// Copyright (c) 2015  Geometry Factory
// All rights reserved.
//
// This file is part of CGAL (www.cgal.org).
// 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 3 of the License, or (at your option) any later version.
//
// Licensees holding a valid commercial license may use this file in
// accordance with the commercial license agreement provided with the software.
//
// This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
// WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
//
// $URL$
// $Id$
//
// Author(s) : Simon Giraudot

#ifndef CGAL_READ_PLY_POINTS_H
#define CGAL_READ_PLY_POINTS_H

#include <CGAL/property_map.h>
#include <CGAL/value_type_traits.h>
#include <CGAL/point_set_processing_assertions.h>
#include <CGAL/Kernel_traits.h>

#include <boost/version.hpp>
#include <boost/cstdint.hpp>

#include <iostream>
#include <sstream>
#include <string>


namespace CGAL {


// PLY types:
// name        type        number of bytes
// ---------------------------------------
// char       character                 1
// uchar      unsigned character        1
// short      short integer             2
// ushort     unsigned short integer    2
// int        integer                   4
// uint       unsigned integer          4
// float      single-precision float    4
// double     double-precision float    8

/// \cond SKIP_IN_MANUAL

namespace internal {

  class Ply_read_number
  {
  protected:
    std::string m_name;
    std::size_t m_format;
    
  public:
    Ply_read_number (std::string name, std::size_t format)
      : m_name (name), m_format (format) { }
    virtual ~Ply_read_number() { }

    const std::string& name () const { return m_name; }

    virtual void get (std::istream& stream) const = 0;

    // The two following functions prevent the stream to only extract
    // ONE character (= what the types char imply) by requiring
    // explicitely an integer object when reading the stream
    void read_ascii (std::istream& stream, boost::int8_t& c) const
    {
      short s;
      stream >> s;
      c = static_cast<char>(s);
    }
    void read_ascii (std::istream& stream, boost::uint8_t& c) const
    {
      unsigned short s;
      stream >> s;
      c = static_cast<unsigned char>(s);
    }

    // Default template when Type is not a char type
    template <typename Type>
    void read_ascii (std::istream& stream, Type& t) const
    {
      stream >> t;
    }
    
    template <typename Type>
    Type read (std::istream& stream) const
    {
      if (m_format == 0) // Ascii
        {
          Type t;
          read_ascii (stream, t);
          return t;
        }
      else // Binary (2 = little endian)
        {
          union
          {
            char uChar[sizeof (Type)];
            Type type;
          } buffer;
          
          std::size_t size = sizeof (Type);

          stream.read(buffer.uChar, size);
      
          if (m_format == 2) // Big endian
            {
              for (std::size_t i = 0; i < size / 2; ++ i)
                {
                  unsigned char tmp = buffer.uChar[i];
                  buffer.uChar[i] = buffer.uChar[size - 1 - i];
                  buffer.uChar[size - 1 - i] = tmp;
                }
            }
          return buffer.type;
        }
      return Type();
    }
  };

  template <typename Type>
  class Ply_read_typed_number : public Ply_read_number
  {
    mutable Type m_buffer;
  public:
    Ply_read_typed_number (std::string name, std::size_t format)
      : Ply_read_number (name, format)
    {
    }
    void get (std::istream& stream) const
    {
      m_buffer = (this->read<Type> (stream));
    }
    const Type& buffer() const
    {
      return m_buffer;
    }
  };
  
} // namespace internal
  

/// \endcond



//===================================================================================
/// \ingroup PkgPointSetProcessing
///
/// The PLY reader is initialized with the correct set of properties (along
/// with their name tags and number types) based on the header of the PLY input
/// file. It loads all the points with their specific properties of the PLY
/// input and delegates the interpretation to a user-specified `PlyInterpreter`.
///
//-----------------------------------------------------------------------------------
class Ply_reader
{

  std::vector<internal::Ply_read_number*> m_readers;
  std::size_t m_nb_points;

public:
  
  /// \cond SKIP_IN_MANUAL
  Ply_reader () : m_nb_points (0) { }

  template <typename Stream>
  bool init (Stream& stream)
  {
    std::size_t lineNumber = 0; // current line number
    enum Format { ASCII = 0, BINARY_LITTLE_ENDIAN = 1, BINARY_BIG_ENDIAN = 2};
    Format format = ASCII;
    
    std::string line;
    std::istringstream iss;

    // Check the order of the properties of the point set
    bool reading_properties = false;
  
    while (getline (stream,line))
      {
        iss.clear();
        iss.str (line);
        ++ lineNumber;

        // Reads file signature on first line
        if (lineNumber == 1)
          {
            std::string signature;
            if (!(iss >> signature) || (signature != "ply"))
              {
                // if wrong file format
                std::cerr << "Error: incorrect file format line " << lineNumber << " of file" << std::endl;
                return false;
              }
          }

        // Reads format on 2nd line
        else if (lineNumber == 2)
          {
            std::string tag, format_string, version;
            if ( !(iss >> tag >> format_string >> version) )
              {
                std::cerr << "Error line " << lineNumber << " of file" << std::endl;
                return false;
              }
            if (format_string == "ascii") format = ASCII;
            else if (format_string == "binary_little_endian") format = BINARY_LITTLE_ENDIAN;
            else if (format_string == "binary_big_endian") format = BINARY_BIG_ENDIAN;
            else
              {
                std::cerr << "Error: unknown file format \"" << format_string << "\" line " << lineNumber << std::endl;
                return false;
              }
          }

        // Comments and vertex properties
        else
          {
            std::string keyword;
            if (!(iss >> keyword))
              {
                std::cerr << "Error line " << lineNumber << " of file" << std::endl;
                return false;
              }

            if (keyword == "property")
              {
                if (!reading_properties)
                  continue;

                std::string type, name;
                if (!(iss >> type >> name))
                  {
                    std::cerr << "Error line " << lineNumber << " of file" << std::endl;
                    return false;
                  }

                if (     type == "char"   || type == "int8")
                  m_readers.push_back (new internal::Ply_read_typed_number<boost::int8_t> (name, format));
                else if (type == "uchar"  || type == "uint8")
                  m_readers.push_back (new internal::Ply_read_typed_number<boost::uint8_t> (name, format));
                else if (type == "short"  || type == "int16")
                  m_readers.push_back (new internal::Ply_read_typed_number<boost::int16_t> (name, format));
                else if (type == "ushort" || type == "uint16")
                  m_readers.push_back (new internal::Ply_read_typed_number<boost::uint16_t> (name, format));
                else if (type == "int"    || type == "int32")
                  m_readers.push_back (new internal::Ply_read_typed_number<boost::int32_t> (name, format));
                else if (type == "uint"   || type == "uint32")
                  m_readers.push_back (new internal::Ply_read_typed_number<boost::uint32_t> (name, format));
                else if (type == "float"  || type == "float32")
                  m_readers.push_back (new internal::Ply_read_typed_number<float> (name, format));
                else if (type == "double" || type == "float64")
                  m_readers.push_back (new internal::Ply_read_typed_number<double> (name, format));
                
                continue;
              }
            else
              reading_properties = false;
            
            // ignore comments and properties (if not in element
            // vertex - cf below - properties are useless in our case)
            if (keyword == "comment" || keyword == "property")
              continue;

            // When end_header is reached, stop loop and begin reading points
            if (keyword == "end_header")
              break;
            
            if (keyword == "element")
              {
                std::string type;
                std::size_t number;
                if (!(iss >> type >> number))
                  {
                    std::cerr << "Error line " << lineNumber << " of file" << std::endl;
                    return false;
                  }
                
                if (type == "vertex")
                  {
                    m_nb_points = number;
                    reading_properties = true;
                  }
                else
                  continue;
              }
            
          }
      }
    return true;
  }

  ~Ply_reader ()
  {
    for (std::size_t i = 0; i < m_readers.size (); ++ i)
      delete m_readers[i];
    m_readers.clear();
  }

  template <typename Stream, typename PlyInterpreter>
  bool read_content (Stream& stream, PlyInterpreter& interpreter)
  {
    std::size_t points_read = 0;
    
    while (!(stream.eof()) && points_read < m_nb_points)
      {
        for (std::size_t i = 0; i < m_readers.size (); ++ i)
          m_readers[i]->get (stream);

        interpreter.process_line (*this);

        ++ points_read;
      }
    // Skip remaining lines

    return (points_read == m_nb_points);
  }
  /// \endcond
  
  /*!
    \tparam Type type of the property (ex: double, float, unsigned char, etc.)
    \param tag name of the property (ex: _nx_ for x normal coordinate)

    \return true if points inside the PLY input contain the property
    `tag` with type `Type`, false otherwise
  */
  template <typename Type>
  bool does_tag_exist (const char* tag)
  {
    return does_tag_exist (tag, Type());
  }

  /*!
    \param t reference to store last read value of the property `tag`
    \param tag name of the required property
  */
  template <typename Type>
  void assign (Type& t, const char* tag)
  {
    for (std::size_t i = 0; i < m_readers.size (); ++ i)
      if (m_readers[i]->name () == tag)
        {
          internal::Ply_read_typed_number<Type>*
            reader = dynamic_cast<internal::Ply_read_typed_number<Type>*>(m_readers[i]);
          CGAL_assertion (reader != NULL);
          t = reader->buffer();
          return;
        }
  }

  /// \cond SKIP_IN_MANUAL
  
  // Convenience functions: a float property in the PLY input can be
  // directly interpreted as a double without loss of information.
  template <typename Type>
  bool does_tag_exist (const char* tag, Type)
  {
    for (std::size_t i = 0; i < m_readers.size (); ++ i)
      if (m_readers[i]->name () == tag)
        return (dynamic_cast<internal::Ply_read_typed_number<Type>*>(m_readers[i]) != NULL);
    return false;
  }
  bool does_tag_exist (const char* tag, double)
  {
    for (std::size_t i = 0; i < m_readers.size (); ++ i)
      if (m_readers[i]->name () == tag)
        return (dynamic_cast<internal::Ply_read_typed_number<double>*>(m_readers[i]) != NULL
                || dynamic_cast<internal::Ply_read_typed_number<float>*>(m_readers[i]) != NULL);

    return false;
  }
  void assign (double& t, const char* tag)
  {
    for (std::size_t i = 0; i < m_readers.size (); ++ i)
      if (m_readers[i]->name () == tag)
        {
          internal::Ply_read_typed_number<double>*
            reader_double = dynamic_cast<internal::Ply_read_typed_number<double>*>(m_readers[i]);
          if (reader_double == NULL)
            {
              internal::Ply_read_typed_number<float>*
                reader_float = dynamic_cast<internal::Ply_read_typed_number<float>*>(m_readers[i]);
              CGAL_assertion (reader_float != NULL);
              t = reader_float->buffer();
            }
          else
            t = reader_double->buffer();
          
          return;
        }
  }
  /// \endcond
  
};

//===================================================================================
/// \ingroup PkgPointSetProcessing
///
/// PLY interpreter designed to fill an output iterator of points and
/// normals based on given property maps. It is used internally by the
/// functions `read_ply_points()` and `read_ply_points_and_normals()`.
///
/// @tparam OutputIteratorValueType type of objects that can be put in `OutputIterator`.
/// @tparam OutputIterator iterator over output points.
/// @tparam PointPMap is a model of `WritablePropertyMap` with  value type `Point_3<Kernel>`.
/// @tparam NormalPMap is a model of `WritablePropertyMap` with value type `Vector_3<Kernel>`.
/// @tparam Kernel Geometric traits class.
///
/// \cgalModels `PlyInterpreter`
//-----------------------------------------------------------------------------------

template <typename OutputIteratorValueType,
          typename OutputIterator,
          typename PointPMap,
          typename NormalPMap,
          typename Kernel>
class Ply_interpreter_points_and_normals_3
{
  // value_type_traits is a workaround as back_insert_iterator's value_type is void
  // typedef typename value_type_traits<OutputIterator>::type Enriched_point;
  typedef OutputIteratorValueType Enriched_point;
  typedef typename Kernel::FT FT;
  typedef typename Kernel::Point_3 Point;
  typedef typename Kernel::Vector_3 Vector;
    
  OutputIterator m_output;
  PointPMap& m_point_pmap;
  NormalPMap& m_normal_pmap;
  
public:
  /*!
    Constructs a PLY interpreter for points and normals.
   */
  Ply_interpreter_points_and_normals_3 (OutputIterator output,
                                        PointPMap& point_pmap,
                                        NormalPMap& normal_pmap)
    : m_output (output),
      m_point_pmap (point_pmap),
      m_normal_pmap (normal_pmap)
  { }

  bool is_applicable (Ply_reader& reader)
  {
    return reader.does_tag_exist<FT> ("x")
      && reader.does_tag_exist<FT> ("y")
      && reader.does_tag_exist<FT> ("z");
  }
  
  void process_line (Ply_reader& reader)
  {
    FT x = (FT)0.,y = (FT)0., z = (FT)0.,
      nx = (FT)0., ny = (FT)0., nz = (FT)0.;
    reader.assign (x, "x");
    reader.assign (y, "y");
    reader.assign (z, "z");
    reader.assign (nx, "nx");
    reader.assign (ny, "ny");
    reader.assign (nz, "nz");

    Point point (x, y, z);
    Vector normal (nx, ny, nz);
    Enriched_point pwn;
      
    put(m_point_pmap,  pwn, point);  // point_pmap[&pwn] = point
    put(m_normal_pmap, pwn, normal); // normal_pmap[&pwn] = normal
    *m_output++ = pwn;
  }

};



//===================================================================================
/// \ingroup PkgPointSetProcessing
/// Reads points from a .ply stream (ASCII or binary) using a custom
/// interpreter provided by the user.
///
/// @tparam PlyInterpreter Interpreter of Ply input, must be a model of `PlyInterpreter`
/// @tparam Kernel Geometric traits class.
///
/// @return true on success.
//-----------------------------------------------------------------------------------
template < typename PlyInterpreter,
           typename Kernel >
bool read_ply_custom_points(std::istream& stream, ///< input stream.
                            PlyInterpreter& interpreter, ///< Custom PLY interpreter
                            const Kernel& /* kernel */) ///< geometric traits.
{
  if(!stream)
    {
      std::cerr << "Error: cannot open file" << std::endl;
      return false;
    }

  Ply_reader reader;
  
  if (!(reader.init (stream)))
    return false;
  
  if (!(interpreter.is_applicable (reader)))
    {
      std::cerr << "Error: PLY interpreter is not applicable to input file" << std::endl;
      return false;
    }

  return reader.read_content (stream, interpreter);
}



//===================================================================================
/// \ingroup PkgPointSetProcessing
/// Reads points (positions + normals, if available) from a .ply
/// stream (ASCII or binary).
/// Potential additional point properties and faces are ignored.
///
/// @tparam OutputIteratorValueType type of objects that can be put in `OutputIterator`.
///         It is default to `value_type_traits<OutputIterator>::%type` and can be omitted when the default is fine.
/// @tparam OutputIterator iterator over output points.
/// @tparam PointPMap is a model of `WritablePropertyMap` with  value type `Point_3<Kernel>`.
///        It can be omitted if the value type of `OutputIterator` is convertible to `Point_3<Kernel>`.
/// @tparam NormalPMap is a model of `WritablePropertyMap` with value type `Vector_3<Kernel>`.
/// @tparam Kernel Geometric traits class.
///        It can be omitted and deduced automatically from the value type of `PointPMap`.
///
/// @return true on success.

// This variant requires all parameters.
//-----------------------------------------------------------------------------------
template < typename OutputIteratorValueType,
           typename OutputIterator,
           typename PointPMap,
           typename NormalPMap,
           typename Kernel >
bool read_ply_points_and_normals(std::istream& stream, ///< input stream.
                                 OutputIterator output, ///< output iterator over points.
                                 PointPMap point_pmap, ///< property map: value_type of OutputIterator -> Point_3.
                                 NormalPMap normal_pmap, ///< property map: value_type of OutputIterator -> Vector_3.
                                 const Kernel& kernel) ///< geometric traits.
{
  Ply_interpreter_points_and_normals_3
    <OutputIteratorValueType, OutputIterator, PointPMap, NormalPMap, Kernel>
    interpreter (output, point_pmap, normal_pmap);

  return read_ply_custom_points (stream, interpreter, kernel);
}

/// @cond SKIP_IN_MANUAL
template < typename OutputIterator,
           typename PointPMap,
           typename NormalPMap,
           typename Kernel >
bool read_ply_points_and_normals(std::istream& stream, ///< input stream.
                                 OutputIterator output, ///< output iterator over points.
                                 PointPMap point_pmap, ///< property map: value_type of OutputIterator -> Point_3.
                                 NormalPMap normal_pmap, ///< property map: value_type of OutputIterator -> Vector_3.
                                 const Kernel& kernel) ///< geometric traits.
{
  // just deduce value_type of OutputIterator
  return read_ply_points_and_normals
    <typename value_type_traits<OutputIterator>::type>(stream,
                                                       output,
                                                       point_pmap,
                                                       normal_pmap,
                                                       kernel);
}
//-----------------------------------------------------------------------------------
/// @endcond

/// @cond SKIP_IN_MANUAL
// This variant deduces the kernel from the point property map.
//-----------------------------------------------------------------------------------
template < typename OutputIteratorValueType,
           typename OutputIterator,
           typename PointPMap,
           typename NormalPMap >
bool read_ply_points_and_normals(std::istream& stream, ///< input stream.
                                 OutputIterator output, ///< output iterator over points.
                                 PointPMap point_pmap, ///< property map: value_type of OutputIterator -> Point_3.
                                 NormalPMap normal_pmap) ///< property map: value_type of OutputIterator -> Vector_3.
{
  typedef typename boost::property_traits<PointPMap>::value_type Point;
  typedef typename Kernel_traits<Point>::Kernel Kernel;
  return read_ply_points_and_normals
    <OutputIteratorValueType>(stream,
                              output,
                              point_pmap,
                              normal_pmap,
                              Kernel());
}

template < typename OutputIterator,
           typename PointPMap,
           typename NormalPMap >
bool read_ply_points_and_normals(std::istream& stream, ///< input stream.
                                 OutputIterator output, ///< output iterator over points.
                                 PointPMap point_pmap, ///< property map: value_type of OutputIterator -> Point_3.
                                 NormalPMap normal_pmap) ///< property map: value_type of OutputIterator -> Vector_3.
{
  // just deduce value_type of OutputIterator
  return read_ply_points_and_normals
    <typename value_type_traits<OutputIterator>::type>(stream,
                                                       output,
                                                       point_pmap,
                                                       normal_pmap);
}
//-----------------------------------------------------------------------------------
/// @endcond

/// @cond SKIP_IN_MANUAL
// This variant creates a default point property map = Identity_property_map.
//-----------------------------------------------------------------------------------
template < typename OutputIteratorValueType,
           typename OutputIterator,
           typename NormalPMap >
bool read_ply_points_and_normals(std::istream& stream, ///< input stream.
                                 OutputIterator output, ///< output iterator over points.
                                 NormalPMap normal_pmap) ///< property map: value_type of OutputIterator -> Vector_3.
{
  return read_ply_points_and_normals
    <OutputIteratorValueType>(stream,
                              output,
                              make_identity_property_map(OutputIteratorValueType()),
                              normal_pmap);
}

template < typename OutputIterator,
           typename NormalPMap >
bool read_ply_points_and_normals(std::istream& stream, ///< input stream.
                                 OutputIterator output, ///< output iterator over points.
                                 NormalPMap normal_pmap) ///< property map: value_type of OutputIterator -> Vector_3.
{
  // just deduce value_type of OutputIterator
  return read_ply_points_and_normals
    <typename value_type_traits<OutputIterator>::type>(stream,
                                                       output,
                                                       normal_pmap);
}
//-----------------------------------------------------------------------------------
/// @endcond


//===================================================================================
/// \ingroup PkgPointSetProcessing
/// Reads points (position only) from a .ply stream (ASCII or binary).
/// Potential additional point properties (including normals) and faces are ignored.
///
/// @tparam OutputIteratorValueType type of objects that can be put in `OutputIterator`.
///         It is default to `value_type_traits<OutputIterator>::%type` and can be omitted when the default is fine.
/// @tparam OutputIterator iterator over output points.
/// @tparam PointPMap is a model of `WritablePropertyMap` with  value_type `Point_3<Kernel>`.
///        It can be omitted if the value type of `OutputIterator` is convertible to `Point_3<Kernel>`.
/// @tparam Kernel Geometric traits class.
///        It can be omitted and deduced automatically from  the value type of `PointPMap`.
///
/// @return `true` on success.

// This variant requires all parameters.
//-----------------------------------------------------------------------------------
template < typename OutputIteratorValueType,
           typename OutputIterator,
           typename PointPMap,
           typename Kernel >
bool read_ply_points(std::istream& stream, ///< input stream.
                     OutputIterator output, ///< output iterator over points.
                     PointPMap point_pmap, ///< property map: value_type of OutputIterator -> Point_3.
                     const Kernel& kernel) ///< geometric traits.
{
  // Calls read_ply_points_and_normals() with a normal property map = boost::dummy_property_map
  return read_ply_points_and_normals
    <OutputIteratorValueType>(stream,
                              output,
                              point_pmap,
                              boost::dummy_property_map(),
                              kernel);
}

/// @cond SKIP_IN_MANUAL
template < typename OutputIterator,
           typename PointPMap,
           typename Kernel >
bool read_ply_points(std::istream& stream, ///< input stream.
                     OutputIterator output, ///< output iterator over points.
                     PointPMap point_pmap, ///< property map: value_type of OutputIterator -> Point_3.
                     const Kernel& kernel) ///< geometric traits.
{
  // just deduce value_type of OutputIterator
  return read_ply_points
    <typename value_type_traits<OutputIterator>::type>(stream,
                                                       output,
                                                       point_pmap,
                                                       kernel);
}
//-----------------------------------------------------------------------------------
/// @endcond

/// @cond SKIP_IN_MANUAL
// This variant deduces the kernel from the point property map.
//-----------------------------------------------------------------------------------
template < typename OutputIteratorValueType,
           typename OutputIterator,
           typename PointPMap >
bool read_ply_points(std::istream& stream, ///< input stream.
                     OutputIterator output, ///< output iterator over points.
                     PointPMap point_pmap) ///< property map: value_type of OutputIterator -> Point_3.
{
  typedef typename boost::property_traits<PointPMap>::value_type Point;
  typedef typename Kernel_traits<Point>::Kernel Kernel;
  return read_ply_points
    <OutputIteratorValueType>(stream,
                              output,
                              point_pmap,
                              Kernel());
}

template < typename OutputIterator,
           typename PointPMap >
bool read_ply_points(std::istream& stream, ///< input stream.
                     OutputIterator output, ///< output iterator over points.
                     PointPMap point_pmap) ///< property map: value_type of OutputIterator -> Point_3.
{
  // just deduce value_type of OutputIterator
  return read_ply_points
    <typename value_type_traits<OutputIterator>::type>(stream,
                                                       output,
                                                       point_pmap);
}
//-----------------------------------------------------------------------------------
/// @endcond

/// @cond SKIP_IN_MANUAL
// This variant creates a default point property map = Identity_property_map.
//-----------------------------------------------------------------------------------
template < typename OutputIteratorValueType,
           typename OutputIterator >
bool read_ply_points(std::istream& stream, ///< input stream.
                     OutputIterator output) ///< output iterator over points.
{
  return read_ply_points
    <OutputIteratorValueType>(stream,
                              output,
                              make_identity_property_map(OutputIteratorValueType())
                              );
}

template < typename OutputIterator>
bool read_ply_points(std::istream& stream, ///< input stream.
                     OutputIterator output) ///< output iterator over points.
{
  // just deduce value_type of OutputIterator
  return read_ply_points
    <typename value_type_traits<OutputIterator>::type>(stream,
                                                       output);
}
//-----------------------------------------------------------------------------------

/// @endcond


} //namespace CGAL

#endif // CGAL_READ_PLY_POINTS_H