## Amazon S3 manager
## Author: Michal Ludvig <michal@logix.cz>
##         http://www.logix.cz/michal
## License: GPL Version 2

from BidirMap import BidirMap
import Utils

class SortedDictIterator(object):
    def __init__(self, sorted_dict, keys):
        self.sorted_dict = sorted_dict
        self.keys = keys

    def next(self):
        try:
            return self.keys.pop(0)
        except IndexError:
            raise StopIteration

class SortedDict(dict):
    def __init__(self, mapping = {}, ignore_case = True, **kwargs):
        """
        WARNING: SortedDict() with ignore_case==True will
                 drop entries differing only in capitalisation!
                 Eg: SortedDict({'auckland':1, 'Auckland':2}).keys() => ['Auckland']
                 With ignore_case==False it's all right
        """
        dict.__init__(self, mapping, **kwargs)
        self.ignore_case = ignore_case
        self.hardlinks = dict() # { dev: { inode : {'md5':, 'relative_files':}}}
        self.by_md5 = dict() # {md5: set(relative_files)}

    def keys(self):
        keys = dict.keys(self)
        if self.ignore_case:
            # Translation map
            xlat_map = BidirMap()
            for key in keys:
                xlat_map[key.lower()] = key
            # Lowercase keys
            lc_keys = xlat_map.keys()
            lc_keys.sort()
            return [xlat_map[k] for k in lc_keys]
        else:
            keys.sort()
            return keys

    def __iter__(self):
        return SortedDictIterator(self, self.keys())


    def record_md5(self, relative_file, md5):
        if md5 not in self.by_md5:
            self.by_md5[md5] = set()
        self.by_md5[md5].add(relative_file)

    def find_md5_one(self, md5):
        try:
            return list(self.by_md5.get(md5, set()))[0]
        except:
            return 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:
            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):
        if dev not in self.hardlinks:
            self.hardlinks[dev] = dict()
        if inode not in self.hardlinks[dev]:
            self.hardlinks[dev][inode] = dict(md5=md5, relative_files=set())
        self.hardlinks[dev][inode]['relative_files'].add(relative_file)

    def get_hardlink_md5(self, relative_file):
        md5 = None
        dev = self[relative_file]['dev']
        inode = self[relative_file]['inode']
        try:
            md5 = self.hardlinks[dev][inode]['md5']
        except:
            pass
        return md5

if __name__ == "__main__":
    d = { 'AWS' : 1, 'Action' : 2, 'america' : 3, 'Auckland' : 4, 'America' : 5 }
    sd = SortedDict(d)
    print "Wanted: Action, america, Auckland, AWS,    [ignore case]"
    print "Got:   ",
    for key in sd:
        print "%s," % key,
    print "   [used: __iter__()]"
    d = SortedDict(d, ignore_case = False)
    print "Wanted: AWS, Action, Auckland, america,    [case sensitive]"
    print "Got:   ",
    for key in d.keys():
        print "%s," % key,
    print "   [used: keys()]"

# vim:et:ts=4:sts=4:ai