text: /*
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public License
   * as published by the Free Software Foundation; either version 2
   * of the License, or (at your option) any later version.
   *
   * This program 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 General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software Foundation,
   * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
   */
  
  /** \file
   * \ingroup pythonintern
   *
   * This file exposed blend file library appending/linking to python, typically
   * this would be done via RNA api but in this case a hand written python api
   * allows us to use Python's context manager (`__enter__` and `__exit__`).
   *
   * Everything here is exposed via `bpy.data.libraries.load(...)` which returns
   * a context manager.
   */
  
  #include <Python.h>
  #include <stddef.h>
  
  #include "BLI_ghash.h"
  #include "BLI_linklist.h"
  #include "BLI_path_util.h"
  #include "BLI_string.h"
  #include "BLI_utildefines.h"
  
  #include "BKE_context.h"
  #include "BKE_idtype.h"
  #include "BKE_lib_id.h"
  #include "BKE_main.h"
  #include "BKE_report.h"
  
  #include "DNA_space_types.h" /* FILE_LINK, FILE_RELPATH */
  
  #include "BLO_readfile.h"
  
  #include "bpy_capi_utils.h"
  #include "bpy_library.h"
  
  #include "../generic/py_capi_utils.h"
  #include "../generic/python_utildefines.h"
  
  /* nifty feature. swap out strings for RNA data */
  #define USE_RNA_DATABLOCKS
  
  #ifdef USE_RNA_DATABLOCKS
  #  include "RNA_access.h"
  #  include "bpy_rna.h"
  #endif
  
  typedef struct {
    PyObject_HEAD /* required python macro */
        /* collection iterator specific parts */
        char relpath[FILE_MAX];
    char abspath[FILE_MAX]; /* absolute path */
    BlendHandle *blo_handle;
    int flag;
    PyObject *dict;
  } BPy_Library;
  
  static PyObject *bpy_lib_load(PyObject *self, PyObject *args, PyObject *kwds);
  static PyObject *bpy_lib_enter(BPy_Library *self);
  static PyObject *bpy_lib_exit(BPy_Library *self, PyObject *args);
  static PyObject *bpy_lib_dir(BPy_Library *self);
  
  static PyMethodDef bpy_lib_methods[] = {
      {"__enter__", (PyCFunction)bpy_lib_enter, METH_NOARGS},
      {"__exit__", (PyCFunction)bpy_lib_exit, METH_VARARGS},
      {"__dir__", (PyCFunction)bpy_lib_dir, METH_NOARGS},
      {NULL} /* sentinel */
  };
  
  static void bpy_lib_dealloc(BPy_Library *self)
  {
    Py_XDECREF(self->dict);
    Py_TYPE(self)->tp_free(self);
  }
  
  static PyTypeObject bpy_lib_Type = {
      PyVarObject_HEAD_INIT(NULL, 0) "bpy_lib", /* tp_name */
      sizeof(BPy_Library),                      /* tp_basicsize */
      0,                                        /* tp_itemsize */
      /* methods */
      (destructor)bpy_lib_dealloc, /* tp_dealloc */
      (printfunc)NULL,             /* printfunc tp_print; */
      NULL,                        /* getattrfunc tp_getattr; */
      NULL,                        /* setattrfunc tp_setattr; */
      NULL,
      /* tp_compare */ /* DEPRECATED in python 3.0! */
      NULL,            /* tp_repr */
  
      /* Method suites for standard classes */
  
      NULL, /* PyNumberMethods *tp_as_number; */
      NULL, /* PySequenceMethods *tp_as_sequence; */
      NULL, /* PyMappingMethods *tp_as_mapping; */
  
      /* More standard operations (here for binary compatibility) */
  
      NULL, /* hashfunc tp_hash; */
      NULL, /* ternaryfunc tp_call; */
      NULL, /* reprfunc tp_str; */
  
      /* will only use these if this is a subtype of a py class */
      NULL /*PyObject_GenericGetAttr is assigned later */, /* getattrofunc tp_getattro; */
      NULL,                                                /* setattrofunc tp_setattro; */
  
      /* Functions to access object as input/output buffer */
      NULL, /* PyBufferProcs *tp_as_buffer; */
  
      /*** Flags to define presence of optional/expanded features ***/
      Py_TPFLAGS_DEFAULT, /* long tp_flags; */
  
      NULL, /*  char *tp_doc;  Documentation string */
      /*** Assigned meaning in release 2.0 ***/
      /* call function for all accessible objects */
      NULL, /* traverseproc tp_traverse; */
  
      /* delete references to contained objects */
      NULL, /* inquiry tp_clear; */
  
      /***  Assigned meaning in release 2.1 ***/
      /*** rich comparisons (subclassed) ***/
      NULL, /* richcmpfunc tp_richcompare; */
  
      /***  weak reference enabler ***/
      0,
      /*** Added in release 2.2 ***/
      /*   Iterators */
      NULL, /* getiterfunc tp_iter; */
      NULL, /* iternextfunc tp_iternext; */
  
      /*** Attribute descriptor and subclassing stuff ***/
      bpy_lib_methods,             /* struct PyMethodDef *tp_methods; */
      NULL,                        /* struct PyMemberDef *tp_members; */
      NULL,                        /* struct PyGetSetDef *tp_getset; */
      NULL,                        /* struct _typeobject *tp_base; */
      NULL,                        /* PyObject *tp_dict; */
      NULL,                        /* descrgetfunc tp_descr_get; */
      NULL,                        /* descrsetfunc tp_descr_set; */
      offsetof(BPy_Library, dict), /* long tp_dictoffset; */
      NULL,                        /* initproc tp_init; */
      NULL,                        /* allocfunc tp_alloc; */
      NULL,                        /* newfunc tp_new; */
      /*  Low-level free-memory routine */
      NULL, /* freefunc tp_free;  */
      /* For PyObject_IS_GC */
      NULL, /* inquiry tp_is_gc;  */
      NULL, /* PyObject *tp_bases; */
      /* method resolution order */
      NULL, /* PyObject *tp_mro;  */
      NULL, /* PyObject *tp_cache; */
      NULL, /* PyObject *tp_subclasses; */
      NULL, /* PyObject *tp_weaklist; */
      NULL,
  };
  
  PyDoc_STRVAR(
      bpy_lib_load_doc,
      ".. method:: load(filepath, link=False, relative=False)\n"
      "\n"
      "   Returns a context manager which exposes 2 library objects on entering.\n"
      "   Each object has attributes matching bpy.data which are lists of strings to be linked.\n"
      "\n"
      "   :arg filepath: The path to a blend file.\n"
      "   :type filepath: string\n"
      "   :arg link: When False reference to the original file is lost.\n"
      "   :type link: bool\n"
      "   :arg relative: When True the path is stored relative to the open blend file.\n"
      "   :type relative: bool\n");
  static PyObject *bpy_lib_load(PyObject *UNUSED(self), PyObject *args, PyObject *kw)
  {
    Main *bmain = CTX_data_main(BPY_context_get());
    BPy_Library *ret;
    const char *filename = NULL;
    bool is_rel = false, is_link = false;
  
    static const char *_keywords[] = {"filepath", "link", "relative", NULL};
    static _PyArg_Parser _parser = {"s|O&O&:load", _keywords, 0};
    if (!_PyArg_ParseTupleAndKeywordsFast(
            args, kw, &_parser, &filename, PyC_ParseBool, &is_link, PyC_ParseBool, &is_rel)) {
      return NULL;
    }
  
    ret = PyObject_New(BPy_Library, &bpy_lib_Type);
  
    BLI_strncpy(ret->relpath, filename, sizeof(ret->relpath));
    BLI_strncpy(ret->abspath, filename, sizeof(ret->abspath));
    BLI_path_abs(ret->abspath, BKE_main_blendfile_path(bmain));
  
    ret->blo_handle = NULL;
    ret->flag = ((is_link ? FILE_LINK : 0) | (is_rel ? FILE_RELPATH : 0));
  
    ret->dict = _PyDict_NewPresized(MAX_LIBARRAY);
  
    return (PyObject *)ret;
  }
  
  static PyObject *_bpy_names(BPy_Library *self, int blocktype)
  {
    PyObject *list;
    LinkNode *l, *names;
    int totnames;
  
    names = BLO_blendhandle_get_datablock_names(self->blo_handle, blocktype, &totnames);
    list = PyList_New(totnames);
  
    if (names) {
      int counter = 0;
      for (l = names; l; l = l->next) {
        PyList_SET_ITEM(list, counter, PyUnicode_FromString((char *)l->link));
        counter++;
      }
      BLI_linklist_free(names, free); /* free linklist *and* each node's data */
    }
  
    return list;
  }
  
  static PyObject *bpy_lib_enter(BPy_Library *self)
  {
    PyObject *ret;
    BPy_Library *self_from;
    PyObject *from_dict = _PyDict_NewPresized(MAX_LIBARRAY);
    ReportList reports;
  
    BKE_reports_init(&reports, RPT_STORE);
  
    self->blo_handle = BLO_blendhandle_from_file(self->abspath, &reports);
  
    if (self->blo_handle == NULL) {
      if (BPy_reports_to_error(&reports, PyExc_IOError, true) != -1) {
        PyErr_Format(PyExc_IOError, "load: %s failed to open blend file", self->abspath);
      }
      return NULL;
    }
  
    int i = 0, code;
    while ((code = BKE_idtype_idcode_iter_step(&i))) {
      if (BKE_idtype_idcode_is_linkable(code)) {
        const char *name_plural = BKE_idtype_idcode_to_name_plural(code);
        PyObject *str = PyUnicode_FromString(name_plural);
        PyObject *item;
  
        PyDict_SetItem(self->dict, str, item = PyList_New(0));
        Py_DECREF(item);
        PyDict_SetItem(from_dict, str, item = _bpy_names(self, code));
        Py_DECREF(item);
  
        Py_DECREF(str);
      }
    }
  
    /* create a dummy */
    self_from = PyObject_New(BPy_Library, &bpy_lib_Type);
    BLI_strncpy(self_from->relpath, self->relpath, sizeof(self_from->relpath));
    BLI_strncpy(self_from->abspath, self->abspath, sizeof(self_from->abspath));
  
    self_from->blo_handle = NULL;
    self_from->flag = 0;
    self_from->dict = from_dict; /* owns the dict */
  
    /* return pair */
    ret = PyTuple_New(2);
    PyTuple_SET_ITEMS(ret, (PyObject *)self_from, (PyObject *)self);
    Py_INCREF(self);
  
    BKE_reports_clear(&reports);
  
    return ret;
  }
  
  static void bpy_lib_exit_warn_idname(BPy_Library *self,
                                       const char *name_plural,
                                       const char *idname)
  {
    PyObject *exc, *val, *tb;
    PyErr_Fetch(&exc, &val, &tb);
    if (PyErr_WarnFormat(PyExc_UserWarning,
                         1,
                         "load: '%s' does not contain %s[\"%s\"]",
                         self->abspath,
                         name_plural,
                         idname)) {
      /* Spurious errors can appear at shutdown */
      if (PyErr_ExceptionMatches(PyExc_Warning)) {
        PyErr_WriteUnraisable((PyObject *)self);
      }
    }
    PyErr_Restore(exc, val, tb);
  }
  
  static void bpy_lib_exit_warn_type(BPy_Library *self, PyObject *item)
  {
    PyObject *exc, *val, *tb;
    PyErr_Fetch(&exc, &val, &tb);
    if (PyErr_WarnFormat(PyExc_UserWarning,
                         1,
                         "load: '%s' expected a string type, not a %.200s",
                         self->abspath,
                         Py_TYPE(item)->tp_name)) {
      /* Spurious errors can appear at shutdown */
      if (PyErr_ExceptionMatches(PyExc_Warning)) {
        PyErr_WriteUnraisable((PyObject *)self);
      }
    }
    PyErr_Restore(exc, val, tb);
  }
  
  static PyObject *bpy_lib_exit(BPy_Library *self, PyObject *UNUSED(args))
  {
    Main *bmain = CTX_data_main(BPY_context_get());
    Main *mainl = NULL;
    const int err = 0;
    const bool do_append = ((self->flag & FILE_LINK) == 0);
  
    BKE_main_id_tag_all(bmain, LIB_TAG_PRE_EXISTING, true);
  
    /* here appending/linking starts */
    struct LibraryLink_Params liblink_params;
    BLO_library_link_params_init(&liblink_params, bmain, self->flag);
  
    mainl = BLO_library_link_begin(&(self->blo_handle), self->relpath, &liblink_params);
  
    {
      int idcode_step = 0, idcode;
      while ((idcode = BKE_idtype_idcode_iter_step(&idcode_step))) {
        if (BKE_idtype_idcode_is_linkable(idcode) && (idcode != ID_WS || do_append)) {
          const char *name_plural = BKE_idtype_idcode_to_name_plural(idcode);
          PyObject *ls = PyDict_GetItemString(self->dict, name_plural);
          // printf("lib: %s\n", name_plural);
          if (ls && PyList_Check(ls)) {
            /* loop */
            const Py_ssize_t size = PyList_GET_SIZE(ls);
            Py_ssize_t i;
  
            for (i = 0; i < size; i++) {
              PyObject *item_src = PyList_GET_ITEM(ls, i);
              PyObject *item_dst; /* must be set below */
              const char *item_idname = _PyUnicode_AsString(item_src);
  
              // printf("  %s\n", item_idname);
  
              if (item_idname) {
                ID *id = BLO_library_link_named_part(
                    mainl, &(self->blo_handle), idcode, item_idname, &liblink_params);
                if (id) {
  #ifdef USE_RNA_DATABLOCKS
                  /* swap name for pointer to the id */
                  item_dst = PyCapsule_New((void *)id, NULL, NULL);
  #else
                  /* leave as is */
                  continue;
  #endif
                }
                else {
                  bpy_lib_exit_warn_idname(self, name_plural, item_idname);
                  /* just warn for now */
                  /* err = -1; */
                  item_dst = Py_INCREF_RET(Py_None);
                }
  
                /* ID or None */
              }
              else {
                /* XXX, could complain about this */
                bpy_lib_exit_warn_type(self, item_src);
                PyErr_Clear();
                item_dst = Py_INCREF_RET(Py_None);
              }
  
              /* item_dst must be new or already incref'd */
              Py_DECREF(item_src);
              PyList_SET_ITEM(ls, i, item_dst);
            }
          }
        }
      }
    }
  
    if (err == -1) {
      /* exception raised above, XXX, this leaks some memory */
      BLO_blendhandle_close(self->blo_handle);
      self->blo_handle = NULL;
      BKE_main_id_tag_all(bmain, LIB_TAG_PRE_EXISTING, false);
      return NULL;
    }
  
    Library *lib = mainl->curlib; /* newly added lib, assign before append end */
    BLO_library_link_end(mainl, &(self->blo_handle), &liblink_params);
    BLO_blendhandle_close(self->blo_handle);
    self->blo_handle = NULL;
  
    GHash *old_to_new_ids = BLI_ghash_ptr_new(__func__);
  
    /* copied from wm_operator.c */
    {
      /* mark all library linked objects to be updated */
      BKE_main_lib_objects_recalc_all(bmain);
  
      /* append, rather than linking */
      if (do_append) {
        BKE_library_make_local(bmain, lib, old_to_new_ids, true, false);
      }
    }
  
    BKE_main_id_tag_all(bmain, LIB_TAG_PRE_EXISTING, false);
  
    /* finally swap the capsules for real bpy objects
     * important since BLO_library_append_end initializes NodeTree types used by srna->refine */
  #ifdef USE_RNA_DATABLOCKS
    {
      int idcode_step = 0, idcode;
      while ((idcode = BKE_idtype_idcode_iter_step(&idcode_step))) {
        if (BKE_idtype_idcode_is_linkable(idcode) && (idcode != ID_WS || do_append)) {
          const char *name_plural = BKE_idtype_idcode_to_name_plural(idcode);
          PyObject *ls = PyDict_GetItemString(self->dict, name_plural);
          if (ls && PyList_Check(ls)) {
            const Py_ssize_t size = PyList_GET_SIZE(ls);
            Py_ssize_t i;
            PyObject *item;
  
            for (i = 0; i < size; i++) {
              item = PyList_GET_ITEM(ls, i);
              if (PyCapsule_CheckExact(item)) {
                PointerRNA id_ptr;
                ID *id;
  
                id = PyCapsule_GetPointer(item, NULL);
                id = BLI_ghash_lookup_default(old_to_new_ids, id, id);
                Py_DECREF(item);
  
                RNA_id_pointer_create(id, &id_ptr);
                item = pyrna_struct_CreatePyObject(&id_ptr);
                PyList_SET_ITEM(ls, i, item);
              }
            }
          }
        }
      }
    }
  #endif /* USE_RNA_DATABLOCKS */
  
    BLI_ghash_free(old_to_new_ids, NULL, NULL);
    Py_RETURN_NONE;
  }
  
  static PyObject *bpy_lib_dir(BPy_Library *self)
  {
    return PyDict_Keys(self->dict);
  }
  
  PyMethodDef BPY_library_load_method_def = {
      "load",
      (PyCFunction)bpy_lib_load,
      METH_STATIC | METH_VARARGS | METH_KEYWORDS,
      bpy_lib_load_doc,
  };
  
  int BPY_library_load_type_ready(void)
  {
  
    /* some compilers don't like accessing this directly, delay assignment */
    bpy_lib_Type.tp_getattro = PyObject_GenericGetAttr;
  
    if (PyType_Ready(&bpy_lib_Type) < 0) {
      return -1;
    }
  
    return 0;
  }
  