/*
 * 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.
 *
 * Copyright 2018, Blender Foundation.
 */

#include "COM_CryptomatteNode.h"
#include "BLI_assert.h"
#include "BLI_hash_mm3.h"
#include "BLI_string.h"
#include "COM_ConvertOperation.h"
#include "COM_CryptomatteOperation.h"
#include "COM_SetAlphaOperation.h"
#include <iterator>

CryptomatteNode::CryptomatteNode(bNode *editorNode) : Node(editorNode)
{
  /* pass */
}

/* This is taken from the Cryptomatte specification 1.0. */
static inline float hash_to_float(uint32_t hash)
{
  uint32_t mantissa = hash & ((1 << 23) - 1);
  uint32_t exponent = (hash >> 23) & ((1 << 8) - 1);
  exponent = max(exponent, (uint32_t)1);
  exponent = min(exponent, (uint32_t)254);
  exponent = exponent << 23;
  uint32_t sign = (hash >> 31);
  sign = sign << 31;
  uint32_t float_bits = sign | exponent | mantissa;
  float f;
  /* Bit casting relies on equal size for both types. */
  BLI_STATIC_ASSERT(sizeof(float) == sizeof(uint32_t), "float and uint32_t are not the same size")
  ::memcpy(&f, &float_bits, sizeof(float));
  return f;
}

void CryptomatteNode::convertToOperations(NodeConverter &converter,
                                          const CompositorContext & /*context*/) const
{
  NodeInput *inputSocketImage = this->getInputSocket(0);
  NodeOutput *outputSocketImage = this->getOutputSocket(0);
  NodeOutput *outputSocketMatte = this->getOutputSocket(1);
  NodeOutput *outputSocketPick = this->getOutputSocket(2);

  bNode *node = this->getbNode();
  NodeCryptomatte *cryptoMatteSettings = (NodeCryptomatte *)node->storage;

  CryptomatteOperation *operation = new CryptomatteOperation(getNumberOfInputSockets() - 1);
  if (cryptoMatteSettings) {
    if (cryptoMatteSettings->matte_id) {
      /* Split the string by commas, ignoring white space. */
      std::string input = cryptoMatteSettings->matte_id;
      std::istringstream ss(input);
      while (ss.good()) {
        std::string token;
        getline(ss, token, ',');
        /* Ignore empty tokens. */
        if (token.length() > 0) {
          size_t first = token.find_first_not_of(' ');
          size_t last = token.find_last_not_of(' ');
          if (first == std::string::npos || last == std::string::npos) {
            break;
          }
          token = token.substr(first, (last - first + 1));
          if (*token.begin() == '<' && *(--token.end()) == '>') {
            operation->addObjectIndex(atof(token.substr(1, token.length() - 2).c_str()));
          }
          else {
            uint32_t hash = BLI_hash_mm3((const unsigned char *)token.c_str(), token.length(), 0);
            operation->addObjectIndex(hash_to_float(hash));
          }
        }
      }
    }
  }

  converter.addOperation(operation);

  for (int i = 0; i < getNumberOfInputSockets() - 1; i++) {
    converter.mapInputSocket(this->getInputSocket(i + 1), operation->getInputSocket(i));
  }

  SeparateChannelOperation *separateOperation = new SeparateChannelOperation;
  separateOperation->setChannel(3);
  converter.addOperation(separateOperation);

  SetAlphaOperation *operationAlpha = new SetAlphaOperation();
  converter.addOperation(operationAlpha);

  converter.addLink(operation->getOutputSocket(0), separateOperation->getInputSocket(0));
  converter.addLink(separateOperation->getOutputSocket(0), operationAlpha->getInputSocket(1));

  SetAlphaOperation *clearAlphaOperation = new SetAlphaOperation();
  converter.addOperation(clearAlphaOperation);
  converter.addInputValue(clearAlphaOperation->getInputSocket(1), 1.0f);

  converter.addLink(operation->getOutputSocket(0), clearAlphaOperation->getInputSocket(0));

  converter.mapInputSocket(inputSocketImage, operationAlpha->getInputSocket(0));
  converter.mapOutputSocket(outputSocketMatte, separateOperation->getOutputSocket(0));
  converter.mapOutputSocket(outputSocketImage, operationAlpha->getOutputSocket(0));
  converter.mapOutputSocket(outputSocketPick, clearAlphaOperation->getOutputSocket(0));
}