# -*- coding: utf-8 -*-
# Copyright (c) 2017 Tomek Wójcik <tomek@bthlabs.pl>
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
#

"""
q3stats.lib.scripts.utils
=========================

This module contains utility functions used by scripts.
"""

import contextlib
import json
import logging
import sys

import q3stats.database

RET_OK = 0
RET_ERROR = 99


def pprint(value, stream=None):
    """JSON-based pretty print. *stream* defaults to ``sys.stdout``."""
    if stream is None:
        stream = sys.stdout

    stream.write(json.dumps(value, indent=4, sort_keys=True) + "\n")


@contextlib.contextmanager
def db_session(config):
    """Context manager for getting the DB session configured for the current
    environment.

    On exception, the session will be rolled back. The session is always
    properly disposed of, regardless of any errors.

    **Example**:

    .. sourcecode:: python

        def some_function():
            with db_session() as session:
                # Do something with the session.
                session.commit()
    """
    if q3stats.database.db_engine is None:
        q3stats.database.db_engine = q3stats.database.create_engine(config)
        q3stats.database.db_session = q3stats.database.create_session(
            q3stats.database.db_engine, config
        )

    session = q3stats.database.db_session
    try:
        yield session
    except:
        session.rollback()
        raise
    finally:
        session.remove()


def get_logger(name, args):
    """Sets up a ``logging.Logger`` instance for script named *name*."""
    logger = logging.getLogger(name)

    handler = logging.StreamHandler()

    formatter = logging.Formatter(
        '%(asctime)s ' + name + ': %(levelname)s: %(message)s'
    )

    handler.setFormatter(formatter)
    logger.addHandler(handler)

    if args.verbose is True:
        logger.setLevel(logging.DEBUG)
    else:
        logger.setLevel(logging.WARNING)

    return logger