/*
 * 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 "BLI_listbase.h"

#include "DNA_cloth_types.h"
#include "DNA_key_types.h"
#include "DNA_mesh_types.h"
#include "DNA_object_types.h"
#include "DNA_scene_types.h"

#include "MEM_guardedalloc.h"

#include "BKE_cloth.h"
#include "BKE_effect.h"
#include "BKE_global.h"
#include "BKE_key.h"
#include "BKE_lib_id.h"
#include "BKE_lib_query.h"
#include "BKE_mesh.h"
#include "BKE_modifier.h"
#include "BKE_pointcache.h"

#include "DEG_depsgraph_physics.h"
#include "DEG_depsgraph_query.h"

#include "MOD_util.h"

static void initData(ModifierData *md)
{
  ClothModifierData *clmd = (ClothModifierData *)md;

  clmd->sim_parms = MEM_callocN(sizeof(ClothSimSettings), "cloth sim parms");
  clmd->coll_parms = MEM_callocN(sizeof(ClothCollSettings), "cloth coll parms");
  clmd->point_cache = BKE_ptcache_add(&clmd->ptcaches);

  /* check for alloc failing */
  if (!clmd->sim_parms || !clmd->coll_parms || !clmd->point_cache) {
    return;
  }

  cloth_init(clmd);
}

static void deformVerts(ModifierData *md,
                        const ModifierEvalContext *ctx,
                        Mesh *mesh,
                        float (*vertexCos)[3],
                        int numVerts)
{
  Mesh *mesh_src;
  ClothModifierData *clmd = (ClothModifierData *)md;
  Scene *scene = DEG_get_evaluated_scene(ctx->depsgraph);

  /* check for alloc failing */
  if (!clmd->sim_parms || !clmd->coll_parms) {
    initData(md);

    if (!clmd->sim_parms || !clmd->coll_parms) {
      return;
    }
  }

  if (mesh == NULL) {
    mesh_src = MOD_deform_mesh_eval_get(ctx->object, NULL, NULL, NULL, numVerts, false, false);
  }
  else {
    /* Not possible to use get_mesh() in this case as we'll modify its vertices
     * and get_mesh() would return 'mesh' directly. */
    BKE_id_copy_ex(NULL, (ID *)mesh, (ID **)&mesh_src, LIB_ID_COPY_LOCALIZE);
  }

  /* TODO(sergey): For now it actually duplicates logic from DerivedMesh.c
   * and needs some more generic solution. But starting experimenting with
   * this so close to the release is not that nice..
   *
   * Also hopefully new cloth system will arrive soon..
   */
  if (mesh == NULL && clmd->sim_parms->shapekey_rest) {
    KeyBlock *kb = BKE_keyblock_from_key(BKE_key_from_object(ctx->object),
                                         clmd->sim_parms->shapekey_rest);
    if (kb && kb->data != NULL) {
      float(*layerorco)[3];
      if (!(layerorco = CustomData_get_layer(&mesh_src->vdata, CD_CLOTH_ORCO))) {
        layerorco = CustomData_add_layer(
            &mesh_src->vdata, CD_CLOTH_ORCO, CD_CALLOC, NULL, mesh_src->totvert);
      }

      memcpy(layerorco, kb->data, sizeof(float) * 3 * numVerts);
    }
  }

  BKE_mesh_vert_coords_apply(mesh_src, vertexCos);

  clothModifier_do(clmd, ctx->depsgraph, scene, ctx->object, mesh_src, vertexCos);

  BKE_id_free(NULL, mesh_src);
}

static void updateDepsgraph(ModifierData *md, const ModifierUpdateDepsgraphContext *ctx)
{
  ClothModifierData *clmd = (ClothModifierData *)md;
  if (clmd != NULL) {
    if (clmd->coll_parms->flags & CLOTH_COLLSETTINGS_FLAG_ENABLED) {
      DEG_add_collision_relations(ctx->node,
                                  ctx->object,
                                  clmd->coll_parms->group,
                                  eModifierType_Collision,
                                  NULL,
                                  "Cloth Collision");
    }
    DEG_add_forcefield_relations(
        ctx->node, ctx->object, clmd->sim_parms->effector_weights, true, 0, "Cloth Field");
  }
  DEG_add_modifier_to_transform_relation(ctx->node, "Cloth Modifier");
}

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

  if (cloth_uses_vgroup(clmd)) {
    r_cddata_masks->vmask |= CD_MASK_MDEFORMVERT;
  }

  if (clmd->sim_parms->shapekey_rest != 0) {
    r_cddata_masks->vmask |= CD_MASK_CLOTH_ORCO;
  }
}

static void copyData(const ModifierData *md, ModifierData *target, const int flag)
{
  const ClothModifierData *clmd = (const ClothModifierData *)md;
  ClothModifierData *tclmd = (ClothModifierData *)target;

  if (tclmd->sim_parms) {
    if (tclmd->sim_parms->effector_weights) {
      MEM_freeN(tclmd->sim_parms->effector_weights);
    }
    MEM_freeN(tclmd->sim_parms);
  }

  if (tclmd->coll_parms) {
    MEM_freeN(tclmd->coll_parms);
  }

  BKE_ptcache_free_list(&tclmd->ptcaches);
  if (flag & LIB_ID_CREATE_NO_MAIN) {
    /* Share the cache with the original object's modifier. */
    tclmd->modifier.flag |= eModifierFlag_SharedCaches;
    tclmd->ptcaches = clmd->ptcaches;
    tclmd->point_cache = clmd->point_cache;
  }
  else {
    tclmd->point_cache = BKE_ptcache_add(&tclmd->ptcaches);
    if (clmd->point_cache != NULL) {
      tclmd->point_cache->step = clmd->point_cache->step;
      tclmd->point_cache->startframe = clmd->point_cache->startframe;
      tclmd->point_cache->endframe = clmd->point_cache->endframe;
    }
  }

  tclmd->sim_parms = MEM_dupallocN(clmd->sim_parms);
  if (clmd->sim_parms->effector_weights) {
    tclmd->sim_parms->effector_weights = MEM_dupallocN(clmd->sim_parms->effector_weights);
  }
  tclmd->coll_parms = MEM_dupallocN(clmd->coll_parms);
  tclmd->clothObject = NULL;
  tclmd->hairdata = NULL;
  tclmd->solver_result = NULL;
}

static bool dependsOnTime(ModifierData *UNUSED(md))
{
  return true;
}

static void freeData(ModifierData *md)
{
  ClothModifierData *clmd = (ClothModifierData *)md;

  if (clmd) {
    if (G.debug & G_DEBUG_SIMDATA) {
      printf("clothModifier_freeData\n");
    }

    cloth_free_modifier_extern(clmd);

    if (clmd->sim_parms) {
      if (clmd->sim_parms->effector_weights) {
        MEM_freeN(clmd->sim_parms->effector_weights);
      }
      MEM_freeN(clmd->sim_parms);
    }
    if (clmd->coll_parms) {
      MEM_freeN(clmd->coll_parms);
    }

    if (md->flag & eModifierFlag_SharedCaches) {
      BLI_listbase_clear(&clmd->ptcaches);
    }
    else {
      BKE_ptcache_free_list(&clmd->ptcaches);
    }
    clmd->point_cache = NULL;

    if (clmd->hairdata) {
      MEM_freeN(clmd->hairdata);
    }

    if (clmd->solver_result) {
      MEM_freeN(clmd->solver_result);
    }
  }
}

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

  if (clmd->coll_parms) {
    walk(userData, ob, (ID **)&clmd->coll_parms->group, IDWALK_CB_NOP);
  }

  if (clmd->sim_parms && clmd->sim_parms->effector_weights) {
    walk(userData, ob, (ID **)&clmd->sim_parms->effector_weights->group, IDWALK_CB_NOP);
  }
}

ModifierTypeInfo modifierType_Cloth = {
    /* name */ "Cloth",
    /* structName */ "ClothModifierData",
    /* structSize */ sizeof(ClothModifierData),
    /* type */ eModifierTypeType_OnlyDeform,
    /* flags */ eModifierTypeFlag_AcceptsMesh | eModifierTypeFlag_UsesPointCache |
        eModifierTypeFlag_Single,

    /* copyData */ copyData,

    /* deformVerts */ deformVerts,
    /* deformMatrices */ NULL,
    /* deformVertsEM */ NULL,
    /* deformMatricesEM */ NULL,
    /* modifyMesh */ NULL,
    /* modifyHair */ NULL,
    /* modifyPointCloud */ NULL,
    /* modifyVolume */ NULL,

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