/*=========================================================================

  Program:   Visualization Toolkit
  Module:    vtkDelimitedTextReader.cxx

  Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
  All rights reserved.
  See Copyright.txt or http://www.kitware.com/Copyright.htm for details.

     This software is distributed WITHOUT ANY WARRANTY; without even
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
     PURPOSE.  See the above copyright notice for more information.

=========================================================================*/
/*-------------------------------------------------------------------------
  Copyright 2008 Sandia Corporation.
  Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation,
  the U.S. Government retains certain rights in this software.
-------------------------------------------------------------------------*/

#include "vtkDelimitedTextReader.h"
#include "vtkCommand.h"
#include "vtkDataSetAttributes.h"
#include "vtkIdTypeArray.h"
#include "vtkInformation.h"
#include "vtkInformationVector.h"
#include "vtkObjectFactory.h"
#include "vtkSmartPointer.h"
#include "vtkStreamingDemandDrivenPipeline.h"
#include "vtkTable.h"
#include "vtkUnicodeStringArray.h"
#include "vtkStringArray.h"
#include "vtkStringToNumeric.h"

#include "vtkTextCodec.h"
#include "vtkTextCodecFactory.h"

#include <sstream>
#include <iostream>
#include <algorithm>
#include <iterator>
#include <stdexcept>
#include <string>
#include <set>
#include <vector>

#include <cctype>

// #include <utf8.h>

////////////////////////////////////////////////////////////////////////////////
// DelimitedTextIterator

/// Output iterator object that parses a stream of Unicode characters into records and
/// fields, inserting them into a vtkTable.

namespace {

class DelimitedTextIterator : public vtkTextCodec::OutputIterator
{
public:
  typedef std::forward_iterator_tag iterator_category;
  typedef vtkUnicodeStringValueType value_type;
  typedef std::string::difference_type difference_type;
  typedef value_type* pointer;
  typedef value_type& reference;

  DelimitedTextIterator(
    const vtkIdType max_records,
    const vtkUnicodeString& record_delimiters,
    const vtkUnicodeString& field_delimiters,
    const vtkUnicodeString& string_delimiters,
    const vtkUnicodeString& whitespace,
    const vtkUnicodeString& escape,
    bool have_headers,
    bool unicode_array_output,
    bool merg_cons_delimiters,
    bool use_string_delimeter,
    vtkTable* const output_table
      ) :
    MaxRecords(max_records),
    MaxRecordIndex(have_headers ? max_records + 1 : max_records),
    RecordDelimiters(record_delimiters.begin(), record_delimiters.end()),
    FieldDelimiters(field_delimiters.begin(), field_delimiters.end()),
    StringDelimiters(string_delimiters.begin(), string_delimiters.end()),
    Whitespace(whitespace.begin(), whitespace.end()),
    EscapeDelimiter(escape.begin(), escape.end()),
    HaveHeaders(have_headers),
    UnicodeArrayOutput(unicode_array_output),
    WhiteSpaceOnlyString(true),
    OutputTable(output_table),
    CurrentRecordIndex(0),
    CurrentFieldIndex(0),
    RecordAdjacent(true),
    MergeConsDelims(merg_cons_delimiters),
    ProcessEscapeSequence(false),
    UseStringDelimiter(use_string_delimeter),
    WithinString(0)
  {
  }

  ~DelimitedTextIterator() override
  {
    // Ensure that all table columns have the same length ...
    for(vtkIdType i = 0; i != this->OutputTable->GetNumberOfColumns(); ++i)
    {
      if(this->OutputTable->GetColumn(i)->GetNumberOfTuples() !=
          this->OutputTable->GetColumn(0)->GetNumberOfTuples())
      {
        this->OutputTable->GetColumn(i)
            ->Resize(this->OutputTable->GetColumn(0)->GetNumberOfTuples());
      }
    }
  }

  DelimitedTextIterator& operator++(int) override
  {
    return *this;
  }

  DelimitedTextIterator& operator*() override
  {
    return *this;
  }

  // Handle windows files that do not have a carriage return line feed on the last line of the file ...
  void ReachedEndOfInput()
  {
    if(this->CurrentField.empty())
    {
      return;
    }
    vtkUnicodeString::value_type value =
        this->CurrentField[this->CurrentField.character_count()-1];
    if(!this->RecordDelimiters.count(value) && !this->Whitespace.count(value))
    {
      this->InsertField();
    }
  }

  DelimitedTextIterator& operator=(const vtkUnicodeString::value_type value) override
  {
    // If we've already read our maximum number of records, we're done ...
    if(this->MaxRecords && this->CurrentRecordIndex == this->MaxRecordIndex)
    {
      return *this;
    }

    // Strip adjacent record delimiters and whitespace...
    if(this->RecordAdjacent && (this->RecordDelimiters.count(value) ||
                                this->Whitespace.count(value)))
    {
      return *this;
    }
    else
    {
      this->RecordAdjacent = false;
    }

    // Look for record delimiters ...
    if(this->RecordDelimiters.count(value))
    {
      this->InsertField();
      this->CurrentRecordIndex += 1;
      this->CurrentFieldIndex = 0;
      this->CurrentField.clear();
      this->RecordAdjacent = true;
      this->WithinString = 0;
      this->WhiteSpaceOnlyString = true;
      return *this;
    }

    // Look for field delimiters unless we're in a string ...
    if(!this->WithinString && this->FieldDelimiters.count(value))
    {
       // Handle special case of merging consective delimiters ...
      if( !(this->CurrentField.empty() && this->MergeConsDelims) )
      {
        this->InsertField();
        this->CurrentFieldIndex += 1;
        this->CurrentField.clear();
      }
      return *this;
    }

    // Check for start of escape sequence ...
    if(!this->ProcessEscapeSequence && this->EscapeDelimiter.count(value))
    {
      this->ProcessEscapeSequence = true;
      return *this;
    }

    // Process escape sequence ...
    if(this->ProcessEscapeSequence)
    {
      vtkUnicodeString curr_char;
      curr_char += value;
      if(curr_char == vtkUnicodeString::from_utf8("0"))
      {
        this->CurrentField += vtkUnicodeString::from_utf8("\0");
      }
      else if(curr_char == vtkUnicodeString::from_utf8("a"))
      {
        this->CurrentField += vtkUnicodeString::from_utf8("\a");
      }
      else if(curr_char == vtkUnicodeString::from_utf8("b"))
      {
        this->CurrentField += vtkUnicodeString::from_utf8("\b");
      }
      else if(curr_char == vtkUnicodeString::from_utf8("t"))
      {
        this->CurrentField += vtkUnicodeString::from_utf8("\t");
      }
      else if(curr_char == vtkUnicodeString::from_utf8("n"))
      {
        this->CurrentField += vtkUnicodeString::from_utf8("\n");
      }
      else if(curr_char == vtkUnicodeString::from_utf8("v"))
      {
        this->CurrentField += vtkUnicodeString::from_utf8("\v");
      }
      else if(curr_char == vtkUnicodeString::from_utf8("f"))
      {
        this->CurrentField += vtkUnicodeString::from_utf8("\f");
      }
      else if(curr_char == vtkUnicodeString::from_utf8("r"))
      {
        this->CurrentField += vtkUnicodeString::from_utf8("\r");
      }
      else if(curr_char == vtkUnicodeString::from_utf8("\\"))
      {
        this->CurrentField += vtkUnicodeString::from_utf8("\\");
      }
      else
      {
        this->CurrentField += value;
      }
      this->ProcessEscapeSequence = false;
      return *this;
    }

    // Start a string ...
    if(!this->WithinString && this->StringDelimiters.count(value) &&
        this->UseStringDelimiter)
    {
      this->WithinString = value;
      this->CurrentField.clear();
      return *this;
    }

    // End a string ...
    if(this->WithinString && (this->WithinString == value) &&
        this->UseStringDelimiter)
    {
      this->WithinString = 0;
      return *this;
    }

    if(!this->Whitespace.count(value))
    {
     this->WhiteSpaceOnlyString = false;
    }
    // Keep growing the current field ...
    this->CurrentField += value;
    return *this;
  }

private:
  void InsertField()
  {
    if(this->CurrentFieldIndex >= this->OutputTable->GetNumberOfColumns() &&
        0 == this->CurrentRecordIndex)
    {
      vtkAbstractArray* array;
      if(this->UnicodeArrayOutput)
      {
        array = vtkUnicodeStringArray::New();
      }
      else
      {
        array = vtkStringArray::New();
      }

      if(this->HaveHeaders)
      {
        array->SetName(this->CurrentField.utf8_str());
      }
      else
      {
        std::stringstream buffer;
        buffer << "Field " << this->CurrentFieldIndex;
        array->SetName(buffer.str().c_str());
        if(this->UnicodeArrayOutput)
        {
          array->SetNumberOfTuples(this->CurrentRecordIndex + 1);
          vtkArrayDownCast<vtkUnicodeStringArray>(array)->SetValue(this->CurrentRecordIndex, this->CurrentField);
        }
        else
        {
          std::string s;
          this->CurrentField.utf8_str(s);
          vtkArrayDownCast<vtkStringArray>(array)->InsertValue(this->CurrentRecordIndex, s);
        }
      }
      this->OutputTable->AddColumn(array);
      array->Delete();
    }
    else if(this->CurrentFieldIndex < this->OutputTable->GetNumberOfColumns())
    {
      // Handle case where input file has header information ...
      vtkIdType rec_index;
      if(this->HaveHeaders)
      {
        rec_index = this->CurrentRecordIndex - 1;
      }
      else
      {
        rec_index = this->CurrentRecordIndex;
      }

      if(this->UnicodeArrayOutput)
      {
        vtkUnicodeStringArray* uarray = vtkArrayDownCast<vtkUnicodeStringArray>(this->OutputTable->GetColumn(this->CurrentFieldIndex));
        uarray->SetNumberOfTuples(rec_index + 1);
        uarray->SetValue(rec_index, this->CurrentField);
      }
      else
      {
        vtkStringArray* sarray = vtkArrayDownCast<vtkStringArray>(this->OutputTable->GetColumn(this->CurrentFieldIndex));
        std::string s;
        this->CurrentField.utf8_str(s);
        sarray->InsertValue(rec_index,s);
      }
    }
  }

  vtkIdType MaxRecords;
  vtkIdType MaxRecordIndex;
  std::set<vtkUnicodeString::value_type> RecordDelimiters;
  std::set<vtkUnicodeString::value_type> FieldDelimiters;
  std::set<vtkUnicodeString::value_type> StringDelimiters;
  std::set<vtkUnicodeString::value_type> Whitespace;
  std::set<vtkUnicodeString::value_type> EscapeDelimiter;
  bool HaveHeaders;
  bool UnicodeArrayOutput;
  bool WhiteSpaceOnlyString;
  vtkTable* OutputTable;
  vtkIdType CurrentRecordIndex;
  vtkIdType CurrentFieldIndex;
  vtkUnicodeString CurrentField;
  bool RecordAdjacent;
  bool MergeConsDelims;
  bool ProcessEscapeSequence;
  bool UseStringDelimiter;
  vtkUnicodeString::value_type WithinString;
};

} // End anonymous namespace

/////////////////////////////////////////////////////////////////////////////////////////
// vtkDelimitedTextReader

vtkStandardNewMacro(vtkDelimitedTextReader);

vtkDelimitedTextReader::vtkDelimitedTextReader() :
  FileName(nullptr),
  UnicodeCharacterSet(nullptr),
  MaxRecords(0),
  UnicodeRecordDelimiters(vtkUnicodeString::from_utf8("\r\n")),
  UnicodeFieldDelimiters(vtkUnicodeString::from_utf8(",")),
  UnicodeStringDelimiters(vtkUnicodeString::from_utf8("\"")),
  UnicodeWhitespace(vtkUnicodeString::from_utf8(" \t\r\n\v\f")),
  UnicodeEscapeCharacter(vtkUnicodeString::from_utf8("\\")),
  HaveHeaders(false),
  ReplacementCharacter('x')
{
  this->SetNumberOfInputPorts(0);
  this->SetNumberOfOutputPorts(1);

  this->ReadFromInputString = 0;
  this->InputString = nullptr;
  this->InputStringLength = 0;
  this->MergeConsecutiveDelimiters = false;
  this->PedigreeIdArrayName = nullptr;
  this->SetPedigreeIdArrayName("id");
  this->GeneratePedigreeIds = true;
  this->OutputPedigreeIds = false;
  this->AddTabFieldDelimiter = false;
  this->UnicodeOutputArrays = false;
  this->FieldDelimiterCharacters = nullptr;
  this->SetFieldDelimiterCharacters(",");
  this->StringDelimiter='"';
  this->UseStringDelimiter = true;
  this->DetectNumericColumns = false;
  this->ForceDouble = false;
  this->DefaultIntegerValue = 0;
  this->DefaultDoubleValue = 0.0;
  this->TrimWhitespacePriorToNumericConversion = false;
}

vtkDelimitedTextReader::~vtkDelimitedTextReader()
{
  this->SetPedigreeIdArrayName(nullptr);
  this->SetUnicodeCharacterSet(nullptr);
  this->SetFileName(nullptr);
  this->SetInputString(nullptr);
  this->SetFieldDelimiterCharacters(nullptr);
}

void vtkDelimitedTextReader::PrintSelf(ostream& os, vtkIndent indent)
{
  this->Superclass::PrintSelf(os, indent);
  os << indent << "FileName: "
     << (this->FileName ? this->FileName : "(none)") << endl;
  os << indent << "ReadFromInputString: "
     << (this->ReadFromInputString ? "On\n" : "Off\n");
  if ( this->InputString )
  {
    os << indent << "Input String: " << this->InputString << "\n";
  }
  else
  {
    os << indent << "Input String: (None)\n";
  }
  os << indent << "UnicodeCharacterSet: "
     << (this->UnicodeCharacterSet ? this->UnicodeCharacterSet : "(none)") << endl;
  os << indent << "MaxRecords: " << this->MaxRecords
     << endl;
  os << indent << "UnicodeRecordDelimiters: '" << this->UnicodeRecordDelimiters.utf8_str()
     << "'" << endl;
  os << indent << "UnicodeFieldDelimiters: '" << this->UnicodeFieldDelimiters.utf8_str()
     << "'" << endl;
  os << indent << "UnicodeStringDelimiters: '" << this->UnicodeStringDelimiters.utf8_str()
     << "'" << endl;
  os << indent << "StringDelimiter: "
     << this->StringDelimiter << endl;
  os << indent << "ReplacementCharacter: " << this->ReplacementCharacter << endl;
  os << indent << "FieldDelimiterCharacters: "
     << (this->FieldDelimiterCharacters ? this->FieldDelimiterCharacters : "(none)") << endl;
  os << indent << "HaveHeaders: "
     << (this->HaveHeaders ? "true" : "false") << endl;
  os << indent << "MergeConsecutiveDelimiters: "
     << (this->MergeConsecutiveDelimiters ? "true" : "false") << endl;
  os << indent << "UseStringDelimiter: "
     << (this->UseStringDelimiter ? "true" : "false") << endl;
  os << indent << "DetectNumericColumns: "
    << (this->DetectNumericColumns? "true" : "false") << endl;
  os << indent << "ForceDouble: "
    << (this->ForceDouble ? "true" : "false") << endl;
  os << indent << "DefaultIntegerValue: "
    << this->DefaultIntegerValue << endl;
  os << indent << "DefaultDoubleValue: "
    << this->DefaultDoubleValue << endl;
  os << indent << "TrimWhitespacePriorToNumericConversion: "
    << (this->TrimWhitespacePriorToNumericConversion ? "true" : "false") << endl;
  os << indent << "GeneratePedigreeIds: "
    << this->GeneratePedigreeIds << endl;
  os << indent << "PedigreeIdArrayName: "
    << this->PedigreeIdArrayName << endl;
  os << indent << "OutputPedigreeIds: "
    << (this->OutputPedigreeIds ? "true" : "false") << endl;
  os << indent << "AddTabFieldDelimiter: "
    << (this->AddTabFieldDelimiter ? "true" : "false") << endl;
}

void vtkDelimitedTextReader::SetInputString(const char *in)
{
  int len = 0;
  if (in != nullptr)
  {
    len = static_cast<int>(strlen(in));
  }
  this->SetInputString(in, len);
}

void vtkDelimitedTextReader::SetInputString(const char *in, int len)
{
  if (this->InputString && in && strncmp(in, this->InputString, len) == 0)
  {
    return;
  }

  delete [] this->InputString;

  if (in && len>0)
  {
    // Add a nullptr terminator so that GetInputString
    // callers (from wrapped languages) get a valid
    // C string in *ALL* cases...
    //
    this->InputString = new char[len+1];
    memcpy(this->InputString,in,len);
    this->InputString[len] = 0;
    this->InputStringLength = len;
  }
   else
   {
    this->InputString = nullptr;
    this->InputStringLength = 0;
   }

  this->Modified();
}

void vtkDelimitedTextReader::SetUnicodeRecordDelimiters(const vtkUnicodeString& delimiters)
{
  this->UnicodeRecordDelimiters = delimiters;
  this->Modified();
}

vtkUnicodeString vtkDelimitedTextReader::GetUnicodeRecordDelimiters()
{
  return this->UnicodeRecordDelimiters;
}

void vtkDelimitedTextReader::SetUTF8RecordDelimiters(const char* delimiters)
{
  this->UnicodeRecordDelimiters = vtkUnicodeString::from_utf8(delimiters);
  this->Modified();
}

const char* vtkDelimitedTextReader::GetUTF8RecordDelimiters()
{
  return this->UnicodeRecordDelimiters.utf8_str();
}

void vtkDelimitedTextReader::SetUnicodeFieldDelimiters(const vtkUnicodeString& delimiters)
{
  this->UnicodeFieldDelimiters = delimiters;
  this->Modified();
}

vtkUnicodeString vtkDelimitedTextReader::GetUnicodeFieldDelimiters()
{
  return this->UnicodeFieldDelimiters;
}

void vtkDelimitedTextReader::SetUTF8FieldDelimiters(const char* delimiters)
{
  this->UnicodeFieldDelimiters = vtkUnicodeString::from_utf8(delimiters);
  this->Modified();
}

const char* vtkDelimitedTextReader::GetUTF8FieldDelimiters()
{
  return this->UnicodeFieldDelimiters.utf8_str();
}

void vtkDelimitedTextReader::SetUnicodeStringDelimiters(const vtkUnicodeString& delimiters)
{
  this->UnicodeStringDelimiters = delimiters;
  this->Modified();
}

vtkUnicodeString vtkDelimitedTextReader::GetUnicodeStringDelimiters()
{
  return this->UnicodeStringDelimiters;
}

void vtkDelimitedTextReader::SetUTF8StringDelimiters(const char* delimiters)
{
  this->UnicodeStringDelimiters = vtkUnicodeString::from_utf8(delimiters);
  this->Modified();
}

const char* vtkDelimitedTextReader::GetUTF8StringDelimiters()
{
  return this->UnicodeStringDelimiters.utf8_str();
}

vtkStdString vtkDelimitedTextReader::GetLastError()
{
  return this->LastError;
}

int vtkDelimitedTextReader::RequestData(
  vtkInformation*,
  vtkInformationVector**,
  vtkInformationVector* outputVector)
{
  vtkTable* const output_table = vtkTable::GetData(outputVector);

  this->LastError = "";

  try
  {
    // We only retrieve one piece ...
    vtkInformation* const outInfo = outputVector->GetInformationObject(0);
    if(outInfo->Has(vtkStreamingDemandDrivenPipeline::UPDATE_PIECE_NUMBER()) &&
      outInfo->Get(vtkStreamingDemandDrivenPipeline::UPDATE_PIECE_NUMBER()) > 0)
    {
      return 1;
    }

    if (!this->PedigreeIdArrayName)
    {
      throw std::runtime_error("You must specify a pedigree id array name");
    }

    istream* input_stream_pt = nullptr;
    ifstream file_stream;
    std::istringstream string_stream;

    if(!this->ReadFromInputString)
    {
      // If the filename hasn't been specified, we're done ...
      if(!this->FileName)
      {
        return 1;
      }
      // Get the total size of the input file in bytes
      file_stream.open(this->FileName, ios::binary);
      if(!file_stream.good())
      {
        throw std::runtime_error(
          "Unable to open input file " + std::string(this->FileName));
      }

      file_stream.seekg(0, ios::end);
      //const vtkIdType total_bytes = file_stream.tellg();
      file_stream.seekg(0, ios::beg);

      input_stream_pt = dynamic_cast<istream*>(&file_stream);
    }
    else
    {
      string_stream.str(this->InputString);
      input_stream_pt = dynamic_cast<istream*>(&string_stream);
    }

    vtkStdString character_set;
    vtkTextCodec* transCodec = nullptr;

    if(this->UnicodeCharacterSet)
    {
      this->UnicodeOutputArrays = true;
      character_set = this->UnicodeCharacterSet;
      transCodec = vtkTextCodecFactory::CodecForName(this->UnicodeCharacterSet);
    }
    else
    {
      char tstring[2];
      tstring[1] = '\0';
      tstring[0] = this->StringDelimiter;
      // don't use Set* methods since they change the MTime in
      // RequestData() !!!!!
      std::string fieldDelimiterCharacters = this->FieldDelimiterCharacters;
      if (this->AddTabFieldDelimiter)
      {
        fieldDelimiterCharacters.push_back('\t');
      }
      this->UnicodeFieldDelimiters =
            vtkUnicodeString::from_utf8(fieldDelimiterCharacters);
      this->UnicodeStringDelimiters =
        vtkUnicodeString::from_utf8(tstring);
      this->UnicodeOutputArrays = false;
      transCodec = vtkTextCodecFactory::CodecToHandle(*input_stream_pt);
    }

    if (nullptr == transCodec)
    {
      // should this use the locale instead??
      return 1;
    }

    DelimitedTextIterator iterator(
      this->MaxRecords,
      this->UnicodeRecordDelimiters,
      this->UnicodeFieldDelimiters,
      this->UnicodeStringDelimiters,
      this->UnicodeWhitespace,
      this->UnicodeEscapeCharacter,
      this->HaveHeaders,
      this->UnicodeOutputArrays,
      this->MergeConsecutiveDelimiters,
      this->UseStringDelimiter,
      output_table);

    vtkTextCodec::OutputIterator& outIter = iterator;

    transCodec->ToUnicode(*input_stream_pt, outIter);
    iterator.ReachedEndOfInput();
    transCodec->Delete();

    if(this->OutputPedigreeIds)
    {
      if (this->GeneratePedigreeIds)
      {
        vtkSmartPointer<vtkIdTypeArray> pedigreeIds =
          vtkSmartPointer<vtkIdTypeArray>::New();
        vtkIdType numRows = output_table->GetNumberOfRows();
        pedigreeIds->SetNumberOfTuples(numRows);
        pedigreeIds->SetName(this->PedigreeIdArrayName);
        for (vtkIdType i = 0; i < numRows; ++i)
        {
          pedigreeIds->InsertValue(i, i);
        }
        output_table->GetRowData()->SetPedigreeIds(pedigreeIds);
      }
      else
      {
        vtkAbstractArray* arr =
          output_table->GetColumnByName(this->PedigreeIdArrayName);
        if (arr)
        {
          output_table->GetRowData()->SetPedigreeIds(arr);
        }
        else
        {
          throw std::runtime_error(
                "Could not find pedigree id array: " +
                vtkStdString(this->PedigreeIdArrayName));
        }
      }
    }

    if (this->DetectNumericColumns && !this->UnicodeOutputArrays)
    {
      vtkStringToNumeric* converter = vtkStringToNumeric::New();
      converter->SetForceDouble(this->ForceDouble);
      converter->SetDefaultIntegerValue(this->DefaultIntegerValue);
      converter->SetDefaultDoubleValue(this->DefaultDoubleValue);
      converter->SetTrimWhitespacePriorToNumericConversion(this->TrimWhitespacePriorToNumericConversion);
      vtkTable* clone = output_table->NewInstance();
      clone->ShallowCopy(output_table);
      converter->SetInputData(clone);
      converter->Update();
      clone->Delete();
      output_table->ShallowCopy(converter->GetOutputDataObject(0));
      converter->Delete();
    }

  }
  catch(std::exception& e)
  {
    vtkErrorMacro(<< "caught exception: " << e.what() << endl);
    this->LastError = e.what();
    output_table->Initialize();
  }
  catch(...)
  {
    vtkErrorMacro(<< "caught unknown exception." << endl);
    this->LastError = "Unknown exception.";
    output_table->Initialize();
  }

  return 1;
}