/* SPDX-FileCopyrightText: 2023 Blender Authors
 *
 * SPDX-License-Identifier: GPL-2.0-or-later */

/** \file
 * \ingroup pythonintern
 *
 * This file adds some helpers related to ID/Main handling, that cannot fit well in RNA itself.
 */

#include <Python.h>
#include <cstddef>

#include "MEM_guardedalloc.h"

#include "BLI_bitmap.h"

#include "BKE_bpath.hh"
#include "BKE_global.hh"
#include "BKE_lib_id.hh"
#include "BKE_lib_query.hh"
#include "BKE_main.hh"

#include "DNA_ID.h"
/* Those following are only to support hack of not listing some internal
 * 'backward' pointers in generated user_map. */

#include "WM_api.hh"
#include "WM_types.hh"

#include "bpy_rna_id_collection.hh"

#include "../generic/py_capi_rna.hh"
#include "../generic/py_capi_utils.hh"
#include "../generic/python_compat.hh" /* IWYU pragma: keep. */

#include "RNA_enum_types.hh"
#include "RNA_prototypes.hh"

#include "bpy_rna.hh"

static Main *pyrna_bmain_FromPyObject(PyObject *obj)
{
  if (!BPy_StructRNA_Check(obj)) {
    PyErr_Format(PyExc_TypeError,
                 "Expected a StructRNA of type BlendData, not %.200s",
                 Py_TYPE(obj)->tp_name);
    return nullptr;
  }
  BPy_StructRNA *pyrna = reinterpret_cast<BPy_StructRNA *>(obj);
  PYRNA_STRUCT_CHECK_OBJ(pyrna);
  if (!(pyrna->ptr && pyrna->ptr->type == &RNA_BlendData && pyrna->ptr->data)) {
    PyErr_Format(PyExc_TypeError,
                 "Expected a StructRNA of type BlendData, not %.200s",
                 Py_TYPE(pyrna)->tp_name);
    return nullptr;
  }
  return static_cast<Main *>(pyrna->ptr->data);
}

struct IDUserMapData {
  /** We loop over data-blocks that this ID points to (do build a reverse lookup table) */
  PyObject *py_id_curr;
  ID *id_curr;

  /** Filter the values we add into the set. */
  BLI_bitmap *types_bitmap;

  /** Set to fill in as we iterate. */
  PyObject *user_map;
  /** true when we're only mapping a subset of all the ID's (subset arg is passed). */
  bool is_subset;
};

static int id_code_as_index(const short idcode)
{
  return int(*((ushort *)&idcode));
}

static bool id_check_type(const ID *id, const BLI_bitmap *types_bitmap)
{
  return BLI_BITMAP_TEST_BOOL(types_bitmap, id_code_as_index(GS(id->name)));
}

static int foreach_libblock_id_user_map_callback(LibraryIDLinkCallbackData *cb_data)
{
  ID **id_p = cb_data->id_pointer;

  if (*id_p) {
    IDUserMapData *data = static_cast<IDUserMapData *>(cb_data->user_data);
    const LibraryForeachIDCallbackFlag cb_flag = cb_data->cb_flag;

    if (data->types_bitmap) {
      if (!id_check_type(*id_p, data->types_bitmap)) {
        return IDWALK_RET_NOP;
      }
    }

    if (cb_flag & IDWALK_CB_LOOPBACK) {
      /* We skip loop-back pointers like Key.from here,
       * since it's some internal pointer which is not relevant info for py/API level. */
      return IDWALK_RET_NOP;
    }

    if (cb_flag & (IDWALK_CB_EMBEDDED | IDWALK_CB_EMBEDDED_NOT_OWNING)) {
      /* We skip private pointers themselves, like root node trees, we'll 'link' their own ID
       * pointers to their 'ID owner' instead. */
      return IDWALK_RET_NOP;
    }

    PyObject *key = pyrna_id_CreatePyObject(*id_p);

    PyObject *set;
    if ((set = PyDict_GetItem(data->user_map, key)) == nullptr) {
      /* limit to key's added already */
      if (data->is_subset) {
        return IDWALK_RET_NOP;
      }

      set = PySet_New(nullptr);
      PyDict_SetItem(data->user_map, key, set);
      Py_DECREF(set);
    }
    Py_DECREF(key);

    if (data->py_id_curr == nullptr) {
      data->py_id_curr = pyrna_id_CreatePyObject(data->id_curr);
    }

    PySet_Add(set, data->py_id_curr);
  }

  return IDWALK_RET_NOP;
}

PyDoc_STRVAR(
    /* Wrap. */
    bpy_user_map_doc,
    ".. method:: user_map(subset, key_types, value_types)\n"
    "\n"
    "   Returns a mapping of all ID data-blocks in current ``bpy.data`` to a set of all "
    "data-blocks using them.\n"
    "\n"
    "   For list of valid set members for key_types & value_types, see: "
    ":class:`bpy.types.KeyingSetPath.id_type`.\n"
    "\n"
    "   :arg subset: When passed, only these data-blocks and their users will be "
    "included as keys/values in the map.\n"
    "   :type subset: Sequence[:class:`bpy.types.ID`]\n"
    "   :arg key_types: Filter the keys mapped by ID types.\n"
    "   :type key_types: set[str]\n"
    "   :arg value_types: Filter the values in the set by ID types.\n"
    "   :type value_types: set[str]\n"
    "   :return: dictionary that maps data-blocks ID's to their users.\n"
    "   :rtype: dict[:class:`bpy.types.ID`, set[:class:`bpy.types.ID`]]\n");
static PyObject *bpy_user_map(PyObject *self, PyObject *args, PyObject *kwds)
{
  Main *bmain = pyrna_bmain_FromPyObject(self);
  if (!bmain) {
    return nullptr;
  }

  ListBase *lb;
  ID *id;

  PyObject *subset = nullptr;

  PyObject *key_types = nullptr;
  PyObject *val_types = nullptr;
  BLI_bitmap *key_types_bitmap = nullptr;
  BLI_bitmap *val_types_bitmap = nullptr;

  PyObject *ret = nullptr;

  IDUserMapData data_cb = {nullptr};

  static const char *_keywords[] = {"subset", "key_types", "value_types", nullptr};
  static _PyArg_Parser _parser = {
      PY_ARG_PARSER_HEAD_COMPAT()
      "|$" /* Optional keyword only arguments. */
      "O"  /* `subset` */
      "O!" /* `key_types` */
      "O!" /* `value_types` */
      ":user_map",
      _keywords,
      nullptr,
  };
  if (!_PyArg_ParseTupleAndKeywordsFast(
          args, kwds, &_parser, &subset, &PySet_Type, &key_types, &PySet_Type, &val_types))
  {
    return nullptr;
  }

  if (key_types) {
    key_types_bitmap = pyrna_enum_bitmap_from_set(
        rna_enum_id_type_items, key_types, sizeof(short), true, USHRT_MAX, "key types");
    if (key_types_bitmap == nullptr) {
      goto error;
    }
  }

  if (val_types) {
    val_types_bitmap = pyrna_enum_bitmap_from_set(
        rna_enum_id_type_items, val_types, sizeof(short), true, USHRT_MAX, "value types");
    if (val_types_bitmap == nullptr) {
      goto error;
    }
  }

  if (subset) {
    PyObject *subset_fast = PySequence_Fast(subset, "user_map");
    if (subset_fast == nullptr) {
      goto error;
    }

    PyObject **subset_array = PySequence_Fast_ITEMS(subset_fast);
    Py_ssize_t subset_len = PySequence_Fast_GET_SIZE(subset_fast);

    data_cb.user_map = _PyDict_NewPresized(subset_len);
    data_cb.is_subset = true;
    for (; subset_len; subset_array++, subset_len--) {
      ID *id;
      if (!pyrna_id_FromPyObject(*subset_array, &id)) {
        PyErr_Format(PyExc_TypeError,
                     "Expected an ID type in `subset` iterable, not %.200s",
                     Py_TYPE(*subset_array)->tp_name);
        Py_DECREF(subset_fast);
        Py_DECREF(data_cb.user_map);
        goto error;
      }

      if (!PyDict_Contains(data_cb.user_map, *subset_array)) {
        PyObject *set = PySet_New(nullptr);
        PyDict_SetItem(data_cb.user_map, *subset_array, set);
        Py_DECREF(set);
      }
    }
    Py_DECREF(subset_fast);
  }
  else {
    data_cb.user_map = PyDict_New();
  }

  data_cb.types_bitmap = key_types_bitmap;

  FOREACH_MAIN_LISTBASE_BEGIN (bmain, lb) {
    FOREACH_MAIN_LISTBASE_ID_BEGIN (lb, id) {
      /* We cannot skip here in case we have some filter on key types... */
      if (key_types_bitmap == nullptr && val_types_bitmap != nullptr) {
        if (!id_check_type(id, val_types_bitmap)) {
          break;
        }
      }

      if (!data_cb.is_subset &&
          /* We do not want to pre-add keys of filtered out types. */
          (key_types_bitmap == nullptr || id_check_type(id, key_types_bitmap)) &&
          /* We do not want to pre-add keys when we have filter on value types,
           * but not on key types. */
          (val_types_bitmap == nullptr || key_types_bitmap != nullptr))
      {
        PyObject *key = pyrna_id_CreatePyObject(id);
        PyObject *set;

        /* We have to insert the key now,
         * otherwise ID unused would be missing from final dict... */
        if ((set = PyDict_GetItem(data_cb.user_map, key)) == nullptr) {
          set = PySet_New(nullptr);
          PyDict_SetItem(data_cb.user_map, key, set);
          Py_DECREF(set);
        }
        Py_DECREF(key);
      }

      if (val_types_bitmap != nullptr && !id_check_type(id, val_types_bitmap)) {
        continue;
      }

      data_cb.id_curr = id;
      BKE_library_foreach_ID_link(
          nullptr, id, foreach_libblock_id_user_map_callback, &data_cb, IDWALK_NOP);

      if (data_cb.py_id_curr) {
        Py_DECREF(data_cb.py_id_curr);
        data_cb.py_id_curr = nullptr;
      }
    }
    FOREACH_MAIN_LISTBASE_ID_END;
  }
  FOREACH_MAIN_LISTBASE_ID_END;

  ret = data_cb.user_map;

error:
  if (key_types_bitmap != nullptr) {
    MEM_freeN(key_types_bitmap);
  }
  if (val_types_bitmap != nullptr) {
    MEM_freeN(val_types_bitmap);
  }

  return ret;
}

struct IDFilePathMapData {
  /* Data unchanged for the whole process. */

  /** Set to fill in as we iterate. */
  PyObject *file_path_map;

  /** Whether to include library filepath of linked IDs or not. */
  bool include_libraries;

  /* Data modified for each processed ID. */

  /** The processed ID. */
  ID *id;
  /** The set of file paths for the processed ID. */
  PyObject *id_file_path_set;
};

static bool foreach_id_file_path_map_callback(BPathForeachPathData *bpath_data,
                                              char * /*path_dst*/,
                                              size_t /*path_dst_maxncpy*/,
                                              const char *path_src)
{
  IDFilePathMapData &data = *static_cast<IDFilePathMapData *>(bpath_data->user_data);
  PyObject *id_file_path_set = data.id_file_path_set;

  BLI_assert(data.id == bpath_data->owner_id);

  if (path_src && *path_src) {
    PyObject *path = PyC_UnicodeFromBytes(path_src);
    PySet_Add(id_file_path_set, path);
    Py_DECREF(path);
  }
  return false;
}

static void foreach_id_file_path_map(BPathForeachPathData &bpath_data)
{
  IDFilePathMapData &data = *static_cast<IDFilePathMapData *>(bpath_data.user_data);
  ID *id = data.id;
  PyObject *id_file_path_set = data.id_file_path_set;

  if (data.include_libraries && ID_IS_LINKED(id)) {
    PyObject *path = PyC_UnicodeFromBytes(id->lib->filepath);
    PySet_Add(id_file_path_set, path);
    Py_DECREF(path);
  }

  BKE_bpath_foreach_path_id(&bpath_data, id);
}

PyDoc_STRVAR(
    /* Wrap. */
    bpy_file_path_map_doc,
    ".. method:: file_path_map(subset=None, key_types=None, include_libraries=False)\n"
    "\n"
    "   Returns a mapping of all ID data-blocks in current ``bpy.data`` to a set of all "
    "file paths used by them.\n"
    "\n"
    "   For list of valid set members for key_types, see: "
    ":class:`bpy.types.KeyingSetPath.id_type`.\n"
    "\n"
    "   :arg subset: When given, only these data-blocks and their used file paths "
    "will be included as keys/values in the map.\n"
    "   :type subset: sequence\n"
    "   :arg key_types: When given, filter the keys mapped by ID types. Ignored if ``subset`` is "
    "also given.\n"
    "   :type key_types: set of strings\n"
    "   :arg include_libraries: Include library file paths of linked data. False by default.\n"
    "   :type include_libraries: bool\n"
    "   :return: dictionary of :class:`bpy.types.ID` instances, with sets of file path "
    "strings as their values.\n"
    "   :rtype: dict\n");
static PyObject *bpy_file_path_map(PyObject *self, PyObject *args, PyObject *kwds)
{
  Main *bmain = pyrna_bmain_FromPyObject(self);
  if (!bmain) {
    return nullptr;
  }

  PyObject *subset = nullptr;

  PyObject *key_types = nullptr;
  PyObject *include_libraries = nullptr;
  BLI_bitmap *key_types_bitmap = nullptr;

  PyObject *ret = nullptr;

  IDFilePathMapData filepathmap_data{};
  BPathForeachPathData bpath_data{};

  static const char *_keywords[] = {"subset", "key_types", "include_libraries", nullptr};
  static _PyArg_Parser _parser = {
      PY_ARG_PARSER_HEAD_COMPAT()
      "|$" /* Optional keyword only arguments. */
      "O"  /* `subset` */
      "O!" /* `key_types` */
      "O!" /* `include_libraries` */
      ":file_path_map",
      _keywords,
      nullptr,
  };
  if (!_PyArg_ParseTupleAndKeywordsFast(args,
                                        kwds,
                                        &_parser,
                                        &subset,
                                        &PySet_Type,
                                        &key_types,
                                        &PyBool_Type,
                                        &include_libraries))
  {
    return nullptr;
  }

  if (key_types) {
    key_types_bitmap = pyrna_enum_bitmap_from_set(
        rna_enum_id_type_items, key_types, sizeof(short), true, USHRT_MAX, "key types");
    if (key_types_bitmap == nullptr) {
      goto error;
    }
  }

  bpath_data.bmain = bmain;
  bpath_data.callback_function = foreach_id_file_path_map_callback;
  /* TODO: needs to be controllable from caller (add more options to the API). */
  bpath_data.flag = BKE_BPATH_FOREACH_PATH_SKIP_PACKED | BKE_BPATH_TRAVERSE_SKIP_WEAK_REFERENCES;
  bpath_data.user_data = &filepathmap_data;

  filepathmap_data.include_libraries = (include_libraries == Py_True);

  if (subset) {
    PyObject *subset_fast = PySequence_Fast(subset, "user_map");
    if (subset_fast == nullptr) {
      goto error;
    }

    PyObject **subset_array = PySequence_Fast_ITEMS(subset_fast);
    Py_ssize_t subset_len = PySequence_Fast_GET_SIZE(subset_fast);

    filepathmap_data.file_path_map = _PyDict_NewPresized(subset_len);
    for (; subset_len; subset_array++, subset_len--) {
      if (PyDict_Contains(filepathmap_data.file_path_map, *subset_array)) {
        continue;
      }

      ID *id;
      if (!pyrna_id_FromPyObject(*subset_array, &id)) {
        PyErr_Format(PyExc_TypeError,
                     "Expected an ID type in `subset` iterable, not %.200s",
                     Py_TYPE(*subset_array)->tp_name);
        Py_DECREF(subset_fast);
        Py_DECREF(filepathmap_data.file_path_map);
        goto error;
      }

      filepathmap_data.id_file_path_set = PySet_New(nullptr);
      PyDict_SetItem(
          filepathmap_data.file_path_map, *subset_array, filepathmap_data.id_file_path_set);
      Py_DECREF(filepathmap_data.id_file_path_set);

      filepathmap_data.id = id;
      foreach_id_file_path_map(bpath_data);
    }
    Py_DECREF(subset_fast);
  }
  else {
    ListBase *lb;
    ID *id;
    filepathmap_data.file_path_map = PyDict_New();

    FOREACH_MAIN_LISTBASE_BEGIN (bmain, lb) {
      FOREACH_MAIN_LISTBASE_ID_BEGIN (lb, id) {
        /* We can skip here in case we have some filter on key types. */
        if (key_types_bitmap && !id_check_type(id, key_types_bitmap)) {
          break;
        }

        PyObject *key = pyrna_id_CreatePyObject(id);
        filepathmap_data.id_file_path_set = PySet_New(nullptr);
        PyDict_SetItem(filepathmap_data.file_path_map, key, filepathmap_data.id_file_path_set);
        Py_DECREF(filepathmap_data.id_file_path_set);
        Py_DECREF(key);

        filepathmap_data.id = id;
        foreach_id_file_path_map(bpath_data);
      }
      FOREACH_MAIN_LISTBASE_ID_END;
    }
    FOREACH_MAIN_LISTBASE_ID_END;
  }

  ret = filepathmap_data.file_path_map;

error:
  if (key_types_bitmap != nullptr) {
    MEM_freeN(key_types_bitmap);
  }

  return ret;
}

PyDoc_STRVAR(
    /* Wrap. */
    bpy_batch_remove_doc,
    ".. method:: batch_remove(ids)\n"
    "\n"
    "   Remove (delete) several IDs at once.\n"
    "\n"
    "   Note that this function is quicker than individual calls to :func:`remove()` "
    "(from :class:`bpy.types.BlendData`\n"
    "   ID collections), but less safe/versatile (it can break Blender, e.g. by removing "
    "all scenes...).\n"
    "\n"
    "   :arg ids: Sequence of IDs (types can be mixed).\n"
    "   :type ids: Sequence[:class:`bpy.types.ID`]\n");
static PyObject *bpy_batch_remove(PyObject *self, PyObject *args, PyObject *kwds)
{
  Main *bmain = pyrna_bmain_FromPyObject(self);
  if (!bmain) {
    return nullptr;
  }

  PyObject *ids = nullptr;

  static const char *_keywords[] = {"ids", nullptr};
  static _PyArg_Parser _parser = {
      PY_ARG_PARSER_HEAD_COMPAT()
      "O" /* `ids` */
      ":batch_remove",
      _keywords,
      nullptr,
  };
  if (!_PyArg_ParseTupleAndKeywordsFast(args, kwds, &_parser, &ids)) {
    return nullptr;
  }

  if (!ids) {
    return nullptr;
  }

  PyObject *ids_fast = PySequence_Fast(ids, "batch_remove");
  if (ids_fast == nullptr) {
    return nullptr;
  }

  PyObject **ids_array = PySequence_Fast_ITEMS(ids_fast);
  Py_ssize_t ids_len = PySequence_Fast_GET_SIZE(ids_fast);
  blender::Set<ID *> ids_to_delete;
  for (; ids_len; ids_array++, ids_len--) {
    ID *id;
    if (!pyrna_id_FromPyObject(*ids_array, &id)) {
      PyErr_Format(
          PyExc_TypeError, "Expected an ID type, not %.200s", Py_TYPE(*ids_array)->tp_name);
      Py_DECREF(ids_fast);
      return nullptr;
    }

    ids_to_delete.add(id);
  }
  Py_DECREF(ids_fast);

  BKE_id_multi_delete(bmain, ids_to_delete);
  /* Force full redraw, mandatory to avoid crashes when running this from UI... */
  WM_main_add_notifier(NC_WINDOW, nullptr);

  Py_RETURN_NONE;
}

PyDoc_STRVAR(
    /* Wrap. */
    bpy_orphans_purge_doc,
    ".. method:: orphans_purge()\n"
    "\n"
    "   Remove (delete) all IDs with no user.\n"
    "\n"
    "   :arg do_local_ids: Include unused local IDs in the deletion, defaults to True\n"
    "   :type do_local_ids: bool, optional\n"
    "   :arg do_linked_ids: Include unused linked IDs in the deletion, defaults to True\n"
    "   :type do_linked_ids: bool, optional\n"
    "   :arg do_recursive: Recursively check for unused IDs, ensuring no orphaned one "
    "remain after a single run of that function, defaults to False\n"
    "   :type do_recursive: bool, optional\n"
    "   :return: The number of deleted IDs.\n");
static PyObject *bpy_orphans_purge(PyObject *self, PyObject *args, PyObject *kwds)
{
  Main *bmain = pyrna_bmain_FromPyObject(self);
  if (!bmain) {
    return nullptr;
  }

  LibQueryUnusedIDsData unused_ids_data;
  unused_ids_data.do_local_ids = true;
  unused_ids_data.do_linked_ids = true;
  unused_ids_data.do_recursive = false;

  static const char *_keywords[] = {"do_local_ids", "do_linked_ids", "do_recursive", nullptr};
  static _PyArg_Parser _parser = {
      PY_ARG_PARSER_HEAD_COMPAT()
      "|"  /* Optional arguments. */
      "O&" /* `do_local_ids` */
      "O&" /* `do_linked_ids` */
      "O&" /* `do_recursive` */
      ":orphans_purge",
      _keywords,
      nullptr,
  };
  if (!_PyArg_ParseTupleAndKeywordsFast(args,
                                        kwds,
                                        &_parser,
                                        PyC_ParseBool,
                                        &unused_ids_data.do_local_ids,
                                        PyC_ParseBool,
                                        &unused_ids_data.do_linked_ids,
                                        PyC_ParseBool,
                                        &unused_ids_data.do_recursive))
  {
    return nullptr;
  }

  /* Tag all IDs to delete. */
  BKE_lib_query_unused_ids_tag(bmain, ID_TAG_DOIT, unused_ids_data);

  if (unused_ids_data.num_total[INDEX_ID_NULL] == 0) {
    return PyLong_FromSize_t(0);
  }

  const size_t num_datablocks_deleted = BKE_id_multi_tagged_delete(bmain);
  /* Force full redraw, mandatory to avoid crashes when running this from UI... */
  WM_main_add_notifier(NC_WINDOW, nullptr);

  return PyLong_FromSize_t(num_datablocks_deleted);
}

#ifdef __GNUC__
#  ifdef __clang__
#    pragma clang diagnostic push
#    pragma clang diagnostic ignored "-Wcast-function-type"
#  else
#    pragma GCC diagnostic push
#    pragma GCC diagnostic ignored "-Wcast-function-type"
#  endif
#endif

PyMethodDef BPY_rna_id_collection_user_map_method_def = {
    "user_map",
    (PyCFunction)bpy_user_map,
    METH_VARARGS | METH_KEYWORDS,
    bpy_user_map_doc,
};
PyMethodDef BPY_rna_id_collection_file_path_map_method_def = {
    "file_path_map",
    (PyCFunction)bpy_file_path_map,
    METH_VARARGS | METH_KEYWORDS,
    bpy_file_path_map_doc,
};
PyMethodDef BPY_rna_id_collection_batch_remove_method_def = {
    "batch_remove",
    (PyCFunction)bpy_batch_remove,
    METH_VARARGS | METH_KEYWORDS,
    bpy_batch_remove_doc,
};
PyMethodDef BPY_rna_id_collection_orphans_purge_method_def = {
    "orphans_purge",
    (PyCFunction)bpy_orphans_purge,
    METH_VARARGS | METH_KEYWORDS,
    bpy_orphans_purge_doc,
};

#ifdef __GNUC__
#  ifdef __clang__
#    pragma clang diagnostic pop
#  else
#    pragma GCC diagnostic pop
#  endif
#endif
