#!/usr/bin/python
# coding: utf-8
from __future__ import absolute_import

import sys
import os
from builtins import input

UNICODE_LITERALS = 'from __future__ import unicode_literals'

ALLOWED_EXTENSION = '.py'
IGNORED_DIRS = ('__init__', '.idea', '.sass-cache', 'media', 'migrations', 'node_modules', 'static', 'templates')


def listar_arquivos_sem_unicode_literals(directory):
    file_list = []
    for root, subdirs, files in os.walk(directory):
        for filename in files:

            if not filename.endswith(ALLOWED_EXTENSION):
                continue

            file_path = os.path.join(root, filename)

            if any([word in file_path for word in IGNORED_DIRS]):
                continue

            valid_file = is_file_valid(file_path)
            if not valid_file:
                continue

            have_import = is_file_have_unicode_literals(file_path)
            if not have_import:
                file_list.append(file_path)
    return file_list


def is_file_valid(one_file):
    with open(one_file, 'r') as myfile:
        num_lines = sum(1 for line in myfile)
    return num_lines >= 4


def is_file_have_unicode_literals(one_file):
    with open(one_file, 'r') as myfile:
        content = myfile.read()
        return UNICODE_LITERALS in content


def add_unicode_literals(one_file):
    with open(one_file, 'r') as original_file:
        conteudo = original_file.read()

        original_file.seek(0)
        lines = conteudo.splitlines()

        if 'coding' in conteudo:
            lines[0] = '# coding: utf-8'
            lines.insert(1, UNICODE_LITERALS)
            if lines[2] != '':
                lines.insert(2, '')
            if 'class' in lines[3]:
                lines.insert(3, '')
            if 'def' in lines[3]:
                lines.insert(3, '')
        else:
            lines.insert(0, UNICODE_LITERALS)
            if lines[1] != '':
                lines.insert(1, '')
            if 'class' in lines[2]:
                lines.insert(2, '')
            if 'def' in lines[2]:
                lines.insert(2, '')

    lines.append('')

    with open(one_file, 'w') as output_file:
        new_file_content = '\n'.join(lines)
        output_file.write(new_file_content)


if __name__ == '__main__':
    if len(sys.argv) == 1:
        print('Error, you need to inform a directory')
        exit(1)

    diretorio = sys.argv[1]

    lista_de_arquivos = listar_arquivos_sem_unicode_literals(diretorio)

    quantidade = len(lista_de_arquivos)

    if quantidade > 200:
        resposta = input('Um total de {} arquivos serão alterados, deseja prosseguir? '.format(quantidade))

        if resposta.upper() != 'S':
            exit(0)

    for arquivo in lista_de_arquivos:
        print('- {}'.format(arquivo))
        add_unicode_literals(arquivo)
    print('{} arquivos foram alterados.'.format(quantidade))

    exit(0)