import os
from werkzeug.utils import secure_filename
import hashlib


def mkdir_for_transaction(parentdir, relfilepath):
    filedir = os.path.join(parentdir, os.path.dirname(relfilepath))
    if not os.path.isdir(filedir):
        os.makedirs(filedir)


def get_filepath_for_transaction_attachment(parentdir, transaction, filename):
    "Return absolute and relative filepath of transaction attachment."
    relfilepath = os.path.join(str(transaction.id), secure_filename(filename))
    mkdir_for_transaction(parentdir, relfilepath)
    return (os.path.join(parentdir, relfilepath), os.path.join("/", relfilepath))


def get_hash_of_file(filepath):
    return hashlib.md5(open(filepath, "rb").read()).hexdigest()