import os
from typing import Sequence

import pytest

ROOT_DIR_PATH = os.path.dirname(os.path.realpath(__file__))
PRODUCTION_DOTENVS_DIR_PATH = os.path.join(ROOT_DIR_PATH, '.envs', '.production')
PRODUCTION_DOTENV_FILE_PATHS = [
    os.path.join(PRODUCTION_DOTENVS_DIR_PATH, '.django'),
    os.path.join(PRODUCTION_DOTENVS_DIR_PATH, '.postgres'),
    os.path.join(PRODUCTION_DOTENVS_DIR_PATH, '.caddy'),
]
DOTENV_FILE_PATH = os.path.join(ROOT_DIR_PATH, '.env')


def merge(output_file_path: str,
          merged_file_paths: Sequence[str],
          append_linesep: bool = True) -> None:
    with open(output_file_path, 'w') as output_file:
        for merged_file_path in merged_file_paths:
            with open(merged_file_path, 'r') as merged_file:
                merged_file_content = merged_file.read()
                output_file.write(merged_file_content)
                if append_linesep:
                    output_file.write(os.linesep)


def main():
    merge(DOTENV_FILE_PATH, PRODUCTION_DOTENV_FILE_PATHS)


@pytest.mark.parametrize('merged_file_count', range(3))
@pytest.mark.parametrize('append_linesep', [True, False])
def test_merge(tmpdir_factory,
               merged_file_count: int,
               append_linesep: bool):
    tmp_dir_path = str(tmpdir_factory.getbasetemp())

    output_file_path = os.path.join(tmp_dir_path, '.env')

    expected_output_file_content = ''
    merged_file_paths = []
    for i in range(merged_file_count):
        merged_file_ord = i + 1

        merged_filename = '.service{}'.format(merged_file_ord)
        merged_file_path = os.path.join(tmp_dir_path, merged_filename)

        merged_file_content = merged_filename * merged_file_ord

        with open(merged_file_path, 'w+') as file:
            file.write(merged_file_content)

        expected_output_file_content += merged_file_content
        if append_linesep:
            expected_output_file_content += os.linesep

        merged_file_paths.append(merged_file_path)

    merge(output_file_path, merged_file_paths, append_linesep)

    with open(output_file_path, 'r') as output_file:
        actual_output_file_content = output_file.read()

    assert actual_output_file_content == expected_output_file_content


if __name__ == '__main__':
    main()