#!/usr/bin/env python
# encoding: utf-8


from .generic import flatten_list, isNumber

class Operator(str):

    """The operator class, is a string (representation of the operator) with its arity"""

    PRIORITY = {"^": [0, 5], "/": [0, 4], "*" : [0,3], ":": [0,3], "+": [0,1], "-":[2,1], "(":[0,0]}
    OPERATIONS = { \
            "+": ["", ("__add__","__radd__")],\
            "-": ["__neg__", ("__sub__", "__rsub__")], \
            "*": ["", ("__mul__", "__rmul__")], \
            "/": ["", ("__div__","__rdiv__")], \
            "^": ["", ("__pow__", "")], \
            "(": ["",""],\
            }
    TXT = { \
            "+": ["", "{op1} + {op2}"] ,\
            "-": ["- {op1}", "{op1} - {op2}"] ,\
            "*": ["", "{op1} * {op2}"] ,\
            "/": ["", "{op1} / {op2}"] ,\
            "^": ["", "{op1} ^ {op2}"] ,\
            "(": ["",""],\
            }
    TEX = { \
            "+": ["", "{op1} + {op2}"] ,\
            "-": ["- {op1}", "{op1} - {op2}"] ,\
            "*": ["", "{op1} \\times {op2}"] ,\
            "/": ["", "\\frac{{ {op1} }}{{ {op2} }}"] ,\
            "^": ["", "{op1}^{{ {op2} }}"] ,\
            "(": ["",""],\
            }


    def __new__(cls, operator,  arity = 2):
        op = str.__new__(cls, operator)
        op.arity = arity

        # TODO: Add op.visibility |sam. nov.  8 17:00:08 CET 2014

        op.priority = cls.PRIORITY[operator][arity - 1]
        op.actions = cls.OPERATIONS[operator][arity-1]
        op._txt = cls.TXT[operator][arity-1]
        op._tex = cls.TEX[operator][arity-1]

        op.isOperator = 1

        return op

    def __call__(self, *args):
        """ Calling this operator performs the rigth calculus """
        if self.arity == 1:
            return getattr(args[0], self.actions)()

        elif self.arity == 2:
            if type(args[1]) == int:
                return getattr(args[0], self.actions[0])(args[1])
            else:
                return getattr(args[1], self.actions[1])(args[0])

    def _render(self, link, *args):
        """Global step for __txt__ and __tex__

        :param link: the link between operators
        :param *args: the operands
        :returns: the string with operator and operands

        """
        replacement = {"op"+str(i+1): ' '.join(self.add_parenthesis(op)) for (i,op) in enumerate(args)}
        
        ans = link.format(**replacement)
        ans = save_mainOp(ans, self)
        return ans

    def __txt__(self, *args):
        """Txt rendering for the operator
        
        :*args: Operands for this operation
        :returns: String with operator and his operands

        >>> op.mul.__txt__('1','2')
        '1 * 2'
        >>> op.add.__txt__('1','2')
        '1 + 2'
        >>> f = save_mainOp('2 + 3',op.add)
        >>> op.mul.__txt__(f, '4')
        '( 2 + 3 ) * 4'
        >>> f = save_mainOp('-3',op.sub1)
        >>> op.sub1.__txt__(f)
        '- ( -3 )'
        >>> op.sub1.__txt__('-3')
        '- ( -3 )'
        >>> f = save_mainOp('2 + 3',op.add)
        >>> op.sub1.__txt__(f)
        '- ( 2 + 3 )'
        """
        return self._render(self._txt, *args)

    def __tex__(self, *args):
        """Tex rendering for the operator
        
        :*args: Operands for this operation
        :returns: String with operator and his operands

        >>> op.mul.__tex__('1','2')
        '1 \\\\times 2'
        >>> op.add.__tex__('1','2')
        '1 + 2'
        >>> f = save_mainOp('2 + 3',op.add)
        >>> op.mul.__tex__(f, '4')
        '( 2 + 3 ) \\\\times 4'
        >>> f = save_mainOp('-3',op.sub1)
        >>> op.sub1.__tex__(f)
        '- ( -3 )'
        >>> op.sub1.__tex__('-3')
        '- ( -3 )'
        >>> f = save_mainOp('2 + 3',op.add)
        >>> op.sub1.__tex__(f)
        '- ( 2 + 3 )'
        """
        return self._render(self._tex, *args)

    def __p2i__(self, *args):
        """Fix list transformation for the operator
        
        :*args: Operands for this operation
        :returns: list with the operator surrounded by operands

        # TODO: order doctest  |lun. nov. 24 07:17:29 CET 2014
        >>> op.mul.__p2i__(1,2)
        [1, '*', 2]
        >>> f = save_mainOp([2, op.add, 3],op.add)
        >>> op.mul.__p2i__(f, 4)
        ['(', 2, '+', 3, ')', '*', 4]
        >>> f = save_mainOp([op.sub1, 3],op.sub1)
        >>> op.sub1.__p2i__(f)
        ['-', '(', '-', 3, ')']
        >>> op.sub1.__p2i__(-3)
        ['-', '(', -3, ')']
        >>> f = save_mainOp([2, op.add, 3],op.add)
        >>> op.sub1.__p2i__(f)
        ['-', '(', 2, '+', 3, ')']
        """
        # TODO: Attention à gestion des fractions qui se comportent chelou avec les parenthèses |dim. nov.  9 09:21:52 CET 2014
        if self.arity == 1:
            # TODO: Marche juste avec -, il faudra voir quand il y aura d'autres operateurs unitaires |dim. nov.  9 09:24:53 CET 2014
            op1 = self.add_parenthesis(args[0])
            ans = flatten_list([self, op1])

        elif self.arity == 2:
            op1 = self.add_parenthesis(args[0])
            op2 = self.add_parenthesis(args[1])
            ans = flatten_list([op1, self, op2])
        
        ans = save_mainOp(ans, self)
        return ans

    def add_parenthesis(self, op):
        """ Add parenthesis if necessary """
        try:
            if op.mainOp.priority < self.priority:
                op = flatten_list(["("] + [op] + [")"])
        except AttributeError:
            # op has not the attribute priority
            try:
                if int(op) < 0:
                    op = ['(', op, ')']
            except ValueError:
                pass
        return flatten_list([op])

class Mul(Operator):
    def __new__(cls, visibility = 1):
        op = Operator.__new__(cls, "*")
        op.visibility = visibility
        return op

    def _render(self, link, *args):
        replacement = {"op"+str(i+1): ' '.join(self.add_parenthesis(op)) for (i,op) in enumerate(args)}

        if not self.visibility or args[1][0] == "(" or \
                (type(args[1][0]) == str and args[1][0].isalpha()):
            ans = "{op1} {op2}".format(**replacement)
            ans = save_mainOp(ans, self)
            return ans
        else:
            ans = link.format(**replacement)
            ans = save_mainOp(ans, self)
            return ans

class Div(Operator):
    def __new__(cls, visibility = 1):
        op = Operator.__new__(cls, "/")
        return op

    def __call__(self, op1, op2):
        if op2 == 1:
            return op1
        else:
            return Fraction(op1,op2)

    def __tex__(self, *args):
        # Pas besoin de parenthèses en plus pour \frac
        replacement = {"op"+str(i+1): op for (i,op) in enumerate(args)}
        
        ans = self._tex.format(**replacement)
        ans = save_mainOp(ans, self)
        return ans

class Sub1(Operator):
    def __new__(cls,):
        op = Operator.__new__(cls, "-", 1)
        return op

    def add_parenthesis(self, op):
        """ Add parenthesis if necessary """
        try:
            if op.mainOp.priority <= self.priority:
                op = flatten_list(["("] + [op] + [")"])
        except AttributeError:
            # op has not the attribute priority
            try:
                if int(op) < 0:
                    op = ['(', op, ')']
            except ValueError:
                pass
        return flatten_list([op])



class op(object):
    """ List of admited operations """
    # TODO: On pourrait peut être le faire plus proprement avec des décorateurs? |mar. nov. 11 20:24:54 CET 2014
    add  = Operator("+")
    sub  = Operator("-")
    #mul  = Mul("*")
    #div  = Div("/")
    mul  = Mul()
    div  = Div()
    pw   = Operator("^")
    #sub1 = Operator("-", 1)
    sub1 = Sub1()
    par = Operator("(")

def save_mainOp(obj, mainOp):
    """Create a temporary class build over built-in type to stock the main operation of a calculus
    
    :obj: the object to add the attribute
    :mainOp: the main operator
    :returns: the same object with the main operation attribute
    """
    class Fake(type(obj)):
        """ The fake class """
        def __new__(cls, obj):
            op = type(obj).__new__(cls, obj)
            op.mainOp = mainOp
            return op

    return Fake(obj)

if __name__ == '__main__':
    print(op.mul.__txt__('1','2'))
    print(op.sub.__txt__('1','2'))
    print(op.add.__txt__('1','2'))
    f = save_mainOp('2 + 3',op.add)
    print(op.mul.__txt__(f, '4'))
    f = save_mainOp('-3',op.sub1)
    print(op.sub1.__txt__(f))
    print(op.sub1.__txt__('-3'))
    f = save_mainOp('2 + 3',op.add)
    print(op.sub1.__txt__(f))

    from .fraction import Fraction
    f = Fraction(1, 2)
    print(op.add.__txt__(f.__txt__(),'2'))
    print(op.add.__tex__(f.__tex__(),'2'))
    

    import doctest
    doctest.testmod()





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