/**

* Copyright (c) 2017-present, Gregory Szorc

* All rights reserved.

*

* This software may be modified and distributed under the terms

* of the BSD license. See the LICENSE file for details.

*/

#include "python-zstandard.h"

extern PyObject* ZstdError;

PyDoc_STRVAR(FrameParameters__doc__,

	"FrameParameters: information about a zstd frame");

FrameParametersObject* get_frame_parameters(PyObject* self, PyObject* args) {

	const char* source;

	Py_ssize_t sourceSize;

	ZSTD_frameParams params;

	FrameParametersObject* result = NULL;

	size_t zresult;

#if PY_MAJOR_VERSION >= 3

	if (!PyArg_ParseTuple(args, "y#:get_frame_parameters",

#else

	if (!PyArg_ParseTuple(args, "s#:get_frame_parameters",

#endif

		&source, &sourceSize)) {

		return NULL;

	}

	/* Needed for Python 2 to reject unicode */

	if (!PyBytes_Check(PyTuple_GET_ITEM(args, 0))) {

		PyErr_SetString(PyExc_TypeError, "argument must be bytes");

		return NULL;

	}

	zresult = ZSTD_getFrameParams(&params, (void*)source, sourceSize);

	if (ZSTD_isError(zresult)) {

		PyErr_Format(ZstdError, "cannot get frame parameters: %s", ZSTD_getErrorName(zresult));

		return NULL;

	}

	if (zresult) {

		PyErr_Format(ZstdError, "not enough data for frame parameters; need %zu bytes", zresult);

		return NULL;

	}

	result = PyObject_New(FrameParametersObject, &FrameParametersType);

	if (!result) {

		return NULL;

	}

	result->frameContentSize = params.frameContentSize;

	result->windowSize = params.windowSize;

	result->dictID = params.dictID;

	result->checksumFlag = params.checksumFlag ? 1 : 0;

	return result;

}

static void FrameParameters_dealloc(PyObject* self) {

	PyObject_Del(self);

}

static PyMemberDef FrameParameters_members[] = {

	{ "content_size", T_ULONGLONG,

	  offsetof(FrameParametersObject, frameContentSize), READONLY,

	  "frame content size" },

	{ "window_size", T_UINT,

	  offsetof(FrameParametersObject, windowSize), READONLY,

	  "window size" },

	{ "dict_id", T_UINT,

	  offsetof(FrameParametersObject, dictID), READONLY,

	  "dictionary ID" },

	{ "has_checksum", T_BOOL,

	  offsetof(FrameParametersObject, checksumFlag), READONLY,

	  "checksum flag" },

	{ NULL }

};

PyTypeObject FrameParametersType = {

	PyVarObject_HEAD_INIT(NULL, 0)

	"FrameParameters",          /* tp_name */

	sizeof(FrameParametersObject), /* tp_basicsize */

	0,                         /* tp_itemsize */

	(destructor)FrameParameters_dealloc, /* tp_dealloc */

	0,                         /* tp_print */

	0,                         /* tp_getattr */

	0,                         /* tp_setattr */

	0,                         /* tp_compare */

	0,                         /* tp_repr */

	0,                         /* tp_as_number */

	0,                         /* tp_as_sequence */

	0,                         /* tp_as_mapping */

	0,                         /* tp_hash  */

	0,                         /* tp_call */

	0,                         /* tp_str */

	0,                         /* tp_getattro */

	0,                         /* tp_setattro */

	0,                         /* tp_as_buffer */

	Py_TPFLAGS_DEFAULT,        /* tp_flags */

	FrameParameters__doc__,    /* tp_doc */

	0,                         /* tp_traverse */

	0,                         /* tp_clear */

	0,                         /* tp_richcompare */

	0,                         /* tp_weaklistoffset */

	0,                         /* tp_iter */

	0,                         /* tp_iternext */

	0,                         /* tp_methods */

	FrameParameters_members,   /* tp_members */

	0,                         /* tp_getset */

	0,                         /* tp_base */

	0,                         /* tp_dict */

	0,                         /* tp_descr_get */

	0,                         /* tp_descr_set */

	0,                         /* tp_dictoffset */

	0,                         /* tp_init */

	0,                         /* tp_alloc */

	0,                         /* tp_new */

};

void frameparams_module_init(PyObject* mod) {

	Py_TYPE(&FrameParametersType) = &PyType_Type;

	if (PyType_Ready(&FrameParametersType) < 0) {

		return;

	}

	PyModule_AddObject(mod, "FrameParameters", (PyObject*)&FrameParametersType);

}