""" some helper functions """

from pathlib import Path

import openpyxl

DEFAULT_RECIPIENTS = [
    "frey@imtek.de",
]


def excel_value_as_number(value):
    if value is None:
        return 0
    if isinstance(value, str):
        try:
            return float(value)
        except ValueError:
            return 0
    return value


def get_sheet_of_file(excel_file, sheet=None):
    """ returns a sheet from an excel FileCache

    if name is set to None, the function returns the first sheet
    """
    workbook = openpyxl.open(excel_file)
    if sheet is None:
        all_sheets = workbook.sheetnames
        sheet = all_sheets[0]
    return workbook[sheet]


def is_empty_excel_value(value):
    """ is the cell value considered empty """
    if value is None:
        return True
    if isinstance(value, str) and value.strip() == "":
        return True
    return False


def strip_excel_value(value):
    """ remove whitespace from an excel value if it is a string """
    if isinstance(value, str):
        return value.strip()
    return value


def is_budget_file_name(path_or_name):
    """ checks if a filename has the format "budget[...]-<year>.xlsx """
    path = Path(path_or_name)
    if not path.suffix.lower() == ".xlsx":
        return False
    if not path.name.lower().startswith("budget"):
        return False
    try:
        return int(path.stem[-5:]) <= -2019
    except ValueError:
        pass
    return False


def list_budget_files(folder):
    """ lists all files with the name "budget[...]-<year>.xlsx """
    files = (i for i in Path(folder).iterdir() if i.is_file())
    visible = (i for i in files if not i.name.startswith("."))
    return [i for i in visible if is_budget_file_name(i)]


def find_budget_file(folder, year):
    """ searches for a file with the name "budget[...]-<year>.xlsx """
    for path in list_budget_files(folder):
        if path.stem.endswith(f"-{year}"):
            return path


def find_recipients(folder, filename="recipients.txt"):
    """ finds the recipients of the budget list """
    file_path = folder / filename
    if file_path.is_file():
        with file_path.open() as filehandle:
            stripped = (line.strip() for line in filehandle)
            return [line for line in stripped if line]
    return DEFAULT_RECIPIENTS