'''
pyttsx package.

Copyright (c) 2009, 2013 Peter Parente

Permission to use, copy, modify, and distribute this software for any
purpose with or without fee is hereby granted, provided that the above
copyright notice and this permission notice appear in all copies.

THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
'''
from engine import Engine
import weakref

_activeEngines = weakref.WeakValueDictionary()

def init(driverName=None, debug=False):
    '''
    Constructs a new TTS engine instance or reuses the existing instance for
    the driver name.

    @param driverName: Name of the platform specific driver to use. If
        None, selects the default driver for the operating system.
    @type: str
    @param debug: Debugging output enabled or not
    @type debug: bool
    @return: Engine instance
    @rtype: L{engine.Engine}
    '''
    try:
        eng = _activeEngines[driverName]
    except KeyError:
        eng = Engine(driverName, debug)
        _activeEngines[driverName] = eng
    return eng