# -*- coding: utf-8 -*-
"""
app.api.utils
~~~~~~~~~~~~~

This module implements useful functions for the API.

:copyright: (c) 2017 European Spallation Source ERIC
:license: BSD 2-Clause, see LICENSE for more details.

"""
import sqlalchemy as sa
from flask import current_app, jsonify, request
from ..extensions import db
from .. import utils


def commit():
    try:
        db.session.commit()
    except (sa.exc.IntegrityError, sa.exc.DataError) as e:
        db.session.rollback()
        raise utils.CSEntryError(str(e), status_code=422)


def get_generic_model(model, args, order_by=None):
    """Return data from model as json

    :param model: model class
    :param MultiDict args: args from the request
    :param order_by: column to order the result by
    :returns: data from model as json
    """
    query = utils.get_query(model.query, request.args)
    if order_by is None:
        order_by = getattr(model, 'name')
    instances = query.order_by(order_by)
    data = [instance.to_dict() for instance in instances]
    return jsonify(data)


def create_generic_model(model, mandatory_fields=('name',), **kwargs):
    data = request.get_json()
    if data is None:
        raise utils.CSEntryError('Body should be a JSON object')
    current_app.logger.debug(f'Received: {data}')
    data.update(kwargs)
    for mandatory_field in mandatory_fields:
        if mandatory_field not in data:
            raise utils.CSEntryError(f"Missing mandatory field '{mandatory_field}'", status_code=422)
    try:
        instance = model(**data)
    except TypeError as e:
        message = str(e).replace('__init__() got an ', '')
        raise utils.CSEntryError(message, status_code=422)
    except ValueError as e:
        raise utils.CSEntryError(str(e), status_code=422)
    db.session.add(instance)
    commit()
    return jsonify(instance.to_dict()), 201