#!/usr/bin/python

import glob
import os
import sys
import md5
import stat
import mmap

MAX_CHECK_SIZE = 1073741824

class Kechikechi(object):
    def __init__(self):
        self.fileMap = {}
        self.totalReduce = 0
        self.linkedCnt = 1
        self.totalCnt = 1

    def __getFileMD5(self, filename):
        st = os.stat(filename)
        size = st[stat.ST_SIZE]
        f = open(filename, "rb")
        content = mmap.mmap(f.fileno(), size, access=mmap.ACCESS_READ)
        try:
            try:
                m = md5.md5(content)
            except IOError, e:
                print "not found %s" % filename
                raise e
        finally:
            content.close()
            f.close()

        return m

    def __getBaseFilename(self, filename, digest, st):
        md5hex = digest.hexdigest()
        key = "%s%d_%d_%d" % (md5hex,
                              st[stat.ST_MODE],
                              st[stat.ST_UID],
                              st[stat.ST_GID])

        baseFilename = "%s/%s/%s/%s" %("kechikechibase", md5hex[0:2], md5hex[2:4], key)

        if os.path.exists(baseFilename):
            return baseFilename
        else:
            try:
                os.link(filename, baseFilename)
            except OSError, e:
                if e[0] == 2:
                    os.makedirs(os.path.dirname(baseFilename))
                    os.link(filename, baseFilename)

        return None

    def __createLink(self, base, filename, tmp):
        os.link(base, "%s.%s" % (filename, tmp))
        os.remove(filename)
        os.rename("%s.%s" % (filename, tmp), filename)

    def __makeFileMap(self, filename):
        self.totalCnt += 1
        st = os.stat(filename)
        size = st[stat.ST_SIZE]
        if size == 0: return
        if size >= MAX_CHECK_SIZE: return

        md5digest = self.__getFileMD5(filename)
        baseFilename = self.__getBaseFilename(filename, md5digest, st)
        if not baseFilename: return

        print "%d / %d: %s (%d : %d) ==> " % (self.linkedCnt, self.totalCnt, filename, size, self.totalReduce),

        if os.path.samefile(filename, baseFilename):
            print "="
            return

        try:
            self.__createLink(baseFilename, filename, md5digest.hexdigest())
        except e:
            print "Error"
            raise e
        else:
            print "OK"
            self.totalReduce += size
            self.linkedCnt += 1

    def makeMap(self, dirname):
        islink = os.path.islink
        isfile = os.path.isfile
        isdir  = os.path.isdir

        print "Directory: %s" % dirname

        files = glob.glob("%s/*" % dirname)

        for filename in files:
            if islink(filename): continue
            if isdir(filename):
                self.makeMap(filename)

            elif isfile(filename):
                self.__makeFileMap(filename)


def main():
    ic = Kechikechi()

    try:
        ic.makeMap(sys.argv[1])
    except IndexError, e:
        ic.makeMap(".")

    print "Total scaned files:  %d files" % ic.totalCnt
    print "Total reduced files: %d files, %d bytes" % (ic.linkedCnt - 1, ic.totalReduce)

if __name__ == '__main__':
    main()