#define PY_SSIZE_T_CLEAN
#include <Python.h>
#include "structmember.h"

/*#include <stdio.h>*/
#define NPY_NO_DEPRECATED_API NPY_API_VERSION
#define _MULTIARRAYMODULE
#include "numpy/arrayobject.h"

#include "npy_config.h"
#include "npy_pycompat.h"
#include "npy_import.h"
#include "common.h"
#include "number.h"
#include "temp_elide.h"

#include "binop_override.h"

/*************************************************************************
 ****************   Implement Number Protocol ****************************
 *************************************************************************/

NPY_NO_EXPORT NumericOps n_ops; /* NB: static objects initialized to zero */

/*
 * Forward declarations. Might want to move functions around instead
 */
static PyObject *
array_inplace_add(PyArrayObject *m1, PyObject *m2);
static PyObject *
array_inplace_subtract(PyArrayObject *m1, PyObject *m2);
static PyObject *
array_inplace_multiply(PyArrayObject *m1, PyObject *m2);
#if !defined(NPY_PY3K)
static PyObject *
array_inplace_divide(PyArrayObject *m1, PyObject *m2);
#endif
static PyObject *
array_inplace_true_divide(PyArrayObject *m1, PyObject *m2);
static PyObject *
array_inplace_floor_divide(PyArrayObject *m1, PyObject *m2);
static PyObject *
array_inplace_bitwise_and(PyArrayObject *m1, PyObject *m2);
static PyObject *
array_inplace_bitwise_or(PyArrayObject *m1, PyObject *m2);
static PyObject *
array_inplace_bitwise_xor(PyArrayObject *m1, PyObject *m2);
static PyObject *
array_inplace_left_shift(PyArrayObject *m1, PyObject *m2);
static PyObject *
array_inplace_right_shift(PyArrayObject *m1, PyObject *m2);
static PyObject *
array_inplace_remainder(PyArrayObject *m1, PyObject *m2);
static PyObject *
array_inplace_power(PyArrayObject *a1, PyObject *o2, PyObject *NPY_UNUSED(modulo));

/*
 * Dictionary can contain any of the numeric operations, by name.
 * Those not present will not be changed
 */

/* FIXME - macro contains a return */
#define SET(op)   temp = PyDict_GetItemString(dict, #op); \
    if (temp != NULL) { \
        if (!(PyCallable_Check(temp))) { \
            return -1; \
        } \
        Py_INCREF(temp); \
        Py_XDECREF(n_ops.op); \
        n_ops.op = temp; \
    }


/*NUMPY_API
 *Set internal structure with number functions that all arrays will use
 */
NPY_NO_EXPORT int
PyArray_SetNumericOps(PyObject *dict)
{
    PyObject *temp = NULL;
    SET(add);
    SET(subtract);
    SET(multiply);
    SET(divide);
    SET(remainder);
    SET(divmod);
    SET(power);
    SET(square);
    SET(reciprocal);
    SET(_ones_like);
    SET(sqrt);
    SET(cbrt);
    SET(negative);
    SET(positive);
    SET(absolute);
    SET(invert);
    SET(left_shift);
    SET(right_shift);
    SET(bitwise_and);
    SET(bitwise_or);
    SET(bitwise_xor);
    SET(less);
    SET(less_equal);
    SET(equal);
    SET(not_equal);
    SET(greater);
    SET(greater_equal);
    SET(floor_divide);
    SET(true_divide);
    SET(logical_or);
    SET(logical_and);
    SET(floor);
    SET(ceil);
    SET(maximum);
    SET(minimum);
    SET(rint);
    SET(conjugate);
    return 0;
}

/* FIXME - macro contains goto */
#define GET(op) if (n_ops.op &&                                         \
                    (PyDict_SetItemString(dict, #op, n_ops.op)==-1))    \
        goto fail;

/*NUMPY_API
  Get dictionary showing number functions that all arrays will use
*/
NPY_NO_EXPORT PyObject *
PyArray_GetNumericOps(void)
{
    PyObject *dict;
    if ((dict = PyDict_New())==NULL)
        return NULL;
    GET(add);
    GET(subtract);
    GET(multiply);
    GET(divide);
    GET(remainder);
    GET(divmod);
    GET(power);
    GET(square);
    GET(reciprocal);
    GET(_ones_like);
    GET(sqrt);
    GET(negative);
    GET(positive);
    GET(absolute);
    GET(invert);
    GET(left_shift);
    GET(right_shift);
    GET(bitwise_and);
    GET(bitwise_or);
    GET(bitwise_xor);
    GET(less);
    GET(less_equal);
    GET(equal);
    GET(not_equal);
    GET(greater);
    GET(greater_equal);
    GET(floor_divide);
    GET(true_divide);
    GET(logical_or);
    GET(logical_and);
    GET(floor);
    GET(ceil);
    GET(maximum);
    GET(minimum);
    GET(rint);
    GET(conjugate);
    return dict;

 fail:
    Py_DECREF(dict);
    return NULL;
}

static PyObject *
_get_keywords(int rtype, PyArrayObject *out)
{
    PyObject *kwds = NULL;
    if (rtype != NPY_NOTYPE || out != NULL) {
        kwds = PyDict_New();
        if (rtype != NPY_NOTYPE) {
            PyArray_Descr *descr;
            descr = PyArray_DescrFromType(rtype);
            if (descr) {
                PyDict_SetItemString(kwds, "dtype", (PyObject *)descr);
                Py_DECREF(descr);
            }
        }
        if (out != NULL) {
            PyDict_SetItemString(kwds, "out", (PyObject *)out);
        }
    }
    return kwds;
}

NPY_NO_EXPORT PyObject *
PyArray_GenericReduceFunction(PyArrayObject *m1, PyObject *op, int axis,
                              int rtype, PyArrayObject *out)
{
    PyObject *args, *ret = NULL, *meth;
    PyObject *kwds;
    if (op == NULL) {
        Py_INCREF(Py_NotImplemented);
        return Py_NotImplemented;
    }
    args = Py_BuildValue("(Oi)", m1, axis);
    kwds = _get_keywords(rtype, out);
    meth = PyObject_GetAttrString(op, "reduce");
    if (meth && PyCallable_Check(meth)) {
        ret = PyObject_Call(meth, args, kwds);
    }
    Py_DECREF(args);
    Py_DECREF(meth);
    Py_XDECREF(kwds);
    return ret;
}


NPY_NO_EXPORT PyObject *
PyArray_GenericAccumulateFunction(PyArrayObject *m1, PyObject *op, int axis,
                                  int rtype, PyArrayObject *out)
{
    PyObject *args, *ret = NULL, *meth;
    PyObject *kwds;
    if (op == NULL) {
        Py_INCREF(Py_NotImplemented);
        return Py_NotImplemented;
    }
    args = Py_BuildValue("(Oi)", m1, axis);
    kwds = _get_keywords(rtype, out);
    meth = PyObject_GetAttrString(op, "accumulate");
    if (meth && PyCallable_Check(meth)) {
        ret = PyObject_Call(meth, args, kwds);
    }
    Py_DECREF(args);
    Py_DECREF(meth);
    Py_XDECREF(kwds);
    return ret;
}


NPY_NO_EXPORT PyObject *
PyArray_GenericBinaryFunction(PyArrayObject *m1, PyObject *m2, PyObject *op)
{
    /*
     * I suspect that the next few lines are buggy and cause NotImplemented to
     * be returned at weird times... but if we raise an error here, then
     * *everything* breaks. (Like, 'arange(10) + 1' and just
     * 'repr(arange(10))' both blow up with an error here.) Not sure what's
     * going on with that, but I'll leave it alone for now. - njs, 2015-06-21
     */
    if (op == NULL) {
        Py_INCREF(Py_NotImplemented);
        return Py_NotImplemented;
    }

    return PyObject_CallFunctionObjArgs(op, m1, m2, NULL);
}

NPY_NO_EXPORT PyObject *
PyArray_GenericUnaryFunction(PyArrayObject *m1, PyObject *op)
{
    if (op == NULL) {
        Py_INCREF(Py_NotImplemented);
        return Py_NotImplemented;
    }
    return PyObject_CallFunctionObjArgs(op, m1, NULL);
}

static PyObject *
PyArray_GenericInplaceBinaryFunction(PyArrayObject *m1,
                                     PyObject *m2, PyObject *op)
{
    if (op == NULL) {
        Py_INCREF(Py_NotImplemented);
        return Py_NotImplemented;
    }
    return PyObject_CallFunctionObjArgs(op, m1, m2, m1, NULL);
}

static PyObject *
PyArray_GenericInplaceUnaryFunction(PyArrayObject *m1, PyObject *op)
{
    if (op == NULL) {
        Py_INCREF(Py_NotImplemented);
        return Py_NotImplemented;
    }
    return PyObject_CallFunctionObjArgs(op, m1, m1, NULL);
}

static PyObject *
array_add(PyArrayObject *m1, PyObject *m2)
{
    PyObject *res;

    BINOP_GIVE_UP_IF_NEEDED(m1, m2, nb_add, array_add);
    if (try_binary_elide(m1, m2, &array_inplace_add, &res, 1)) {
        return res;
    }
    return PyArray_GenericBinaryFunction(m1, m2, n_ops.add);
}

static PyObject *
array_subtract(PyArrayObject *m1, PyObject *m2)
{
    PyObject *res;

    BINOP_GIVE_UP_IF_NEEDED(m1, m2, nb_subtract, array_subtract);
    if (try_binary_elide(m1, m2, &array_inplace_subtract, &res, 0)) {
        return res;
    }
    return PyArray_GenericBinaryFunction(m1, m2, n_ops.subtract);
}

static PyObject *
array_multiply(PyArrayObject *m1, PyObject *m2)
{
    PyObject *res;

    BINOP_GIVE_UP_IF_NEEDED(m1, m2, nb_multiply, array_multiply);
    if (try_binary_elide(m1, m2, &array_inplace_multiply, &res, 1)) {
        return res;
    }
    return PyArray_GenericBinaryFunction(m1, m2, n_ops.multiply);
}

#if !defined(NPY_PY3K)
static PyObject *
array_divide(PyArrayObject *m1, PyObject *m2)
{
    PyObject *res;

    BINOP_GIVE_UP_IF_NEEDED(m1, m2, nb_divide, array_divide);
    if (try_binary_elide(m1, m2, &array_inplace_divide, &res, 0)) {
        return res;
    }
    return PyArray_GenericBinaryFunction(m1, m2, n_ops.divide);
}
#endif

static PyObject *
array_remainder(PyArrayObject *m1, PyObject *m2)
{
    BINOP_GIVE_UP_IF_NEEDED(m1, m2, nb_remainder, array_remainder);
    return PyArray_GenericBinaryFunction(m1, m2, n_ops.remainder);
}

static PyObject *
array_divmod(PyArrayObject *m1, PyObject *m2)
{
    BINOP_GIVE_UP_IF_NEEDED(m1, m2, nb_divmod, array_divmod);
    return PyArray_GenericBinaryFunction(m1, m2, n_ops.divmod);
}

#if PY_VERSION_HEX >= 0x03050000
/* Need this to be version dependent on account of the slot check */
static PyObject *
array_matrix_multiply(PyArrayObject *m1, PyObject *m2)
{
    static PyObject *matmul = NULL;

    npy_cache_import("numpy.core.multiarray", "matmul", &matmul);
    if (matmul == NULL) {
        return NULL;
    }
    BINOP_GIVE_UP_IF_NEEDED(m1, m2, nb_matrix_multiply, array_matrix_multiply);
    return PyArray_GenericBinaryFunction(m1, m2, matmul);
}

static PyObject *
array_inplace_matrix_multiply(PyArrayObject *m1, PyObject *m2)
{
    PyErr_SetString(PyExc_TypeError,
                    "In-place matrix multiplication is not (yet) supported. "
                    "Use 'a = a @ b' instead of 'a @= b'.");
    return NULL;
}
#endif

/*
 * Determine if object is a scalar and if so, convert the object
 * to a double and place it in the out_exponent argument
 * and return the "scalar kind" as a result.   If the object is
 * not a scalar (or if there are other error conditions)
 * return NPY_NOSCALAR, and out_exponent is undefined.
 */
static NPY_SCALARKIND
is_scalar_with_conversion(PyObject *o2, double* out_exponent)
{
    PyObject *temp;
    const int optimize_fpexps = 1;

    if (PyInt_Check(o2)) {
        *out_exponent = (double)PyInt_AsLong(o2);
        return NPY_INTPOS_SCALAR;
    }
    if (optimize_fpexps && PyFloat_Check(o2)) {
        *out_exponent = PyFloat_AsDouble(o2);
        return NPY_FLOAT_SCALAR;
    }
    if (PyArray_Check(o2)) {
        if ((PyArray_NDIM((PyArrayObject *)o2) == 0) &&
                ((PyArray_ISINTEGER((PyArrayObject *)o2) ||
                 (optimize_fpexps && PyArray_ISFLOAT((PyArrayObject *)o2))))) {
            temp = Py_TYPE(o2)->tp_as_number->nb_float(o2);
            if (temp == NULL) {
                return NPY_NOSCALAR;
            }
            *out_exponent = PyFloat_AsDouble(o2);
            Py_DECREF(temp);
            if (PyArray_ISINTEGER((PyArrayObject *)o2)) {
                return NPY_INTPOS_SCALAR;
            }
            else { /* ISFLOAT */
                return NPY_FLOAT_SCALAR;
            }
        }
    }
    else if (PyArray_IsScalar(o2, Integer) ||
                (optimize_fpexps && PyArray_IsScalar(o2, Floating))) {
        temp = Py_TYPE(o2)->tp_as_number->nb_float(o2);
        if (temp == NULL) {
            return NPY_NOSCALAR;
        }
        *out_exponent = PyFloat_AsDouble(o2);
        Py_DECREF(temp);

        if (PyArray_IsScalar(o2, Integer)) {
                return NPY_INTPOS_SCALAR;
        }
        else { /* IsScalar(o2, Floating) */
            return NPY_FLOAT_SCALAR;
        }
    }
    else if (PyIndex_Check(o2)) {
        PyObject* value = PyNumber_Index(o2);
        Py_ssize_t val;
        if (value==NULL) {
            if (PyErr_Occurred()) {
                PyErr_Clear();
            }
            return NPY_NOSCALAR;
        }
        val = PyInt_AsSsize_t(value);
        if (error_converting(val)) {
            PyErr_Clear();
            return NPY_NOSCALAR;
        }
        *out_exponent = (double) val;
        return NPY_INTPOS_SCALAR;
    }
    return NPY_NOSCALAR;
}

/*
 * optimize float array or complex array to a scalar power
 * returns 0 on success, -1 if no optimization is possible
 * the result is in value (can be NULL if an error occurred)
 */
static int
fast_scalar_power(PyArrayObject *a1, PyObject *o2, int inplace,
                  PyObject **value)
{
    double exponent;
    NPY_SCALARKIND kind;   /* NPY_NOSCALAR is not scalar */

    if (PyArray_Check(a1) &&
            !PyArray_ISOBJECT(a1) &&
            ((kind=is_scalar_with_conversion(o2, &exponent))>0)) {
        PyObject *fastop = NULL;
        if (PyArray_ISFLOAT(a1) || PyArray_ISCOMPLEX(a1)) {
            if (exponent == 1.0) {
                fastop = n_ops.positive;
            }
            else if (exponent == -1.0) {
                fastop = n_ops.reciprocal;
            }
            else if (exponent ==  0.0) {
                fastop = n_ops._ones_like;
            }
            else if (exponent ==  0.5) {
                fastop = n_ops.sqrt;
            }
            else if (exponent ==  2.0) {
                fastop = n_ops.square;
            }
            else {
                return -1;
            }

            if (inplace || can_elide_temp_unary(a1)) {
                *value = PyArray_GenericInplaceUnaryFunction(a1, fastop);
            }
            else {
                *value = PyArray_GenericUnaryFunction(a1, fastop);
            }
            return 0;
        }
        /* Because this is called with all arrays, we need to
         *  change the output if the kind of the scalar is different
         *  than that of the input and inplace is not on ---
         *  (thus, the input should be up-cast)
         */
        else if (exponent == 2.0) {
            fastop = n_ops.square;
            if (inplace) {
                *value = PyArray_GenericInplaceUnaryFunction(a1, fastop);
            }
            else {
                /* We only special-case the FLOAT_SCALAR and integer types */
                if (kind == NPY_FLOAT_SCALAR && PyArray_ISINTEGER(a1)) {
                    PyArray_Descr *dtype = PyArray_DescrFromType(NPY_DOUBLE);
                    a1 = (PyArrayObject *)PyArray_CastToType(a1, dtype,
                            PyArray_ISFORTRAN(a1));
                    if (a1 != NULL) {
                        /* cast always creates a new array */
                        *value = PyArray_GenericInplaceUnaryFunction(a1, fastop);
                        Py_DECREF(a1);
                    }
                }
                else {
                    *value = PyArray_GenericUnaryFunction(a1, fastop);
                }
            }
            return 0;
        }
    }
    /* no fast operation found */
    return -1;
}

static PyObject *
array_power(PyArrayObject *a1, PyObject *o2, PyObject *modulo)
{
    PyObject *value = NULL;

    if (modulo != Py_None) {
        /* modular exponentiation is not implemented (gh-8804) */
        Py_INCREF(Py_NotImplemented);
        return Py_NotImplemented;
    }

    BINOP_GIVE_UP_IF_NEEDED(a1, o2, nb_power, array_power);
    if (fast_scalar_power(a1, o2, 0, &value) != 0) {
        value = PyArray_GenericBinaryFunction(a1, o2, n_ops.power);
    }
    return value;
}


static PyObject *
array_negative(PyArrayObject *m1)
{
    if (can_elide_temp_unary(m1)) {
        return PyArray_GenericInplaceUnaryFunction(m1, n_ops.negative);
    }
    return PyArray_GenericUnaryFunction(m1, n_ops.negative);
}

static PyObject *
array_absolute(PyArrayObject *m1)
{
    if (can_elide_temp_unary(m1) && !PyArray_ISCOMPLEX(m1)) {
        return PyArray_GenericInplaceUnaryFunction(m1, n_ops.absolute);
    }
    return PyArray_GenericUnaryFunction(m1, n_ops.absolute);
}

static PyObject *
array_invert(PyArrayObject *m1)
{
    if (can_elide_temp_unary(m1)) {
        return PyArray_GenericInplaceUnaryFunction(m1, n_ops.invert);
    }
    return PyArray_GenericUnaryFunction(m1, n_ops.invert);
}

static PyObject *
array_left_shift(PyArrayObject *m1, PyObject *m2)
{
    PyObject *res;

    BINOP_GIVE_UP_IF_NEEDED(m1, m2, nb_lshift, array_left_shift);
    if (try_binary_elide(m1, m2, &array_inplace_left_shift, &res, 0)) {
        return res;
    }
    return PyArray_GenericBinaryFunction(m1, m2, n_ops.left_shift);
}

static PyObject *
array_right_shift(PyArrayObject *m1, PyObject *m2)
{
    PyObject *res;

    BINOP_GIVE_UP_IF_NEEDED(m1, m2, nb_rshift, array_right_shift);
    if (try_binary_elide(m1, m2, &array_inplace_right_shift, &res, 0)) {
        return res;
    }
    return PyArray_GenericBinaryFunction(m1, m2, n_ops.right_shift);
}

static PyObject *
array_bitwise_and(PyArrayObject *m1, PyObject *m2)
{
    PyObject *res;

    BINOP_GIVE_UP_IF_NEEDED(m1, m2, nb_and, array_bitwise_and);
    if (try_binary_elide(m1, m2, &array_inplace_bitwise_and, &res, 1)) {
        return res;
    }
    return PyArray_GenericBinaryFunction(m1, m2, n_ops.bitwise_and);
}

static PyObject *
array_bitwise_or(PyArrayObject *m1, PyObject *m2)
{
    PyObject *res;

    BINOP_GIVE_UP_IF_NEEDED(m1, m2, nb_or, array_bitwise_or);
    if (try_binary_elide(m1, m2, &array_inplace_bitwise_or, &res, 1)) {
        return res;
    }
    return PyArray_GenericBinaryFunction(m1, m2, n_ops.bitwise_or);
}

static PyObject *
array_bitwise_xor(PyArrayObject *m1, PyObject *m2)
{
    PyObject *res;

    BINOP_GIVE_UP_IF_NEEDED(m1, m2, nb_xor, array_bitwise_xor);
    if (try_binary_elide(m1, m2, &array_inplace_bitwise_xor, &res, 1)) {
        return res;
    }
    return PyArray_GenericBinaryFunction(m1, m2, n_ops.bitwise_xor);
}

static PyObject *
array_inplace_add(PyArrayObject *m1, PyObject *m2)
{
    INPLACE_GIVE_UP_IF_NEEDED(
            m1, m2, nb_inplace_add, array_inplace_add);
    return PyArray_GenericInplaceBinaryFunction(m1, m2, n_ops.add);
}

static PyObject *
array_inplace_subtract(PyArrayObject *m1, PyObject *m2)
{
    INPLACE_GIVE_UP_IF_NEEDED(
            m1, m2, nb_inplace_subtract, array_inplace_subtract);
    return PyArray_GenericInplaceBinaryFunction(m1, m2, n_ops.subtract);
}

static PyObject *
array_inplace_multiply(PyArrayObject *m1, PyObject *m2)
{
    INPLACE_GIVE_UP_IF_NEEDED(
            m1, m2, nb_inplace_multiply, array_inplace_multiply);
    return PyArray_GenericInplaceBinaryFunction(m1, m2, n_ops.multiply);
}

#if !defined(NPY_PY3K)
static PyObject *
array_inplace_divide(PyArrayObject *m1, PyObject *m2)
{
    INPLACE_GIVE_UP_IF_NEEDED(
            m1, m2, nb_inplace_divide, array_inplace_divide);
    return PyArray_GenericInplaceBinaryFunction(m1, m2, n_ops.divide);
}
#endif

static PyObject *
array_inplace_remainder(PyArrayObject *m1, PyObject *m2)
{
    INPLACE_GIVE_UP_IF_NEEDED(
            m1, m2, nb_inplace_remainder, array_inplace_remainder);
    return PyArray_GenericInplaceBinaryFunction(m1, m2, n_ops.remainder);
}

static PyObject *
array_inplace_power(PyArrayObject *a1, PyObject *o2, PyObject *NPY_UNUSED(modulo))
{
    /* modulo is ignored! */
    PyObject *value = NULL;

    INPLACE_GIVE_UP_IF_NEEDED(
            a1, o2, nb_inplace_power, array_inplace_power);
    if (fast_scalar_power(a1, o2, 1, &value) != 0) {
        value = PyArray_GenericInplaceBinaryFunction(a1, o2, n_ops.power);
    }
    return value;
}

static PyObject *
array_inplace_left_shift(PyArrayObject *m1, PyObject *m2)
{
    INPLACE_GIVE_UP_IF_NEEDED(
            m1, m2, nb_inplace_lshift, array_inplace_left_shift);
    return PyArray_GenericInplaceBinaryFunction(m1, m2, n_ops.left_shift);
}

static PyObject *
array_inplace_right_shift(PyArrayObject *m1, PyObject *m2)
{
    INPLACE_GIVE_UP_IF_NEEDED(
            m1, m2, nb_inplace_rshift, array_inplace_right_shift);
    return PyArray_GenericInplaceBinaryFunction(m1, m2, n_ops.right_shift);
}

static PyObject *
array_inplace_bitwise_and(PyArrayObject *m1, PyObject *m2)
{
    INPLACE_GIVE_UP_IF_NEEDED(
            m1, m2, nb_inplace_and, array_inplace_bitwise_and);
    return PyArray_GenericInplaceBinaryFunction(m1, m2, n_ops.bitwise_and);
}

static PyObject *
array_inplace_bitwise_or(PyArrayObject *m1, PyObject *m2)
{
    INPLACE_GIVE_UP_IF_NEEDED(
            m1, m2, nb_inplace_or, array_inplace_bitwise_or);
    return PyArray_GenericInplaceBinaryFunction(m1, m2, n_ops.bitwise_or);
}

static PyObject *
array_inplace_bitwise_xor(PyArrayObject *m1, PyObject *m2)
{
    INPLACE_GIVE_UP_IF_NEEDED(
            m1, m2, nb_inplace_xor, array_inplace_bitwise_xor);
    return PyArray_GenericInplaceBinaryFunction(m1, m2, n_ops.bitwise_xor);
}

static PyObject *
array_floor_divide(PyArrayObject *m1, PyObject *m2)
{
    PyObject *res;

    BINOP_GIVE_UP_IF_NEEDED(m1, m2, nb_floor_divide, array_floor_divide);
    if (try_binary_elide(m1, m2, &array_inplace_floor_divide, &res, 0)) {
        return res;
    }
    return PyArray_GenericBinaryFunction(m1, m2, n_ops.floor_divide);
}

static PyObject *
array_true_divide(PyArrayObject *m1, PyObject *m2)
{
    PyObject *res;

    BINOP_GIVE_UP_IF_NEEDED(m1, m2, nb_true_divide, array_true_divide);
    if (PyArray_CheckExact(m1) &&
            (PyArray_ISFLOAT(m1) || PyArray_ISCOMPLEX(m1)) &&
            try_binary_elide(m1, m2, &array_inplace_true_divide, &res, 0)) {
        return res;
    }
    return PyArray_GenericBinaryFunction(m1, m2, n_ops.true_divide);
}

static PyObject *
array_inplace_floor_divide(PyArrayObject *m1, PyObject *m2)
{
    INPLACE_GIVE_UP_IF_NEEDED(
            m1, m2, nb_inplace_floor_divide, array_inplace_floor_divide);
    return PyArray_GenericInplaceBinaryFunction(m1, m2,
                                                n_ops.floor_divide);
}

static PyObject *
array_inplace_true_divide(PyArrayObject *m1, PyObject *m2)
{
    INPLACE_GIVE_UP_IF_NEEDED(
            m1, m2, nb_inplace_true_divide, array_inplace_true_divide);
    return PyArray_GenericInplaceBinaryFunction(m1, m2,
                                                n_ops.true_divide);
}


static int
_array_nonzero(PyArrayObject *mp)
{
    npy_intp n;

    n = PyArray_SIZE(mp);
    if (n == 1) {
        int res;
        if (Npy_EnterRecursiveCall(" while converting array to bool")) {
            return -1;
        }
        res = PyArray_DESCR(mp)->f->nonzero(PyArray_DATA(mp), mp);
        /* nonzero has no way to indicate an error, but one can occur */
        if (PyErr_Occurred()) {
            res = -1;
        }
        Py_LeaveRecursiveCall();
        return res;
    }
    else if (n == 0) {
        /* 2017-09-25, 1.14 */
        if (DEPRECATE("The truth value of an empty array is ambiguous. "
                      "Returning False, but in future this will result in an error. "
                      "Use `array.size > 0` to check that an array is not empty.") < 0) {
            return -1;
        }
        return 0;
    }
    else {
        PyErr_SetString(PyExc_ValueError,
                        "The truth value of an array "
                        "with more than one element is ambiguous. "
                        "Use a.any() or a.all()");
        return -1;
    }
}

/*
 * Convert the array to a scalar if allowed, and apply the builtin function
 * to it. The where argument is passed onto Py_EnterRecursiveCall when the
 * array contains python objects.
 */
NPY_NO_EXPORT PyObject *
array_scalar_forward(PyArrayObject *v,
                     PyObject *(*builtin_func)(PyObject *),
                     const char *where)
{
    PyObject *scalar;
    if (PyArray_SIZE(v) != 1) {
        PyErr_SetString(PyExc_TypeError, "only size-1 arrays can be"\
                        " converted to Python scalars");
        return NULL;
    }

    scalar = PyArray_GETITEM(v, PyArray_DATA(v));
    if (scalar == NULL) {
        return NULL;
    }

    /* Need to guard against recursion if our array holds references */
    if (PyDataType_REFCHK(PyArray_DESCR(v))) {
        PyObject *res;
        if (Npy_EnterRecursiveCall(where) != 0) {
            Py_DECREF(scalar);
            return NULL;
        }
        res = builtin_func(scalar);
        Py_DECREF(scalar);
        Py_LeaveRecursiveCall();
        return res;
    }
    else {
        PyObject *res;
        res = builtin_func(scalar);
        Py_DECREF(scalar);
        return res;
    }
}


NPY_NO_EXPORT PyObject *
array_float(PyArrayObject *v)
{
    return array_scalar_forward(v, &PyNumber_Float, " in ndarray.__float__");
}

#if defined(NPY_PY3K)

NPY_NO_EXPORT PyObject *
array_int(PyArrayObject *v)
{
    return array_scalar_forward(v, &PyNumber_Long, " in ndarray.__int__");
}

#else

NPY_NO_EXPORT PyObject *
array_int(PyArrayObject *v)
{
    return array_scalar_forward(v, &PyNumber_Int, " in ndarray.__int__");
}

NPY_NO_EXPORT PyObject *
array_long(PyArrayObject *v)
{
    return array_scalar_forward(v, &PyNumber_Long, " in ndarray.__long__");
}

/* hex and oct aren't exposed to the C api, but we need a function pointer */
static PyObject *
_PyNumber_Oct(PyObject *o) {
    PyObject *res;
    PyObject *mod = PyImport_ImportModule("__builtin__");
    if (mod == NULL) {
        return NULL;
    }
    res = PyObject_CallMethod(mod, "oct", "(O)", o);
    Py_DECREF(mod);
    return res;
}

static PyObject *
_PyNumber_Hex(PyObject *o) {
    PyObject *res;
    PyObject *mod = PyImport_ImportModule("__builtin__");
    if (mod == NULL) {
        return NULL;
    }
    res = PyObject_CallMethod(mod, "hex", "(O)", o);
    Py_DECREF(mod);
    return res;
}

NPY_NO_EXPORT PyObject *
array_oct(PyArrayObject *v)
{
    return array_scalar_forward(v, &_PyNumber_Oct, " in ndarray.__oct__");
}

NPY_NO_EXPORT PyObject *
array_hex(PyArrayObject *v)
{
    return array_scalar_forward(v, &_PyNumber_Hex, " in ndarray.__hex__");
}

#endif

static PyObject *
_array_copy_nice(PyArrayObject *self)
{
    return PyArray_Return((PyArrayObject *) PyArray_Copy(self));
}

static PyObject *
array_index(PyArrayObject *v)
{
    if (!PyArray_ISINTEGER(v) || PyArray_NDIM(v) != 0) {
        PyErr_SetString(PyExc_TypeError,
            "only integer scalar arrays can be converted to a scalar index");
        return NULL;
    }
    return PyArray_GETITEM(v, PyArray_DATA(v));
}


NPY_NO_EXPORT PyNumberMethods array_as_number = {
    (binaryfunc)array_add,                      /*nb_add*/
    (binaryfunc)array_subtract,                 /*nb_subtract*/
    (binaryfunc)array_multiply,                 /*nb_multiply*/
#if !defined(NPY_PY3K)
    (binaryfunc)array_divide,                   /*nb_divide*/
#endif
    (binaryfunc)array_remainder,                /*nb_remainder*/
    (binaryfunc)array_divmod,                   /*nb_divmod*/
    (ternaryfunc)array_power,                   /*nb_power*/
    (unaryfunc)array_negative,                  /*nb_neg*/
    (unaryfunc)_array_copy_nice,                /*nb_pos*/
    (unaryfunc)array_absolute,                  /*(unaryfunc)array_abs,*/
    (inquiry)_array_nonzero,                    /*nb_nonzero*/
    (unaryfunc)array_invert,                    /*nb_invert*/
    (binaryfunc)array_left_shift,               /*nb_lshift*/
    (binaryfunc)array_right_shift,              /*nb_rshift*/
    (binaryfunc)array_bitwise_and,              /*nb_and*/
    (binaryfunc)array_bitwise_xor,              /*nb_xor*/
    (binaryfunc)array_bitwise_or,               /*nb_or*/
#if !defined(NPY_PY3K)
    0,                                          /*nb_coerce*/
#endif
    (unaryfunc)array_int,                       /*nb_int*/
#if defined(NPY_PY3K)
    0,                                          /*nb_reserved*/
#else
    (unaryfunc)array_long,                      /*nb_long*/
#endif
    (unaryfunc)array_float,                     /*nb_float*/
#if !defined(NPY_PY3K)
    (unaryfunc)array_oct,                       /*nb_oct*/
    (unaryfunc)array_hex,                       /*nb_hex*/
#endif

    /*
     * This code adds augmented assignment functionality
     * that was made available in Python 2.0
     */
    (binaryfunc)array_inplace_add,              /*nb_inplace_add*/
    (binaryfunc)array_inplace_subtract,         /*nb_inplace_subtract*/
    (binaryfunc)array_inplace_multiply,         /*nb_inplace_multiply*/
#if !defined(NPY_PY3K)
    (binaryfunc)array_inplace_divide,           /*nb_inplace_divide*/
#endif
    (binaryfunc)array_inplace_remainder,        /*nb_inplace_remainder*/
    (ternaryfunc)array_inplace_power,           /*nb_inplace_power*/
    (binaryfunc)array_inplace_left_shift,       /*nb_inplace_lshift*/
    (binaryfunc)array_inplace_right_shift,      /*nb_inplace_rshift*/
    (binaryfunc)array_inplace_bitwise_and,      /*nb_inplace_and*/
    (binaryfunc)array_inplace_bitwise_xor,      /*nb_inplace_xor*/
    (binaryfunc)array_inplace_bitwise_or,       /*nb_inplace_or*/

    (binaryfunc)array_floor_divide,             /*nb_floor_divide*/
    (binaryfunc)array_true_divide,              /*nb_true_divide*/
    (binaryfunc)array_inplace_floor_divide,     /*nb_inplace_floor_divide*/
    (binaryfunc)array_inplace_true_divide,      /*nb_inplace_true_divide*/
    (unaryfunc)array_index,                     /*nb_index */
#if PY_VERSION_HEX >= 0x03050000
    (binaryfunc)array_matrix_multiply,          /*nb_matrix_multiply*/
    (binaryfunc)array_inplace_matrix_multiply,  /*nb_inplace_matrix_multiply*/
#endif
};
