#include "io/gpr/NormalizedRadarVolumeBridge.hpp"

#include <cstddef>
#include <cstdint>
#include <fstream>
#include <sstream>
#include <stdexcept>
#include <vector>

#include "io/gpr/LocalPath.hpp"
#include "io/gpr/NormalizedRadarReader.hpp"
#include "io/gpr/RadarVolumeAssembler.hpp"

namespace geopro::io::gpr {

geopro::core::BuiltI16 buildLineVolumeFromNormalized(const std::string& lineDir,
                                                     const std::string& linePrefix,
                                                     int coarse, double targetDy) {
  const std::string head = lineDir + "/" + linePrefix + ".head";
  const std::string data = lineDir + "/" + linePrefix + ".data";

  std::string headText;
  {
    std::ifstream f(localPath(head));
    if (!f) throw std::runtime_error("打开 .head 失败: " + head);
    std::stringstream ss;
    ss << f.rdbuf();
    headText = ss.str();
  }

  const RadarHeader h = parseRadarHead(headText);
  const std::vector<std::int16_t> cube = readRadarDataCube(data, h);
  const int M = h.channels;
  const int N = h.samples;

  RadarCubeDesc d;
  d.channels = M;
  d.traces = h.traces;
  d.samples = N;
  d.chXOffsets = h.chXOffsets;
  d.dxBase = h.distanceInterval > 1e-9 ? h.distanceInterval : 1.0;
  d.dyWhenNotInterpolated =
      (h.chXOffsets.size() >= 2 && M > 1)
          ? (h.chXOffsets.back() - h.chXOffsets.front()) / (M - 1)
          : 1.0;
  d.dz = depthSpacingZ(h) > 1e-12 ? depthSpacingZ(h) : 1.0;

  // position-major 立方体索引 ((t*M + c)*N + s)，与 readRadarDataCube 一致。
  CubeSampler sample = [&cube, M, N](int c, int t, int s) {
    return static_cast<double>(cube[(static_cast<std::size_t>(t) * M + c) * N + s]);
  };

  return assembleRadarVolume(d, sample, coarse, targetDy);
}

}  // namespace geopro::io::gpr