"""Common utility functions."""

import re
from urllib import parse

import common_config
from constants import statuses
from constants import errors


def parse_file_key(key):
    """Parse file key.

    Args:
        key (str): S3 file key

    Returns:
        dict: empty dict or attachment attributes (label_id, filename etc.)

    """
    key = parse.unquote_plus(key)
    match = re.search(common_config.FILE_KEY_REGEXP, key)
    if match is None:
        return {}
    return match.groupdict()


def get_file_name_from_key(key):
    """Extract file name from S3 file key.

    Args:
        key (str): file key from S3 event

    Returns:
        str: file name part of the file key

    """
    file_name = key.split('/')[-1]
    return parse.unquote_plus(file_name)


def get_quarter_periods_by_period(period_id):
    """Find out all period ids in quarter by period id.

    Args:
        period_id (int): period id

    Returns:
        list: list of quarter period ids

    """
    period_id = int(period_id)
    fractional_part = period_id / 3 - int(period_id / 3)
    if fractional_part == 0:
        # last period in quarter
        period_list = [period_id - 2, period_id - 1, period_id]
    elif round(fractional_part, 1) == 0.7:
        # middle period in quarter
        period_list = [period_id - 1, period_id, period_id + 1]
    else:
        # first period in quarter
        period_list = [period_id, period_id + 1, period_id + 2]
    return period_list


def format_quarter_file_name(file_name, period_id):
    """Format file name for quarter with defined pattern.

    Args:
        file_name (str): original file name, e.g. test.txt
        period_id (int): period id, e.g  217

    Returns:
        str: Formatted file name for sorting, e.g. test.txt(217)

    """
    pattern = '{file_name}({period_id})'
    return pattern.format(file_name=file_name,
                          period_id=period_id)


def get_attachment_primary_key_value(account_type, account_id, period_ids):
    """Get formatted attachment primary key value.

    Args:
        account_type (str): account type from GRASS.
        account_id (int): account id (vendor id).
        period_ids (list): list of accounting periods.

    Returns:
        str: Formatted primary key value

    """
    primary_key_account_type_id = '{}{}'.format(account_type, account_id)
    periods_str = '_'.join(str(period_id) for period_id in period_ids)
    return '{}_{}'.format(primary_key_account_type_id, periods_str)


def s3_event_get_attachment_details(s3_event, file_attrs):
    """Get attachment details from s3_event.

    Args:
        s3_event (dict): AWS S3 event object.
        file_attrs (dict): Attachment file attributes

    Returns:
        dict: standardized dictionary with needed attachment fields.

    """
    try:
        s3_object = s3_event['Records'][0]['s3']['object']
        s3_bucket = s3_event['Records'][0]['s3']['bucket']
        key = parse.unquote_plus(s3_object['key'])

        data = {
            'file_key': key,
            'file_name': file_attrs['filename'],
            'original_file_name': file_attrs['filename'],
            'file_type': file_attrs['extension'],
            'bucket_name': s3_bucket['name'],
            'file_size': s3_object['size'],
            'etag': s3_object['eTag'],
            'account_type': file_attrs['account_type'],
            'label_id': file_attrs['label_id'],
            'period_ids': file_attrs['period_id'],
            'status': statuses.STATUS_COMPLETED,
            'upload_date': s3_event['Records'][0]['eventTime']
        }
        return data

    except KeyError as e:
        raise KeyError(
            errors.MISSING_KEY_EXCEPTION.format(key=str(e)))
    except Exception as e:
        raise Exception(
            errors.CANNOT_PARSE_BODY.format(
                error=str(e)))