/* -*- Mode: C; c-basic-offset: 4 -*-
 * vim: tabstop=4 shiftwidth=4 expandtab
 *
 * Copyright (C) 2011 John (J5) Palmieri <johnp@redhat.com>
 * Copyright (C) 2013 Simon Feltman <sfeltman@gnome.org>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
 */

#ifndef __PYGI_CACHE_H__
#define __PYGI_CACHE_H__

#include <Python.h>
#include <girepository.h>
#include <girffi.h>

#include "pygi-invoke-state-struct.h"

G_BEGIN_DECLS

typedef struct _PyGIArgCache PyGIArgCache;
typedef struct _PyGICallableCache PyGICallableCache;
typedef struct _PyGIFunctionCache PyGIFunctionCache;
typedef struct _PyGIVFuncCache PyGIVFuncCache;

typedef PyGIFunctionCache PyGICCallbackCache;
typedef PyGIFunctionCache PyGIConstructorCache;
typedef PyGIFunctionCache PyGIFunctionWithInstanceCache;
typedef PyGIFunctionCache PyGIMethodCache;
typedef PyGICallableCache PyGIClosureCache;

typedef gboolean (*PyGIMarshalFromPyFunc) (PyGIInvokeState   *state,
                                           PyGICallableCache *callable_cache,
                                           PyGIArgCache      *arg_cache,
                                           PyObject          *py_arg,
                                           GIArgument        *arg,
                                           gpointer          *cleanup_data);

typedef PyObject *(*PyGIMarshalToPyFunc) (PyGIInvokeState   *state,
                                          PyGICallableCache *callable_cache,
                                          PyGIArgCache      *arg_cache,
                                          GIArgument        *arg);

typedef void (*PyGIMarshalCleanupFunc) (PyGIInvokeState *state,
                                        PyGIArgCache    *arg_cache,
                                        PyObject        *py_arg, /* always NULL for to_py cleanup */
                                        gpointer         data,
                                        gboolean         was_processed);

/* Argument meta types denote how we process the argument:
 *  - PYGI_META_ARG_TYPE_PARENT - parents may or may not have children
 *    but are always processed via the normal marshaller for their
 *    actual GI type.  If they have children the marshaller will
 *    also handle marshalling the children.
 *  - PYGI_META_ARG_TYPE_CHILD - Children without python argument are
 *    ignored by the marshallers and handled directly by their parents
 *    marshaller.
 *  - Children with pyargs (PYGI_META_ARG_TYPE_CHILD_WITH_PYARG) are processed
 *    the same as other child args but also have an index into the 
 *    python parameters passed to the invoker
 */
typedef enum {
    PYGI_META_ARG_TYPE_PARENT,
    PYGI_META_ARG_TYPE_CHILD,
    PYGI_META_ARG_TYPE_CHILD_WITH_PYARG,
    PYGI_META_ARG_TYPE_CLOSURE,
} PyGIMetaArgType;

/*
 * Argument direction types denotes how we marshal,
 * e.g. to Python or from Python or both.
 */
typedef enum {
    PYGI_DIRECTION_TO_PYTHON     = 1 << 0,
    PYGI_DIRECTION_FROM_PYTHON   = 1 << 1,
    PYGI_DIRECTION_BIDIRECTIONAL = PYGI_DIRECTION_TO_PYTHON | PYGI_DIRECTION_FROM_PYTHON
 } PyGIDirection;

/*
 * In PyGI IN and OUT arguments mean different things depending on the context
 * of the callable, e.g. is it a callback that is being called from C or a
 * function that is being called from Python.
 */
typedef enum {
    PYGI_CALLING_CONTEXT_IS_FROM_C,
    PYGI_CALLING_CONTEXT_IS_FROM_PY
} PyGICallingContext;


struct _PyGIArgCache
{
    const gchar *arg_name;

    PyGIMetaArgType meta_type;
    gboolean is_pointer;
    gboolean is_caller_allocates;
    gboolean is_skipped;
    gboolean allow_none;
    gboolean has_default;

    PyGIDirection direction;
    GITransfer transfer;
    GITypeTag type_tag;
    GITypeInfo *type_info;

    PyGIMarshalFromPyFunc from_py_marshaller;
    PyGIMarshalToPyFunc to_py_marshaller;

    PyGIMarshalCleanupFunc from_py_cleanup;
    PyGIMarshalCleanupFunc to_py_cleanup;

    GDestroyNotify destroy_notify;

    gssize c_arg_index;
    gssize py_arg_index;

    /* Set when has_default is true. */
    GIArgument default_value;
};

typedef struct _PyGISequenceCache
{
    PyGIArgCache arg_cache;
    PyGIArgCache *item_cache;
} PyGISequenceCache;

typedef struct _PyGIArgGArray
{
    PyGISequenceCache seq_cache;
    gssize fixed_size;
    gssize len_arg_index;
    gboolean is_zero_terminated;
    gsize item_size;
    GIArrayType array_type;
} PyGIArgGArray;

typedef struct _PyGIInterfaceCache
{
    PyGIArgCache arg_cache;
    gboolean is_foreign;
    GType g_type;
    PyObject *py_type;
    GIInterfaceInfo *interface_info;
    gchar *type_name;
} PyGIInterfaceCache;

struct _PyGICallableCache
{
    const gchar *name;
    const gchar *container_name;
    const gchar *namespace;

    PyGICallingContext calling_context;

    PyGIArgCache *return_cache;
    GPtrArray *args_cache;
    GSList *to_py_args;
    GSList *arg_name_list; /* for keyword arg matching */
    GHashTable *arg_name_hash;
    gboolean throws;

    /* Index of user_data arg passed to a callable. */
    gssize user_data_index;

    /* Index of user_data arg that can eat variable args passed to a callable. */
    gssize user_data_varargs_index;

    /* Number of args already added */
    gssize args_offset;

    /* Number of out args passed to g_function_info_invoke.
     * This is used for the length of PyGIInvokeState.out_values */
    gssize n_to_py_args;

    /* If the callable return value gets used */
    gboolean has_return;

    /* The type used for returning multiple values or NULL */
    PyTypeObject* resulttuple_type;

    /* Number of out args for g_function_info_invoke that will be skipped
     * when marshaling to Python due to them being implicitly available
     * (list/array length).
     */
    gssize n_to_py_child_args;

    /* Number of Python arguments expected for invoking the gi function. */
    gssize n_py_args;

    /* Minimum number of args required to call the callable from Python.
     * This count does not include args with defaults. */
    gssize n_py_required_args;

    void     (*deinit)              (PyGICallableCache *callable_cache);

    gboolean (*generate_args_cache) (PyGICallableCache *callable_cache,
                                     GICallableInfo *callable_info);
};

struct _PyGIFunctionCache {
    PyGICallableCache callable_cache;

    /* An invoker with ffi_cif already setup */
    GIFunctionInvoker invoker;

    PyObject *(*invoke) (PyGIFunctionCache *function_cache,
                         PyGIInvokeState *state,
                         PyObject *py_args,
                         PyObject *py_kwargs);
} ;

struct _PyGIVFuncCache {
    PyGIFunctionWithInstanceCache fwi_cache;

    GIBaseInfo *info;
};


gboolean
pygi_arg_base_setup      (PyGIArgCache *arg_cache,
                          GITypeInfo   *type_info,
                          GIArgInfo    *arg_info,  /* may be NULL for return arguments */
                          GITransfer    transfer,
                          PyGIDirection direction);

gboolean
pygi_arg_interface_setup (PyGIInterfaceCache *iface_cache,
                          GITypeInfo         *type_info,
                          GIArgInfo          *arg_info,  /* may be NULL for return arguments */
                          GITransfer          transfer,
                          PyGIDirection       direction,
                          GIInterfaceInfo    *iface_info);

gboolean
pygi_arg_sequence_setup  (PyGISequenceCache  *sc,
                          GITypeInfo         *type_info,
                          GIArgInfo          *arg_info,    /* may be NULL for return arguments */
                          GITransfer          transfer,
                          PyGIDirection       direction,
                          PyGICallableCache  *callable_cache);

PyGIArgCache *
pygi_arg_interface_new_from_info (GITypeInfo         *type_info,
                                  GIArgInfo          *arg_info,     /* may be NULL for return arguments */
                                  GITransfer          transfer,
                                  PyGIDirection       direction,
                                  GIInterfaceInfo    *iface_info);

PyGIArgCache *
pygi_arg_cache_alloc     (void);

PyGIArgCache *
pygi_arg_cache_new       (GITypeInfo *type_info,
                          GIArgInfo *arg_info,
                          GITransfer transfer,
                          PyGIDirection direction,
                          PyGICallableCache *callable_cache,
                          /* will be removed */
                          gssize c_arg_index,
                          gssize py_arg_index);

void
pygi_arg_cache_free      (PyGIArgCache *cache);

void
pygi_callable_cache_free    (PyGICallableCache *cache);

gchar *
pygi_callable_cache_get_full_name (PyGICallableCache *cache);

PyGIFunctionCache *
pygi_function_cache_new     (GICallableInfo *info);

PyObject *
pygi_function_cache_invoke  (PyGIFunctionCache *function_cache,
                             PyObject *py_args,
                             PyObject *py_kwargs);

PyGIFunctionCache *
pygi_ccallback_cache_new    (GICallableInfo *info,
                             GCallback function_ptr);

PyObject *
pygi_ccallback_cache_invoke (PyGIFunctionCache *function_cache,
                             PyObject *py_args,
                             PyObject *py_kwargs,
                             gpointer user_data);

PyGIFunctionCache *
pygi_constructor_cache_new  (GICallableInfo *info);

PyGIFunctionCache *
pygi_method_cache_new       (GICallableInfo *info);

PyGIFunctionCache *
pygi_vfunc_cache_new        (GICallableInfo *info);

PyGIClosureCache *
pygi_closure_cache_new      (GICallableInfo *info);

#define _pygi_callable_cache_args_len(cache) ((cache)->args_cache)->len

inline static PyGIArgCache *
_pygi_callable_cache_get_arg (PyGICallableCache *cache, guint index) {
    return (PyGIArgCache *) g_ptr_array_index (cache->args_cache, index);
}

inline static void
_pygi_callable_cache_set_arg (PyGICallableCache *cache, guint index, PyGIArgCache *arg_cache) {
    cache->args_cache->pdata[index] = arg_cache;
}

G_END_DECLS

#endif /* __PYGI_CACHE_H__ */
