/*
 * 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) 2013 Blender Foundation.
 * All rights reserved.
 */

/** \file
 * \ingroup depsgraph
 *
 * Methods for constructing depsgraph's nodes
 */

#include "intern/builder/deg_builder_nodes.h"

#include <stdio.h>
#include <stdlib.h>

#include "MEM_guardedalloc.h"

#include "BLI_blenlib.h"
#include "BLI_string.h"
#include "BLI_utildefines.h"

#include "DNA_anim_types.h"
#include "DNA_armature_types.h"
#include "DNA_constraint_types.h"
#include "DNA_object_types.h"
#include "DNA_scene_types.h"

#include "BKE_action.h"
#include "BKE_armature.h"
#include "BKE_constraint.h"

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

#include "intern/builder/deg_builder.h"
#include "intern/depsgraph_type.h"
#include "intern/eval/deg_eval_copy_on_write.h"
#include "intern/node/deg_node.h"
#include "intern/node/deg_node_component.h"
#include "intern/node/deg_node_operation.h"

namespace DEG {

void DepsgraphNodeBuilder::build_pose_constraints(Object *object,
                                                  bPoseChannel *pchan,
                                                  int pchan_index,
                                                  bool is_object_visible)
{
  /* Pull indirect dependencies via constraints. */
  BuilderWalkUserData data;
  data.builder = this;
  data.is_parent_visible = is_object_visible;
  BKE_constraints_id_loop(&pchan->constraints, constraint_walk, &data);
  /* Create node for constraint stack. */
  add_operation_node(&object->id,
                     NodeType::BONE,
                     pchan->name,
                     OperationCode::BONE_CONSTRAINTS,
                     function_bind(BKE_pose_constraints_evaluate,
                                   _1,
                                   get_cow_datablock(scene_),
                                   get_cow_datablock(object),
                                   pchan_index));
}

/* IK Solver Eval Steps */
void DepsgraphNodeBuilder::build_ik_pose(Object *object, bPoseChannel *pchan, bConstraint *con)
{
  bKinematicConstraint *data = (bKinematicConstraint *)con->data;

  /* Find the chain's root. */
  bPoseChannel *rootchan = BKE_armature_ik_solver_find_root(pchan, data);
  if (rootchan == nullptr) {
    return;
  }

  if (has_operation_node(
          &object->id, NodeType::EVAL_POSE, rootchan->name, OperationCode::POSE_IK_SOLVER)) {
    return;
  }

  int rootchan_index = BLI_findindex(&object->pose->chanbase, rootchan);
  BLI_assert(rootchan_index != -1);
  /* Operation node for evaluating/running IK Solver. */
  add_operation_node(&object->id,
                     NodeType::EVAL_POSE,
                     rootchan->name,
                     OperationCode::POSE_IK_SOLVER,
                     function_bind(BKE_pose_iktree_evaluate,
                                   _1,
                                   get_cow_datablock(scene_),
                                   get_cow_datablock(object),
                                   rootchan_index));
}

/* Spline IK Eval Steps */
void DepsgraphNodeBuilder::build_splineik_pose(Object *object,
                                               bPoseChannel *pchan,
                                               bConstraint *con)
{
  bSplineIKConstraint *data = (bSplineIKConstraint *)con->data;

  /* Find the chain's root. */
  bPoseChannel *rootchan = BKE_armature_splineik_solver_find_root(pchan, data);

  /* Operation node for evaluating/running Spline IK Solver.
   * Store the "root bone" of this chain in the solver, so it knows where to
   * start. */
  int rootchan_index = BLI_findindex(&object->pose->chanbase, rootchan);
  BLI_assert(rootchan_index != -1);
  add_operation_node(&object->id,
                     NodeType::EVAL_POSE,
                     rootchan->name,
                     OperationCode::POSE_SPLINE_IK_SOLVER,
                     function_bind(BKE_pose_splineik_evaluate,
                                   _1,
                                   get_cow_datablock(scene_),
                                   get_cow_datablock(object),
                                   rootchan_index));
}

/* Pose/Armature Bones Graph */
void DepsgraphNodeBuilder::build_rig(Object *object, bool is_object_visible)
{
  bArmature *armature = (bArmature *)object->data;
  Scene *scene_cow = get_cow_datablock(scene_);
  Object *object_cow = get_cow_datablock(object);
  OperationNode *op_node;
  /* Animation and/or drivers linking pose-bones to base-armature used to define them.
   *
   * NOTE: AnimData here is really used to control animated deform properties,
   *       which ideally should be able to be unique across different
   *       instances. Eventually, we need some type of proxy/isolation
   *       mechanism in-between here to ensure that we can use same rig
   *       multiple times in same scene. */
  /* Armature. */
  build_armature(armature);
  /* Rebuild pose if not up to date. */
  if (object->pose == nullptr || (object->pose->flag & POSE_RECALC)) {
    /* By definition, no need to tag depsgraph as dirty from here, so we can pass nullptr bmain. */
    BKE_pose_rebuild(nullptr, object, armature, true);
  }
  /* Speed optimization for animation lookups. */
  if (object->pose != nullptr) {
    BKE_pose_channels_hash_make(object->pose);
    if (object->pose->flag & POSE_CONSTRAINTS_NEED_UPDATE_FLAGS) {
      BKE_pose_update_constraint_flags(object->pose);
    }
  }
  /**
   * Pose Rig Graph
   * ==============
   *
   * Pose Component:
   * - Mainly used for referencing Bone components.
   * - This is where the evaluation operations for init/exec/cleanup
   *   (ik) solvers live, and are later hooked up (so that they can be
   *   interleaved during runtime) with bone-operations they depend on/affect.
   * - init_pose_eval() and cleanup_pose_eval() are absolute first and last
   *   steps of pose eval process. ALL bone operations must be performed
   *   between these two...
   *
   * Bone Component:
   * - Used for representing each bone within the rig
   * - Acts to encapsulate the evaluation operations (base matrix + parenting,
   *   and constraint stack) so that they can be easily found.
   * - Everything else which depends on bone-results hook up to the component
   *   only so that we can redirect those to point at either the
   *   post-IK/post-constraint/post-matrix steps, as needed. */
  /* Pose eval context. */
  op_node = add_operation_node(&object->id,
                               NodeType::EVAL_POSE,
                               OperationCode::POSE_INIT,
                               function_bind(BKE_pose_eval_init, _1, scene_cow, object_cow));
  op_node->set_as_entry();

  op_node = add_operation_node(&object->id,
                               NodeType::EVAL_POSE,
                               OperationCode::POSE_INIT_IK,
                               function_bind(BKE_pose_eval_init_ik, _1, scene_cow, object_cow));

  add_operation_node(&object->id,
                     NodeType::EVAL_POSE,
                     OperationCode::POSE_CLEANUP,
                     function_bind(BKE_pose_eval_cleanup, _1, scene_cow, object_cow));

  op_node = add_operation_node(&object->id,
                               NodeType::EVAL_POSE,
                               OperationCode::POSE_DONE,
                               function_bind(BKE_pose_eval_done, _1, object_cow));
  op_node->set_as_exit();
  /* Bones. */
  int pchan_index = 0;
  LISTBASE_FOREACH (bPoseChannel *, pchan, &object->pose->chanbase) {
    /* Node for bone evaluation. */
    op_node = add_operation_node(
        &object->id, NodeType::BONE, pchan->name, OperationCode::BONE_LOCAL);
    op_node->set_as_entry();

    add_operation_node(&object->id,
                       NodeType::BONE,
                       pchan->name,
                       OperationCode::BONE_POSE_PARENT,
                       function_bind(BKE_pose_eval_bone, _1, scene_cow, object_cow, pchan_index));

    /* NOTE: Dedicated noop for easier relationship construction. */
    add_operation_node(&object->id, NodeType::BONE, pchan->name, OperationCode::BONE_READY);

    op_node = add_operation_node(&object->id,
                                 NodeType::BONE,
                                 pchan->name,
                                 OperationCode::BONE_DONE,
                                 function_bind(BKE_pose_bone_done, _1, object_cow, pchan_index));

    /* B-Bone shape computation - the real last step if present. */
    if (check_pchan_has_bbone(object, pchan)) {
      op_node = add_operation_node(
          &object->id,
          NodeType::BONE,
          pchan->name,
          OperationCode::BONE_SEGMENTS,
          function_bind(BKE_pose_eval_bbone_segments, _1, object_cow, pchan_index));
    }

    op_node->set_as_exit();

    /* Custom properties. */
    if (pchan->prop != nullptr) {
      build_idproperties(pchan->prop);
      add_operation_node(
          &object->id, NodeType::PARAMETERS, OperationCode::PARAMETERS_EVAL, nullptr, pchan->name);
    }
    /* Build constraints. */
    if (pchan->constraints.first != nullptr) {
      build_pose_constraints(object, pchan, pchan_index, is_object_visible);
    }
    /**
     * IK Solvers.
     *
     * - These require separate processing steps are pose-level
     *   to be executed between chains of bones (i.e. once the
     *   base transforms of a bunch of bones is done)
     *
     * Unsolved Issues:
     * - Care is needed to ensure that multi-headed trees work out the same
     *   as in ik-tree building
     * - Animated chain-lengths are a problem. */
    LISTBASE_FOREACH (bConstraint *, con, &pchan->constraints) {
      switch (con->type) {
        case CONSTRAINT_TYPE_KINEMATIC:
          build_ik_pose(object, pchan, con);
          break;

        case CONSTRAINT_TYPE_SPLINEIK:
          build_splineik_pose(object, pchan, con);
          break;

        default:
          break;
      }
    }
    /* Custom shape. */
    if (pchan->custom != nullptr) {
      /* TODO(sergey): Use own visibility. */
      build_object(-1, pchan->custom, DEG_ID_LINKED_INDIRECTLY, is_object_visible);
    }
    pchan_index++;
  }
}

void DepsgraphNodeBuilder::build_proxy_rig(Object *object)
{
  bArmature *armature = (bArmature *)object->data;
  OperationNode *op_node;
  Object *object_cow = get_cow_datablock(object);
  /* Sanity check. */
  BLI_assert(object->pose != nullptr);
  /* Armature. */
  build_armature(armature);
  /* speed optimization for animation lookups */
  BKE_pose_channels_hash_make(object->pose);
  if (object->pose->flag & POSE_CONSTRAINTS_NEED_UPDATE_FLAGS) {
    BKE_pose_update_constraint_flags(object->pose);
  }
  op_node = add_operation_node(&object->id,
                               NodeType::EVAL_POSE,
                               OperationCode::POSE_INIT,
                               function_bind(BKE_pose_eval_proxy_init, _1, object_cow));
  op_node->set_as_entry();

  int pchan_index = 0;
  LISTBASE_FOREACH (bPoseChannel *, pchan, &object->pose->chanbase) {
    op_node = add_operation_node(
        &object->id, NodeType::BONE, pchan->name, OperationCode::BONE_LOCAL);
    op_node->set_as_entry();
    /* Bone is ready for solvers. */
    add_operation_node(&object->id, NodeType::BONE, pchan->name, OperationCode::BONE_READY);
    /* Bone is fully evaluated. */
    op_node = add_operation_node(
        &object->id,
        NodeType::BONE,
        pchan->name,
        OperationCode::BONE_DONE,
        function_bind(BKE_pose_eval_proxy_copy_bone, _1, object_cow, pchan_index));
    op_node->set_as_exit();

    /* Custom properties. */
    if (pchan->prop != nullptr) {
      build_idproperties(pchan->prop);
      add_operation_node(
          &object->id, NodeType::PARAMETERS, OperationCode::PARAMETERS_EVAL, nullptr, pchan->name);
    }

    pchan_index++;
  }
  op_node = add_operation_node(&object->id,
                               NodeType::EVAL_POSE,
                               OperationCode::POSE_CLEANUP,
                               function_bind(BKE_pose_eval_proxy_cleanup, _1, object_cow));
  op_node = add_operation_node(&object->id,
                               NodeType::EVAL_POSE,
                               OperationCode::POSE_DONE,
                               function_bind(BKE_pose_eval_proxy_done, _1, object_cow));
  op_node->set_as_exit();
}

}  // namespace DEG