#! /home/phd/.local/bin/python3
# -*- coding: koi8-r -*-

import argparse
import sys

from m_lib.defenc import default_encoding


def parse_args(default=None):
    parser = argparse.ArgumentParser(description='Recode filenames')
    parser.add_argument('-f', '--from-encoding', help='from encoding')
    parser.add_argument('-t', '--to-encoding', help='to encoding')
    parser.add_argument('filename', nargs='*' if default else '+',
                        default=[default], help='filenames to recode')
    args = parser.parse_args()

    from_encoding = args.from_encoding
    to_encoding = args.to_encoding

    if from_encoding:
        if to_encoding:
            pass  # Everything is defined, no need to guess
        elif from_encoding == 'utf-8':
            if default_encoding == 'utf-8':
                sys.exit('Cannot guess to_encoding')
            else:
                to_encoding = default_encoding
        else:
            to_encoding = 'utf-8'
    elif to_encoding:
        if to_encoding == default_encoding:
            if default_encoding == 'utf-8':
                sys.exit('Cannot guess from_encoding')
            else:
                from_encoding = 'utf-8'
        else:
            from_encoding = default_encoding
    else:
        if default_encoding == 'utf-8':
            sys.exit('Cannot guess encodings')
        else:
            from_encoding = default_encoding
            to_encoding = 'utf-8'

    return from_encoding, to_encoding, args.filename


def build_recode(from_encoding, to_encoding):
    if from_encoding == "translit":
        if to_encoding == "koi8-r":
            from m_lib.rus.lat2rus import lat2koi as _recode
        elif to_encoding == "cp1251":
            from m_lib.rus.lat2rus import lat2win as _recode
        else:
            raise NotImplementedError(
                "destination encoding must be koi8-r or cp1251, "
                "not `%s'" % to_encoding)

    elif to_encoding == "translit":
        if from_encoding == "koi8-r":
            from m_lib.rus.rus2lat import koi2lat as _recode
        elif from_encoding == "cp1251":
            from m_lib.rus.rus2lat import win2lat as _recode
        else:
            raise NotImplementedError(
                "source encoding must be koi8-r or cp1251, "
                "not `%s'" % from_encoding)

        from m_lib.rus.rus2lat import koi2lat_d
        koi2lat_d["ÿ"] = ''  # remove apostrophs -
        koi2lat_d["ø"] = ''  # they are not very good characters in filenames
        koi2lat_d["ß"] = ''  # especially on Windoze
        koi2lat_d["Ø"] = ''  # :-)

    elif from_encoding == "url":
        try:
            from_encoding, to_encoding = to_encoding.split('/')
        except ValueError:
            from_encoding = to_encoding
        from urllib.parse import unquote
        from m_lib.opstring import recode

        def _recode(s):
            s = unquote(s)
            if from_encoding != to_encoding:
                s = recode(s, from_encoding, to_encoding, "replace")
            return s

    elif to_encoding == "url":
        try:
            from_encoding, to_encoding = from_encoding.split('/')
        except ValueError:
            to_encoding = from_encoding
        from urllib.parse import quote
        from m_lib.opstring import recode

        def _recode(s):
            if from_encoding != to_encoding:
                s = recode(s, from_encoding, to_encoding, "replace")
            #                wget treats them as safe
            #                     vvvvvvvvvvvvv
            return quote(s, safe=";/?:@&=+$,()'")

    else:
        def _recode(s):
            return s.encode(to_encoding, "surrogateescape").\
                decode(from_encoding, "surrogateescape")

    return _recode


if __name__ == "__main__":
    import os
    from_encoding, to_encoding, filenames = parse_args()
    _recode = build_recode(from_encoding, to_encoding)
    for filename in filenames:
        new_name = _recode(filename)
        if not isinstance(new_name, str):
            new_name = new_name.decode()
        if new_name != filename:
            sys.stdout.buffer.write(
                b'%s %s / %s -> %s\n' % (
                    from_encoding.encode(), to_encoding.encode(),
                    filename.encode(default_encoding, 'replace'),
                    new_name.encode(to_encoding, 'replace'))
                )
            os.rename(filename, new_name)