"""Defines utilities for different operations on files."""


import gzip
import logging
import os
import shutil
import tempfile
from operator import itemgetter


def provide_directory(path):
    if os.path.isfile(path):
        provide_directory(os.path.dirname(path))
    if not os.path.isdir(path):
        try:
            os.makedirs(path)
        except FileExistsError:
            pass


def produce_compressed_storage_pdf_object_name(path_no_ext, ext="pdf"):
    return f"{path_no_ext}.ORIGIN.{ext}.gz"


def dossier_id_and_file_id_to_compressed_storage_pdf_object_name(dossier_id, file_id):
    path_no_ext = os.path.join(dossier_id, file_id)
    pdf_object_name = produce_compressed_storage_pdf_object_name(path_no_ext)
    return pdf_object_name


def path_to_compressed_storage_pdf_object_name(path):
    path_no_ext, ext = os.path.splitext(path)
    path_gz = produce_compressed_storage_pdf_object_name(path_no_ext)
    return path_gz


def unzip(gz_path, pdf_dir):
    def inner():

        path, ext = os.path.splitext(gz_path)
        basename = os.path.basename(path)
        dossier_id = os.path.basename(os.path.dirname(gz_path))
        target_dir = os.path.join(pdf_dir, dossier_id)
        provide_directory(target_dir)
        target_path = os.path.join(target_dir, basename)

        assert ext == ".gz"

        logging.debug(f"unzipping {gz_path} into {target_path}")

        with gzip.open(gz_path, "rb") as f_in:
            with open(target_path, "wb") as f_out:
                shutil.copyfileobj(f_in, f_out)

        logging.debug(f"unzipped {gz_path} into {target_path}")

        return target_path

    try:
        unzipped_file_path = inner()
    finally:
        shutil.rmtree(os.path.dirname(gz_path))

    return unzipped_file_path


def download(storage_client, object_name, target_root_dir):
    downloaded_file_path = storage_client.download_file(object_name, target_root_dir=target_root_dir)
    logging.debug(f"Downloaded {object_name} into {downloaded_file_path}.")
    return downloaded_file_path


def download_pdf_from_storage_via_request_payload(storage_client, payload: dict, pdf_dir: str):

    provide_directory(pdf_dir)

    with tempfile.TemporaryDirectory() as pdf_compressed_dir:

        dossier_id, file_id = itemgetter("dossierId", "fileId")(payload)
        object_name = dossier_id_and_file_id_to_compressed_storage_pdf_object_name(dossier_id, file_id)
        downloaded_file_path = download(storage_client, object_name, pdf_compressed_dir)
        unzipped_file_path = unzip(downloaded_file_path, pdf_dir)
        return unzipped_file_path


def get_file_paths(directory):
    return [os.path.join(directory, f) for f in os.listdir(directory)]