/*
 MDAL - Mesh Data Abstraction Library (MIT License)
 Copyright (C) 2018 Peter Petrik (zilolv at gmail dot com)
*/

#ifndef MDAL_UTILS_HPP
#define MDAL_UTILS_HPP

#include <string>
#include <vector>
#include <stddef.h>
#include <limits>
#include <sstream>
#include <fstream>

#include <algorithm>

#include "mdal_data_model.hpp"
#include "mdal_memory_data_model.hpp"
#include "mdal_datetime.hpp"

// avoid unused variable warnings
#define MDAL_UNUSED(x) (void)x;
#define MDAL_NAN std::numeric_limits<double>::quiet_NaN()

namespace MDAL
{
  // endianness
  bool isNativeLittleEndian();

  // numbers
  bool equals( double val1, double val2, double eps = std::numeric_limits<double>::epsilon() );

  //! returns quiet_NaN if value equals nodata value, otherwise returns val itself
  double safeValue( double val, double nodata, double eps = std::numeric_limits<double>::epsilon() );

  // debugging
  void debug( const std::string &message );

  /** Return whether file exists */
  bool fileExists( const std::string &filename );
  std::string baseName( const std::string &filename );
  std::string dirName( const std::string &filename );
  std::string pathJoin( const std::string &path1, const std::string &path2 );
  std::string readFileToString( const std::string &filename );

  // strings
  enum ContainsBehaviour
  {
    CaseSensitive,
    CaseInsensitive
  };

  bool startsWith( const std::string &str, const std::string &substr, ContainsBehaviour behaviour = CaseSensitive );
  bool endsWith( const std::string &str, const std::string &substr, ContainsBehaviour behaviour = CaseSensitive );
  bool contains( const std::string &str, const std::string &substr, ContainsBehaviour behaviour = CaseSensitive );
  bool contains( const std::vector<std::string> &list, const std::string &str );
  std::string replace( const std::string &str, const std::string &substr, const std::string &replacestr, ContainsBehaviour behaviour = CaseSensitive );
  //! left justify and truncate, resulting string will always have width chars
  std::string leftJustified( const std::string &str, size_t width, char fill = ' ' );

  std::string toLower( const std::string &std );

  //! Get a first line from stream clipped to first 100 characters
  bool getHeaderLine( std::ifstream &stream, std::string &line );

  /** Return 0 if not possible to convert */
  size_t toSizeT( const std::string &str );
  size_t toSizeT( const char &str );
  int toInt( const std::string &str );
  double toDouble( const std::string &str );
  bool toBool( const std::string &str );

  //! Returns the string with a adapted format to coordinate
  //! precision is the number of digits after the digital point if fabs(value)>180 (seems to not be a geographic coordinate)
  //! precision+6 is the number of digits after the digital point if fabs(value)<=180 (could be a geographic coordinate)
  std::string coordinateToString( double coordinate, int precision = 2 );

  //! Returns a string with scientific format
  //! precision is the number of signifiant digits
  std::string doubleToString( double value, int precision = 6 );

  /**
   * Splits by deliminer and skips empty parts.
   * Faster than version with std::string
   */
  std::vector<std::string> split( const std::string &str, const char delimiter );

  //! Splits by deliminer and skips empty parts
  std::vector<std::string> split( const std::string &str, const std::string &delimiter );

  std::string join( const std::vector<std::string> parts, const std::string &delimiter );

  //! Right trim
  std::string rtrim(
    const std::string &s,
    const std::string &delimiters = " \f\n\r\t\v" );

  //! Left trim
  std::string ltrim(
    const std::string &s,
    const std::string &delimiters = " \f\n\r\t\v" );

  //! Right and left trim
  std::string trim(
    const std::string &s,
    const std::string &delimiters = " \f\n\r\t\v" );

  // extent
  BBox computeExtent( const Vertices &vertices );

  // time
  //! Returns a delimiter to get time in hours
  double parseTimeUnits( const std::string &units );
  //! Returns current time stamp in YYYY-mm-ddTHH:MM:SSzoneOffset
  std::string getCurrentTimeStamp();

  // statistics
  void combineStatistics( Statistics &main, const Statistics &other );

  //! Calculates statistics for dataset group
  Statistics calculateStatistics( std::shared_ptr<DatasetGroup> grp );
  Statistics calculateStatistics( DatasetGroup *grp );

  //! Calculates statistics for dataset
  Statistics calculateStatistics( std::shared_ptr<Dataset> dataset );

  // mesh & datasets
  //! Adds bed elevatiom dataset group to mesh
  void addBedElevationDatasetGroup( MDAL::Mesh *mesh, const Vertices &vertices );
  //! Adds altitude dataset group to mesh
  void addFaceScalarDatasetGroup( MDAL::Mesh *mesh, const std::vector<double> &values, const std::string &name );

  //! function used to read all of type of value. Option to change the endianness is provided
  template<typename T>
  bool readValue( T &value, std::ifstream &in, bool changeEndianness = false )
  {
    char *const p = reinterpret_cast<char *>( &value );

    if ( !in.read( p, sizeof( T ) ) )
      return false;

    if ( changeEndianness )
      std::reverse( p, p + sizeof( T ) );

    return true;
  }

  //! Prepend 0 to string to have n char
  std::string prependZero( const std::string &str, size_t length );

  RelativeTimestamp::Unit parseDurationTimeUnit( const std::string &timeUnit );

  //! parse the time unit in the CF convention string format "XXXX since 2019-01-01 00:00:00"
  //! https://www.unidata.ucar.edu/software/netcdf-java/current/CDM/CalendarDateTime.html
  RelativeTimestamp::Unit parseCFTimeUnit( std::string timeInformation );

  //! parse the reference time in the CF convention string format "XXXX since 2019-01-01 00:00:00"
  //! https://www.unidata.ucar.edu/software/netcdf-java/current/CDM/CalendarDateTime.html
  MDAL::DateTime parseCFReferenceTime( const std::string &timeInformation, const std::string &calendarString );

} // namespace MDAL
#endif //MDAL_UTILS_HPP