""" Replace UPPERCASE chars in filenames to lowercase,
and (in future) fix include directives respectively to new filenames. It's
needed for cross-platform compilation C++ code: on Windows, you can not doubt
about headers name. But, when you try to build it on *nix system case does
matter.

Usage:
    renamer.py DIRECTORY [--dry-run]
    renamer.py (-h | --help)
Options:
    DIRECTORY               Run rename recursive
    FILES                   rename only given files
    --dry-run               just display what wanna do
    -h, --help              Show this help text
    -v, --version           Stow version
"""

import os
import string
import shutil

from docopt import docopt

pattern = string.Template("$dir/$this -> $dir/$result )")


def inform(f, dp):
    print(pattern.substitute(this=f, result=f.lower(), dir=dp))


def determine_path():
    if not os.path.abspath(directoryToProcess):
        if not os.path.abspath("/".join([os.path.curdir, directoryToProcess])):
            print("can't find directory %s in current directory, also it's not "
                  "a absolute-path directory. Exit.")
            exit()
        else:
            path = "/".join([os.path.curdir, directoryToProcess])
    else:
        path = directoryToProcess

    return path.replace("\\", "/")


if __name__ == '__main__':
    arguments = docopt(__doc__, version='0.1')

    dryRun = arguments['--dry-run']
    directoryToProcess = arguments["DIRECTORY"]

    path = determine_path()

    print("Start replacing in %s" % path)
    # make reserve
    reserve_path = path.rpartition("/")[0] + "/backup"

    if not dryRun:
        shutil.copytree(path, reserve_path)
    print("create reserve %s" % reserve_path)

    for dirpath, dirs, files in os.walk(path):
        dp = dirpath.replace('\\', '/') + "/"
        for f in files:
            src_path, dst_path = dp + f, dp + f.lower()
            if not dryRun:
                os.rename(src_path, dst_path)
            inform(f, dp)