/***************************************************************************
     qgsclipboard.cpp  -  QGIS internal clipboard for storage of features
     --------------------------------------------------------------------
    begin                : 20 May, 2005
    copyright            : (C) 2005 by Brendan Morley
    email                : morb at ozemail dot com dot au
 ***************************************************************************/

/***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/

#include <fstream>

#include <QApplication>
#include <QObject>
#include <QString>
#include <QStringList>
#include <QClipboard>
#include <QMimeData>
#include <QTextCodec>

#include "qgsclipboard.h"
#include "qgsfeature.h"
#include "qgsfeaturestore.h"
#include "qgsfields.h"
#include "qgsgeometry.h"
#include "qgscoordinatereferencesystem.h"
#include "qgslogger.h"
#include "qgsvectorlayer.h"
#include "qgsogrutils.h"
#include "qgsjsonutils.h"
#include "qgssettings.h"
#include "qgisapp.h"
#include "qgsmapcanvas.h"
#include "qgsproject.h"
#include "qgsapplication.h"

QgsClipboard::QgsClipboard()
{
  connect( QApplication::clipboard(), &QClipboard::dataChanged, this, &QgsClipboard::systemClipboardChanged );
}

void QgsClipboard::replaceWithCopyOf( QgsVectorLayer *src )
{
  if ( !src )
    return;

  // Replace the QGIS clipboard.
  mFeatureFields = src->fields();
  mFeatureClipboard = src->selectedFeatures();
  mCRS = src->crs();
  mSrcLayer = src;
  QgsDebugMsg( QStringLiteral( "replaced QGIS clipboard." ) );

  setSystemClipboard();
  mUseSystemClipboard = false;
  emit changed();
}

void QgsClipboard::replaceWithCopyOf( QgsFeatureStore &featureStore )
{
  QgsDebugMsg( QStringLiteral( "features count = %1" ).arg( featureStore.features().size() ) );
  mFeatureFields = featureStore.fields();
  mFeatureClipboard = featureStore.features();
  mCRS = featureStore.crs();
  mSrcLayer = nullptr;
  setSystemClipboard();
  mUseSystemClipboard = false;
  emit changed();
}

void QgsClipboard::generateClipboardText( QString &textContent, QString &htmlContent ) const
{
  const CopyFormat format = QgsSettings().enumValue( QStringLiteral( "qgis/copyFeatureFormat" ),  AttributesWithWKT );

  textContent.clear();
  htmlContent.clear();

  switch ( format )
  {
    case AttributesOnly:
    case AttributesWithWKT:
    {
      QStringList textLines, htmlLines;
      QStringList textFields, htmlFields;

      // first do the field names
      if ( format == AttributesWithWKT )
      {
        // only include the "wkt_geom" field IF we have other fields -- otherwise it's redundant and we should just set the clipboard to WKT text directly
        if ( !mFeatureFields.isEmpty() )
          textFields += QStringLiteral( "wkt_geom" );

        htmlFields += QStringLiteral( "<td>wkt_geom</td>" );
      }

      textFields.reserve( mFeatureFields.size() );
      htmlFields.reserve( mFeatureFields.size() );
      for ( const QgsField &field : mFeatureFields )
      {
        textFields += field.name();
        htmlFields += QStringLiteral( "<td>%1</td>" ).arg( field.name() );
      }
      if ( !textFields.empty() )
        textLines += textFields.join( QLatin1Char( '\t' ) );
      htmlLines += htmlFields.join( QString() );
      textFields.clear();
      htmlFields.clear();

      // then the field contents
      for ( QgsFeatureList::const_iterator it = mFeatureClipboard.constBegin(); it != mFeatureClipboard.constEnd(); ++it )
      {
        const QgsAttributes attributes = it->attributes();

        // TODO: Set up Paste Transformations to specify the order in which fields are added.
        if ( format == AttributesWithWKT )
        {
          if ( it->hasGeometry() )
          {
            const QString wkt = it->geometry().asWkt();
            textFields += wkt;
            htmlFields += QStringLiteral( "<td>%1</td>" ).arg( wkt );
          }
          else
          {
            textFields += QgsApplication::nullRepresentation();
            htmlFields += QStringLiteral( "<td>%1</td>" ).arg( QgsApplication::nullRepresentation() );
          }
        }

        for ( int idx = 0; idx < attributes.count(); ++idx )
        {
          QString value = attributes.at( idx ).toString();
          if ( value.contains( '\n' ) || value.contains( '\t' ) )
            textFields += '"' + value.replace( '"', QLatin1String( "\"\"" ) ) + '\"';
          else
          {
            textFields += value;
          }
          value = attributes.at( idx ).toString();
          value.replace( '\n', QLatin1String( "<br>" ) ).replace( '\t', QLatin1String( "&emsp;" ) );
          htmlFields += QStringLiteral( "<td>%1</td>" ).arg( value );
        }

        textLines += textFields.join( QLatin1Char( '\t' ) );
        htmlLines += htmlFields.join( QString() );
        textFields.clear();
        htmlFields.clear();
      }

      textContent = textLines.join( '\n' );
      htmlContent = QStringLiteral( "<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.0 Transitional//EN\"><html><head><meta http-equiv=\"content-type\" content=\"text/html; charset=utf-8\"/></head><body><table border=\"1\"><tr>" ) + htmlLines.join( QLatin1String( "</tr><tr>" ) ) + QStringLiteral( "</tr></table></body></html>" );
      break;
    }
    case GeoJSON:
    {
      QgsJsonExporter exporter;
      exporter.setSourceCrs( mCRS );

      textContent = exporter.exportFeatures( mFeatureClipboard );
    }
  }
}

void QgsClipboard::setSystemClipboard()
{
  // avoid overwriting internal clipboard - note that on Windows, the call to QClipboard::setText
  // below doesn't immediately trigger QClipboard::dataChanged, and accordingly the call to
  // systemClipboardChanged() is delayed. So by setting mIgnoreNextSystemClipboardChange we indicate
  // that just the next call to systemClipboardChanged() should be ignored
  mIgnoreNextSystemClipboardChange = true;

  QClipboard *cb = QApplication::clipboard();

  // Copy text into the clipboard
  QString textCopy, htmlCopy;
  generateClipboardText( textCopy, htmlCopy );
  QMimeData *m = new QMimeData();
  m->setText( textCopy );

  if ( mFeatureClipboard.count() < 1000 && !htmlCopy.isEmpty() )
  {
    m->setHtml( htmlCopy );
  }

  // With qgis running under Linux, but with a Windows based X
  // server (Xwin32), ::Selection was necessary to get the data into
  // the Windows clipboard (which seems contrary to the Qt
  // docs). With a Linux X server, ::Clipboard was required.
  // The simple solution was to put the text into both clipboards.
#ifdef Q_OS_LINUX
  cb->setMimeData( m, QClipboard::Selection );
#endif
  cb->setMimeData( m, QClipboard::Clipboard );

  QgsDebugMsgLevel( QStringLiteral( "replaced system clipboard with: %1." ).arg( textCopy ), 4 );
}

QgsFeatureList QgsClipboard::stringToFeatureList( const QString &string, const QgsFields &fields ) const
{
  //first try using OGR to read string
  QgsFeatureList features = QgsOgrUtils::stringToFeatureList( string, fields, QTextCodec::codecForName( "System" ) );

  if ( !features.isEmpty() )
    return features;

  // otherwise try to read in as WKT
  if ( string.isEmpty() || string.split( '\n' ).count() == 0 )
    return features;

  // Poor man's csv parser
  bool isInsideQuotes {false};
  QgsAttributes attrs;
  QgsGeometry geom;
  QString attrVal;
  bool isFirstLine {string.startsWith( QLatin1String( "wkt_geom" ) )};
  // it seems there is no other way to check for header
  const bool hasHeader{string.startsWith( QLatin1String( "wkt_geom" ) )};
  QgsGeometry geometry;
  bool setFields {fields.isEmpty()};
  QgsFields fieldsFromClipboard;

  auto parseFunc = [ & ]( const QChar & c )
  {

    // parse geom only if it wasn't successfully set before
    if ( geometry.isNull() )
    {
      geometry = QgsGeometry::fromWkt( attrVal );
    }

    if ( isFirstLine ) // ... name
    {
      if ( attrVal != QLatin1String( "wkt_geom" ) ) // ignore this one
      {
        fieldsFromClipboard.append( QgsField{attrVal, QVariant::String } );
      }
    }
    else // ... or value
    {
      attrs.append( attrVal );
    }

    // end of record, create a new feature if it's not the header
    if ( c == QChar( '\n' ) )
    {
      if ( isFirstLine )
      {
        isFirstLine = false;
      }
      else
      {
        QgsFeature feature{setFields ? fieldsFromClipboard : fields};
        feature.setGeometry( geometry );
        if ( hasHeader || !geometry.isNull() )
        {
          attrs.pop_front();
        }
        feature.setAttributes( attrs );
        features.append( feature );
        geometry = QgsGeometry();
        attrs.clear();
      }
    }
    attrVal.clear();
  };

  for ( auto c = string.constBegin(); c < string.constEnd(); ++c )
  {
    if ( *c == QChar( '\n' ) || *c == QChar( '\t' ) )
    {
      if ( isInsideQuotes )
      {
        attrVal.append( *c );
      }
      else
      {
        parseFunc( *c );
      }
    }
    else if ( *c == QChar( '\"' ) )
    {
      isInsideQuotes = !isInsideQuotes;
    }
    else
    {
      attrVal.append( *c );
    }
  }

  // handle missing newline
  if ( !string.endsWith( QChar( '\n' ) ) )
  {
    parseFunc( QChar( '\n' ) );
  }

  return features;
}

QgsFields QgsClipboard::retrieveFields() const
{
  QClipboard *cb = QApplication::clipboard();

#ifdef Q_OS_LINUX
  const QString string = cb->text( QClipboard::Selection );
#else
  QString string = cb->text( QClipboard::Clipboard );
#endif

  QgsFields f = QgsOgrUtils::stringToFields( string, QTextCodec::codecForName( "System" ) );
  if ( f.size() < 1 )
  {
    if ( string.isEmpty() )
    {
      return f;
    }

    //wkt?
    const QString firstLine = string.section( '\n', 0, 0 );
    if ( !firstLine.isEmpty() )
    {
      const QStringList fieldNames = firstLine.split( '\t' );
      //wkt / text always has wkt_geom as first attribute (however values can be NULL)
      if ( fieldNames.at( 0 ) != QLatin1String( "wkt_geom" ) )
      {
        return f;
      }

      for ( int i = 0; i < fieldNames.size(); ++i )
      {
        const QString fieldName = fieldNames.at( i );
        if ( fieldName == QLatin1String( "wkt_geom" ) )
        {
          continue;
        }

        f.append( QgsField( fieldName, QVariant::String ) );
      }
    }
  }
  return f;
}

QgsFeatureList QgsClipboard::copyOf( const QgsFields &fields ) const
{
  QgsDebugMsg( QStringLiteral( "returning clipboard." ) );
  if ( !mUseSystemClipboard )
    return mFeatureClipboard;

  QClipboard *cb = QApplication::clipboard();

#ifdef Q_OS_LINUX
  QString text = cb->text( QClipboard::Selection );
#else
  QString text = cb->text( QClipboard::Clipboard );
#endif

  if ( text.endsWith( '\n' ) )
  {
    text.chop( 1 );
    // In case Windows <EOL> marker (CRLF) makes it into the variable "text"
    if ( text.endsWith( '\r' ) )
    {
      text.chop( 1 );
    }
  }

  return stringToFeatureList( text, fields );
}

void QgsClipboard::clear()
{
  mFeatureClipboard.clear();

  QgsDebugMsg( QStringLiteral( "cleared clipboard." ) );
  emit changed();
}

void QgsClipboard::insert( const QgsFeature &feature )
{
  mFeatureClipboard.push_back( feature );

  QgsDebugMsgLevel( "inserted " + feature.geometry().asWkt(), 4 );
  mUseSystemClipboard = false;
  emit changed();
}

bool QgsClipboard::isEmpty() const
{
  QClipboard *cb = QApplication::clipboard();
#ifdef Q_OS_LINUX
  const QString text = cb->text( QClipboard::Selection );
#else
  QString text = cb->text( QClipboard::Clipboard );
#endif
  return text.isEmpty() && mFeatureClipboard.empty();
}

QgsFeatureList QgsClipboard::transformedCopyOf( const QgsCoordinateReferenceSystem &destCRS, const QgsFields &fields ) const
{
  QgsFeatureList featureList = copyOf( fields );

  QgisApp::instance()->askUserForDatumTransform( crs(), destCRS );
  const QgsCoordinateTransform ct = QgsCoordinateTransform( crs(), destCRS, QgsProject::instance() );

  QgsDebugMsg( QStringLiteral( "transforming clipboard." ) );
  for ( QgsFeatureList::iterator iter = featureList.begin(); iter != featureList.end(); ++iter )
  {
    QgsGeometry g = iter->geometry();
    g.transform( ct );
    iter->setGeometry( g );
  }

  return featureList;
}

QgsCoordinateReferenceSystem QgsClipboard::crs() const
{
  return mCRS;
}

void QgsClipboard::setData( const QString &mimeType, const QByteArray &data, const QString &text )
{
  mUseSystemClipboard = true;
  QMimeData *mdata = new QMimeData();
  mdata->setData( mimeType, data );
  if ( !text.isEmpty() )
  {
    mdata->setText( text );
  }
  // Transfers ownership to the clipboard object
#ifdef Q_OS_LINUX
  QApplication::clipboard()->setMimeData( mdata, QClipboard::Selection );
#endif
  QApplication::clipboard()->setMimeData( mdata, QClipboard::Clipboard );
}

void QgsClipboard::setText( const QString &text )
{
#ifdef Q_OS_LINUX
  QApplication::clipboard()->setText( text, QClipboard::Selection );
#endif
  QApplication::clipboard()->setText( text, QClipboard::Clipboard );
}

bool QgsClipboard::hasFormat( const QString &mimeType ) const
{
  return QApplication::clipboard()->mimeData()->hasFormat( mimeType );
}

QByteArray QgsClipboard::data( const QString &mimeType ) const
{
  return QApplication::clipboard()->mimeData()->data( mimeType );
}

QgsFields QgsClipboard::fields() const
{
  if ( !mUseSystemClipboard )
    return mFeatureFields;
  else
    return retrieveFields();
}

void QgsClipboard::systemClipboardChanged()
{
  if ( mIgnoreNextSystemClipboardChange )
  {
    mIgnoreNextSystemClipboardChange = false;
    return;
  }

  mUseSystemClipboard = true;
  emit changed();
}
