#File: purify.py
#This should use Python3.
import os

#For tempory file stuff.
from tempfile import mkstemp
from shutil import move

def maybe_delete_tilde(filename):
    if filename.endswith('~'):
        print('deleting ' + filename)
        os.remove(filename)
        return True
    return False

def ok_byte(x, filename):
    if x == ord('\r'):
        print('removing \\r character from ' + filename)
        return False
    return True

#Need to figure out the proper way to do
#the next function.  What I have cannot be the
#best way.
#x should be of integer type between 0 and 255 inclusive.
def length_one_byte_string(x):
    return bytes(chr(x), encoding='UTF-8')

def purify_file(filename):
    print('purifying file ' + filename)
    old_f = open(filename, 'rb')
    #Have a perfectly good file descriptor
    #in the variable fh, but heck with it.
    fh, abs_path = mkstemp()
    new_f = open(abs_path, 'wb')
    try:
        bs = old_f.read(1)
        while len(bs) == 1:
            x = bs[0]
            if x == ord('\r'):
                print('removing \\r character from ' + filename)
            elif x == ord('\t'):
                print('replacing \\t character with 4 spaces in ' + filename)
                for i in range(4):
                    new_f.write(length_one_byte_string(32))
            elif x > 127:
                print('WTF: removing character ' + chr(x) + ' (which is not ASCII)')
            else:
                #Doing the normal thing.
                new_f.write(length_one_byte_string(x))
            bs = old_f.read(1)
    finally:
        new_f.close()
        os.close(fh)
        old_f.close()
        os.remove(filename)
        move(abs_path, filename)

def handle_file(filename):
    #Deleting if ends with '~':
    if maybe_delete_tilde(filename):
	    return
    if filename.endswith('.h') or \
       filename.endswith('.cpp') or \
       filename.endswith('.txt'):
       purify_file(filename)

root_dir = '.'
for dir_name, subdirs, files in os.walk(root_dir):
    for file in files:
        filename = dir_name + '/' + file
        handle_file(filename)