#pragma once

#define PyObject_HEAD     PyObject    ob_base;
#define PyObject_VAR_HEAD PyVarObject ob_base;

typedef struct _object {
    Py_ssize_t ob_refcnt;
    Py_ssize_t ob_pypy_link;
    struct _typeobject *ob_type;
} PyObject;

typedef struct {
    PyObject ob_base;
	Py_ssize_t ob_size; /* Number of items in variable part */
} PyVarObject;

struct _typeobject;
typedef void (*freefunc)(void *);
typedef void (*destructor)(PyObject *);
typedef Py_ssize_t printfunc;
typedef PyObject *(*getattrfunc)(PyObject *, char *);
typedef PyObject *(*getattrofunc)(PyObject *, PyObject *);
typedef int (*setattrfunc)(PyObject *, char *, PyObject *);
typedef int (*setattrofunc)(PyObject *, PyObject *, PyObject *);
typedef int (*cmpfunc)(PyObject *, PyObject *);
typedef PyObject *(*reprfunc)(PyObject *);
typedef Py_hash_t (*hashfunc)(PyObject *);
typedef PyObject *(*richcmpfunc) (PyObject *, PyObject *, int);
typedef PyObject *(*getiterfunc) (PyObject *);
typedef PyObject *(*iternextfunc) (PyObject *);
typedef PyObject *(*descrgetfunc) (PyObject *, PyObject *, PyObject *);
typedef int (*descrsetfunc) (PyObject *, PyObject *, PyObject *);
typedef int (*initproc)(PyObject *, PyObject *, PyObject *);
typedef PyObject *(*newfunc)(struct _typeobject *, PyObject *, PyObject *);
typedef PyObject *(*allocfunc)(struct _typeobject *, Py_ssize_t);

typedef PyObject * (*unaryfunc)(PyObject *);
typedef PyObject * (*binaryfunc)(PyObject *, PyObject *);
typedef PyObject * (*ternaryfunc)(PyObject *, PyObject *, PyObject *);
typedef int (*inquiry)(PyObject *);
typedef Py_ssize_t (*lenfunc)(PyObject *);
typedef PyObject *(*ssizeargfunc)(PyObject *, Py_ssize_t);
typedef PyObject *(*ssizessizeargfunc)(PyObject *, Py_ssize_t, Py_ssize_t);
typedef int(*ssizeobjargproc)(PyObject *, Py_ssize_t, PyObject *);
typedef int(*ssizessizeobjargproc)(PyObject *, Py_ssize_t, Py_ssize_t, PyObject *);
typedef int(*objobjargproc)(PyObject *, PyObject *, PyObject *);


/* Py3k buffer interface, adapted for PyPy */
/* Changing this constant changes the ABI */
#define PyBUF_MAX_NDIM 36
typedef struct bufferinfo {
    void *buf;
    PyObject *obj;        /* owned reference */
    Py_ssize_t len;
    Py_ssize_t itemsize;  /* This is Py_ssize_t so it can be
                             pointed to by strides in simple case.*/
    int readonly;
    int ndim;
    char *format;
    Py_ssize_t *shape;
    Py_ssize_t *strides;
    Py_ssize_t *suboffsets; /* alway NULL for app-level objects*/
    void *internal; /* always NULL for app-level objects */
    /* PyPy extensions */
    int flags;
    Py_ssize_t _strides[PyBUF_MAX_NDIM];
    Py_ssize_t _shape[PyBUF_MAX_NDIM];
    /* static store for shape and strides of
       mono-dimensional buffers. */
    /* Py_ssize_t smalltable[2]; */
} Py_buffer;

typedef int (*getbufferproc)(PyObject *, Py_buffer *, int);
typedef void (*releasebufferproc)(PyObject *, Py_buffer *);
/* end Py3k buffer interface */
typedef PyObject *(*vectorcallfunc)(PyObject *callable, PyObject *const *args,
                                    size_t nargsf, PyObject *kwnames);

typedef int (*objobjproc)(PyObject *, PyObject *);
typedef int (*visitproc)(PyObject *, void *);
typedef int (*traverseproc)(PyObject *, visitproc, void *);


typedef struct {
    /* Number implementations must check *both*
       arguments for proper type and implement the necessary conversions
       in the slot functions themselves. */

    binaryfunc nb_add;
    binaryfunc nb_subtract;
    binaryfunc nb_multiply;
    binaryfunc nb_remainder;
    binaryfunc nb_divmod;
    ternaryfunc nb_power;
    unaryfunc nb_negative;
    unaryfunc nb_positive;
    unaryfunc nb_absolute;
    inquiry nb_bool;
    unaryfunc nb_invert;
    binaryfunc nb_lshift;
    binaryfunc nb_rshift;
    binaryfunc nb_and;
    binaryfunc nb_xor;
    binaryfunc nb_or;
    unaryfunc nb_int;
    void *nb_reserved;  /* the slot formerly known as nb_long */
    unaryfunc nb_float;

    binaryfunc nb_inplace_add;
    binaryfunc nb_inplace_subtract;
    binaryfunc nb_inplace_multiply;
    binaryfunc nb_inplace_remainder;
    ternaryfunc nb_inplace_power;
    binaryfunc nb_inplace_lshift;
    binaryfunc nb_inplace_rshift;
    binaryfunc nb_inplace_and;
    binaryfunc nb_inplace_xor;
    binaryfunc nb_inplace_or;

    binaryfunc nb_floor_divide;
    binaryfunc nb_true_divide;
    binaryfunc nb_inplace_floor_divide;
    binaryfunc nb_inplace_true_divide;

    unaryfunc nb_index;

    binaryfunc nb_matrix_multiply;
    binaryfunc nb_inplace_matrix_multiply;
} PyNumberMethods;

typedef struct {
    lenfunc sq_length;
    binaryfunc sq_concat;
    ssizeargfunc sq_repeat;
    ssizeargfunc sq_item;
    void *was_sq_slice;
    ssizeobjargproc sq_ass_item;
    void *was_sq_ass_slice;
    objobjproc sq_contains;

    binaryfunc sq_inplace_concat;
    ssizeargfunc sq_inplace_repeat;
} PySequenceMethods;

typedef struct {
    lenfunc mp_length;
    binaryfunc mp_subscript;
    objobjargproc mp_ass_subscript;
} PyMappingMethods;

/* Result of calling PyIter_Send */
typedef enum {
    PYGEN_RETURN = 0,
    PYGEN_ERROR = -1,
    PYGEN_NEXT = 1,
} PySendResult;

typedef int (*sendfunc)(PyObject *iter, PyObject *value, PyObject **result);

typedef struct {
    unaryfunc am_await;
    unaryfunc am_aiter;
    unaryfunc am_anext;
    sendfunc am_send;
} PyAsyncMethods;

typedef struct {
     getbufferproc bf_getbuffer;
     releasebufferproc bf_releasebuffer;
} PyBufferProcs;

/* from methodobject.h (the `PyObject **` are `PyObject *const *` in CPython) */
typedef PyObject *(*PyCFunction)(PyObject *, PyObject *);
typedef PyObject *(*_PyCFunctionFast) (PyObject *, PyObject **, Py_ssize_t);
typedef PyObject *(*PyCFunctionWithKeywords)(PyObject *, PyObject *,
                                             PyObject *);
typedef PyObject *(*_PyCFunctionFastWithKeywords) (PyObject *,
                                                   PyObject **, Py_ssize_t,
                                                   PyObject *);

typedef PyObject *(*PyNoArgsFunction)(PyObject *);

struct PyMethodDef {
    const char  *ml_name;   /* The name of the built-in function/method */
    PyCFunction  ml_meth;   /* The C function that implements it */
    int          ml_flags;  /* Combination of METH_xxx flags, which mostly
                               describe the args expected by the C func */
    const char  *ml_doc;    /* The __doc__ attribute, or NULL */
};
typedef struct PyMethodDef PyMethodDef;

typedef struct {
    PyObject_HEAD
    PyMethodDef *m_ml; /* Description of the C function to call */
    PyObject    *m_self; /* Passed as 'self' arg to the C func, can be NULL */
    PyObject    *m_module; /* The __module__ attribute, can be anything */
    PyObject    *m_weakreflist; /* List of weak references */
} PyCFunctionObject;

/* from structmember.h */
typedef struct PyMemberDef {
    /* Current version, use this */
    const char *name;
    int type;
    Py_ssize_t offset;
    int flags;
    const char *doc;
} PyMemberDef;


typedef struct _typeobject {
    PyObject_VAR_HEAD
    const char *tp_name; /* For printing, in format "<module>.<name>" */
    Py_ssize_t tp_basicsize, tp_itemsize; /* For allocation */

    /* Methods to implement standard operations */

    destructor tp_dealloc;
    Py_ssize_t tp_vectorcall_offset;
    getattrfunc tp_getattr;
    setattrfunc tp_setattr;
    PyAsyncMethods *tp_as_async; /* formerly known as tp_compare (Python 2)
                                    or tp_reserved (Python 3) */
    reprfunc tp_repr;

    /* Method suites for standard classes */

    PyNumberMethods *tp_as_number;
    PySequenceMethods *tp_as_sequence;
    PyMappingMethods *tp_as_mapping;

    /* More standard operations (here for binary compatibility) */

    hashfunc tp_hash;
    ternaryfunc tp_call;
    reprfunc tp_str;
    getattrofunc tp_getattro;
    setattrofunc tp_setattro;

    /* Functions to access object as input/output buffer */
    PyBufferProcs *tp_as_buffer;

    /* Flags to define presence of optional/expanded features */
    unsigned long tp_flags;

    const char *tp_doc; /* Documentation string */

    /* Assigned meaning in release 2.0 */
    /* call function for all accessible objects */
    traverseproc tp_traverse;

    /* delete references to contained objects */
    inquiry tp_clear;

    /* Assigned meaning in release 2.1 */
    /* rich comparisons */
    richcmpfunc tp_richcompare;

    /* weak reference enabler */
    Py_ssize_t tp_weaklistoffset;

    /* Iterators */
    getiterfunc tp_iter;
    iternextfunc tp_iternext;

    /* Attribute descriptor and subclassing stuff */
    struct PyMethodDef *tp_methods;
    struct PyMemberDef *tp_members;
    struct PyGetSetDef *tp_getset;
    struct _typeobject *tp_base;
    PyObject *tp_dict;
    descrgetfunc tp_descr_get;
    descrsetfunc tp_descr_set;
    Py_ssize_t tp_dictoffset;
    initproc tp_init;
    allocfunc tp_alloc;
    newfunc tp_new;
    freefunc tp_free; /* Low-level free-memory routine */
    inquiry tp_is_gc; /* For PyObject_IS_GC */
    PyObject *tp_bases;
    PyObject *tp_mro; /* method resolution order */
    PyObject *tp_cache;
    PyObject *tp_subclasses;
    PyObject *tp_weaklist;
    destructor tp_del;

    /* Type attribute cache version tag. Added in version 2.6 */
    unsigned int tp_version_tag;

    destructor tp_finalize;
    vectorcallfunc tp_vectorcall;
} PyTypeObject;

typedef struct{
    int slot;    /* slot id, see below */
    void *pfunc; /* function pointer */
} PyType_Slot;

typedef struct{
    const char* name;
    int basicsize;
    int itemsize;
    unsigned int flags;
    PyType_Slot *slots; /* terminated by slot==0. */
} PyType_Spec;

typedef struct _heaptypeobject {
    PyTypeObject ht_type;
    PyAsyncMethods as_async;
    PyNumberMethods as_number;
    PyMappingMethods as_mapping;
    PySequenceMethods as_sequence;
    PyBufferProcs as_buffer;
    PyObject *ht_name, *ht_slots, *ht_qualname;
    PyObject *ht_module;
} PyHeapTypeObject;

/* access macro to the members which are floating "behind" the object */
#define PyHeapType_GET_MEMBERS(etype) \
    ((PyMemberDef *)(((char *)etype) + Py_TYPE(etype)->tp_basicsize))

typedef struct {
    PyCFunctionObject func;
    PyTypeObject *mm_class; /* Class that defines this method */
} PyCMethodObject;

/* CPython uses PyObject *const * for the third arg, but we drop the const */
typedef PyObject *(*PyCMethod)(PyObject *, PyTypeObject *, PyObject **,
                               size_t, PyObject *);

