# -*- coding: utf-8 -*-
 
 from __future__ import absolute_import
 
 try:
     # python 3 support
     import cPickle as pickle
 except ImportError:
     import pickle
 from .Utils import deunicodise
 
 class HashCache(object):
     def __init__(self):
         self.inodes = dict()
 
     def add(self, dev, inode, mtime, size, md5):
         if dev == 0 or inode == 0: return # Windows
         if dev not in self.inodes:
             self.inodes[dev] = dict()
         if inode not in self.inodes[dev]:
             self.inodes[dev][inode] = dict()
         self.inodes[dev][inode][mtime] = dict(md5=md5, size=size)
 
     def md5(self, dev, inode, mtime, size):
         try:
             d = self.inodes[dev][inode][mtime]
             if d['size'] != size:
                 return None

         except Exception:

             return None
         return d['md5']
 
     def mark_all_for_purge(self):

         for d in tuple(self.inodes):
             for i in tuple(self.inodes[d]):
                 for c in tuple(self.inodes[d][i]):

                     self.inodes[d][i][c]['purge'] = True
 
     def unmark_for_purge(self, dev, inode, mtime, size):
         try:
             d = self.inodes[dev][inode][mtime]
         except KeyError:
             return
         if d['size'] == size and 'purge' in d:
             del self.inodes[dev][inode][mtime]['purge']
 
     def purge(self):

         for d in tuple(self.inodes):
             for i in tuple(self.inodes[d]):
                 for m in tuple(self.inodes[d][i]):

                     if 'purge' in self.inodes[d][i][m]:
                         del self.inodes[d][i]
                         break
 
     def save(self, f):
         d = dict(inodes=self.inodes, version=1)
         with open(deunicodise(f), 'wb') as fp:
             pickle.dump(d, fp)
 
     def load(self, f):
         with open(deunicodise(f), 'rb') as fp:
             d = pickle.load(fp)
         if d.get('version') == 1 and 'inodes' in d:
             self.inodes = d['inodes']