/* 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 2014, Blender Foundation.
 */

#include "COM_PlaneCornerPinOperation.h"
#include "COM_ConstantOperation.h"
#include "COM_ReadBufferOperation.h"

#include "MEM_guardedalloc.h"

#include "BLI_listbase.h"
#include "BLI_math.h"
#include "BLI_math_color.h"

#include "BKE_node.h"

namespace blender::compositor {

constexpr int LOWER_LEFT_CORNER_INDEX = 0;
constexpr int LOWER_RIGHT_CORNER_INDEX = 1;
constexpr int UPPER_RIGHT_CORNER_INDEX = 2;
constexpr int UPPER_LEFT_CORNER_INDEX = 3;

static bool check_corners(float corners[4][2])
{
  int i, next, prev;
  float cross = 0.0f;

  for (i = 0; i < 4; i++) {
    float v1[2], v2[2], cur_cross;

    next = (i + 1) % 4;
    prev = (4 + i - 1) % 4;

    sub_v2_v2v2(v1, corners[i], corners[prev]);
    sub_v2_v2v2(v2, corners[next], corners[i]);

    cur_cross = cross_v2v2(v1, v2);
    if (fabsf(cur_cross) <= FLT_EPSILON) {
      return false;
    }

    if (cross == 0.0f) {
      cross = cur_cross;
    }
    else if (cross * cur_cross < 0.0f) {
      return false;
    }
  }

  return true;
}

/* TODO(manzanilla): to be removed with tiled implementation. */
static void readCornersFromSockets(rcti *rect, SocketReader *readers[4], float corners[4][2])
{
  for (int i = 0; i < 4; i++) {
    float result[4] = {0.0f, 0.0f, 0.0f, 0.0f};
    readers[i]->readSampled(result, rect->xmin, rect->ymin, PixelSampler::Nearest);
    corners[i][0] = result[0];
    corners[i][1] = result[1];
  }

  /* convexity check:
   * concave corners need to be prevented, otherwise
   * BKE_tracking_homography_between_two_quads will freeze
   */
  if (!check_corners(corners)) {
    /* simply revert to default corners
     * there could be a more elegant solution,
     * this prevents freezing at least.
     */
    corners[0][0] = 0.0f;
    corners[0][1] = 0.0f;
    corners[1][0] = 1.0f;
    corners[1][1] = 0.0f;
    corners[2][0] = 1.0f;
    corners[2][1] = 1.0f;
    corners[3][0] = 0.0f;
    corners[3][1] = 1.0f;
  }
}

static void set_default_corner(const int corner_idx, float corner[2])
{
  BLI_assert(corner_idx >= 0 && corner_idx < 4);
  switch (corner_idx) {
    case LOWER_LEFT_CORNER_INDEX:
      corner[0] = 0.0f;
      corner[1] = 0.0f;
      break;
    case LOWER_RIGHT_CORNER_INDEX:
      corner[0] = 1.0f;
      corner[1] = 0.0f;
      break;
    case UPPER_RIGHT_CORNER_INDEX:
      corner[0] = 1.0f;
      corner[1] = 1.0f;
      break;
    case UPPER_LEFT_CORNER_INDEX:
      corner[0] = 0.0f;
      corner[1] = 1.0f;
      break;
  }
}

static void read_input_corners(NodeOperation *op, const int first_input_idx, float r_corners[4][2])
{
  for (const int i : IndexRange(4)) {
    NodeOperation *input = op->get_input_operation(i + first_input_idx);
    if (input->get_flags().is_constant_operation) {
      ConstantOperation *corner_input = static_cast<ConstantOperation *>(input);
      copy_v2_v2(r_corners[i], corner_input->get_constant_elem());
    }
    else {
      set_default_corner(i, r_corners[i]);
    }
  }

  /* Convexity check: concave corners need to be prevented, otherwise
   * #BKE_tracking_homography_between_two_quads will freeze. */
  if (!check_corners(r_corners)) {
    /* Revert to default corners. There could be a more elegant solution,
     * this prevents freezing at least. */
    for (const int i : IndexRange(4)) {
      set_default_corner(i, r_corners[i]);
    }
  }
}

/* ******** PlaneCornerPinMaskOperation ******** */

PlaneCornerPinMaskOperation::PlaneCornerPinMaskOperation() : m_corners_ready(false)
{
  addInputSocket(DataType::Vector);
  addInputSocket(DataType::Vector);
  addInputSocket(DataType::Vector);
  addInputSocket(DataType::Vector);

  /* XXX this is stupid: we need to make this "complex",
   * so we can use the initializeTileData function
   * to read corners from input sockets ...
   */
  flags.complex = true;
}

void PlaneCornerPinMaskOperation::init_data()
{
  if (execution_model_ == eExecutionModel::FullFrame) {
    float corners[4][2];
    read_input_corners(this, 0, corners);
    calculateCorners(corners, true, 0);
  }
}

/* TODO(manzanilla): to be removed with tiled implementation. Same for #deinitExecution and do the
 * same on #PlaneCornerPinWarpImageOperation. */
void PlaneCornerPinMaskOperation::initExecution()
{
  PlaneDistortMaskOperation::initExecution();

  initMutex();
}

void PlaneCornerPinMaskOperation::deinitExecution()
{
  PlaneDistortMaskOperation::deinitExecution();

  deinitMutex();
}

void *PlaneCornerPinMaskOperation::initializeTileData(rcti *rect)
{
  void *data = PlaneDistortMaskOperation::initializeTileData(rect);

  /* get corner values once, by reading inputs at (0,0)
   * XXX this assumes invariable values (no image inputs),
   * we don't have a nice generic system for that yet
   */
  lockMutex();
  if (!m_corners_ready) {
    SocketReader *readers[4] = {
        getInputSocketReader(0),
        getInputSocketReader(1),
        getInputSocketReader(2),
        getInputSocketReader(3),
    };
    float corners[4][2];
    readCornersFromSockets(rect, readers, corners);
    calculateCorners(corners, true, 0);

    m_corners_ready = true;
  }
  unlockMutex();

  return data;
}

void PlaneCornerPinMaskOperation::determine_canvas(const rcti &preferred_area, rcti &r_area)
{
  if (execution_model_ == eExecutionModel::FullFrame) {
    /* Determine input canvases. */
    PlaneDistortMaskOperation::determine_canvas(preferred_area, r_area);
  }
  r_area = preferred_area;
}

void PlaneCornerPinMaskOperation::get_area_of_interest(const int UNUSED(input_idx),
                                                       const rcti &UNUSED(output_area),
                                                       rcti &r_input_area)
{
  /* All corner inputs are used as constants. */
  r_input_area = COM_CONSTANT_INPUT_AREA_OF_INTEREST;
}

/* ******** PlaneCornerPinWarpImageOperation ******** */

PlaneCornerPinWarpImageOperation::PlaneCornerPinWarpImageOperation() : m_corners_ready(false)
{
  addInputSocket(DataType::Vector);
  addInputSocket(DataType::Vector);
  addInputSocket(DataType::Vector);
  addInputSocket(DataType::Vector);
}

void PlaneCornerPinWarpImageOperation::init_data()
{
  if (execution_model_ == eExecutionModel::FullFrame) {
    float corners[4][2];
    read_input_corners(this, 1, corners);
    calculateCorners(corners, true, 0);
  }
}

void PlaneCornerPinWarpImageOperation::initExecution()
{
  PlaneDistortWarpImageOperation::initExecution();

  initMutex();
}

void PlaneCornerPinWarpImageOperation::deinitExecution()
{
  PlaneDistortWarpImageOperation::deinitExecution();

  deinitMutex();
}

void *PlaneCornerPinWarpImageOperation::initializeTileData(rcti *rect)
{
  void *data = PlaneDistortWarpImageOperation::initializeTileData(rect);

  /* get corner values once, by reading inputs at (0,0)
   * XXX this assumes invariable values (no image inputs),
   * we don't have a nice generic system for that yet
   */
  lockMutex();
  if (!m_corners_ready) {
    /* corner sockets start at index 1 */
    SocketReader *readers[4] = {
        getInputSocketReader(1),
        getInputSocketReader(2),
        getInputSocketReader(3),
        getInputSocketReader(4),
    };
    float corners[4][2];
    readCornersFromSockets(rect, readers, corners);
    calculateCorners(corners, true, 0);

    m_corners_ready = true;
  }
  unlockMutex();

  return data;
}

bool PlaneCornerPinWarpImageOperation::determineDependingAreaOfInterest(
    rcti *input, ReadBufferOperation *readOperation, rcti *output)
{
  for (int i = 0; i < 4; i++) {
    if (getInputOperation(i + 1)->determineDependingAreaOfInterest(input, readOperation, output)) {
      return true;
    }
  }

  /* XXX this is bad, but unavoidable with the current design:
   * we don't know the actual corners and matrix at this point,
   * so all we can do is get the full input image
   */
  output->xmin = 0;
  output->ymin = 0;
  output->xmax = getInputOperation(0)->getWidth();
  output->ymax = getInputOperation(0)->getHeight();
  return true;
#if 0
  return PlaneDistortWarpImageOperation::determineDependingAreaOfInterest(
      input, readOperation, output);
#endif
}

void PlaneCornerPinWarpImageOperation::get_area_of_interest(const int input_idx,
                                                            const rcti &output_area,
                                                            rcti &r_input_area)
{
  if (input_idx == 0) {
    PlaneDistortWarpImageOperation::get_area_of_interest(input_idx, output_area, r_input_area);
  }
  else {
    /* Corner inputs are used as constants. */
    r_input_area = COM_CONSTANT_INPUT_AREA_OF_INTEREST;
  }
}

}  // namespace blender::compositor