/******************************************************************************************************
 * (C) 2014 markummitchell@github.com. This file is part of Engauge Digitizer, which is released      *
 * under GNU General Public License version 2 (GPLv2) or (at your option) any later version. See file *
 * LICENSE or go to gnu.org/licenses for details. Distribution requires prior written permission.     *
 ******************************************************************************************************/

#include "Curve.h"
#include "CurvesGraphs.h"
#include "CurveStyle.h"
#include "DocumentSerialize.h"
#include "EngaugeAssert.h"
#include "Logger.h"
#include "MigrateToVersion6.h"
#include "Point.h"
#include "PointComparator.h"
#include <QDataStream>
#include <QDebug>
#include <qmath.h>
#include <QMultiMap>
#include <QTextStream>
#include <QXmlStreamReader>
#include <QXmlStreamWriter>
#include "Transformation.h"
#include "Xml.h"

const QString AXIS_CURVE_NAME ("Axes");
const QString DEFAULT_GRAPH_CURVE_NAME ("Curve1");
const QString DUMMY_CURVE_NAME ("dummy");
const QString SCALE_CURVE_NAME ("Scale"); // Used for pre-version 6 input files
const QString TAB_DELIMITER ("\t");

// This has to be a multimap instead of a map since some users may mistakenly allow multiple points with the
// same x coordinate in their functions even though that should not happen
typedef QMultiMap<double, QString> XOrThetaToPointIdentifier;

Curve::Curve(const QString &curveName,
             const ColorFilterSettings &colorFilterSettings,
             const CurveStyle &curveStyle) :
  m_curveName (curveName),
  m_colorFilterSettings (colorFilterSettings),
  m_curveStyle (curveStyle)
{
}

Curve::Curve (const Curve &curve) :
  m_curveName (curve.curveName ()),
  m_points (curve.points ()),
  m_colorFilterSettings (curve.colorFilterSettings ()),
  m_curveStyle (curve.curveStyle ())
{
}

Curve::Curve (QDataStream &str)
{
  const int CONVERT_ENUM_TO_RADIUS = 6;
  MigrateToVersion6 migrate;

  qint32 int32, xScreen, yScreen;
  double xGraph, yGraph;

  str >> m_curveName;

  // Scale bar points are handled as if they are axis points
  if (m_curveName == SCALE_CURVE_NAME) {
    m_curveName = AXIS_CURVE_NAME;
  }

  str >> int32;
  m_curveStyle.setPointShape(migrate.pointShape (int32));
  str >> int32;
  m_curveStyle.setPointRadius(int32 + CONVERT_ENUM_TO_RADIUS);
  str >> int32;
  m_curveStyle.setPointLineWidth (int32);
  str >> int32;
  m_curveStyle.setPointColor(migrate.colorPalette (int32));
  str >> int32; // Point interior color
  str >> int32;
  m_curveStyle.setLineWidth(int32);
  str >> int32;
  if (m_curveName == AXIS_CURVE_NAME) {
    m_curveStyle.setLineColor(migrate.colorPalette (int32));
  } else {
    m_curveStyle.setLineColor(COLOR_PALETTE_TRANSPARENT);
  }
  str >> int32;
  m_curveStyle.setLineConnectAs(migrate.curveConnectAs (int32));

  str >> int32;
  int count = int32;
  int ordinal = 0;
  for (int i = 0; i < count; i++) {

    str >> xScreen;
    str >> yScreen;
    str >> xGraph;
    str >> yGraph;
    if (m_curveName == AXIS_CURVE_NAME) {

      // Axis point, with graph coordinates set by user and managed here
      Point point (m_curveName,
                   QPointF (xScreen, yScreen),
                   QPointF (xGraph, yGraph),
                   ordinal++,
                   false);

      addPoint(point);
    } else {

      // Curve point, with graph coordinates managed elsewhere
      Point point (m_curveName,
                   QPointF (xScreen, yScreen));
      point.setOrdinal (ordinal++);

      addPoint(point);
    }
  }
}

Curve::Curve (QXmlStreamReader &reader)
{
  loadXml(reader);
}

Curve &Curve::operator=(const Curve &curve)
{
  m_curveName = curve.curveName ();
  m_points = curve.points ();
  m_colorFilterSettings = curve.colorFilterSettings ();
  m_curveStyle = curve.curveStyle ();

  return *this;
}

void Curve::addPoint (const Point &point)
{
  m_points.push_back (point);
}

ColorFilterSettings Curve::colorFilterSettings () const
{
  return m_colorFilterSettings;
}

QString Curve::curveName () const
{
  return  m_curveName;
}

CurveStyle Curve::curveStyle() const
{
  return m_curveStyle;
}

void Curve::editPointAxis (const QPointF &posGraph,
                           const QString &identifier)
{
  // Search for the point with matching identifier
  QList<Point>::iterator itr;
  for (itr = m_points.begin (); itr != m_points.end (); itr++) {

    Point &point = *itr;
    if (point.identifier () == identifier) {

      point.setPosGraph (posGraph);
      break;

    }
  }
}

void Curve::editPointGraph (bool isX,
                            bool isY,
                            double x,
                            double y,
                            const QStringList &identifiers,
                            const Transformation &transformation)
{
  LOG4CPP_INFO_S ((*mainCat)) << "Curve::editPointGraph"
                              << " identifiers=" << identifiers.join(" ").toLatin1().data();

  if (transformation.transformIsDefined()) {

    // Search for the point with matching identifier
    QList<Point>::iterator itr;
    for (itr = m_points.begin(); itr != m_points.end(); itr++) {

      Point &point = *itr;

      if (identifiers.contains (point.identifier ())) {

        // Although one or more graph coordinates are specified, it is the screen coordinates that must be
        // moved. This is because only the screen coordinates of the graph points are tracked (not the graph coordinates).
        // So we compute posScreen and call Point::setPosScreen instead of Point::setPosGraph

        // Get original graph coordinates
        QPointF posScreen = point.posScreen ();
        QPointF posGraph;
        transformation.transformScreenToRawGraph (posScreen,
                                                  posGraph);

        // Override one or both coordinates
        if (isX) {
          posGraph.setX (x);
        }

        if (isY) {
          posGraph.setY (y);
        }

        // Set the screen coordinates
        transformation.transformRawGraphToScreen(posGraph,
                                                 posScreen);

        point.setPosScreen (posScreen);
      }
    }
  }
}

void Curve::exportToClipboard (const QHash<QString, bool> &selectedHash,
                               const Transformation &transformation,
                               QTextStream &strCsv,
                               QTextStream &strHtml,
                               CurvesGraphs &curvesGraphs) const
{
  LOG4CPP_INFO_S ((*mainCat)) << "Curve::exportToClipboard"
                              << " hashCount=" << selectedHash.count();

  // This method assumes Copy is only allowed when Transformation is valid

  bool isFirst = true;
  QList<Point>::const_iterator itr;
  for (itr = m_points.begin (); itr != m_points.end (); itr++) {

    const Point &point = *itr;
    if (selectedHash.contains (point.identifier ())) {

      if (isFirst) {

        // Insert headers to identify the points that follow
        isFirst = false;
        strCsv << "X" << TAB_DELIMITER << m_curveName << "\n";
        strHtml << "<table>\n"
                << "<tr><th>X</th><th>" << m_curveName << "</th></tr>\n";
      }

      // Default curve style
      CurveStyle curveStyleDefault;
      curveStyleDefault.setLineStyle(LineStyle::defaultAxesCurve());
      curveStyleDefault.setPointStyle(PointStyle::defaultGraphCurve (curvesGraphs.numCurves ()));

      // Check if this curve already exists from a previously exported point
      if (curvesGraphs.curveForCurveName (m_curveName) == nullptr) {
        Curve curve(m_curveName,
                    ColorFilterSettings::defaultFilter (),
                    curveStyleDefault);
        curvesGraphs.addGraphCurveAtEnd(curve);
      }

      // Start with screen coordinates
      QPointF pos = point.posScreen();
      if (transformation.transformIsDefined()) {

        // Replace with graph coordinates which are almost always more useful
        QPointF posGraph;
        transformation.transformScreenToRawGraph(pos,
                                                 posGraph);
        pos = posGraph;
      }

      // Add point to text going to clipboard
      strCsv << pos.x() << TAB_DELIMITER << pos.y() << "\n";
      strHtml << "<tr><td>" << pos.x() << "</td><td>" << pos.y() << "</td></tr>\n";

      // Add point to list for undo/redo
      curvesGraphs.curveForCurveName (m_curveName)->addPoint (point);
    }
  }

  if (!isFirst) {
    strHtml << "</table>\n";
  }
}

bool Curve::isXOnly(const QString &pointIdentifier) const
{
  // Search for point with matching identifier
  Points::const_iterator itr;
  for (itr = m_points.begin (); itr != m_points.end (); itr++) {
    const Point &point = *itr;
    if (pointIdentifier == point.identifier ()) {
      return point.isXOnly();
    }
  }

  LOG4CPP_ERROR_S ((*mainCat)) << "Curve::isXOnly encountered unknown indentifier "
                               << pointIdentifier.toLatin1().data();
  ENGAUGE_ASSERT (false);

  return false;
}

void Curve::iterateThroughCurvePoints (const Functor2wRet<const QString &, const Point&, CallbackSearchReturn> &ftorWithCallback) const
{
  QList<Point>::const_iterator itr;
  for (itr = m_points.begin (); itr != m_points.end (); itr++) {

    const Point &point = *itr;

    CallbackSearchReturn rtn = ftorWithCallback (m_curveName, point);

    if (rtn == CALLBACK_SEARCH_RETURN_INTERRUPT) {
      break;
    }
  }
}

void Curve::iterateThroughCurveSegments (const Functor2wRet<const Point&, const Point&, CallbackSearchReturn> &ftorWithCallback) const
{
  // Loop through Points. They are assumed to be already sorted by their ordinals, but we do NOT
  // check the ordinal ordering since this could be called before, or while, the ordinal sorting is done
  QList<Point>::const_iterator itr;
  const Point *pointBefore = nullptr;
  for (itr = m_points.begin(); itr != m_points.end(); itr++) {

    const Point &point = *itr;

    if (pointBefore != nullptr) {

      CallbackSearchReturn rtn = ftorWithCallback (*pointBefore,
                                                   point);

      if (rtn == CALLBACK_SEARCH_RETURN_INTERRUPT) {
        break;
      }

    }
    pointBefore = &point;
  }
}

void Curve::loadCurvePoints(QXmlStreamReader &reader)
{
  LOG4CPP_INFO_S ((*mainCat)) << "Curve::loadCurvePoints";

  bool success = true;

  while ((reader.tokenType() != QXmlStreamReader::EndElement) ||
         (reader.name() != DOCUMENT_SERIALIZE_CURVE_POINTS)) {

    QXmlStreamReader::TokenType tokenType = loadNextFromReader(reader);

    if (reader.atEnd()) {
      success = false;
      break;
    }

    if (tokenType == QXmlStreamReader::StartElement) {

      if (reader.name () == DOCUMENT_SERIALIZE_POINT) {

        Point point (reader);
        m_points.push_back (point);
      }
    }
  }

  if (!success) {
    reader.raiseError(QObject::tr ("Cannot read curve data"));
  }
}

void Curve::loadXml(QXmlStreamReader &reader)
{
  LOG4CPP_INFO_S ((*mainCat)) << "Curve::loadXml";

  bool success = true;

  QXmlStreamAttributes attributes = reader.attributes();

  if (attributes.hasAttribute (DOCUMENT_SERIALIZE_CURVE_NAME)) {

    setCurveName (attributes.value (DOCUMENT_SERIALIZE_CURVE_NAME).toString());

    // Read until end of this subtree
    while ((reader.tokenType() != QXmlStreamReader::EndElement) ||
           (reader.name() != DOCUMENT_SERIALIZE_CURVE)){

      QXmlStreamReader::TokenType tokenType = loadNextFromReader(reader);

      if (reader.atEnd()) {
        success = false;
        break;
      }

      if (tokenType == QXmlStreamReader::StartElement) {

        if (reader.name() == DOCUMENT_SERIALIZE_COLOR_FILTER) {
          m_colorFilterSettings.loadXml(reader);
        } else if (reader.name() == DOCUMENT_SERIALIZE_CURVE_POINTS) {
          loadCurvePoints(reader);
        } else if (reader.name() == DOCUMENT_SERIALIZE_CURVE_STYLE) {
          m_curveStyle.loadXml(reader);
        } else {
          success = false;
          break;
        }
      }

      if (reader.hasError()) {
        // No need to set success flag to indicate failure, which raises the error, since the error was already raised. Just
        // need to exit the loop immediately
        break;
      }
    }
  } else {
    success = false;
  }

  if (!success) {
    reader.raiseError (QObject::tr ("Cannot read curve data"));
  }
}

void Curve::movePoint (const QString &pointIdentifier,
                       const QPointF &deltaScreen)
{
  Point *point = pointForPointIdentifier (pointIdentifier);

  QPointF posScreen = deltaScreen + point->posScreen ();
  point->setPosScreen (posScreen);
}

int Curve::numPoints () const
{
  return m_points.count ();
}

Point *Curve::pointForPointIdentifier (const QString pointIdentifier)
{
  Points::iterator itr;
  for (itr = m_points.begin (); itr != m_points.end (); itr++) {
    Point &point = *itr;
    if (pointIdentifier == point.identifier ()) {
      return &point;
    }
  }

  LOG4CPP_ERROR_S ((*mainCat)) << "Curve::pointForPointIdentifier encountered unknown indentifier "
                               << pointIdentifier.toLatin1().data();  
  ENGAUGE_ASSERT (false);
  return nullptr;
}

const Points Curve::points () const
{
  return m_points;
}

QPointF Curve::positionGraph (const QString &pointIdentifier) const
{
  QPointF posGraph;

  // Search for point with matching identifier
  Points::const_iterator itr;
  for (itr = m_points.begin (); itr != m_points.end (); itr++) {
    const Point &point = *itr;
    if (pointIdentifier == point.identifier ()) {
      posGraph = point.posGraph ();
      break;
    }
  }

  return posGraph;
}

QPointF Curve::positionScreen (const QString &pointIdentifier) const
{
  QPointF posScreen;

  // Search for point with matching identifier
  Points::const_iterator itr;
  for (itr = m_points.begin (); itr != m_points.end (); itr++) {
    const Point &point = *itr;
    if (pointIdentifier == point.identifier ()) {
      posScreen = point.posScreen ();
      break;
    }
  }

  return posScreen;
}

void Curve::printStream (QString indentation,
                         QTextStream &str) const
{
  str << indentation << "Curve=" << m_curveName << "\n";

  indentation += INDENTATION_DELTA;

  Points::const_iterator itr;
  for (itr = m_points.begin (); itr != m_points.end (); itr++) {
    const Point &point = *itr;
    point.printStream (indentation, 
                       str);
  }

  m_colorFilterSettings.printStream (indentation,
                                     str);
  m_curveStyle.printStream (indentation,
                            str);
}

void Curve::removePoint (const QString &identifier)
{
  // Search for point with matching identifier
  Points::iterator itr;
  for (itr = m_points.begin (); itr != m_points.end (); itr++) {
    Point point = *itr;
    if (point.identifier () == identifier) {
      m_points.erase (itr);
      break;
    }
  }
}

void Curve::saveXml(QXmlStreamWriter &writer) const
{
  LOG4CPP_INFO_S ((*mainCat)) << "Curve::saveXml";

  writer.writeStartElement(DOCUMENT_SERIALIZE_CURVE);
  writer.writeAttribute(DOCUMENT_SERIALIZE_CURVE_NAME, m_curveName);
  m_colorFilterSettings.saveXml (writer,
                                 m_curveName);
  m_curveStyle.saveXml (writer,
                        m_curveName);

  // Loop through points
  writer.writeStartElement(DOCUMENT_SERIALIZE_CURVE_POINTS);
  Points::const_iterator itr;
  for (itr = m_points.begin (); itr != m_points.end (); itr++) {
    const Point &point = *itr;
    point.saveXml (writer);
  }
  writer.writeEndElement();

  writer.writeEndElement();
}

void Curve::setColorFilterSettings (const ColorFilterSettings &colorFilterSettings)
{
  m_colorFilterSettings = colorFilterSettings;
}

void Curve::setCurveName (const QString &curveName)
{
  m_curveName = curveName;

  // Pass to member objects
  QList<Point>::iterator itr;
  for (itr = m_points.begin(); itr != m_points.end(); itr++) {
    Point &point = *itr;
    point.setCurveName (curveName);
  }
}

void Curve::setCurveStyle (const CurveStyle &curveStyle)
{
  m_curveStyle = curveStyle;
}

void Curve::updatePointOrdinals (const Transformation &transformation)
{
  CurveConnectAs curveConnectAs = m_curveStyle.lineStyle().curveConnectAs();

  LOG4CPP_INFO_S ((*mainCat)) << "Curve::updatePointOrdinals"
                              << " curve=" << m_curveName.toLatin1().data()
                              << " connectAs=" << curveConnectAsToString(curveConnectAs).toLatin1().data();

  // Make sure ordinals are properly ordered. Sorting is done afterward

  if (curveConnectAs == CONNECT_AS_FUNCTION_SMOOTH ||
      curveConnectAs == CONNECT_AS_FUNCTION_STRAIGHT) {

    updatePointOrdinalsFunctions (transformation);

  } else if (curveConnectAs == CONNECT_AS_RELATION_SMOOTH ||
             curveConnectAs == CONNECT_AS_RELATION_STRAIGHT) {

    updatePointOrdinalsRelations ();

  } else {

    LOG4CPP_ERROR_S ((*mainCat)) << "Curve::updatePointOrdinals encountered unexpected connection configuration";
    ENGAUGE_ASSERT (false);

  }

  std::sort (m_points.begin(),
             m_points.end(),
             PointComparator());
}

void Curve::updatePointOrdinalsFunctions (const Transformation &transformation)
{
  CurveConnectAs curveConnectAs = m_curveStyle.lineStyle().curveConnectAs();

  LOG4CPP_INFO_S ((*mainCat)) << "Curve::updatePointOrdinalsFunctions"
                              << " curve=" << m_curveName.toLatin1().data()
                              << " connectAs=" << curveConnectAsToString(curveConnectAs).toLatin1().data();

  // Get a map of x/theta values as keys with point identifiers as the values. This has to be a multimap since
  // some users will have two (or maybe more) points with the same x coordinate, even though true functions should
  // never have that happen
  XOrThetaToPointIdentifier xOrThetaToPointIdentifier;
  Points::iterator itr;
  for (itr = m_points.begin (); itr != m_points.end (); itr++) {
    Point &point = *itr;

    QPointF posGraph;
    if (transformation.transformIsDefined()) {

      // Transformation is available so use it
      transformation.transformScreenToRawGraph (point.posScreen (),
                                                posGraph);
    } else {

      // Transformation is not available so we just use the screen coordinates. Effectively, the
      // transformation is the identity matrix
      posGraph= point.posScreen();
    }

    xOrThetaToPointIdentifier.insert (posGraph.x(),
                                      point.identifier());
  }

  // Every point in m_points must be in the map. Failure to perform this check will probably result in the assert
  // below getting triggered
  ENGAUGE_ASSERT (xOrThetaToPointIdentifier.count () == m_points.count ());

  // Since m_points is a list (and therefore does not provide direct access to elements), we build a temporary map of
  // point identifier to ordinal, by looping through the sorted x/theta values. Since QMap is used, the x/theta keys are sorted
  QMap<QString, double> pointIdentifierToOrdinal;
  int ordinal = 0;
  XOrThetaToPointIdentifier::const_iterator itrX;
  for (itrX = xOrThetaToPointIdentifier.begin(); itrX != xOrThetaToPointIdentifier.end(); itrX++) {

    QString pointIdentifier = itrX.value();
    pointIdentifierToOrdinal [pointIdentifier] = ordinal++;
  }

  // Override the old ordinal values
  for (itr = m_points.begin(); itr != m_points.end(); itr++) {
    Point &point = *itr;

    // Make sure point is in the map list. If this test is skipped then the square bracket operator
    // will insert an entry with a zero ordinal, and the presence of multiple points with the same zero ordinal will
    // cause problems downstream
    ENGAUGE_ASSERT (pointIdentifierToOrdinal.contains (point.identifier()));

    // Point is to be included since it is in the map list.
    int ordinalNew = qFloor (pointIdentifierToOrdinal [point.identifier()]);
    point.setOrdinal (ordinalNew);
  }
}

void Curve::updatePointOrdinalsRelations ()
{
  CurveConnectAs curveConnectAs = m_curveStyle.lineStyle().curveConnectAs();

  LOG4CPP_INFO_S ((*mainCat)) << "Curve::updatePointOrdinalsRelations"
                              << " curve=" << m_curveName.toLatin1().data()
                              << " connectAs=" << curveConnectAsToString(curveConnectAs).toLatin1().data();

    // Keep the ordinal numbering, but make sure the ordinals are evenly spaced
    Points::iterator itr;
    int ordinal = 0;
    for (itr = m_points.begin(); itr != m_points.end(); itr++) {
      Point &point = *itr;
      point.setOrdinal (ordinal++);
    }
}
