# vim: fileencoding=utf-8
#
from calculate.utils.files import Process
from os import path


class DiffFormat():
    def __init__(self, document_text: str):
        self._patch_text = document_text
        self._root_path = ''
        self._last_level = 0

        # вынести в более общий класс или куда-то еще.
        self._changed_files_list = []

    def execute_format(self, root_path):
        if path.exists(root_path):
            self._root_path = root_path
        else:
            # Какая-то обработка ошибки.
            error_message = 'Root path does not exist.'
            print(error_message)
            return False

        if self._patch_text:
            return self._patch_document()
        else:
            # Какая-то обработка ошибки.
            error_message = 'Empty patch file.'
            print(error_message)
            return False

    def _patch_document(self):
        for level in range(0, 4):
            patch_dry_run = Process('patch', '--dry-run',
                                    '-p{}'.format(level), cwd=self._root_path)
            patch_dry_run.write(self._patch_text)
            if patch_dry_run.success():
                break

            patch_dry_run = Process('patch', '-R', '--dry-run',
                                    '-p{}'.format(level), cwd=self._root_path)
            patch_dry_run.write(self._patch_text)
            if patch_dry_run.success():
                return ''
        else:
            # Какая-то обработка ошибки.
            error_message = 'Correction failed.'
            print(error_message)
            return False

        self._last_level = level
        patch_run = Process('patch', '-p{}'.format(level), cwd=self._root_path)
        patch_run.write(self._patch_text)

        if patch_run.success():
            for line in patch_run:
                if line.startswith('patching file'):
                    self._changed_files_list.append(line[13:].strip())
            return patch_run.read()
        else:
            return ''