#!/usr/bin/env python

"""
Copyright (c) 2006-2019 sqlmap developers (http://sqlmap.org/)
See the file 'LICENSE' for copying permission
"""

import functools
import os
import random
import shutil
import stat
import string

from lib.core.common import getSafeExString
from lib.core.compat import xrange
from lib.core.data import logger

def purge(directory):
    """
    Safely removes content from a given directory
    """

    if not os.path.isdir(directory):
        warnMsg = "skipping purging of directory '%s' as it does not exist" % directory
        logger.warn(warnMsg)
        return

    infoMsg = "purging content of directory '%s'..." % directory
    logger.info(infoMsg)

    filepaths = []
    dirpaths = []

    for rootpath, directories, filenames in os.walk(directory):
        dirpaths.extend(os.path.abspath(os.path.join(rootpath, _)) for _ in directories)
        filepaths.extend(os.path.abspath(os.path.join(rootpath, _)) for _ in filenames)

    logger.debug("changing file attributes")
    for filepath in filepaths:
        try:
            os.chmod(filepath, stat.S_IREAD | stat.S_IWRITE)
        except:
            pass

    logger.debug("writing random data to files")
    for filepath in filepaths:
        try:
            filesize = os.path.getsize(filepath)
            with open(filepath, "w+b") as f:
                f.write("".join(chr(random.randint(0, 255)) for _ in xrange(filesize)))
        except:
            pass

    logger.debug("truncating files")
    for filepath in filepaths:
        try:
            with open(filepath, 'w') as f:
                pass
        except:
            pass

    logger.debug("renaming filenames to random values")
    for filepath in filepaths:
        try:
            os.rename(filepath, os.path.join(os.path.dirname(filepath), "".join(random.sample(string.ascii_letters, random.randint(4, 8)))))
        except:
            pass

    dirpaths.sort(key=functools.cmp_to_key(lambda x, y: y.count(os.path.sep) - x.count(os.path.sep)))

    logger.debug("renaming directory names to random values")
    for dirpath in dirpaths:
        try:
            os.rename(dirpath, os.path.join(os.path.dirname(dirpath), "".join(random.sample(string.ascii_letters, random.randint(4, 8)))))
        except:
            pass

    logger.debug("deleting the whole directory tree")
    os.chdir(os.path.join(directory, ".."))

    try:
        shutil.rmtree(directory)
    except OSError as ex:
        logger.error("problem occurred while removing directory '%s' ('%s')" % (directory, getSafeExString(ex)))