/*-
 * Copyright (c) 2006 Allan Saddi <allan@saddi.com>
 * All rights reserved.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 THE AUTHOR OR CONTRIBUTORS 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.
 *
 * $Id$
 */

#include <Python.h>

#include "wsgi-int.h"


static void FileWrapper_dealloc ( FileWrapper *self )
{
    PyObject *tmp;

    tmp = ( PyObject * ) self->filelike;
    self->filelike = NULL;
    Py_XDECREF ( tmp );

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


static PyObject *FileWrapper_new ( PyTypeObject *type, PyObject *args, PyObject *kwds )
{
    FileWrapper *self;

    self = ( FileWrapper * ) type->tp_alloc ( type, 0 );
    if ( self != NULL )
    {
        self->filelike = NULL;
    }

    return ( PyObject * ) self;
}


static int FileWrapper_init ( FileWrapper *self, PyObject *args, PyObject *kwds )
{
    PyObject *filelike;
    int blocksize = 4096;

    if ( !PyArg_ParseTuple ( args, "O|i", &filelike, &blocksize ) )
        return -1;

    Py_INCREF ( filelike );
    self->filelike = filelike;
    self->blocksize = blocksize;

    return 0;
}


/* __iter__() implementation. Simply returns self. */
static PyObject *FileWrapper_iter ( FileWrapper *self )
{
    Py_INCREF ( self );
    return ( PyObject * ) self;
}


/* next() implementation for iteration protocol support. Calls read()
   on the file-like and emits strings according to the blocksize.
   This is only used for compatibility (the normal path uses
   wsgiSendFile()). */
static PyObject *FileWrapper_iternext ( FileWrapper *self )
{
    PyObject *pRead, *args, *data;
    int len;

    if ( ( pRead = PyObject_GetAttrString ( self->filelike, "read" ) ) == NULL )
        return NULL;

    if ( ( args = Py_BuildValue ( "(i)", self->blocksize ) ) == NULL )
    {
        Py_DECREF ( pRead );
        return NULL;
    }

    data = PyObject_CallObject ( pRead, args );
    Py_DECREF ( args );
    Py_DECREF ( pRead );
    if ( data == NULL )
        return NULL;

    len = PyBytes_Size ( data );
    if ( PyErr_Occurred() )
    {
        Py_DECREF ( data );
        return NULL;
    }

    if ( len == 0 )
    {
        Py_DECREF ( data );
        PyErr_Clear();
        return NULL;
    }

    return data;
}


/* Calls the file-like's close() method, if present. */
static PyObject *FileWrapper_close ( FileWrapper *self, PyObject *args )
{
    PyObject *pClose, *args2, *result;

    if ( PyObject_HasAttrString ( self->filelike, "close" ) )
    {
        if ( ( pClose = PyObject_GetAttrString ( self->filelike, "close" ) ) == NULL )
            return NULL;

        if ( ( args2 = PyTuple_New ( 0 ) ) == NULL )
        {
            Py_DECREF ( pClose );
            return NULL;
        }

        result = PyObject_CallObject ( pClose, args2 );
        Py_DECREF ( args2 );
        Py_DECREF ( pClose );
        if ( result == NULL )
            return NULL;
    }

    Py_INCREF ( Py_None );
    return Py_None;
}


static PyMethodDef FileWrapper_methods[] =
{
    { "close", ( PyCFunction ) FileWrapper_close, METH_VARARGS,
        "Calls the file-like object's close method" },
    { NULL }
};


#if PY_MAJOR_VERSION >=3
#  define Py_TPFLAGS_HAVE_ITER 0
#endif


PyTypeObject FileWrapper_Type =
{
    PyVarObject_HEAD_INIT(NULL, 0)
    "lsapi_wsgi.FileWrapper",    /*tp_name*/
    sizeof ( FileWrapper ),    /*tp_basicsize*/
    0,                         /*tp_itemsize*/
    ( destructor ) FileWrapper_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 | Py_TPFLAGS_HAVE_ITER, /*tp_flags*/
    "wsgi.file_wrapper implementation", /* tp_doc */
    0,                     /* tp_traverse */
    0,                     /* tp_clear */
    0,                     /* tp_richcompare */
    0,                     /* tp_weaklistoffset */
    ( getiterfunc ) FileWrapper_iter, /* tp_iter */
    ( iternextfunc ) FileWrapper_iternext, /* tp_iternext */
    FileWrapper_methods,       /* tp_methods */
    0,                         /* tp_members */
    0,                         /* tp_getset */
    0,                         /* tp_base */
    0,                         /* tp_dict */
    0,                         /* tp_descr_get */
    0,                         /* tp_descr_set */
    0,                         /* tp_dictoffset */
    ( initproc ) FileWrapper_init, /* tp_init */
    0,                         /* tp_alloc */
    FileWrapper_new,           /* tp_new */
};