#include "input.h"

#define IO_MAXFREELIST 1024

static InputObject *io_free_list[IO_MAXFREELIST];
static int io_numfree = 0;

void
InputObject_list_fill(void)
{
    InputObject *io;
    while (io_numfree < IO_MAXFREELIST) {
        io = PyObject_NEW(InputObject, &InputObjectType);
        io_free_list[io_numfree++] = io;
    }
}

void
InputObject_list_clear(void)
{
    InputObject *op;

    while (io_numfree) {
        op = io_free_list[--io_numfree];
        PyObject_DEL(op);
    }
}

static InputObject*
alloc_InputObject(void)
{
    InputObject *io;
    if (io_numfree) {
        io = io_free_list[--io_numfree];
        _Py_NewReference((PyObject *)io);
        //DEBUG("use pooled StringIOObject %p", io);
    }else{
        io = PyObject_NEW(InputObject, &InputObjectType);
        //DEBUG("alloc StringIOObject %p", io);
    }
    return io;
}

static void
dealloc_InputObject(InputObject *io)
{
    if(io->buffer){
        free_buffer(io->buffer);
        io->buffer = NULL;
    }
    if (io_numfree < IO_MAXFREELIST){
        //DEBUG("back to StringIOObject pool %p\n", io);
        io_free_list[io_numfree++] = io;
    }else{
        PyObject_DEL(io);
    }
}

int
Check_InputObject(PyObject *obj)
{
    if (obj->ob_type != &InputObjectType){
        return 0;
    }
    return 1;
}

PyObject*
InputObject_New(buffer_t *buf)
{
    InputObject *io;
    io = alloc_InputObject();
    if(io == NULL){
        return NULL;
    }
    io->buffer = buf;
    io->pos = 0;
    return (PyObject *)io;
}

void
InputObject_dealloc(InputObject *self)
{
    if(self->buffer){
        free_buffer(self->buffer);
        self->buffer = NULL;
    }
    dealloc_InputObject(self);
}

static int
is_close(InputObject *self)
{
    if(self->buffer == NULL){
        PyErr_SetString(PyExc_IOError, "closed");
        return 1;
    }
    return 0;
}

static PyObject*
InputObject_read(InputObject *self, PyObject *args)
{
    Py_ssize_t n = -1, l = 0;
    PyObject *s;

    if (!PyArg_ParseTuple(args, "|n:read", &n)){
        return NULL;
    }
   
    if(is_close(self)){
        return NULL;
    }
    l = self->buffer->len - self->pos;
    if (n < 0 || n > l) {
        n = l;
        if (n < 0) {
            n = 0;
        }
    }
    s = PyBytes_FromStringAndSize(self->buffer->buf + self->pos, n);
    if(!s){
        return NULL;
    }
    self->pos += n;
    return s;
}

static int
inner_readline(InputObject *self, char **output)
{
    char *start, *end;
    Py_ssize_t l = 0;

    start = self->buffer->buf + self->pos;
    end = self->buffer->buf + self->buffer->len;

    while(start < end){
        if(*start == '\n'){
            break;
        }
        start++;
        l++;
    }

    if (start < end){
        start++;
        l++;
    }
    //seek current pos
    *output = self->buffer->buf + self->pos;
    self->pos += l;
    return (int)l;
}

static PyObject* 
InputObject_readline(InputObject *self, PyObject *args)
{
    int len, size = -1, delta;
    char *output;

    if(args){
        if (!PyArg_ParseTuple(args, "|i:readline", &size)){
            return NULL;
        }
    }
    if(is_close(self)){
        return NULL;
    }

    if((len = inner_readline(self, &output)) < 0){
        return NULL;
    }
    if (size >= 0 && size < len) {
        delta = len - size;
        len -= delta;
        //back
        self->pos -= delta;
    }
    return PyBytes_FromStringAndSize(output, len);
}

static PyObject* 
InputObject_readlines(InputObject *self, PyObject *args)
{
    int len;
    char *output;
    PyObject *result, *new_line;
    int sizehint = 0, length = 0;
    
    if (!PyArg_ParseTuple(args, "|i:readlines", &sizehint)){
        return NULL;
    }
    if(is_close(self)){
        return NULL;
    }

    result = PyList_New(0);
    if (!result){
        return NULL;
    }

    while (1){
        if((len = inner_readline(self, &output)) < 0){
            goto err;
        }
        if (len == 0){
            break;
        }
        new_line = PyBytes_FromStringAndSize(output, len);
        if (!new_line){
            goto err;
        }
        if (PyList_Append(result, new_line) == -1) {
            Py_DECREF(new_line);
            goto err;
        }
        Py_DECREF(new_line);
        length += len;
        if (sizehint > 0 && length >= sizehint){
            break;
        }
    }
    return result;
 err:
    Py_DECREF(result);
    return NULL;
}

static PyObject *
InputObject_iternext(InputObject *self)
{
    PyObject *next;
    if(is_close(self)){
        return NULL;
    }
    next = InputObject_readline(self, NULL);
    if (!next){
        return NULL;
    }
    if (!PyBytes_GET_SIZE(next)) {
        Py_DECREF(next);
        PyErr_SetNone(PyExc_StopIteration);
        return NULL;
    }
    return next;
}

static struct PyMethodDef InputObject_methods[] = {
  {"read",    (PyCFunction)InputObject_read,     METH_VARARGS, ""},
  {"readline",    (PyCFunction)InputObject_readline, METH_VARARGS, ""},
  {"readlines",    (PyCFunction)InputObject_readlines,METH_VARARGS, ""},
  {NULL,    NULL}
};

static PyGetSetDef file_getsetlist[] = {
    {0},
};


PyTypeObject InputObjectType = {
#ifdef PY3
    PyVarObject_HEAD_INIT(NULL, 0)
#else
    PyObject_HEAD_INIT(NULL)
    0,                    /* ob_size */
#endif
    "meinheld.input",             /*tp_name*/
    sizeof(InputObject), /*tp_basicsize*/
    0,                         /*tp_itemsize*/
    (destructor)InputObject_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*/
    "Input",                 /* tp_doc */
    0,                       /* tp_traverse */
    0,                       /* tp_clear */
    0,                       /* tp_richcompare */
    0,                       /* tp_weaklistoffset */
    PyObject_SelfIter,        /*tp_iter */
    (iternextfunc)InputObject_iternext,        /* tp_iternext */
    InputObject_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 */
    0,                      /* tp_init */
    0,                         /* tp_alloc */
    0,                           /* tp_new */
};