/*
 * 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.
 *
 * The Original Code is Copyright (C) 2005 by the Blender Foundation.
 * All rights reserved.
 */

/** \file
 * \ingroup modifiers
 */

#include <string.h>

#include "BLI_utildefines.h"

#include "BLT_translation.h"

#include "DNA_defaults.h"
#include "DNA_mesh_types.h"
#include "DNA_object_types.h"
#include "DNA_scene_types.h"
#include "DNA_screen_types.h"

#include "BKE_context.h"
#include "BKE_curve.h"
#include "BKE_deform.h"
#include "BKE_editmesh.h"
#include "BKE_lib_id.h"
#include "BKE_lib_query.h"
#include "BKE_mesh.h"
#include "BKE_mesh_wrapper.h"
#include "BKE_modifier.h"
#include "BKE_screen.h"

#include "UI_interface.h"
#include "UI_resources.h"

#include "RNA_access.h"

#include "DEG_depsgraph.h"
#include "DEG_depsgraph_build.h"
#include "DEG_depsgraph_query.h"

#include "MOD_modifiertypes.h"
#include "MOD_ui_common.h"
#include "MOD_util.h"

static void initData(ModifierData *md)
{
  CurveModifierData *cmd = (CurveModifierData *)md;

  BLI_assert(MEMCMP_STRUCT_AFTER_IS_ZERO(cmd, modifier));

  MEMCPY_STRUCT_AFTER(cmd, DNA_struct_default_get(CurveModifierData), modifier);
}

static void requiredDataMask(Object *UNUSED(ob),
                             ModifierData *md,
                             CustomData_MeshMasks *r_cddata_masks)
{
  CurveModifierData *cmd = (CurveModifierData *)md;

  /* ask for vertexgroups if we need them */
  if (cmd->name[0] != '\0') {
    r_cddata_masks->vmask |= CD_MASK_MDEFORMVERT;
  }
}

static bool isDisabled(const Scene *UNUSED(scene), ModifierData *md, bool UNUSED(userRenderParams))
{
  CurveModifierData *cmd = (CurveModifierData *)md;

  /* The object type check is only needed here in case we have a placeholder
   * object assigned (because the library containing the curve is missing).
   *
   * In other cases it should be impossible to have a type mismatch.
   */
  return !cmd->object || cmd->object->type != OB_CURVE;
}

static void foreachIDLink(ModifierData *md, Object *ob, IDWalkFunc walk, void *userData)
{
  CurveModifierData *cmd = (CurveModifierData *)md;

  walk(userData, ob, (ID **)&cmd->object, IDWALK_CB_NOP);
}

static void updateDepsgraph(ModifierData *md, const ModifierUpdateDepsgraphContext *ctx)
{
  CurveModifierData *cmd = (CurveModifierData *)md;
  if (cmd->object != NULL) {
    /* TODO(sergey): Need to do the same eval_flags trick for path
     * as happening in legacy depsgraph callback.
     */
    /* TODO(sergey): Currently path is evaluated as a part of modifier stack,
     * might be changed in the future.
     */
    DEG_add_object_relation(ctx->node, cmd->object, DEG_OB_COMP_TRANSFORM, "Curve Modifier");
    DEG_add_object_relation(ctx->node, cmd->object, DEG_OB_COMP_GEOMETRY, "Curve Modifier");
    DEG_add_special_eval_flag(ctx->node, &cmd->object->id, DAG_EVAL_NEED_CURVE_PATH);
  }

  DEG_add_modifier_to_transform_relation(ctx->node, "Curve Modifier");
}

static void deformVerts(ModifierData *md,
                        const ModifierEvalContext *ctx,
                        Mesh *mesh,
                        float (*vertexCos)[3],
                        int numVerts)
{
  CurveModifierData *cmd = (CurveModifierData *)md;
  Mesh *mesh_src = NULL;

  if (ctx->object->type == OB_MESH && cmd->name[0] != '\0') {
    /* mesh_src is only needed for vgroups. */
    mesh_src = MOD_deform_mesh_eval_get(ctx->object, NULL, mesh, NULL, numVerts, false, false);
  }

  struct MDeformVert *dvert = NULL;
  int defgrp_index = -1;
  MOD_get_vgroup(ctx->object, mesh_src, cmd->name, &dvert, &defgrp_index);

  /* Silly that defaxis and BKE_curve_deform_coords are off by 1
   * but leave for now to save having to call do_versions */

  BKE_curve_deform_coords(cmd->object,
                          ctx->object,
                          vertexCos,
                          numVerts,
                          dvert,
                          defgrp_index,
                          cmd->flag,
                          cmd->defaxis - 1);

  if (!ELEM(mesh_src, NULL, mesh)) {
    BKE_id_free(NULL, mesh_src);
  }
}

static void deformVertsEM(ModifierData *md,
                          const ModifierEvalContext *ctx,
                          BMEditMesh *em,
                          Mesh *mesh,
                          float (*vertexCos)[3],
                          int numVerts)
{
  if (mesh != NULL) {
    deformVerts(md, ctx, mesh, vertexCos, numVerts);
    return;
  }

  CurveModifierData *cmd = (CurveModifierData *)md;
  bool use_dverts = false;
  int defgrp_index = -1;

  if (ctx->object->type == OB_MESH && cmd->name[0] != '\0') {
    defgrp_index = BKE_object_defgroup_name_index(ctx->object, cmd->name);
    if (defgrp_index != -1) {
      use_dverts = true;
    }
  }

  if (use_dverts) {
    BKE_curve_deform_coords_with_editmesh(cmd->object,
                                          ctx->object,
                                          vertexCos,
                                          numVerts,
                                          defgrp_index,
                                          cmd->flag,
                                          cmd->defaxis - 1,
                                          em);
  }
  else {
    BKE_curve_deform_coords(cmd->object,
                            ctx->object,
                            vertexCos,
                            numVerts,
                            NULL,
                            defgrp_index,
                            cmd->flag,
                            cmd->defaxis - 1);
  }
}

static void panel_draw(const bContext *UNUSED(C), Panel *panel)
{
  uiLayout *layout = panel->layout;

  PointerRNA ob_ptr;
  PointerRNA *ptr = modifier_panel_get_property_pointers(panel, &ob_ptr);

  uiLayoutSetPropSep(layout, true);

  uiItemR(layout, ptr, "object", 0, IFACE_("Curve Object"), ICON_NONE);
  uiItemR(layout, ptr, "deform_axis", 0, NULL, ICON_NONE);

  modifier_vgroup_ui(layout, ptr, &ob_ptr, "vertex_group", "invert_vertex_group", NULL);

  modifier_panel_end(layout, ptr);
}

static void panelRegister(ARegionType *region_type)
{
  modifier_panel_register(region_type, eModifierType_Curve, panel_draw);
}

ModifierTypeInfo modifierType_Curve = {
    /* name */ "Curve",
    /* structName */ "CurveModifierData",
    /* structSize */ sizeof(CurveModifierData),
    /* srna */ &RNA_CurveModifier,
    /* type */ eModifierTypeType_OnlyDeform,
    /* flags */ eModifierTypeFlag_AcceptsCVs | eModifierTypeFlag_AcceptsVertexCosOnly |
        eModifierTypeFlag_SupportsEditmode,
    /* icon */ ICON_MOD_CURVE,

    /* copyData */ BKE_modifier_copydata_generic,

    /* deformVerts */ deformVerts,
    /* deformMatrices */ NULL,
    /* deformVertsEM */ deformVertsEM,
    /* deformMatricesEM */ NULL,
    /* modifyMesh */ NULL,
    /* modifyGeometrySet */ NULL,

    /* initData */ initData,
    /* requiredDataMask */ requiredDataMask,
    /* freeData */ NULL,
    /* isDisabled */ isDisabled,
    /* updateDepsgraph */ updateDepsgraph,
    /* dependsOnTime */ NULL,
    /* dependsOnNormals */ NULL,
    /* foreachIDLink */ foreachIDLink,
    /* foreachTexLink */ NULL,
    /* freeRuntimeData */ NULL,
    /* panelRegister */ panelRegister,
    /* blendWrite */ NULL,
    /* blendRead */ NULL,
};