"""
Attachment Model
=============

Model function for getting statement attachment information.
"""

from ows_accounting import config
from ows_accounting import response
from ows_accounting.constants import error
from ows_accounting.utils import dynamodb


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 _prepare_attachment_item(item):
    """Prepare attachment data for json serialization.

    Args:
        item (dict): attachment data

    Returns:
        dict: attachment data ready for json serialization.

    """
    item['file_size'] = int(item['file_size'])
    return item


def get_attachments(
        account_type, account_id, period_ids):
    """Get attachments information for account by periods.
        Args:
            account_type (str): account type from GRASS.
            account_id (int): account id (vendor id).
            period_ids (list): list of accounting periods.

    Returns:
        Response: response object with a list of integer values of
            accounting period ids.  Response error if key is not found.
    """
    table = dynamodb.get_table(
        config.ACCOUNTING_STATEMENT_ATTACHMENT_TABLE)

    primary_key = _get_attachment_primary_key_value(
        account_type, account_id, period_ids
    )
    records = dynamodb.query_items(
        table, 'label_type_id_period_id', primary_key)

    if records:
        prepared_records = [
            _prepare_attachment_item(item) for item in records]
        return response.Response(prepared_records)

    return response.create_error_response(
        code=error.ERROR_CODE_INVALID_ATTACHMENT_PERIOD,
        message=error.ERROR_MESSAGE_INVALID_ATTACHMENT_PERIOD)


def get_attachment(
        account_type, account_id, period_ids, file_name):
    """Get single attachment information for account by periods.
        Args:
            account_type (str): account type from GRASS.
            account_id (int): account id (vendor id).
            period_ids (list): list of accounting periods.
            file_name (str): file name with ext., e.g. test.txt.

    Returns:
        Response: response object with a list of integer values of
            accounting period ids.  Response error if key is not found.
    """
    table = dynamodb.get_table(
        config.ACCOUNTING_STATEMENT_ATTACHMENT_TABLE)

    primary_key = _get_attachment_primary_key_value(
        account_type, account_id, period_ids
    )
    records = dynamodb.query_items(
        table, 'label_type_id_period_id', primary_key, 'file_name', file_name)

    if len(records) == 1:
        record = records[0]
        return response.Response(_prepare_attachment_item(record))

    return response.create_error_response(
        code=error.ERROR_CODE_INVALID_ATTACHMENT_PERIOD,
        message=error.ERROR_MESSAGE_INVALID_ATTACHMENT_PERIOD)