/*
 * GStreamer gstreamer-objectdetectorutils
 * Copyright (C) 2023 Collabora Ltd
 *
 * gstobjectdetectorutils.cpp
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */

#include "gstobjectdetectorutils.h"

#include <fstream>
#include "tensor/gsttensorid.h"

GstMlBoundingBox::GstMlBoundingBox (std::string lbl, float score, float _x0,
    float _y0, float _width, float _height):
label (lbl),
score (score),
x0 (_x0),
y0 (_y0),
width (_width),
height (_height)
{
}

GstMlBoundingBox::GstMlBoundingBox ():
GstMlBoundingBox ("", 0.0f, 0.0f, 0.0f, 0.0f, 0.0f)
{
}

namespace GstObjectDetectorUtils
{

  GstObjectDetectorUtils::GstObjectDetectorUtils ()
  {
  }

  std::vector < std::string >
      GstObjectDetectorUtils::ReadLabels (const std::string & labelsFile)
  {
    std::vector < std::string > labels;
    std::string line;
    std::ifstream fp (labelsFile);
    while (std::getline (fp, line))
      labels.push_back (line);

    return labels;
  }

  std::vector < GstMlBoundingBox > GstObjectDetectorUtils::run (int32_t w,
      int32_t h, GstTensorMeta * tmeta, std::string labelPath,
      float scoreThreshold)
  {

    auto classIndex = gst_tensor_meta_get_index_from_id (tmeta,
        gst_tensorid_get_quark (GST_MODEL_OBJECT_DETECTOR_CLASSES));
    if (classIndex == GST_TENSOR_MISSING_ID) {
      GST_ERROR ("Missing class tensor id");
      return std::vector < GstMlBoundingBox > ();
    }
    auto type = tmeta->tensor[classIndex].type;
    return (type == GST_TENSOR_TYPE_FLOAT32) ?
        doRun < float >(w, h, tmeta, labelPath, scoreThreshold)
    : doRun < int >(w, h, tmeta, labelPath, scoreThreshold);
  }

  template < typename T > std::vector < GstMlBoundingBox >
      GstObjectDetectorUtils::doRun (int32_t w, int32_t h,
      GstTensorMeta * tmeta, std::string labelPath, float scoreThreshold)
  {
    std::vector < GstMlBoundingBox > boundingBoxes;
    GstMapInfo map_info[GstObjectDetectorMaxNodes];
    GstMemory *memory[GstObjectDetectorMaxNodes] = { NULL };
    std::vector < std::string > labels;
    gint index;
    T *numDetections = nullptr, *bboxes = nullptr, *scores =
        nullptr, *labelIndex = nullptr;

    // number of detections
    index = gst_tensor_meta_get_index_from_id (tmeta,
        gst_tensorid_get_quark (GST_MODEL_OBJECT_DETECTOR_NUM_DETECTIONS));
    if (index == GST_TENSOR_MISSING_ID) {
      GST_WARNING ("Missing tensor data for tensor index %d", index);
      goto cleanup;
    }
    memory[index] = gst_buffer_peek_memory (tmeta->tensor[index].data, 0);
    if (!memory[index]) {
      GST_WARNING ("Missing tensor data for tensor index %d", index);
      goto cleanup;
    }
    if (!gst_memory_map (memory[index], map_info + index, GST_MAP_READ)) {
      GST_WARNING ("Failed to map tensor memory for index %d", index);
      goto cleanup;
    }
    numDetections = (T *) map_info[index].data;

    // bounding boxes
    index =
        gst_tensor_meta_get_index_from_id (tmeta,
        gst_tensorid_get_quark (GST_MODEL_OBJECT_DETECTOR_BOXES));
    if (index == GST_TENSOR_MISSING_ID) {
      GST_WARNING ("Missing tensor data for tensor index %d", index);
      goto cleanup;
    }
    memory[index] = gst_buffer_peek_memory (tmeta->tensor[index].data, 0);
    if (!memory[index]) {
      GST_WARNING ("Failed to map tensor memory for index %d", index);
      goto cleanup;
    }
    if (!gst_memory_map (memory[index], map_info + index, GST_MAP_READ)) {
      GST_ERROR ("Failed to map GstMemory");
      goto cleanup;
    }
    bboxes = (T *) map_info[index].data;

    // scores
    index =
        gst_tensor_meta_get_index_from_id (tmeta,
        gst_tensorid_get_quark (GST_MODEL_OBJECT_DETECTOR_SCORES));
    if (index == GST_TENSOR_MISSING_ID) {
      GST_ERROR ("Missing scores tensor id");
      goto cleanup;
    }
    memory[index] = gst_buffer_peek_memory (tmeta->tensor[index].data, 0);
    if (!memory[index]) {
      GST_WARNING ("Missing tensor data for tensor index %d", index);
      goto cleanup;
    }
    if (!gst_memory_map (memory[index], map_info + index, GST_MAP_READ)) {
      GST_ERROR ("Failed to map GstMemory");
      goto cleanup;
    }
    scores = (T *) map_info[index].data;

    // optional label
    labelIndex = nullptr;
    index =
        gst_tensor_meta_get_index_from_id (tmeta,
        gst_tensorid_get_quark (GST_MODEL_OBJECT_DETECTOR_CLASSES));
    if (index != GST_TENSOR_MISSING_ID) {
      memory[index] = gst_buffer_peek_memory (tmeta->tensor[index].data, 0);
      if (!memory[index]) {
        GST_WARNING ("Missing tensor data for tensor index %d", index);
        goto cleanup;
      }
      if (!gst_memory_map (memory[index], map_info + index, GST_MAP_READ)) {
        GST_ERROR ("Failed to map GstMemory");
        goto cleanup;
      }
      labelIndex = (T *) map_info[index].data;
    }

    if (!labelPath.empty ())
      labels = ReadLabels (labelPath);

    for (int i = 0; i < numDetections[0]; ++i) {
      if (scores[i] > scoreThreshold) {
        std::string label = "";

        if (labelIndex && !labels.empty ())
          label = labels[labelIndex[i] - 1];
        auto score = scores[i];
        auto y0 = bboxes[i * 4] * h;
        auto x0 = bboxes[i * 4 + 1] * w;
        auto bheight = bboxes[i * 4 + 2] * h - y0;
        auto bwidth = bboxes[i * 4 + 3] * w - x0;
        boundingBoxes.push_back (GstMlBoundingBox (label, score, x0, y0, bwidth,
                bheight));
      }
    }

  cleanup:
    for (int i = 0; i < GstObjectDetectorMaxNodes; ++i) {
      if (memory[i])
        gst_memory_unmap (memory[i], map_info + i);

    }

    return boundingBoxes;
  }

}