/**
  * @RDE_HEADER@
  * Tile Map Service Layer for Esri
  * $Id$
  * $HeadURL$
  * $Author$
  * License: BSD 2-Clause
  */


#include "tms_layer.h"

#include <QCoreApplication>
#include <QDomDocument>
#include <QNetworkAccessManager>


namespace EsriExtension
{

TMSLayer::TMSLayer(const QString &url, QObject *parent)
  : EsriRuntimeQt::TiledMapServiceLayer(url, parent)
  , m_nam(nullptr)
{
  connect(this, SIGNAL(requestTile(int,int,int)),
          this, SLOT(onRequestTMSTile(int,int,int)));
}

TMSLayer::~TMSLayer()
{
  delete m_nam;
}

void TMSLayer::initialize()
{
  if (!m_nam)
  {
    m_nam = new QNetworkAccessManager(this);
    connect(m_nam, SIGNAL(finished(QNetworkReply*)),
            this, SLOT(replyBaseXmlFinished(QNetworkReply*)));
  }

  QNetworkReply *reply = m_nam->get(QNetworkRequest(QUrl(url())));
  connect(reply, SIGNAL(error(QNetworkReply::NetworkError)),
          this, SLOT(replyBaseXmlError(QNetworkReply::NetworkError)));
}

void TMSLayer::replyBaseXmlFinished(QNetworkReply *reply)
{
  if (!reply || reply->error() != QNetworkReply::NoError)
  {
    cleanupNetworkReply(reply);
    return;
  }
  QDomDocument doc(QLatin1String("TMSLayerDoc"));
  doc.setContent(reply);
  const QDomElement domRoot = doc.documentElement();
  const QDomElement domSRS = domRoot.firstChildElement(QLatin1String("SRS"));
  const QDomElement domBoundingBox = domRoot.firstChildElement(QLatin1String("BoundingBox"));
  const QDomElement domOrigin = domRoot.firstChildElement(QLatin1String("Origin"));
  const QDomElement domTileFormat = domRoot.firstChildElement(QLatin1String("TileFormat"));
  const QDomElement domTileSets = domRoot.firstChildElement(QLatin1String("TileSets"));

  if (domSRS.isNull() ||
      domBoundingBox.isNull() ||
      domOrigin.isNull() ||
      domTileFormat.isNull() ||
      domTileSets.isNull())
  {
    cleanupNetworkReply(reply);
    const QString errStr(QString(QLatin1String("Got invalid xml from tms server (url: %1)")).arg(url()));
    layerCreateError(errStr);
    qWarning("%s", qPrintable(errStr));
    return;
  }

  // optional
  if (domTileFormat.hasAttribute(QLatin1String("extension")))
    m_extension = domTileFormat.attribute(QLatin1String("extension"));

  //LODs:
  const double dpi = 90.7;  // according to spec
  const double ipf = 12.0;  // inch per foot
  const double dpu = dpi * ipf; // dots per unit

  // We expect a SRS string in the format 'EPSG:<number>' here ...
  const EsriRuntimeQt::SpatialReference sr(domSRS.text().split(QLatin1Char(':')).at(1).toInt());
  // Setting the image format is not needed (the image reader correctly guesses the format)
  // Setting the spatial reference is also not needed - if not set, the default one
  //   from the layer is used.
  EsriRuntimeQt::TileInfo tileInfo;

  tileInfo.setCols(domTileFormat.attribute(QLatin1String("width")).toInt());
  tileInfo.setRows(domTileFormat.attribute(QLatin1String("height")).toInt());

  tileInfo.setDpi(dpi);

  EsriRuntimeQt::LOD lod;
  QList<EsriRuntimeQt::LOD> lods;
  const double minX = domBoundingBox.attribute(QLatin1String("minx")).toDouble();
  const double minY = domBoundingBox.attribute(QLatin1String("miny")).toDouble();
  const double maxX = domBoundingBox.attribute(QLatin1String("maxx")).toDouble();
  const double maxY = domBoundingBox.attribute(QLatin1String("maxy")).toDouble();

  // Since ArcGIS calculates from upper left (instead lower left as tms defines),
  // we need to make sure all our zoom levels have the same upper y value
  // TODO: use from zoom level
  const double utm32MaxYcalc = 16384 * 256 * 3; // 3 - Anzahl kacheln lowest zoom level
  const double utm32MinX = 166021.44309607695;  // min utm 32 boundary - calc from proj4 or smth. like this

  const QString tsAttr(QLatin1String("TileSet"));
  QDomElement tileSetSibling = domTileSets.firstChildElement(tsAttr);
  for (; !tileSetSibling.isNull(); tileSetSibling = tileSetSibling.nextSiblingElement(tsAttr))
  {
    if (!tileSetSibling.hasAttribute(QLatin1String("order")))
    {
      qWarning("Could not find 'order' attribute for LOD - skipping lod");
      continue;
    }
    const int lodLevel = tileSetSibling.attribute(QLatin1String("order")).toInt();

    lod.setLevel(lodLevel);
    lod.setResolution(tileSetSibling.attribute(QLatin1String("units-per-pixel")).toDouble());
    lod.setScale(lod.resolution() / dpu);

    if (!tileSetSibling.hasAttribute(QLatin1String("href")))
    {
      qWarning("Could not find 'href' attribute for LOD - skipping lod");
      continue;
    }

    lods.append(lod);
    m_tileUrls.insert(lodLevel, tileSetSibling.attribute(QLatin1String("href")));

    // Since ArcGIS calculates from upper left (instead lower left as tms defines),
    // we need to make sure all our zoom levels have the same upper y value
    m_tilesYAxis.insert(lodLevel, qRound(utm32MaxYcalc / (lod.resolution() * tileInfo.cols())));
    //qWarning("LOD: %d, %lf %lf, %lf", lodLevel, lod.resolution(), lod.scale(),
    // lod.resolution() * 256 * m_tilesYAxis.value(lodLevel));

    //qWarning("Y Tile count for level %d is %d - %lf", lodLevel, m_tilesYAxis.value(lodLevel),
    //         utm32MaxYcalc / (lod.resolution() * tileInfo.cols()));
  }
  if (lods.isEmpty())
  {
    const QString errStr(QLatin1String("Could not find any layer in the xml file!"));
    layerCreateError(errStr);
    qWarning("%s", qPrintable(errStr));
    cleanupNetworkReply(reply);
    return;
  }
  tileInfo.setLODs(lods);

  const EsriRuntimeQt::Envelope envelope(minX, minY, maxX, maxY, sr);
  // TMS service origin is bottom left, arcgis upper left
  tileInfo.setOrigin({utm32MinX, utm32MaxYcalc, sr});

  setDefaultSpatialReference(sr);
  setFullExtent(envelope);
  setInitialExtent(envelope);
  setTileInfo(tileInfo);

  // TODO: setMin/Max scale ?

  EsriRuntimeQt::TiledMapServiceLayer::initialize();

  // clean up
  cleanupNetworkReply(reply);
}

void TMSLayer::replyBaseXmlError(QNetworkReply::NetworkError error)
{
  const QString errStr(QString(QLatin1String("Error retrieving xml from %1, error: %2")).arg(url()).arg(error));
  emit layerCreateError(errStr);
  qWarning("%s", qPrintable(errStr));
}

void TMSLayer::onRequestTMSTile(int level, int col, int row)
{
  if (!m_tilesYAxis.contains(level))
  {
    qWarning("Invalud zoom level (%d)!", level);
    return;
  }
  // TMS starts counting from bottom left, ArcGIS from upper left
  // -> we need to mirror the y-axis
  int reqRow = m_tilesYAxis.value(level) - row - 1;
  //qWarning("onRequestTMSTile: %d, %d, %d (%d)", level, col, reqRow, row);
  QString requestUrl(m_tileUrls.value(level) +
                     QLatin1Char('/') + QString::number(col) +
                     QLatin1Char('/') + QString::number(reqRow));
  if (!m_extension.isEmpty())
    requestUrl += QLatin1Char('.') + m_extension;
  //qWarning("RequestUrl: %s", qPrintable(requestUrl));
  setTile(level, col, row, QUrl(requestUrl));
}

void TMSLayer::cleanupNetworkReply(QNetworkReply *reply)
{
  if (reply)
  {
    reply->deleteLater();
    reply->disconnect(this);
  }
  if (m_nam)
  {
    m_nam->disconnect(this);
    m_nam->deleteLater();
    m_nam = nullptr;
  }
}

} // namespace EsriExtension