#!/usr/bin/python
# -*- coding: utf-8 -*-

"""
gcp: Goffi's CoPier
Copyright (C) 2010, 2011  Jérôme Poisson <goffi@goffi.org>

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
"""

from __future__ import with_statement
import tempfile
import unittest
from os import getcwd, chdir, system, mkdir, makedirs, listdir
from os.path import join, isdir
from shutil import rmtree
from random import randrange
from hashlib import sha1

#size shorcuts
S10K = 1024 * 10
S100K = 1024 * 100
S1M = 1024 * 1024
S10M = 1024 * 1024 * 10
S100M = 1024 * 1024 * 100


def sha1sum(filename, buf_size=4096):
    """Return the SHA1 hash of a file
    @param filename: path to the file
    @param buf_size: size of the buffer to use for calculation"""
    csum = sha1()
    with open(filename) as fd:
        data = fd.read(buf_size)
        while data:
            csum.update(data)
            data = fd.read(buf_size)
    return csum.digest()

def dirCheck(dir_path):
    """Recursively calculate SHA1 sum of a dir
    @param path: path of the dir to check
    @return: a dict in the form [{filepath: sum,...}]
    """
    def recursive_sum(directory, result):
        for current_path in listdir(directory):
            full_path = join(directory, current_path)
            if isdir(full_path):
                recursive_sum(full_path, result)
            else:
                result[full_path] = sha1sum(full_path) 
    
    result = {}
    _ori_dir = getcwd()
    chdir(dir_path)
    recursive_sum(".", result)
    chdir(_ori_dir)
    return result

#def makeRandomFile(path, size, buf_size=4096):
#    """Create a fake file
#    @param path: where the file is created
#    @param size: size of the file to create in bytes"""
#    def seq(size):
#        return ''.join(chr(randrange(256)) for i in range(size))
#    fd = open(path, 'w')
#    for byte in range(size//buf_size):
#        fd.write(seq(buf_size))
#    fd.write(seq(size%buf_size))
#    fd.close()

def makeRandomFile(path, size=S10K, buf_size=4096):
    """Create a fake file using /dev/urandom
    @param path: where the file must be created
    @param size: size of the file to create in bytes"""
    source = open('/dev/urandom','r')
    dest = open(path, 'w')
    for byte in range(size//buf_size):
        dest.write(source.read(buf_size))
    dest.write(source.read(size%buf_size))
    dest.close()

def makeTestDir(path):
    """Helper method to easily create a test dir
    @param path: where the dir must be created"""
    
    for i in range(2):
        subdir = join(path,'subdir_%d' % i)
        makedirs(subdir)
        for j in range(2):
            makeRandomFile(join(subdir, 'file_%d' % j), S10K)
    for i in range(2):
        makeRandomFile(join(path,'file_%d' % i), S10K)

class TestCopyCases(unittest.TestCase):
    """Test basic copy use cases, using gcp externally
    gcp must be available in the PATH"""
    #TODO: check journal

    def setUp(self):
        self.ori_dir = getcwd()
        self.tmp_dir = tempfile.mkdtemp()
        chdir(self.tmp_dir)

    def tearDown(self):
        chdir(self.ori_dir)
        rmtree(self.tmp_dir)

    def test_one_file_copy(self):
        """Copy one file and test the result"""
        makeRandomFile('file_1', S10K)
        ori_sum = sha1sum('file_1')
        ret = system("gcp file_1 file_2")
        self.assertEqual(ret,0)
        dest_sum = sha1sum('file_2')
        self.assertEqual(ori_sum, dest_sum)

    def test_one_file_copy_already_exists(self):
        """Check that an existing file is not overwritten"""
        makeRandomFile('file_1', S10K)
        makeRandomFile('file_2', S10K)
        file_2_sum = sha1sum('file_2')
        ret = system("gcp file_1 file_2")
        self.assertNotEqual(ret,0)
        file_2_sum_bis = sha1sum('file_2')
        self.assertEqual(file_2_sum, file_2_sum_bis)

    def test_one_file_copy_already_exists_force(self):
        """Check that an existing file is overwritten with --force"""
        makeRandomFile('file_1', S10K)
        makeRandomFile('file_2', S10K)
        file_1_sum = sha1sum('file_1')
        ret = system("gcp -f file_1 file_2")
        self.assertEqual(ret,0)
        file_2_sum_bis = sha1sum('file_2')
        self.assertEqual(file_1_sum, file_2_sum_bis)

    def test_one_dir_copy(self):
        """Check copy of one dir to a non existant path"""
        makeTestDir('dir_1')
        check_1 = dirCheck('dir_1')
        ret = system("gcp -r dir_1 dir_2")
        self.assertEqual(ret,0)
        check_2 = dirCheck('dir_2')
        self.assertEqual(check_1, check_2)

    def test_one_dir_copy_nocopy(self):
        """Check that a dir is not copied without the recursive option"""
        makeTestDir('dir_1')
        check_before = dirCheck('.')
        ret = system("gcp dir_1 dir_2")
        self.assertEqual(ret,0)
        check_after = dirCheck('.')
        self.assertEqual(check_before, check_after)

    def test_one_dir_copy_existing_dest(self):
        """Check that a dir is copied inside an existing destination"""
        makeTestDir('dir_1')
        mkdir('dir_2')
        check_1 = dirCheck('dir_1')
        ret = system("gcp -r dir_1 dir_2")
        self.assertEqual(ret,0)
        self.assertEqual(listdir('dir_2'), ['dir_1'])
        check_2 = dirCheck('dir_2/dir_1')
        self.assertEqual(check_1, check_2)

    def test_mixt_copy_existing_dest(self):
        """Check that a mixt copy (files + dir) to an existing dest work as expected"""
        for i in range(2):
            makeRandomFile('file_%d' % i, S10K)
            makeTestDir('dir_%d' % i)
        check_1 = dirCheck('.')
        mkdir('dest_dir')
        ret = system("gcp -r file_0 file_1 dir_0 dir_1 dest_dir")
        self.assertEqual(ret,0)
        check_2 = dirCheck('dest_dir')
        self.assertEqual(check_1, check_2)

    def test_mixt_copy_nonexisting_dest(self):
        """Check that a mixt copy (files + dir) to an non existing dest work as expected
        /!\\ the behavious is different of the one of cp in this case ! (cp doesn't copy at all, while gcp create the dest)"""
        for i in range(2):
            makeRandomFile('file_%d' % i, S10K)
            makeTestDir('dir_%d' % i)
        check_1 = dirCheck('.')
        ret = system("gcp -r file_0 file_1 dir_0 dir_1 dest_dir")
        self.assertEqual(ret,0)
        check_2 = dirCheck('dest_dir')
        self.assertEqual(check_1, check_2)
    
    def test_mixt_copy_existing_dest_nonrecursive(self):
        """Check that a mixt copy (files + dir) to an existing dest without the recursive option work as expected"""
        for i in range(2):
            makeRandomFile('file_%d' % i, S10K)
            makeTestDir('dir_%d' % i)
        mkdir('dest_dir')
        ret = system("gcp file_0 file_1 dir_0 dir_1 dest_dir")
        self.assertEqual(ret,0)
        self.assertEqual(set(listdir('dest_dir')), set(['file_0', 'file_1']))
        self.assertEqual(sha1sum('file_0'), sha1sum('dest_dir/file_0'))
        self.assertEqual(sha1sum('file_1'), sha1sum('dest_dir/file_1'))

    def test_mixt_copy_nonexisting_dest_nonrecursive(self):
        """Check that a mixt copy (files + dir) to an existing dest without the recursive option work as expected"""
        for i in range(2):
            makeRandomFile('file_%d' % i, S10K)
            makeTestDir('dir_%d' % i)
        check_before = dirCheck('.')
        ret = system("gcp file_0 file_1 dir_0 dir_1 dest_dir")
        self.assertEqual(ret >> 8, 1)
        check_after = dirCheck('.')
        self.assertEqual(check_before, check_after)

if __name__ == '__main__':
    unittest.main()