#!/usr/bin/env python3

import sys
import os
import argparse
import shutil

_DESCRIPTION = "Strip extended characters from all non-hidden files in a path."

def _get_args():
    parser = \
        argparse.ArgumentParser(
            description=_DESCRIPTION)

    parser.add_argument(
        'root_path',
        help="Root path")

    parser.add_argument(
        '-bp', '--backup-path',
        help="Path to copy originals to before modifying")

    args = parser.parse_args()
    return args

def _main():
    args = _get_args()

    ignores = []
    len_ = len(args.root_path)
    for path, folders, files in os.walk(args.root_path):
        rel_path = path[len_ + 1:]

        for folder in folders:
            if folder[0] == '.':
                ignores.append(os.path.join(rel_path, folder))

        if rel_path in ignores:
            continue

        for filename in files:
            filepath = os.path.join(path, filename)
            with open(filepath, 'rb') as f:
                data = f.read()

            parts = []
            last_change = None
            fixes = 0
            for i, c in enumerate(data):
                try:
                    o = ord(c)
                except TypeError:
                    o = c

                if o <= 0x7f:
                    continue

                if last_change is None:
                    parts.append(data[:i])
                else:
                    parts.append(data[last_change + 1:i])

                parts.append('.')
                last_change = i

            if parts:
                print("{} characters stripped. Updating [{}].".format(
                      (len(parts) - 1) / 2, filepath[len(args.root_path) + 1:]))

                if args.backup_path is not None:
                    backup_path = os.path.join(args.backup_path, rel_path)
                    backup_filepath = os.path.join(backup_path, filename)
                    if os.path.exists(backup_path) is False:
                        os.makedirs(backup_path)

                    with open(filepath, 'rb') as f:
                        with open(backup_filepath, 'wb') as g:
                            shutil.copyfileobj(f, g)

                with open(filepath, 'wb') as f:
                    f.write(''.join(parts))

_main()