/* SPDX-License-Identifier: GPL-2.0-or-later
 * Copyright 2005 Blender Foundation. All rights reserved. */

/** \file
 * \ingroup modifiers
 */

#include "BLI_utildefines.h"

#include "BLI_bitmap.h"
#include "BLI_math.h"

#include "BLT_translation.h"

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

#include "BKE_action.h"
#include "BKE_colortools.h"
#include "BKE_context.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 "BLO_read_write.h"

#include "RNA_access.h"
#include "RNA_prototypes.h"

#include "DEG_depsgraph_query.h"

#include "MEM_guardedalloc.h"

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

static void initData(ModifierData *md)
{
  HookModifierData *hmd = (HookModifierData *)md;

  BLI_assert(MEMCMP_STRUCT_AFTER_IS_ZERO(hmd, modifier));

  MEMCPY_STRUCT_AFTER(hmd, DNA_struct_default_get(HookModifierData), modifier);

  hmd->curfalloff = BKE_curvemapping_add(1, 0.0f, 0.0f, 1.0f, 1.0f);
}

static void copyData(const ModifierData *md, ModifierData *target, const int flag)
{
  const HookModifierData *hmd = (const HookModifierData *)md;
  HookModifierData *thmd = (HookModifierData *)target;

  BKE_modifier_copydata_generic(md, target, flag);

  thmd->curfalloff = BKE_curvemapping_copy(hmd->curfalloff);

  thmd->indexar = MEM_dupallocN(hmd->indexar);
}

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

  /* ask for vertexgroups if we need them */
  if (hmd->name[0] != '\0') {
    r_cddata_masks->vmask |= CD_MASK_MDEFORMVERT;
  }
  if (hmd->indexar != NULL) {
    /* TODO: check which origindex are actually needed? */
    r_cddata_masks->vmask |= CD_MASK_ORIGINDEX;
    r_cddata_masks->emask |= CD_MASK_ORIGINDEX;
    r_cddata_masks->pmask |= CD_MASK_ORIGINDEX;
  }
}

static void freeData(ModifierData *md)
{
  HookModifierData *hmd = (HookModifierData *)md;

  BKE_curvemapping_free(hmd->curfalloff);

  MEM_SAFE_FREE(hmd->indexar);
}

static bool isDisabled(const struct Scene *UNUSED(scene),
                       ModifierData *md,
                       bool UNUSED(useRenderParams))
{
  HookModifierData *hmd = (HookModifierData *)md;

  return !hmd->object;
}

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

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

static void updateDepsgraph(ModifierData *md, const ModifierUpdateDepsgraphContext *ctx)
{
  HookModifierData *hmd = (HookModifierData *)md;
  if (hmd->object != NULL) {
    if (hmd->subtarget[0]) {
      DEG_add_bone_relation(
          ctx->node, hmd->object, hmd->subtarget, DEG_OB_COMP_BONE, "Hook Modifier");
    }
    DEG_add_object_relation(ctx->node, hmd->object, DEG_OB_COMP_TRANSFORM, "Hook Modifier");
  }
  /* We need own transformation as well. */
  DEG_add_modifier_to_transform_relation(ctx->node, "Hook Modifier");
}

struct HookData_cb {
  float (*vertexCos)[3];

  /**
   * When anything other than -1, use deform groups.
   * This is not the same as checking `dvert` for NULL when we have edit-meshes.
   */
  int defgrp_index;

  struct CurveMapping *curfalloff;

  char falloff_type;
  float falloff;
  float falloff_sq;
  float fac_orig;

  uint use_falloff : 1;
  uint use_uniform : 1;

  float cent[3];

  float mat_uniform[3][3];
  float mat[4][4];

  bool invert_vgroup;
};

static BLI_bitmap *hook_index_array_to_bitmap(HookModifierData *hmd, const int verts_num)
{
  BLI_bitmap *indexar_used = BLI_BITMAP_NEW(verts_num, __func__);
  int i;
  int *index_pt;
  for (i = 0, index_pt = hmd->indexar; i < hmd->indexar_num; i++, index_pt++) {
    const int j = *index_pt;
    if (j < verts_num) {
      BLI_BITMAP_ENABLE(indexar_used, i);
    }
  }
  return indexar_used;
}

static float hook_falloff(const struct HookData_cb *hd, const float len_sq)
{
  BLI_assert(hd->falloff_sq);
  if (len_sq > hd->falloff_sq) {
    return 0.0f;
  }
  if (len_sq > 0.0f) {
    float fac;

    if (hd->falloff_type == eHook_Falloff_Const) {
      fac = 1.0f;
      goto finally;
    }
    else if (hd->falloff_type == eHook_Falloff_InvSquare) {
      /* avoid sqrt below */
      fac = 1.0f - (len_sq / hd->falloff_sq);
      goto finally;
    }

    fac = 1.0f - (sqrtf(len_sq) / hd->falloff);

    /* closely match PROP_SMOOTH and similar */
    switch (hd->falloff_type) {
#if 0
      case eHook_Falloff_None:
        fac = 1.0f;
        break;
#endif
      case eHook_Falloff_Curve:
        fac = BKE_curvemapping_evaluateF(hd->curfalloff, 0, fac);
        break;
      case eHook_Falloff_Sharp:
        fac = fac * fac;
        break;
      case eHook_Falloff_Smooth:
        fac = 3.0f * fac * fac - 2.0f * fac * fac * fac;
        break;
      case eHook_Falloff_Root:
        fac = sqrtf(fac);
        break;
      case eHook_Falloff_Linear:
        /* pass */
        break;
#if 0
      case eHook_Falloff_Const:
        fac = 1.0f;
        break;
#endif
      case eHook_Falloff_Sphere:
        fac = sqrtf(2 * fac - fac * fac);
        break;
#if 0
      case eHook_Falloff_InvSquare:
        fac = fac * (2.0f - fac);
        break;
#endif
    }

  finally:
    return fac * hd->fac_orig;
  }
  else {
    return hd->fac_orig;
  }
}

static void hook_co_apply(struct HookData_cb *hd, int j, const MDeformVert *dv)
{
  float *co = hd->vertexCos[j];
  float fac;

  if (hd->use_falloff) {
    float len_sq;

    if (hd->use_uniform) {
      float co_uniform[3];
      mul_v3_m3v3(co_uniform, hd->mat_uniform, co);
      len_sq = len_squared_v3v3(hd->cent, co_uniform);
    }
    else {
      len_sq = len_squared_v3v3(hd->cent, co);
    }

    fac = hook_falloff(hd, len_sq);
  }
  else {
    fac = hd->fac_orig;
  }

  if (fac) {
    if (dv != NULL) {
      fac *= hd->invert_vgroup ? 1.0f - BKE_defvert_find_weight(dv, hd->defgrp_index) :
                                 BKE_defvert_find_weight(dv, hd->defgrp_index);
    }

    if (fac) {
      float co_tmp[3];
      mul_v3_m4v3(co_tmp, hd->mat, co);
      interp_v3_v3v3(co, co, co_tmp, fac);
    }
  }
}

static void deformVerts_do(HookModifierData *hmd,
                           const ModifierEvalContext *UNUSED(ctx),
                           Object *ob,
                           Mesh *mesh,
                           BMEditMesh *em,
                           float (*vertexCos)[3],
                           int verts_num)
{
  Object *ob_target = hmd->object;
  bPoseChannel *pchan = BKE_pose_channel_find_name(ob_target->pose, hmd->subtarget);
  float dmat[4][4];
  int i, *index_pt;
  MDeformVert *dvert;
  struct HookData_cb hd;
  const bool invert_vgroup = (hmd->flag & MOD_HOOK_INVERT_VGROUP) != 0;

  if (hmd->curfalloff == NULL) {
    /* should never happen, but bad lib linking could cause it */
    hmd->curfalloff = BKE_curvemapping_add(1, 0.0f, 0.0f, 1.0f, 1.0f);
  }

  if (hmd->curfalloff) {
    BKE_curvemapping_init(hmd->curfalloff);
  }

  /* Generic data needed for applying per-vertex calculations (initialize all members) */
  hd.vertexCos = vertexCos;

  MOD_get_vgroup(ob, mesh, hmd->name, &dvert, &hd.defgrp_index);
  int cd_dvert_offset = -1;

  if (hd.defgrp_index != -1) {
    /* Edit-mesh. */
    if (em != NULL) {
      cd_dvert_offset = CustomData_get_offset(&em->bm->vdata, CD_MDEFORMVERT);
      if (cd_dvert_offset == -1) {
        hd.defgrp_index = -1;
      }
    }
    else {
      /* Regular mesh. */
      if (dvert == NULL) {
        hd.defgrp_index = -1;
      }
    }
  }

  hd.curfalloff = hmd->curfalloff;

  hd.falloff_type = hmd->falloff_type;
  hd.falloff = (hmd->falloff_type == eHook_Falloff_None) ? 0.0f : hmd->falloff;
  hd.falloff_sq = square_f(hd.falloff);
  hd.fac_orig = hmd->force;

  hd.use_falloff = (hd.falloff_sq != 0.0f);
  hd.use_uniform = (hmd->flag & MOD_HOOK_UNIFORM_SPACE) != 0;

  hd.invert_vgroup = invert_vgroup;

  if (hd.use_uniform) {
    copy_m3_m4(hd.mat_uniform, hmd->parentinv);
    mul_v3_m3v3(hd.cent, hd.mat_uniform, hmd->cent);
  }
  else {
    unit_m3(hd.mat_uniform); /* unused */
    copy_v3_v3(hd.cent, hmd->cent);
  }

  /* get world-space matrix of target, corrected for the space the verts are in */
  if (hmd->subtarget[0] && pchan) {
    /* bone target if there's a matching pose-channel */
    mul_m4_m4m4(dmat, ob_target->obmat, pchan->pose_mat);
  }
  else {
    /* just object target */
    copy_m4_m4(dmat, ob_target->obmat);
  }
  invert_m4_m4(ob->imat, ob->obmat);
  mul_m4_series(hd.mat, ob->imat, dmat, hmd->parentinv);
  /* --- done with 'hd' init --- */

  /* Regarding index range checking below.
   *
   * This should always be true and I don't generally like
   * "paranoid" style code like this, but old files can have
   * indices that are out of range because old blender did
   * not correct them on exit edit-mode. - zr
   */

  if (hmd->force == 0.0f) {
    /* do nothing, avoid annoying checks in the loop */
  }
  else if (hmd->indexar) { /* vertex indices? */
    const int *origindex_ar;
    /* if mesh is present and has original index data, use it */
    if (mesh && (origindex_ar = CustomData_get_layer(&mesh->vdata, CD_ORIGINDEX))) {
      int verts_orig_num = verts_num;
      if (ob->type == OB_MESH) {
        const Mesh *me_orig = ob->data;
        verts_orig_num = me_orig->totvert;
      }
      BLI_bitmap *indexar_used = hook_index_array_to_bitmap(hmd, verts_orig_num);
      for (i = 0; i < verts_num; i++) {
        int i_orig = origindex_ar[i];
        BLI_assert(i_orig < verts_orig_num);
        if (BLI_BITMAP_TEST(indexar_used, i_orig)) {
          hook_co_apply(&hd, i, dvert ? &dvert[i] : NULL);
        }
      }
      MEM_freeN(indexar_used);
    }
    else { /* missing mesh or ORIGINDEX */
      if ((em != NULL) && (hd.defgrp_index != -1)) {
        BLI_assert(em->bm->totvert == verts_num);
        BLI_bitmap *indexar_used = hook_index_array_to_bitmap(hmd, verts_num);
        BMIter iter;
        BMVert *v;
        BM_ITER_MESH_INDEX (v, &iter, em->bm, BM_VERTS_OF_MESH, i) {
          if (BLI_BITMAP_TEST(indexar_used, i)) {
            const MDeformVert *dv = BM_ELEM_CD_GET_VOID_P(v, cd_dvert_offset);
            hook_co_apply(&hd, i, dv);
          }
        }
        MEM_freeN(indexar_used);
      }
      else {
        for (i = 0, index_pt = hmd->indexar; i < hmd->indexar_num; i++, index_pt++) {
          const int j = *index_pt;
          if (j < verts_num) {
            hook_co_apply(&hd, j, dvert ? &dvert[j] : NULL);
          }
        }
      }
    }
  }
  else if (hd.defgrp_index != -1) { /* vertex group hook */
    if (em != NULL) {
      BLI_assert(em->bm->totvert == verts_num);
      BMIter iter;
      BMVert *v;
      BM_ITER_MESH_INDEX (v, &iter, em->bm, BM_VERTS_OF_MESH, i) {
        const MDeformVert *dv = BM_ELEM_CD_GET_VOID_P(v, cd_dvert_offset);
        hook_co_apply(&hd, i, dv);
      }
    }
    else {
      BLI_assert(dvert != NULL);
      for (i = 0; i < verts_num; i++) {
        hook_co_apply(&hd, i, &dvert[i]);
      }
    }
  }
}

static void deformVerts(struct ModifierData *md,
                        const struct ModifierEvalContext *ctx,
                        struct Mesh *mesh,
                        float (*vertexCos)[3],
                        int verts_num)
{
  HookModifierData *hmd = (HookModifierData *)md;
  Mesh *mesh_src = MOD_deform_mesh_eval_get(
      ctx->object, NULL, mesh, NULL, verts_num, false, false);

  deformVerts_do(hmd, ctx, ctx->object, mesh_src, NULL, vertexCos, verts_num);

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

static void deformVertsEM(struct ModifierData *md,
                          const struct ModifierEvalContext *ctx,
                          struct BMEditMesh *editData,
                          struct Mesh *mesh,
                          float (*vertexCos)[3],
                          int verts_num)
{
  HookModifierData *hmd = (HookModifierData *)md;

  deformVerts_do(hmd, ctx, ctx->object, mesh, mesh ? NULL : editData, vertexCos, verts_num);
}

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

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

  PointerRNA hook_object_ptr = RNA_pointer_get(ptr, "object");

  uiLayoutSetPropSep(layout, true);

  col = uiLayoutColumn(layout, false);
  uiItemR(col, ptr, "object", 0, NULL, ICON_NONE);
  if (!RNA_pointer_is_null(&hook_object_ptr) &&
      RNA_enum_get(&hook_object_ptr, "type") == OB_ARMATURE) {
    PointerRNA hook_object_data_ptr = RNA_pointer_get(&hook_object_ptr, "data");
    uiItemPointerR(
        col, ptr, "subtarget", &hook_object_data_ptr, "bones", IFACE_("Bone"), ICON_NONE);
  }
  modifier_vgroup_ui(layout, ptr, &ob_ptr, "vertex_group", "invert_vertex_group", NULL);

  uiItemR(layout, ptr, "strength", UI_ITEM_R_SLIDER, NULL, ICON_NONE);

  if (RNA_enum_get(&ob_ptr, "mode") == OB_MODE_EDIT) {
    row = uiLayoutRow(layout, true);
    uiItemO(row, IFACE_("Reset"), ICON_NONE, "OBJECT_OT_hook_reset");
    uiItemO(row, IFACE_("Recenter"), ICON_NONE, "OBJECT_OT_hook_recenter");
    row = uiLayoutRow(layout, true);
    uiItemO(row, IFACE_("Select"), ICON_NONE, "OBJECT_OT_hook_select");
    uiItemO(row, IFACE_("Assign"), ICON_NONE, "OBJECT_OT_hook_assign");
  }

  modifier_panel_end(layout, ptr);
}

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

  PointerRNA *ptr = modifier_panel_get_property_pointers(panel, NULL);

  bool use_falloff = RNA_enum_get(ptr, "falloff_type") != eWarp_Falloff_None;

  uiLayoutSetPropSep(layout, true);

  uiItemR(layout, ptr, "falloff_type", 0, IFACE_("Type"), ICON_NONE);

  row = uiLayoutRow(layout, false);
  uiLayoutSetActive(row, use_falloff);
  uiItemR(row, ptr, "falloff_radius", 0, NULL, ICON_NONE);

  uiItemR(layout, ptr, "use_falloff_uniform", 0, NULL, ICON_NONE);

  if (RNA_enum_get(ptr, "falloff_type") == eWarp_Falloff_Curve) {
    uiTemplateCurveMapping(layout, ptr, "falloff_curve", 0, false, false, false, false);
  }
}

static void panelRegister(ARegionType *region_type)
{
  PanelType *panel_type = modifier_panel_register(region_type, eModifierType_Hook, panel_draw);
  modifier_subpanel_register(
      region_type, "falloff", "Falloff", NULL, falloff_panel_draw, panel_type);
}

static void blendWrite(BlendWriter *writer, const ModifierData *md)
{
  const HookModifierData *hmd = (const HookModifierData *)md;

  if (hmd->curfalloff) {
    BKE_curvemapping_blend_write(writer, hmd->curfalloff);
  }

  BLO_write_int32_array(writer, hmd->indexar_num, hmd->indexar);
}

static void blendRead(BlendDataReader *reader, ModifierData *md)
{
  HookModifierData *hmd = (HookModifierData *)md;

  BLO_read_data_address(reader, &hmd->curfalloff);
  if (hmd->curfalloff) {
    BKE_curvemapping_blend_read(reader, hmd->curfalloff);
  }

  BLO_read_int32_array(reader, hmd->indexar_num, &hmd->indexar);
}

ModifierTypeInfo modifierType_Hook = {
    /* name */ "Hook",
    /* structName */ "HookModifierData",
    /* structSize */ sizeof(HookModifierData),
    /* srna */ &RNA_HookModifier,
    /* type */ eModifierTypeType_OnlyDeform,
    /* flags */ eModifierTypeFlag_AcceptsCVs | eModifierTypeFlag_AcceptsVertexCosOnly |
        eModifierTypeFlag_SupportsEditmode,
    /* icon */ ICON_HOOK,
    /* copyData */ copyData,

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

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