"""
Mathematica code printer
"""

from __future__ import print_function, division
from sympy.core import S, C
from sympy.printing.codeprinter import CodePrinter
from sympy.printing.str import StrPrinter
from sympy.printing.precedence import precedence

# Used in MCodePrinter._print_Function(self)
known_functions = {
    "exp": [(lambda x: True, "Exp")],
    "log": [(lambda x: True, "Log")],
    "sin": [(lambda x: True, "Sin")],
    "cos": [(lambda x: True, "Cos")],
    "tan": [(lambda x: True, "Tan")],
    "cot": [(lambda x: True, "Cot")],
    "asin": [(lambda x: True, "ArcSin")],
    "acos": [(lambda x: True, "ArcCos")],
    "atan": [(lambda x: True, "ArcTan")],
}


class MCodePrinter(CodePrinter):
    """A printer to convert python expressions to
    strings of the Wolfram's Mathematica code
    """
    printmethod = "_mcode"

    _default_settings = {
        'order': None,
        'full_prec': 'auto',
        'precision': 15,
        'user_functions': {},
        'human': True,
    }

    _number_symbols = set()
    _not_supported = set()

    def __init__(self, settings={}):
        """Register function mappings supplied by user"""
        CodePrinter.__init__(self, settings)
        self.known_functions = dict(known_functions)
        userfuncs = settings.get('user_functions', {})
        for k, v in userfuncs.items():
            if not isinstance(v, list):
                userfuncs[k] = [(lambda *x: True, v)]
                self.known_functions.update(userfuncs)

    doprint = StrPrinter.doprint

    def _print_Pow(self, expr):
        PREC = precedence(expr)
        return '%s^%s' % (self.parenthesize(expr.base, PREC),
                          self.parenthesize(expr.exp, PREC))

    def _print_Mul(self, expr):
        PREC = precedence(expr)
        c, nc = expr.args_cnc()
        res = super(MCodePrinter, self)._print_Mul(expr.func(*c))
        if nc:
            res += '*'
            res += '**'.join(self.parenthesize(a, PREC) for a in nc)
        return res

    def _print_Pi(self, expr):
        return 'Pi'

    def _print_Infinity(self, expr):
        return 'Infinity'

    def _print_NegativeInfinity(self, expr):
        return '-Infinity'

    def _print_list(self, expr):
        return '{' + ', '.join(self.doprint(a) for a in expr) + '}'
    _print_tuple = _print_list
    _print_Tuple = _print_list

    def _print_Function(self, expr):
        if expr.func.__name__ in self.known_functions:
            cond_mfunc = self.known_functions[expr.func.__name__]
            for cond, mfunc in cond_mfunc:
                if cond(*expr.args):
                    return "%s[%s]" % (mfunc, self.stringify(expr.args, ", "))
        return expr.func.__name__ + "[%s]" % self.stringify(expr.args, ", ")

    def _print_Integral(self, expr):
        if len(expr.variables) == 1 and not expr.limits[0][1:]:
            args = [expr.args[0], expr.variables[0]]
        else:
            args = expr.args
        return "Hold[Integrate[" + ', '.join(self.doprint(a) for a in args) + "]]"

    def _print_Sum(self, expr):
        return "Hold[Sum[" + ', '.join(self.doprint(a) for a in expr.args) + "]]"


def mathematica_code(expr, **settings):
    r"""Converts an expr to a string of the Wolfram Mathematica code

    Examples
    ========

    >>> from sympy import mathematica_code as mcode, symbols, sin
    >>> x = symbols('x')
    >>> mcode(sin(x).series(x).removeO())
    '(1/120)*x^5 - 1/6*x^3 + x'
    """
    return MCodePrinter(settings).doprint(expr)
