/*
Copyright (C) 2008-2012 Association of Universities for Research in Astronomy (AURA)

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

    1. Redistributions of source code must retain the above copyright
      notice, this list of conditions and the following disclaimer.

    2. Redistributions in binary form must reproduce the above
      copyright notice, this list of conditions and the following
      disclaimer in the documentation and/or other materials provided
      with the distribution.

    3. The name of AURA and its representatives may not be used to
      endorse or promote products derived from this software without
      specific prior written permission.

THIS SOFTWARE IS PROVIDED BY AURA ``AS IS'' AND ANY EXPRESS OR IMPLIED
WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL AURA BE LIABLE FOR ANY DIRECT, INDIRECT,
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
DAMAGE.
*/

/*
 Author: Michael Droettboom
         mdroe@stsci.edu
*/

#define NO_IMPORT_ARRAY

#include "wcslib_units_wrap.h"

#include <wcsunits.h>

/*
 It gets to be really tedious to type long docstrings in ANSI C syntax
 (since multi-line strings literals are not valid).  Therefore, the
 docstrings are written in doc/docstrings.py, which are then converted
 by setup.py into docstrings.h, which we include here.
*/
#include "docstrings.h"

/***************************************************************************
 * PyTabprm methods
 */

static int
PyUnits_traverse(
    PyUnits* self, visitproc visit, void *arg) {

  return 0;
}

static int
PyUnits_clear(
    PyUnits* self) {

  return 0;
}

static void
PyUnits_dealloc(
    PyUnits* self) {

  PyUnits_clear(self);
  Py_TYPE(self)->tp_free((PyObject*)self);
}

PyUnits*
PyUnits_cnew(
    const char* const have,
    const char* const want,
    const double scale,
    const double offset,
    const double power) {

  PyUnits* self;
  self = (PyUnits*)(&PyUnitsType)->tp_alloc(&PyUnitsType, 0);
  if (have == NULL) {
    self->have[0] = 0;
  } else {
    strncpy(self->have, have, 80);
  }
  if (want == NULL) {
    self->want[0] = 0;
  } else {
    strncpy(self->want, want, 80);
  }
  self->scale = scale;
  self->offset = offset;
  self->power = power;
  return self;
}

static PyObject *
PyUnits_new(
    PyTypeObject* type,
    /*@unused@*/ PyObject* args,
    /*@unused@*/ PyObject* kwds) {

  PyUnits* self;
  self = (PyUnits*)type->tp_alloc(type, 0);
  self->have[0] = 0;
  self->want[0] = 0;
  self->scale = 1.0;
  self->offset = 0.0;
  self->power = 1.0;
  return (PyObject*)self;
}

static int
PyUnits_init(
    PyUnits* self,
    PyObject* args,
    PyObject* kwds) {

  int            status     = -1;
  char*          have;
  char*          want;
  char*          ctrl_str   = NULL;
  int            ctrl       = 0;
  const char*    keywords[] = {"have", "want", "translate_units", NULL};
  struct wcserr* err        = NULL;

  if (!PyArg_ParseTupleAndKeywords(args, kwds, "ss|s:UnitConverter.__init__",
                                   (char **)keywords, &have, &want,
                                   &ctrl_str)) {
    goto exit;
  }

  if (ctrl_str != NULL) {
    if (parse_unsafe_unit_conversion_spec(ctrl_str, &ctrl)) {
      goto exit;
    }
  }

  /* Copy the strings since we can't have wcslib monkeying with the
     data in a Python string */
  strncpy(self->have, have, 80);
  strncpy(self->want, want, 80);

  status = wcsutrne(ctrl, self->have, &err);
  if (status != -1 && status != 0) {
    goto exit;
  }

  status = wcsutrne(ctrl, self->want, &err);
  if (status != -1 && status != 0) {
    goto exit;
  }

  status = wcsunitse(self->have, self->want,
                     &self->scale, &self->offset, &self->power, &err);

 exit:

  if (PyErr_Occurred()) {
    return -1;
  } else if (status == 0) {
    return 0;
  } else {
    wcserr_units_to_python_exc(err);
    free(err);
    return -1;
  }
}

/*@null@*/ static PyObject*
PyUnits___str__(
    PyUnits* self) {

  #define BUF_SIZE 1 << 8
  char buffer[BUF_SIZE];
  char scale[BUF_SIZE];
  char offset[BUF_SIZE];
  char power[BUF_SIZE];

  if (self->scale != 1.0) {
    snprintf(scale, BUF_SIZE, "*%.12g", self->scale);
  } else {
    scale[0] = 0;
  }

  if (self->offset != 0.0) {
    snprintf(offset, BUF_SIZE, " + %.12g", self->offset);
  } else {
    offset[0] = 0;
  }

  if (self->power != 1.0) {
    snprintf(power, BUF_SIZE, " ** %.12g", self->power);
  } else {
    power[0] = 0;
  }

  snprintf(buffer, 1 << 8, "<pywcs.UnitConverter '%s' to '%s' (x%s%s)%s>",
           self->have, self->want, scale, offset, power);

  #if PY3K
  return PyUnicode_FromString(buffer);
  #else
  return PyString_FromString(buffer);
  #endif
}

static PyObject*
PyUnits_convert(
    PyUnits* self,
    PyObject* args,
    PyObject* kwds) {

  int            status       = 1;
  PyObject*      input        = NULL;
  PyArrayObject* input_arr    = NULL;
  PyArrayObject* output_arr   = NULL;
  PyObject*      input_iter   = NULL;
  PyObject*      output_iter  = NULL;
  double         input_val;
  double         output_val;

  if (!PyArg_ParseTuple(args, "O:UnitConverter.convert", &input)) {
    goto exit;
  }

  input_arr = (PyArrayObject*)PyArray_FromObject(
      input, NPY_DOUBLE, 0, NPY_MAXDIMS);
  if (input_arr == NULL) {
    goto exit;
  }

  output_arr = (PyArrayObject*)PyArray_SimpleNew(
      PyArray_NDIM(input_arr), PyArray_DIMS(input_arr), PyArray_DOUBLE);
  if (output_arr == NULL) {
    goto exit;
  }

  input_iter = PyArray_IterNew((PyObject*)input_arr);
  if (input_iter == NULL) {
    goto exit;
  }

  output_iter = PyArray_IterNew((PyObject*)output_arr);
  if (output_iter == NULL) {
    goto exit;
  }

  if (self->power != 1.0) {
    while (PyArray_ITER_NOTDONE(input_iter)) {
      input_val = *(double *)PyArray_ITER_DATA(input_iter);
      output_val = pow(self->scale*input_val + self->offset, self->power);
      if (errno) {
        PyErr_SetFromErrno(PyExc_ValueError);
        goto exit;
      }
      *(double *)PyArray_ITER_DATA(output_iter) = output_val;
      PyArray_ITER_NEXT(input_iter);
      PyArray_ITER_NEXT(output_iter);
    }
  } else {
    while (PyArray_ITER_NOTDONE(input_iter)) {
      input_val = *(double *)PyArray_ITER_DATA(input_iter);
      output_val = self->scale*input_val + self->offset;
      *(double *)PyArray_ITER_DATA(output_iter) = output_val;
      PyArray_ITER_NEXT(input_iter);
      PyArray_ITER_NEXT(output_iter);
    }
  }

  status = 0;

 exit:

  Py_XDECREF((PyObject*)input_arr);
  Py_XDECREF(input_iter);
  Py_XDECREF(output_iter);
  if (status) {
    Py_XDECREF((PyObject*)output_arr);
    return NULL;
  }
  return (PyObject*)output_arr;
}

/***************************************************************************
 * Member getters/setters (properties)
 */

/*@null@*/ static PyObject*
PyUnits_get_have(
    PyUnits* self,
    /*@unused@*/ void* closure) {

  #if PY3K
  return PyUnicode_FromString(self->have);
  #else
  return PyString_FromString(self->have);
  #endif
}

/*@null@*/ static PyObject*
PyUnits_get_want(
    PyUnits* self,
    /*@unused@*/ void* closure) {

  #if PY3K
  return PyUnicode_FromString(self->want);
  #else
  return PyString_FromString(self->want);
  #endif
}

/*@null@*/ static PyObject*
PyUnits_get_scale(
    PyUnits* self,
    /*@unused@*/ void* closure) {

  return get_double("scale", self->scale);
}

/*@null@*/ static PyObject*
PyUnits_get_offset(
    PyUnits* self,
    /*@unused@*/ void* closure) {

  return get_double("offset", self->offset);
}

/*@null@*/ static PyObject*
PyUnits_get_power(
    PyUnits* self,
    /*@unused@*/ void* closure) {

  return get_double("power", self->power);
}

/***************************************************************************
 * PyUnits definition structures
 */

static PyGetSetDef PyUnits_getset[] = {
  {"have", (getter)PyUnits_get_have, NULL, (char *)doc_have},
  {"want", (getter)PyUnits_get_want, NULL, (char *)doc_want},
  {"scale", (getter)PyUnits_get_scale, NULL, (char *)doc_scale},
  {"offset", (getter)PyUnits_get_offset, NULL, (char *)doc_offset},
  {"power", (getter)PyUnits_get_power, NULL, (char *)doc_power},
  {NULL}
};

static PyMethodDef PyUnits_methods[] = {
  {"convert", (PyCFunction)PyUnits_convert, METH_VARARGS, doc_convert},
  {NULL}
};

PyTypeObject PyUnitsType = {
  #if PY3K
  PyVarObject_HEAD_INIT(NULL, 0)
  #else
  PyObject_HEAD_INIT(NULL)
  0,                            /*ob_size*/
  #endif
  "pywcs.UnitConverter",        /*tp_name*/
  sizeof(PyUnits),              /*tp_basicsize*/
  0,                            /*tp_itemsize*/
  (destructor)PyUnits_dealloc,  /*tp_dealloc*/
  0,                            /*tp_print*/
  0,                            /*tp_getattr*/
  0,                            /*tp_setattr*/
  0,                            /*tp_compare*/
  (reprfunc)PyUnits___str__,    /*tp_repr*/
  0,                            /*tp_as_number*/
  0,                            /*tp_as_sequence*/
  0,                            /*tp_as_mapping*/
  0,                            /*tp_hash */
  0,                            /*tp_call*/
  (reprfunc)PyUnits___str__,    /*tp_str*/
  0,                            /*tp_getattro*/
  0,                            /*tp_setattro*/
  0,                            /*tp_as_buffer*/
  Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /*tp_flags*/
  doc_UnitConverter,            /* tp_doc */
  (traverseproc)PyUnits_traverse, /* tp_traverse */
  (inquiry)PyUnits_clear,       /* tp_clear */
  0,                            /* tp_richcompare */
  0,                            /* tp_weaklistoffset */
  0,                            /* tp_iter */
  0,                            /* tp_iternext */
  PyUnits_methods,              /* tp_methods */
  0,                            /* tp_members */
  PyUnits_getset,               /* tp_getset */
  0,                            /* tp_base */
  0,                            /* tp_dict */
  0,                            /* tp_descr_get */
  0,                            /* tp_descr_set */
  0,                            /* tp_dictoffset */
  (initproc)PyUnits_init,       /* tp_init */
  0,                            /* tp_alloc */
  PyUnits_new,                  /* tp_new */
};

int
_setup_units_type(
    PyObject* m) {

  if (PyType_Ready(&PyUnitsType) < 0) {
    return -1;
  }

  Py_INCREF(&PyUnitsType);

  PyModule_AddObject(m, "UnitConverter", (PyObject *)&PyUnitsType);

  return 0;
}
