#! /usr/bin/env python
# -*- coding: utf-8 -*-
# vim:fenc=utf-8
#
# Copyright © 2017 lafrite <lafrite@Poivre>
#
# Distributed under terms of the MIT license.

"""
Multiply MO
"""

from ..tree import Tree
from ..MO.mo import MO, MOnumber
from ..MO.fraction import MOFraction
from .exceptions import MultiplyError


def multiply(left, right):
    """ Perform the addition of left and right

    :param left: left MO
    :param right: right MO
    :returns: Tree or MO

    >>> a = MOnumber(4)
    >>> b = MOnumber(6)
    >>> multiply(a, b)
    <MOnumber 24>
    >>> b = MOnumber(0)
    >>> multiply(a, b)
    <MOnumber 0>

    """
    if left.value == 0 or right.value ==  0:
        return MOnumber(0)
    elif left.value ==  1:
        return right
    elif right.value ==  1:
        return left

    return MULFUNCTIONS[(type(left), type(right))](left, right)

def monumber_monumber(left, right):
    """ Multiply 2 monumbers

    :param left: left MOnumber
    :param right: right MOnumber
    :returns: MONumber

    >>> a = MOnumber(4)
    >>> b = MOnumber(6)
    >>> monumber_monumber(a, b)
    <MOnumber 24>

    """
    return MO.factory(left.value * right.value)

def monumber_mofraction(left, right):
    """ Multiply a monumber and a mofraction

    :param left: a monumber
    :param right: a mofraction
    :returns: Tree with the multiplication on the numerator

    >>> a = MOnumber(4)
    >>> b = MOFraction(6, 5)
    >>> print(monumber_mofraction(a, b))
    /
     > *
     | > 4
     | > 6
     > 5
    >>> b = MOFraction(6, 5, True)
    >>> print(monumber_mofraction(a, b))
    /
     > *
     | > 4
     | > -
     | | > None
     | | > 6
     > 5

    """
    if not isinstance(left, MOnumber) or not isinstance(right, MOFraction):
        raise MultiplyError(f"Wrong type for left (got {left.__class__.__name__}) \
                or right (got {right.__class__.__name__})")

    num = Tree("*", left, right.numerator)
    return Tree("/", num, right._denominator)

def mofraction_monumber(left, right):
    """ Adding a monumber and a mofraction

    :param left: a mofraction
    :param right: a monumber
    :returns: Tree with the number converted into a mofraction

    >>> a = MOFraction(6, 5)
    >>> b = MOnumber(4)
    >>> print(mofraction_monumber(a, b))
    /
     > *
     | > 6
     | > 4
     > 5
    """

    if not isinstance(left, MOFraction) or not isinstance(right, MOnumber):
        raise MultiplyError(f"Wrong type for left (got {left.__class__.__name__})"
                f"or right (got {right.__class__.__name__})")

    num = Tree("*", left.numerator, right)
    return Tree("/", num, left._denominator)

# TODO: Faire un décorateur pour un enregistrement automatique |dim. mars 11 18:24:32 EAT 2018
MULFUNCTIONS = {
    (MOnumber, MOnumber): monumber_monumber,
    (MOnumber, MOFraction): monumber_mofraction,
    (MOFraction, MOnumber): mofraction_monumber,
    }

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