/*
 * 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 blenloader
 */

/* allow readfile to use deprecated functionality */
#define DNA_DEPRECATED_ALLOW

#include <float.h>
#include <string.h>

#include "BLI_math.h"
#include "BLI_string.h"
#include "BLI_utildefines.h"

#include "DNA_color_types.h"
#include "DNA_light_types.h"
#include "DNA_node_types.h"
#include "DNA_particle_types.h"

#include "BKE_colortools.h"
#include "BKE_idprop.h"
#include "BKE_main.h"
#include "BKE_node.h"

#include "BLO_readfile.h"
#include "readfile.h"

static float *cycles_node_socket_float_value(bNodeSocket *socket)
{
  bNodeSocketValueFloat *socket_data = socket->default_value;
  return &socket_data->value;
}

static IDProperty *cycles_properties_from_ID(ID *id)
{
  IDProperty *idprop = IDP_GetProperties(id, false);
  return (idprop) ? IDP_GetPropertyTypeFromGroup(idprop, "cycles", IDP_GROUP) : NULL;
}

static float cycles_property_float(IDProperty *idprop, const char *name, float default_value)
{
  IDProperty *prop = IDP_GetPropertyTypeFromGroup(idprop, name, IDP_FLOAT);
  return (prop) ? IDP_Float(prop) : default_value;
}

static bool cycles_property_boolean(IDProperty *idprop, const char *name, bool default_value)
{
  IDProperty *prop = IDP_GetPropertyTypeFromGroup(idprop, name, IDP_INT);
  return (prop) ? IDP_Int(prop) : default_value;
}

static void displacement_node_insert(bNodeTree *ntree)
{
  bool need_update = false;

  /* Iterate backwards from end so we don't encounter newly added links. */
  bNodeLink *prevlink;
  for (bNodeLink *link = ntree->links.last; link; link = prevlink) {
    prevlink = link->prev;

    /* Detect link to replace. */
    bNode *fromnode = link->fromnode;
    bNodeSocket *fromsock = link->fromsock;
    bNode *tonode = link->tonode;
    bNodeSocket *tosock = link->tosock;

    if (!(tonode->type == SH_NODE_OUTPUT_MATERIAL && fromnode->type != SH_NODE_DISPLACEMENT &&
          STREQ(tosock->identifier, "Displacement"))) {
      continue;
    }

    /* Replace link with displacement node. */
    nodeRemLink(ntree, link);

    /* Add displacement node. */
    bNode *node = nodeAddStaticNode(NULL, ntree, SH_NODE_DISPLACEMENT);
    node->locx = 0.5f * (fromnode->locx + tonode->locx);
    node->locy = 0.5f * (fromnode->locy + tonode->locy);

    bNodeSocket *scale_socket = nodeFindSocket(node, SOCK_IN, "Scale");
    bNodeSocket *midlevel_socket = nodeFindSocket(node, SOCK_IN, "Midlevel");
    bNodeSocket *height_socket = nodeFindSocket(node, SOCK_IN, "Height");
    bNodeSocket *displacement_socket = nodeFindSocket(node, SOCK_OUT, "Displacement");

    /* Set default values for compatibility. */
    *cycles_node_socket_float_value(scale_socket) = 0.1f;
    *cycles_node_socket_float_value(midlevel_socket) = 0.0f;

    /* Link to input and material output node. */
    nodeAddLink(ntree, fromnode, fromsock, node, height_socket);
    nodeAddLink(ntree, node, displacement_socket, tonode, tosock);

    need_update = true;
  }

  if (need_update) {
    ntreeUpdateTree(NULL, ntree);
  }
}

static void displacement_principled_nodes(bNode *node)
{
  if (node->type == SH_NODE_DISPLACEMENT) {
    if (node->custom1 != SHD_SPACE_WORLD) {
      node->custom1 = SHD_SPACE_OBJECT;
    }
  }
  else if (node->type == SH_NODE_BSDF_PRINCIPLED) {
    if (node->custom2 != SHD_SUBSURFACE_RANDOM_WALK) {
      node->custom2 = SHD_SUBSURFACE_BURLEY;
    }
  }
}

static bool node_has_roughness(bNode *node)
{
  return ELEM(node->type,
              SH_NODE_BSDF_ANISOTROPIC,
              SH_NODE_BSDF_GLASS,
              SH_NODE_BSDF_GLOSSY,
              SH_NODE_BSDF_REFRACTION);
}

static void square_roughness_node_insert(bNodeTree *ntree)
{
  bool need_update = false;

  /* Update default values */
  for (bNode *node = ntree->nodes.first; node; node = node->next) {
    if (node_has_roughness(node)) {
      bNodeSocket *roughness_input = nodeFindSocket(node, SOCK_IN, "Roughness");
      float *roughness_value = cycles_node_socket_float_value(roughness_input);
      *roughness_value = sqrtf(max_ff(*roughness_value, 0.0f));
    }
  }

  /* Iterate backwards from end so we don't encounter newly added links. */
  bNodeLink *prevlink;
  for (bNodeLink *link = ntree->links.last; link; link = prevlink) {
    prevlink = link->prev;

    /* Detect link to replace. */
    bNode *fromnode = link->fromnode;
    bNodeSocket *fromsock = link->fromsock;
    bNode *tonode = link->tonode;
    bNodeSocket *tosock = link->tosock;

    if (!(node_has_roughness(tonode) && STREQ(tosock->identifier, "Roughness"))) {
      continue;
    }

    /* Replace links with sqrt node */
    nodeRemLink(ntree, link);

    /* Add sqrt node. */
    bNode *node = nodeAddStaticNode(NULL, ntree, SH_NODE_MATH);
    node->custom1 = NODE_MATH_POW;
    node->locx = 0.5f * (fromnode->locx + tonode->locx);
    node->locy = 0.5f * (fromnode->locy + tonode->locy);

    /* Link to input and material output node. */
    *cycles_node_socket_float_value(node->inputs.last) = 0.5f;
    nodeAddLink(ntree, fromnode, fromsock, node, node->inputs.first);
    nodeAddLink(ntree, node, node->outputs.first, tonode, tosock);

    need_update = true;
  }

  if (need_update) {
    ntreeUpdateTree(NULL, ntree);
  }
}

static void mapping_node_order_flip(bNode *node)
{
  /* Flip euler order of mapping shader node */
  if (node->type == SH_NODE_MAPPING) {
    TexMapping *texmap = node->storage;

    float quat[4];
    eulO_to_quat(quat, texmap->rot, EULER_ORDER_ZYX);
    quat_to_eulO(texmap->rot, EULER_ORDER_XYZ, quat);
  }
}

static void vector_curve_node_remap(bNode *node)
{
  /* Remap values of vector curve node from normalized to absolute values */
  if (node->type == SH_NODE_CURVE_VEC) {
    CurveMapping *mapping = node->storage;
    mapping->flag &= ~CUMA_DO_CLIP;

    for (int curve_index = 0; curve_index < CM_TOT; curve_index++) {
      CurveMap *cm = &mapping->cm[curve_index];
      if (cm->curve) {
        for (int i = 0; i < mapping->cm->totpoint; i++) {
          cm->curve[i].x = (cm->curve[i].x * 2.0f) - 1.0f;
          cm->curve[i].y = (cm->curve[i].y - 0.5f) * 2.0f;
        }
      }
    }

    curvemapping_changed_all(mapping);
  }
}

static void ambient_occlusion_node_relink(bNodeTree *ntree)
{
  bool need_update = false;

  /* Set default values. */
  for (bNode *node = ntree->nodes.first; node; node = node->next) {
    if (node->type == SH_NODE_AMBIENT_OCCLUSION) {
      node->custom1 = 1; /* samples */
      node->custom2 &= ~SHD_AO_LOCAL;

      bNodeSocket *distance_socket = nodeFindSocket(node, SOCK_IN, "Distance");
      *cycles_node_socket_float_value(distance_socket) = 0.0f;
    }
  }

  /* Iterate backwards from end so we don't encounter newly added links. */
  bNodeLink *prevlink;
  for (bNodeLink *link = ntree->links.last; link; link = prevlink) {
    prevlink = link->prev;

    /* Detect link to replace. */
    bNode *fromnode = link->fromnode;
    bNode *tonode = link->tonode;
    bNodeSocket *tosock = link->tosock;

    if (!(fromnode->type == SH_NODE_AMBIENT_OCCLUSION)) {
      continue;
    }

    /* Replace links with color socket. */
    nodeRemLink(ntree, link);
    bNodeSocket *color_socket = nodeFindSocket(fromnode, SOCK_OUT, "Color");
    nodeAddLink(ntree, fromnode, color_socket, tonode, tosock);

    need_update = true;
  }

  if (need_update) {
    ntreeUpdateTree(NULL, ntree);
  }
}

void blo_do_versions_cycles(FileData *UNUSED(fd), Library *UNUSED(lib), Main *bmain)
{
  /* Particle shape shared with Eevee. */
  if (!MAIN_VERSION_ATLEAST(bmain, 280, 16)) {
    for (ParticleSettings *part = bmain->particles.first; part; part = part->id.next) {
      IDProperty *cpart = cycles_properties_from_ID(&part->id);

      if (cpart) {
        part->shape = cycles_property_float(cpart, "shape", 0.0);
        part->rad_root = cycles_property_float(cpart, "root_width", 1.0);
        part->rad_tip = cycles_property_float(cpart, "tip_width", 0.0);
        part->rad_scale = cycles_property_float(cpart, "radius_scale", 0.01);
        if (cycles_property_boolean(cpart, "use_closetip", true)) {
          part->shape_flag |= PART_SHAPE_CLOSE_TIP;
        }
      }
    }
  }
}

void do_versions_after_linking_cycles(Main *bmain)
{
  if (!MAIN_VERSION_ATLEAST(bmain, 280, 5)) {
    /* Shader node tree changes. After lib linking so we have all the typeinfo
     * pointers and updated sockets and we can use the high level node API to
     * manipulate nodes. */
    FOREACH_NODETREE_BEGIN (bmain, ntree, id) {
      if (ntree->type != NTREE_SHADER) {
        continue;
      }

      if (!MAIN_VERSION_ATLEAST(bmain, 273, 5)) {
        /* Euler order was ZYX in previous versions. */
        for (bNode *node = ntree->nodes.first; node; node = node->next) {
          mapping_node_order_flip(node);
        }
      }

      if (!MAIN_VERSION_ATLEAST(bmain, 276, 6)) {
        for (bNode *node = ntree->nodes.first; node; node = node->next) {
          vector_curve_node_remap(node);
        }
      }

      if (!MAIN_VERSION_ATLEAST(bmain, 279, 2) ||
          (MAIN_VERSION_ATLEAST(bmain, 280, 0) && !MAIN_VERSION_ATLEAST(bmain, 280, 4))) {
        displacement_node_insert(ntree);
      }

      if (!MAIN_VERSION_ATLEAST(bmain, 279, 3)) {
        for (bNode *node = ntree->nodes.first; node; node = node->next) {
          displacement_principled_nodes(node);
        }
      }

      if (!MAIN_VERSION_ATLEAST(bmain, 279, 4) ||
          (MAIN_VERSION_ATLEAST(bmain, 280, 0) && !MAIN_VERSION_ATLEAST(bmain, 280, 5))) {
        /* Switch to squared roughness convention */
        square_roughness_node_insert(ntree);
      }

      if (!MAIN_VERSION_ATLEAST(bmain, 279, 5)) {
        ambient_occlusion_node_relink(ntree);
      }
    }
    FOREACH_NODETREE_END;
  }
}