/*
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * 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 General Public License for more details.
 *
 * You should have received a copy of the GNU 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.
 *
 * Contributor(s): Joseph Gilbert, Campbell Barton
 *
 * ***** END GPL LICENSE BLOCK *****
 */

/** \file blender/python/mathutils/mathutils.c
 *  \ingroup pymathutils
 */

#include <Python.h>

#include "mathutils.h"

#include "BLI_math.h"
#include "BLI_utildefines.h"

#include "../generic/python_utildefines.h"

#ifndef MATH_STANDALONE
#  include "BLI_dynstr.h"
#endif

PyDoc_STRVAR(M_Mathutils_doc,
"This module provides access to math operations.\n"
"\n"
".. note::\n"
"\n"
"   Classes, methods and attributes that accept vectors also accept other numeric sequences,\n"
"   such as tuples, lists."
"\n\n"
"Submodules:\n"
"\n"
".. toctree::\n"
"   :maxdepth: 1\n"
"\n"
"   mathutils.geometry.rst\n"
"   mathutils.bvhtree.rst\n"
"   mathutils.kdtree.rst\n"
"   mathutils.interpolate.rst\n"
"   mathutils.noise.rst\n"
"\n"
"The :mod:`mathutils` module provides the following classes:\n"
"\n"
"- :class:`Color`,\n"
"- :class:`Euler`,\n"
"- :class:`Matrix`,\n"
"- :class:`Quaternion`,\n"
"- :class:`Vector`,\n"
);
static int mathutils_array_parse_fast(float *array,
                                      int size,
                                      PyObject *value_fast,
                                      const char *error_prefix)
{
	PyObject *item;
	PyObject **value_fast_items = PySequence_Fast_ITEMS(value_fast);

	int i;

	i = size;
	do {
		i--;
		if (((array[i] = PyFloat_AsDouble((item = value_fast_items[i]))) == -1.0f) &&
		    PyErr_Occurred())
		{
			PyErr_Format(PyExc_TypeError,
			             "%.200s: sequence index %d expected a number, "
			             "found '%.200s' type, ",
			             error_prefix, i, Py_TYPE(item)->tp_name);
			size = -1;
			break;
		}
	} while (i);

	return size;
}

/**
 * helper function that returns a Python ``__hash__``.
 *
 * \note consistent with the equivalent tuple of floats (CPython's 'tuplehash')
 */
Py_hash_t mathutils_array_hash(const float *array, size_t array_len)
{
	int i;
	Py_uhash_t x;  /* Unsigned for defined overflow behavior. */
	Py_hash_t y;
	Py_uhash_t mult;
	Py_ssize_t len;

	mult = _PyHASH_MULTIPLIER;
	len = array_len;
	x = 0x345678UL;
	i = 0;
	while (--len >= 0) {
		y = _Py_HashDouble((double)(array[i++]));
		if (y == -1)
			return -1;
		x = (x ^ y) * mult;
		/* the cast might truncate len; that doesn't change hash stability */
		mult += (Py_hash_t)(82520UL + len + len);
	}
	x += 97531UL;
	if (x == (Py_uhash_t)-1)
		x = -2;
	return x;
}

/* helper function returns length of the 'value', -1 on error */
int mathutils_array_parse(float *array, int array_min, int array_max, PyObject *value, const char *error_prefix)
{
	const unsigned int flag = array_max;
	int size;

	array_max &= ~MU_ARRAY_FLAGS;

#if 1 /* approx 6x speedup for mathutils types */

	if ((size = VectorObject_Check(value)     ? ((VectorObject *)value)->size : 0) ||
	    (size = EulerObject_Check(value)      ? 3 : 0) ||
	    (size = QuaternionObject_Check(value) ? 4 : 0) ||
	    (size = ColorObject_Check(value)      ? 3 : 0))
	{
		if (BaseMath_ReadCallback((BaseMathObject *)value) == -1) {
			return -1;
		}

		if (flag & MU_ARRAY_SPILL) {
			CLAMP_MAX(size, array_max);
		}

		if (size > array_max || size < array_min) {
			if (array_max == array_min) {
				PyErr_Format(PyExc_ValueError,
				             "%.200s: sequence size is %d, expected %d",
				             error_prefix, size, array_max);
			}
			else {
				PyErr_Format(PyExc_ValueError,
				             "%.200s: sequence size is %d, expected [%d - %d]",
				             error_prefix, size, array_min, array_max);
			}
			return -1;
		}

		memcpy(array, ((BaseMathObject *)value)->data, size * sizeof(float));
	}
	else
#endif
	{
		PyObject *value_fast = NULL;

		/* non list/tuple cases */
		if (!(value_fast = PySequence_Fast(value, error_prefix))) {
			/* PySequence_Fast sets the error */
			return -1;
		}

		size = PySequence_Fast_GET_SIZE(value_fast);

		if (flag & MU_ARRAY_SPILL) {
			CLAMP_MAX(size, array_max);
		}

		if (size > array_max || size < array_min) {
			if (array_max == array_min) {
				PyErr_Format(PyExc_ValueError,
				             "%.200s: sequence size is %d, expected %d",
				             error_prefix, size, array_max);
			}
			else {
				PyErr_Format(PyExc_ValueError,
				             "%.200s: sequence size is %d, expected [%d - %d]",
				             error_prefix, size, array_min, array_max);
			}
			Py_DECREF(value_fast);
			return -1;
		}

		size = mathutils_array_parse_fast(array, size, value_fast, error_prefix);
		Py_DECREF(value_fast);
	}

	if (size != -1) {
		if (flag & MU_ARRAY_ZERO) {
			int size_left = array_max - size;
			if (size_left) {
				memset(&array[size], 0, sizeof(float) * size_left);
			}
		}
	}

	return size;
}

/* on error, -1 is returned and no allocation is made */
int mathutils_array_parse_alloc(float **array, int array_min, PyObject *value, const char *error_prefix)
{
	int size;

#if 1 /* approx 6x speedup for mathutils types */

	if ((size = VectorObject_Check(value)     ? ((VectorObject *)value)->size : 0) ||
	    (size = EulerObject_Check(value)      ? 3 : 0) ||
	    (size = QuaternionObject_Check(value) ? 4 : 0) ||
	    (size = ColorObject_Check(value)      ? 3 : 0))
	{
		if (BaseMath_ReadCallback((BaseMathObject *)value) == -1) {
			return -1;
		}

		if (size < array_min) {
			PyErr_Format(PyExc_ValueError,
			             "%.200s: sequence size is %d, expected > %d",
			             error_prefix, size, array_min);
			return -1;
		}

		*array = PyMem_Malloc(size * sizeof(float));
		memcpy(*array, ((BaseMathObject *)value)->data, size * sizeof(float));
		return size;
	}
	else
#endif
	{
		PyObject *value_fast = NULL;
		// *array = NULL;
		int ret;

		/* non list/tuple cases */
		if (!(value_fast = PySequence_Fast(value, error_prefix))) {
			/* PySequence_Fast sets the error */
			return -1;
		}

		size = PySequence_Fast_GET_SIZE(value_fast);

		if (size < array_min) {
			Py_DECREF(value_fast);
			PyErr_Format(PyExc_ValueError,
			             "%.200s: sequence size is %d, expected > %d",
			             error_prefix, size, array_min);
			return -1;
		}

		*array = PyMem_Malloc(size * sizeof(float));

		ret = mathutils_array_parse_fast(*array, size, value_fast, error_prefix);
		Py_DECREF(value_fast);

		if (ret == -1) {
			PyMem_Free(*array);
		}

		return ret;
	}
}

/* parse an array of vectors */
int mathutils_array_parse_alloc_v(float **array, int array_dim, PyObject *value, const char *error_prefix)
{
	PyObject *value_fast;
	const int array_dim_flag = array_dim;
	int i, size;

	/* non list/tuple cases */
	if (!(value_fast = PySequence_Fast(value, error_prefix))) {
		/* PySequence_Fast sets the error */
		return -1;
	}

	size = PySequence_Fast_GET_SIZE(value_fast);

	if (size != 0) {
		PyObject **value_fast_items = PySequence_Fast_ITEMS(value_fast);
		float *fp;

		array_dim &= ~MU_ARRAY_FLAGS;

		fp = *array = PyMem_Malloc(size * array_dim * sizeof(float));

		for (i = 0; i < size; i++, fp += array_dim) {
			PyObject *item = value_fast_items[i];

			if (mathutils_array_parse(fp, array_dim, array_dim_flag, item, error_prefix) == -1) {
				PyMem_Free(*array);
				*array = NULL;
				size = -1;
				break;
			}
		}
	}

	Py_DECREF(value_fast);
	return size;
}

int mathutils_any_to_rotmat(float rmat[3][3], PyObject *value, const char *error_prefix)
{
	if (EulerObject_Check(value)) {
		if (BaseMath_ReadCallback((BaseMathObject *)value) == -1) {
			return -1;
		}
		else {
			eulO_to_mat3(rmat, ((EulerObject *)value)->eul, ((EulerObject *)value)->order);
			return 0;
		}
	}
	else if (QuaternionObject_Check(value)) {
		if (BaseMath_ReadCallback((BaseMathObject *)value) == -1) {
			return -1;
		}
		else {
			float tquat[4];
			normalize_qt_qt(tquat, ((QuaternionObject *)value)->quat);
			quat_to_mat3(rmat, tquat);
			return 0;
		}
	}
	else if (MatrixObject_Check(value)) {
		if (BaseMath_ReadCallback((BaseMathObject *)value) == -1) {
			return -1;
		}
		else if (((MatrixObject *)value)->num_row < 3 || ((MatrixObject *)value)->num_col < 3) {
			PyErr_Format(PyExc_ValueError,
			             "%.200s: matrix must have minimum 3x3 dimensions",
			             error_prefix);
			return -1;
		}
		else {
			matrix_as_3x3(rmat, (MatrixObject *)value);
			normalize_m3(rmat);
			return 0;
		}
	}
	else {
		PyErr_Format(PyExc_TypeError,
		             "%.200s: expected a Euler, Quaternion or Matrix type, "
		             "found %.200s", error_prefix, Py_TYPE(value)->tp_name);
		return -1;
	}
}


/* ----------------------------------MATRIX FUNCTIONS-------------------- */


/* Utility functions */

/* LomontRRDCompare4, Ever Faster Float Comparisons by Randy Dillon */
/* XXX We may want to use 'safer' BLI's compare_ff_relative ultimately?
 *     LomontRRDCompare4() is an optimized version of Dawson's AlmostEqual2sComplement() (see [1] and [2]).
 *     Dawson himself now claims this is not a 'safe' thing to do (pushing ULP method beyond its limits),
 *     an recommends using work from [3] instead, which is done in BLI func...
 *
 *     [1] http://www.randydillon.org/Papers/2007/everfast.htm
 *     [2] http://www.cygnus-software.com/papers/comparingfloats/comparingfloats.htm
 *     [3] https://randomascii.wordpress.com/2012/02/25/comparing-floating-point-numbers-2012-edition/ instead
 */
#define SIGNMASK(i) (-(int)(((unsigned int)(i)) >> 31))

int EXPP_FloatsAreEqual(float af, float bf, int maxDiff)
{
	/* solid, fast routine across all platforms
	 * with constant time behavior */
	int ai = *(int *)(&af);
	int bi = *(int *)(&bf);
	int test = SIGNMASK(ai ^ bi);
	int diff, v1, v2;

	assert((0 == test) || (0xFFFFFFFF == test));
	diff = (ai ^ (test & 0x7fffffff)) - bi;
	v1 = maxDiff + diff;
	v2 = maxDiff - diff;
	return (v1 | v2) >= 0;
}

/*---------------------- EXPP_VectorsAreEqual -------------------------
 * Builds on EXPP_FloatsAreEqual to test vectors */
int EXPP_VectorsAreEqual(const float *vecA, const float *vecB, int size, int floatSteps)
{
	int x;
	for (x = 0; x < size; x++) {
		if (EXPP_FloatsAreEqual(vecA[x], vecB[x], floatSteps) == 0)
			return 0;
	}
	return 1;
}

#ifndef MATH_STANDALONE
/* dynstr as python string utility funcions, frees 'ds'! */
PyObject *mathutils_dynstr_to_py(struct DynStr *ds)
{
	const int ds_len = BLI_dynstr_get_len(ds); /* space for \0 */
	char *ds_buf     = PyMem_Malloc(ds_len + 1);
	PyObject *ret;
	BLI_dynstr_get_cstring_ex(ds, ds_buf);
	BLI_dynstr_free(ds);
	ret = PyUnicode_FromStringAndSize(ds_buf, ds_len);
	PyMem_Free(ds_buf);
	return ret;
}
#endif

/* silly function, we dont use arg. just check its compatible with __deepcopy__ */
int mathutils_deepcopy_args_check(PyObject *args)
{
	PyObject *dummy_pydict;
	return PyArg_ParseTuple(args, "|O!:__deepcopy__", &PyDict_Type, &dummy_pydict) != 0;
}

/* Mathutils Callbacks */

/* for mathutils internal use only, eventually should re-alloc but to start with we only have a few users */
#define MATHUTILS_TOT_CB 17
static Mathutils_Callback *mathutils_callbacks[MATHUTILS_TOT_CB] = {NULL};

unsigned char Mathutils_RegisterCallback(Mathutils_Callback *cb)
{
	unsigned char i;

	/* find the first free slot */
	for (i = 0; mathutils_callbacks[i]; i++) {
		if (mathutils_callbacks[i] == cb) /* already registered? */
			return i;
	}

	BLI_assert(i + 1 < MATHUTILS_TOT_CB);

	mathutils_callbacks[i] = cb;
	return i;
}

/* use macros to check for NULL */
int _BaseMathObject_ReadCallback(BaseMathObject *self)
{
	Mathutils_Callback *cb = mathutils_callbacks[self->cb_type];
	if (LIKELY(cb->get(self, self->cb_subtype) != -1)) {
		return 0;
	}

	if (!PyErr_Occurred()) {
		PyErr_Format(PyExc_RuntimeError,
		             "%s read, user has become invalid",
		             Py_TYPE(self)->tp_name);
	}
	return -1;
}

int _BaseMathObject_WriteCallback(BaseMathObject *self)
{
	Mathutils_Callback *cb = mathutils_callbacks[self->cb_type];
	if (LIKELY(cb->set(self, self->cb_subtype) != -1)) {
		return 0;
	}

	if (!PyErr_Occurred()) {
		PyErr_Format(PyExc_RuntimeError,
		             "%s write, user has become invalid",
		             Py_TYPE(self)->tp_name);
	}
	return -1;
}

int _BaseMathObject_ReadIndexCallback(BaseMathObject *self, int index)
{
	Mathutils_Callback *cb = mathutils_callbacks[self->cb_type];
	if (LIKELY(cb->get_index(self, self->cb_subtype, index) != -1)) {
		return 0;
	}

	if (!PyErr_Occurred()) {
		PyErr_Format(PyExc_RuntimeError,
		             "%s read index, user has become invalid",
		             Py_TYPE(self)->tp_name);
	}
	return -1;
}

int _BaseMathObject_WriteIndexCallback(BaseMathObject *self, int index)
{
	Mathutils_Callback *cb = mathutils_callbacks[self->cb_type];
	if (LIKELY(cb->set_index(self, self->cb_subtype, index) != -1)) {
		return 0;
	}

	if (!PyErr_Occurred()) {
		PyErr_Format(PyExc_RuntimeError,
		             "%s write index, user has become invalid",
		             Py_TYPE(self)->tp_name);
	}
	return -1;
}

void _BaseMathObject_RaiseFrozenExc(const BaseMathObject *self)
{
	PyErr_Format(PyExc_TypeError,
	             "%s is frozen (immutable)",
	             Py_TYPE(self)->tp_name);
}

void _BaseMathObject_RaiseNotFrozenExc(const BaseMathObject *self)
{
	PyErr_Format(PyExc_TypeError,
	             "%s is not frozen (mutable), call freeze first",
	             Py_TYPE(self)->tp_name);
}

/* BaseMathObject generic functions for all mathutils types */
char BaseMathObject_owner_doc[] = "The item this is wrapping or None  (read-only).";
PyObject *BaseMathObject_owner_get(BaseMathObject *self, void *UNUSED(closure))
{
	PyObject *ret = self->cb_user ? self->cb_user : Py_None;
	return Py_INCREF_RET(ret);
}

char BaseMathObject_is_wrapped_doc[] = "True when this object wraps external data (read-only).\n\n:type: boolean";
PyObject *BaseMathObject_is_wrapped_get(BaseMathObject *self, void *UNUSED(closure))
{
	return PyBool_FromLong((self->flag & BASE_MATH_FLAG_IS_WRAP) != 0);
}

char BaseMathObject_is_frozen_doc[] = "True when this object has been frozen (read-only).\n\n:type: boolean";
PyObject *BaseMathObject_is_frozen_get(BaseMathObject *self, void *UNUSED(closure))
{
	return PyBool_FromLong((self->flag & BASE_MATH_FLAG_IS_FROZEN) != 0);
}

char BaseMathObject_freeze_doc[] =
".. function:: freeze()\n"
"\n"
"   Make this object immutable.\n"
"\n"
"   After this the object can be hashed, used in dictionaries & sets.\n"
"\n"
"   :return: An instance of this object.\n"
;
PyObject *BaseMathObject_freeze(BaseMathObject *self)
{
	if ((self->flag & BASE_MATH_FLAG_IS_WRAP) || (self->cb_user != NULL)) {
		PyErr_SetString(PyExc_TypeError, "Cannot freeze wrapped/owned data");
		return NULL;
	}

	self->flag |= BASE_MATH_FLAG_IS_FROZEN;

	return Py_INCREF_RET((PyObject *)self);
}

int BaseMathObject_traverse(BaseMathObject *self, visitproc visit, void *arg)
{
	Py_VISIT(self->cb_user);
	return 0;
}

int BaseMathObject_clear(BaseMathObject *self)
{
	Py_CLEAR(self->cb_user);
	return 0;
}

void BaseMathObject_dealloc(BaseMathObject *self)
{
	/* only free non wrapped */
	if ((self->flag & BASE_MATH_FLAG_IS_WRAP) == 0) {
		PyMem_Free(self->data);
	}

	if (self->cb_user) {
		PyObject_GC_UnTrack(self);
		BaseMathObject_clear(self);
	}

	Py_TYPE(self)->tp_free(self); // PyObject_DEL(self); // breaks subtypes
}

/*----------------------------MODULE INIT-------------------------*/
static struct PyMethodDef M_Mathutils_methods[] = {
	{NULL, NULL, 0, NULL}
};

static struct PyModuleDef M_Mathutils_module_def = {
	PyModuleDef_HEAD_INIT,
	"mathutils",  /* m_name */
	M_Mathutils_doc,  /* m_doc */
	0,  /* m_size */
	M_Mathutils_methods,  /* m_methods */
	NULL,  /* m_reload */
	NULL,  /* m_traverse */
	NULL,  /* m_clear */
	NULL,  /* m_free */
};


/* submodules only */
#include "mathutils_geometry.h"
#include "mathutils_interpolate.h"
#ifndef MATH_STANDALONE
#  include "mathutils_bvhtree.h"
#  include "mathutils_kdtree.h"
#  include "mathutils_noise.h"
#endif

PyMODINIT_FUNC PyInit_mathutils(void)
{
	PyObject *mod;
	PyObject *submodule;
	PyObject *sys_modules = PyThreadState_GET()->interp->modules;

	if (PyType_Ready(&vector_Type) < 0)
		return NULL;
	if (PyType_Ready(&matrix_Type) < 0)
		return NULL;
	if (PyType_Ready(&matrix_access_Type) < 0)
		return NULL;
	if (PyType_Ready(&euler_Type) < 0)
		return NULL;
	if (PyType_Ready(&quaternion_Type) < 0)
		return NULL;
	if (PyType_Ready(&color_Type) < 0)
		return NULL;

	mod = PyModule_Create(&M_Mathutils_module_def);

	/* each type has its own new() function */
	PyModule_AddObject(mod, vector_Type.tp_name,     (PyObject *)&vector_Type);
	PyModule_AddObject(mod, matrix_Type.tp_name,     (PyObject *)&matrix_Type);
	PyModule_AddObject(mod, euler_Type.tp_name,      (PyObject *)&euler_Type);
	PyModule_AddObject(mod, quaternion_Type.tp_name, (PyObject *)&quaternion_Type);
	PyModule_AddObject(mod, color_Type.tp_name,      (PyObject *)&color_Type);

	/* submodule */
	PyModule_AddObject(mod, "geometry",       (submodule = PyInit_mathutils_geometry()));
	/* XXX, python doesnt do imports with this usefully yet
	 * 'from mathutils.geometry import PolyFill'
	 * ...fails without this. */
	PyDict_SetItem(sys_modules, PyModule_GetNameObject(submodule), submodule);
	Py_INCREF(submodule);

	PyModule_AddObject(mod, "interpolate",    (submodule = PyInit_mathutils_interpolate()));
	/* XXX, python doesnt do imports with this usefully yet
	 * 'from mathutils.geometry import PolyFill'
	 * ...fails without this. */
	PyDict_SetItem(sys_modules, PyModule_GetNameObject(submodule), submodule);
	Py_INCREF(submodule);

#ifndef MATH_STANDALONE
	/* Noise submodule */
	PyModule_AddObject(mod, "noise", (submodule = PyInit_mathutils_noise()));
	PyDict_SetItem(sys_modules, PyModule_GetNameObject(submodule), submodule);
	Py_INCREF(submodule);

	/* BVHTree submodule */
	PyModule_AddObject(mod, "bvhtree", (submodule = PyInit_mathutils_bvhtree()));
	PyDict_SetItem(sys_modules, PyModule_GetNameObject(submodule), submodule);
	Py_INCREF(submodule);

	/* KDTree submodule */
	PyModule_AddObject(mod, "kdtree", (submodule = PyInit_mathutils_kdtree()));
	PyDict_SetItem(sys_modules, PyModule_GetNameObject(submodule), submodule);
	Py_INCREF(submodule);
#endif

	mathutils_matrix_row_cb_index = Mathutils_RegisterCallback(&mathutils_matrix_row_cb);
	mathutils_matrix_col_cb_index = Mathutils_RegisterCallback(&mathutils_matrix_col_cb);
	mathutils_matrix_translation_cb_index = Mathutils_RegisterCallback(&mathutils_matrix_translation_cb);

	return mod;
}
