#ifndef NOMINMAX
#define NOMINMAX
#endif

#include "RoiLoader.h"
#include "dcmIO.h"

#include <QFileInfo>
#include <QFile>
#include <QJsonDocument>
#include <QJsonObject>
#include <QJsonArray>
#include <QDir>

#include <itkResampleImageFilter.h>
#include <itkNearestNeighborInterpolateImageFunction.h>
#include <itkImageRegionIterator.h>
#include <itkImageDuplicator.h>

#include <gdcmReader.h>
#include <gdcmMediaStorage.h>
#include <gdcmTag.h>
#include <gdcmDataSet.h>

DropContentKind classifyMedicalPath(const QString& path)
{
  if (path.isEmpty())
    return DropContentKind::Unknown;
  const QString lower = path.toLower();
  if (lower.endsWith(QStringLiteral(".json"))) {
    QFile f(path);
    if (!f.open(QIODevice::ReadOnly))
      return DropContentKind::Unknown;
    const QJsonDocument doc = QJsonDocument::fromJson(f.readAll());
    if (doc.isObject() && doc.object().contains(QStringLiteral("roiList")))
      return DropContentKind::Structure;
    return DropContentKind::Unknown;
  }
  if (lower.endsWith(QStringLiteral(".mhd")) || lower.endsWith(QStringLiteral(".mha"))
      || lower.endsWith(QStringLiteral(".nii")) || lower.endsWith(QStringLiteral(".nii.gz")))
    return DropContentKind::Dose;

  if (lower.endsWith(QStringLiteral(".dcm")) || lower.endsWith(QStringLiteral(".dicom"))) {
    gdcm::Reader reader;
    reader.SetFileName(path.toLocal8Bit().constData());
    if (!reader.Read())
      return DropContentKind::Unknown;
    gdcm::MediaStorage ms;
    ms.SetFromFile(reader.GetFile());
    if (ms == gdcm::MediaStorage::RTStructureSetStorage)
      return DropContentKind::Structure;
    if (ms == gdcm::MediaStorage::RTDoseStorage)
      return DropContentKind::Dose;
    // Other DICOM: treat as dose candidate (CT series folder is handled separately).
    const gdcm::DataSet& ds = reader.GetFile().GetDataSet();
    if (ds.FindDataElement(gdcm::Tag(0x3006, 0x0020)))
      return DropContentKind::Structure;
    if (ds.FindDataElement(gdcm::Tag(0x3004, 0x000e)) || ds.FindDataElement(gdcm::Tag(0x3004, 0x000E)))
      return DropContentKind::Dose;
    return DropContentKind::Dose;
  }
  return DropContentKind::Unknown;
}

int loadRoiStructures(
    const QString& path,
    RoiFloatImage::Pointer referenceImage,
    std::vector<std::string>& nameVec,
    std::vector<RoiMaskType::Pointer>& maskVec,
    QString* error)
{
  nameVec.clear();
  maskVec.clear();
  if (!referenceImage) {
    if (error)
      *error = QStringLiteral("缺少参考图像网格");
    return -1;
  }
  if (path.isEmpty() || !QFileInfo::exists(path)) {
    if (error)
      *error = QStringLiteral("勾画文件不存在");
    return -1;
  }

  const QString lower = path.toLower();
  if (lower.endsWith(QStringLiteral(".dcm")) || lower.endsWith(QStringLiteral(".dicom"))) {
    const int ret = itkRtStructureReader(path.toLocal8Bit().constData(), referenceImage, nameVec, maskVec);
    if (ret < 0) {
      if (error)
        *error = QStringLiteral("读取 RTSTRUCT 失败 (%1)").arg(ret);
      return ret;
    }
    return 0;
  }

  if (lower.endsWith(QStringLiteral(".json"))) {
    QFile f(path);
    if (!f.open(QIODevice::ReadOnly)) {
      if (error)
        *error = QStringLiteral("无法打开 JSON");
      return -1;
    }
    const QJsonDocument doc = QJsonDocument::fromJson(f.readAll());
    if (!doc.isObject()) {
      if (error)
        *error = QStringLiteral("JSON 格式错误");
      return -1;
    }
    const QJsonArray roiList = doc.object().value(QStringLiteral("roiList")).toArray();
    if (roiList.isEmpty()) {
      if (error)
        *error = QStringLiteral("JSON 中没有 roiList");
      return -1;
    }

    const QString folder = QFileInfo(path).absolutePath();
    for (const QJsonValue& v : roiList) {
      const QJsonObject o = v.toObject();
      QString niiPath = o.value(QStringLiteral("niiPath")).toString();
      const QString roiName = o.value(QStringLiteral("roiName")).toString();
      if (niiPath.isEmpty())
        continue;
      if (!QFileInfo(niiPath).isAbsolute())
        niiPath = QDir(folder).filePath(niiPath);

      RoiMaskType::Pointer mask;
      const int ret = itkMetaMaskReader(niiPath.toLocal8Bit().constData(), mask);
      if (ret < 0 || !mask) {
        if (error)
          *error = QStringLiteral("读取 ROI NIfTI 失败: %1").arg(niiPath);
        return -1;
      }
      nameVec.push_back(roiName.isEmpty() ? QFileInfo(niiPath).baseName().toStdString()
                                          : roiName.toStdString());
      maskVec.push_back(mask);
    }
    if (maskVec.empty()) {
      if (error)
        *error = QStringLiteral("未加载到任何 ROI");
      return -1;
    }
    return 0;
  }

  if (error)
    *error = QStringLiteral("仅支持 .dcm RTSTRUCT 或 .json ROI 列表");
  return -1;
}

RoiMaskType::Pointer resampleMaskToImage(
    RoiMaskType::Pointer mask,
    RoiFloatImage::Pointer target)
{
  if (!mask || !target)
    return nullptr;

  using Resample = itk::ResampleImageFilter<RoiMaskType, RoiMaskType>;
  using Interp = itk::NearestNeighborInterpolateImageFunction<RoiMaskType, double>;
  auto filter = Resample::New();
  auto interp = Interp::New();
  filter->SetInterpolator(interp);
  filter->SetInput(mask);
  filter->SetSize(target->GetLargestPossibleRegion().GetSize());
  filter->SetOutputOrigin(target->GetOrigin());
  filter->SetOutputSpacing(target->GetSpacing());
  filter->SetOutputDirection(target->GetDirection());
  filter->SetDefaultPixelValue(0);
  filter->Update();
  return filter->GetOutput();
}

RoiFloatImage::Pointer applyMaskToDose(
    RoiFloatImage::Pointer dose,
    RoiMaskType::Pointer maskOnDoseGrid)
{
  if (!dose)
    return nullptr;

  using Dup = itk::ImageDuplicator<RoiFloatImage>;
  auto dup = Dup::New();
  dup->SetInputImage(dose);
  dup->Update();
  auto out = dup->GetOutput();

  if (!maskOnDoseGrid)
    return out;

  itk::ImageRegionIterator<RoiFloatImage> dit(out, out->GetLargestPossibleRegion());
  itk::ImageRegionConstIterator<RoiMaskType> mit(maskOnDoseGrid, maskOnDoseGrid->GetLargestPossibleRegion());
  for (dit.GoToBegin(), mit.GoToBegin(); !dit.IsAtEnd() && !mit.IsAtEnd(); ++dit, ++mit) {
    if (mit.Get() == 0)
      dit.Set(0.f);
  }
  return out;
}