# Source code for gemseo.uncertainty.distributions.factory

# -*- coding: utf-8 -*-
# Copyright 2021 IRT Saint Exupéry, https://www.irt-saintexupery.com
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with this program; if not, write to the Free Software Foundation,
# Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

# Contributors:
#    INITIAL AUTHORS - initial API and implementation and/or initial
#                           documentation
#        :author: Francois Gallard, Matthias De Lozzo
#    OTHER AUTHORS   - MACROSCOPIC CHANGES

"""Module containing a factory to create an instance of :class:.Distribution."""

from __future__ import division, unicode_literals

from typing import List, Optional, Union

from gemseo.core.factory import Factory
from gemseo.uncertainty.distributions.distribution import (
Distribution,
ParametersType,
StandardParametersType,
)

DistributionParametersType = Union[
int, ParametersType, Optional[StandardParametersType], float
]

[docs]class DistributionFactory(object):
"""Factory to build instances of :class:.Distribution.

At initialization, this factory scans the following modules
to search for subclasses of this class:

- the modules located in "gemseo.uncertainty.distributions" and its sub-packages,
- the modules referenced in the "GEMSEO_PATH",
- the modules referenced in the "PYTHONPATH" and starting with "gemseo_".

Then, it can check if a class is present or return the list of available classes.

Lastly, it can create an instance of a class.

Examples:
>>> from gemseo.uncertainty.distributions.factory import DistributionFactory
>>> factory = DistributionFactory()
>>> factory.is_available("OTNormalDistribution")
True
>>> factory.available_distributions[-3:]
['SPNormalDistribution', 'SPTriangularDistribution', 'SPUniformDistribution']
>>> distribution = factory.create("OTNormalDistribution", "x")
>>> print(distribution)
Normal(mu=0.0, sigma=1.0)
"""

def __init__(self):  # noqa: D107
# type: (...) -> None
self.factory = Factory(Distribution, ("gemseo.uncertainty.distributions",))

[docs]    def create(
self,
distribution_name,  # type: str
variable,  # type: str
**parameters  # type: DistributionParametersType
):
# type: (...) -> Distribution
"""Create a probability distribution for a given random variable.

Args:
distribution_name: The name of a class defining a distribution.
variable: The name of the random variable.
**parameters: The parameters of the distribution.

Returns:
The probability distribution instance.
"""
return self.factory.create(distribution_name, variable=variable, **parameters)

@property
def available_distributions(self):
# type: (...) -> List[str]
"""The available probability distributions."""
return self.factory.classes

[docs]    def is_available(
self,
distribution_name,  # type: str
):
# type: (...) -> bool
"""Check the availability of a probability distribution.

Args:
distribution_name: The name of a class defining a distribution.

Returns:
The availability of the distribution.
"""
return self.factory.is_available(distribution_name)