#!/usr/bin/env python
# dupecheck v0.3
""" A quick dupe-checker. Will first compare file-sizes and if some match, 
will then check their md5 sums. Won't compute md5sums until they're needed.
"""
import md5
import string
import os
import time

sizes = {}

class FileRef:
    """ Lazilly evaluate md5 sum of file """
    def __init__(self, fname, md5 = None):
        self.fname = fname
        self.md5 = md5

    def md5val(self):
        if self.md5 == None:
            self.md5 = md5file(open(self.fname, "rb"))
        return self.md5

def md5file(f):
    """Returns an md5sum hex string of a file."""
    m = md5.new()
    while 1:
        bytes = f.read(8192)
        if not bytes: break
        m.update(bytes)
    return m.hexdigest()

class DupeChecker:
    def __init__(self, actions, verbose=True):
        self.actions = actions

    def execute(self):
        checked=0
        for f in open('/dev/stdin', 'r'):
            f = string.rstrip(f) # chomp
            fstats = os.stat(f)

            checked = checked + 1
            if not (checked / 250):
                print ".",

            # If already know of a file with the same size
            if sizes.has_key(str(fstats.st_size)):
                oldfs = sizes[str(fstats.st_size)]
                newmdsum = md5file(open(f, "rb"))
                found = False
                for realf in oldfs:
                    if realf.md5val() == newmdsum:
                        found = True
                        if self.actions and len(self.actions) > 0:
                            for a in self.actions:
                                if a == 'Print':
                                    print "Dupe! %d\t%s (first was: %s)" % (fstats.st_size, f, realf.fname)
                                elif a == 'Delete':
                                    os.remove(f)
                        else:
                            print '!',

                # If didn't remove it, must be a new file with existing size
                if not found: #os.path.exists(f):
                    #print "%s New hash for an old filesize (%d)" % (newmdsum, fstats.st_size)
                    oldfs.append( FileRef(f, newmdsum) )
            else:
                #print "%d New filesize!" % fstats.st_size
                sizes[str(fstats.st_size)] = []
                sizes[str(fstats.st_size)].append(FileRef(f, None))


def main():
    from optparse import OptionParser
    optparser = OptionParser()
    optparser.add_option("-d", "--delete", dest="actions", 
            action="append_const", const="Delete", 
            help="delete all non-unique files encountered (caution!)")
    (options, args) = optparser.parse_args()

    if not options.actions:
        options.actions = []
    options.actions.append('Print')

    d = DupeChecker(options.actions)
    start = time.time()
    d.execute()
    stop = time.time()
    difftime = stop - start
    print "\nDone! %d seconds elapsed." % (difftime)

if __name__ == "__main__":
    main()