import xlrd

from common.exceptions import ExcelFileError


def check_excel_file(file):

    sheets_names = ['oferta', 'existentes', 'mct', 'rtr']

    try:
        xls = xlrd.open_workbook(file, on_demand=True)
        sheets = xls.sheet_names()
    except Exception:
        raise ExcelFileError(file)
    else:
        not_found = []
        for sheet in sheets_names:
            sheet_exists = sheet in sheets
            if not sheet_exists:
                not_found.append(sheet)

        if not_found:
            msg = 'El archivo no contiene la(s) hoja(s) '
            msg += f'<{", ".join(sheet for sheet in not_found)}>'
            raise ExcelFileError(
                file,
                message=msg)