from __future__ import with_statement

import shutil

import os

from optparse import OptionParser

import time

import logging

import sys

class ComparativeCopy(object):

    def copy_dir(self, src_dir, dest_dir):

        """Copy all files in a source directory to a destination directory

        Will create the directory if it does not exist.

        """

        if not os.path.exists(dest_dir):

            try:

                os.makedirs(dest_dir)

            except WindowsError as e:

                print 'Error creating directory: %s' % e

        self.files_copied = 0

        self.files_skipped = 0

        for file in os.listdir(src_dir):

            self.copy_file(os.path.join(src_dir,file),os.path.join(dest_dir,file))

    def copy_file(self, src, dest):

        """Copy a single file. If the source file does not exist or is smaller than the destination an error is logged. 

        """        

        if not os.path.exists(src):

            logging.debug("File %s does not exist" % src)

        elif (not os.path.exists(dest)) or self.should_copy(src, dest):

            logging.debug("Copying %s to %s" % (src,dest))            

            shutil.copyfile(src,dest)

            self.files_copied += 1 

        else:

            logging.debug("Skipping copy of %s to %s. The source file was not larger than the destination" % (src,dest))

            self.files_skipped += 1

    def should_copy(self, src, dest):    

        return os.path.getsize(src) > os.path.getsize(dest)

def main():

    usage = "usage: %prog [options] source_directory destination_directory"

    parser = OptionParser(usage=usage)

    parser.add_option("-l", type="int", default=20,

                  dest="loglevel",

                  help="set log level [default]")

    (options, args) = parser.parse_args()

    if len(args) != 2:

        parser.error("incorrect number of arguments")

    logging.basicConfig(level=options.loglevel)

    logging.info("Command line was: %s" % " ".join(sys.argv))

    src_dir = args[0]

    dest_dir = args[1]

    c_copy = ComparativeCopy()

    startTime = time.clock()

    c_copy.copy_dir(src_dir, dest_dir)

    timeTaken = time.clock() - startTime

    logging.info("Copied %d and skipped %d files in %.2f seconds " % ( c_copy.files_copied, c_copy.files_skipped, timeTaken))

if __name__ == '__main__':

    main()

import unittest

class TestComparativeCopy(unittest.TestCase):

    def setUp(self):

        self.src_dir=os.path.join(os.getcwd(),"test","tmp_src")

        self.dest_dir=os.path.join(os.getcwd(),"test","tmp_dest")

        os.makedirs(self.src_dir) 

        os.makedirs(self.dest_dir)

        self.c_copy=ComparativeCopy()

    def tearDown(self):

        shutil.rmtree(os.path.join(os.getcwd(),"test"))

    def test_i_copy_files_that_are_larger(self):

        with open(os.path.join(self.src_dir,"aFile.txt"),"w") as theFile:

            theFile.write(commentedFile)

        with open(os.path.join(self.dest_dir,"aFile.txt"),"w") as theFile:

            theFile.write(unCommentedFile)

        self.c_copy.copy_dir(self.src_dir, self.dest_dir)

        self.assertEqual(os.path.getsize(os.path.join(self.dest_dir,"aFile.txt")),197)

    def test_i_dont_copy_files_that_are_smaller(self):

        with open(os.path.join(self.src_dir,"aFile.txt"),"w") as theFile:

            theFile.write(unCommentedFile)

        with open(os.path.join(self.dest_dir,"aFile.txt"),"w") as theFile:

            theFile.write(commentedFile)

        self.c_copy.copy_dir(self.src_dir, self.dest_dir)

        self.assertEqual(os.path.getsize(os.path.join(self.dest_dir,"aFile.txt")),197)

    def test_i_copy_files_that_dont_exist_in_dest(self):

        with open(os.path.join(self.src_dir,"aFile.txt"),"w") as theFile:

            theFile.write(commentedFile)

        self.c_copy.copy_dir(self.src_dir, self.dest_dir)

        self.assertTrue(os.path.exists(os.path.join(self.dest_dir,"aFile.txt")))

unCommentedFile="""#include <iostream>

using namespace std;

int main()

{

    std::cout << "Welcome to the wonderful world of C++!!!\n";

    return 0;

}"""

commentedFile="""#include <iostream>

using namespace std;

/**

 * The main function.

 * @see testMain()

 */

int main()

{

    std::cout << "Welcome to the wonderful world of C++!!!\n";

    return 0;

}"""