignore_case = ignore_case, **kwargs)
         self.hardlinks_md5 = dict() # { dev: { inode : {'md5':, 'relative_files':}}}
         self.by_md5 = dict() # {md5: set(relative_files)}
 
     def record_md5(self, relative_file, md5):
         if not relative_file:
             return
         if md5 is None:
             return
         if md5 == zero_length_md5:
             return
         if md5 not in self.by_md5:
             self.by_md5[md5] = relative_file
 
     def find_md5_one(self, md5):
         if not md5:
             return None
         return self.by_md5.get(md5, None)
 
     def get_md5(self, relative_file):
         """returns md5 if it can, or raises IOError if file is unreadable"""
         md5 = None
         if 'md5' in self[relative_file]:
             return self[relative_file]['md5']
         md5 = self.get_hardlink_md5(relative_file)
         if md5 is None and 'md5' in cfg.sync_checks:
             logging.debug(u"doing file I/O to read md5 of %s" % relative_file)
             md5 = Utils.hash_file_md5(self[relative_file]['full_name'])
         self.record_md5(relative_file, md5)
         self[relative_file]['md5'] = md5
         return md5
 
     def record_hardlink(self, relative_file, dev, inode, md5, size):
         if md5 is None:
             return
         if size == 0:
             # don't record 0-length files
             return
         if dev == 0 or inode == 0:
             # Windows
             return
         if dev not in self.hardlinks_md5:
             self.hardlinks_md5[dev] = dict()
         if inode not in self.hardlinks_md5[dev]:
             self.hardlinks_md5[dev][inode] = md5
 
     def get_hardlink_md5(self, relative_file):
         try:
             dev = self[relative_file]['dev']
             inode = self[relative_file]['inode']
             md5 = self.hardlinks_md5[dev][inode]
         except KeyError:
             md5 = None
         return md5