/***************************************************************************

  PFunctionHandler.cpp

  Author: Andreas Suter
  e-mail: andreas.suter@psi.ch

***************************************************************************/

/***************************************************************************
 *   Copyright (C) 2007-2026 by Andreas Suter                              *
 *   andreas.suter@psi.c                                                   *
 *                                                                         *
 *   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.                                   *
 *                                                                         *
 *   This program is distributed in the hope that it will be useful,       *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
 *   GNU General Public License for more details.                          *
 *                                                                         *
 *   You should have received a copy of the GNU General Public License     *
 *   along with this program; if not, write to the                         *
 *   Free Software Foundation, Inc.,                                       *
 *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
 ***************************************************************************/

#include <string>
#include <cassert>
#include <algorithm>
#include <fstream>

#include <boost/algorithm/string.hpp>

#include "PFunctionHandler.h"

//-------------------------------------------------------------
/**
 * @brief Constructs a PFunctionHandler from a file.
 *
 * Reads the specified file to extract parameter values (PAR block),
 * map indices (MAP block), and function definitions (FUNCTIONS block).
 * Validates that all required blocks are present and that map indices
 * are within parameter bounds.
 *
 * @param fln Filename containing the function definitions
 * @param debug Enable debug output showing parsing details
 */
//-------------------------------------------------------------
PFunctionHandler::PFunctionHandler(char *fln, bool debug) : fDebug(debug), fFileName(fln)
{
  fValid = true;

  std::cout << std::endl << "in PFunctionHandler(char *fln)";
  std::cout << std::endl << "fFileName = " << fFileName;

  fValid = ReadFile();
  if (fValid)
    fValid = MapsAreValid();
}

//-------------------------------------------------------------
/**
 * @brief Constructs a PFunctionHandler from a vector of input lines.
 *
 * Parses the provided lines to extract PAR, MAP, and FUNCTIONS blocks.
 * This constructor is useful for testing or when input comes from
 * sources other than files. Validates that all required blocks are
 * present and that map indices are within parameter bounds.
 *
 * @param lines Vector of strings containing the input (PAR, MAP, FUNCTIONS blocks)
 */
//-------------------------------------------------------------
PFunctionHandler::PFunctionHandler(std::vector<std::string> lines)
{
  fValid = true;
  fFileName = "";

  std::cout << std::endl << "in PFunctionHandler(std::vector<std::string> lines)";

  if (lines.size() == 0) {
    fValid = false;
    return;
  }

  // analyze input
  bool done = false;
  int status;
  int val[10];
  double dval[10];
  bool inFcnBlock = false;
  for (unsigned int i=0; i<lines.size(); i++) {
    if (lines[i].find("#") == 0) // comment hence ignore
      continue;
    boost::to_upper(lines[i]);
    if (lines[i].find("PAR") == 0) {
      std::cout << std::endl << "this is a parameter line ...";
      status = sscanf(lines[i].c_str(), "PAR %lf %lf %lf %lf %lf %lf %lf %lf %lf %lf",
                      &dval[0], &dval[1], &dval[2], &dval[3], &dval[4],
                      &dval[5], &dval[6], &dval[7], &dval[8], &dval[9]);
      std::cout << std::endl << "status=" << status;
      if (status < 0) {
        done = true;
        fValid = false;
        std::cout << std::endl << "invalid PAR line, sorry ...";
      } else { // fill par
        std::cout << std::endl << "PAR line, status = " << status;
        for (int i=0; i<status; i++)
          fParam.push_back(dval[i]);
        std::cout << std::endl << "fParam.size()=" << fParam.size() << std::endl;
        for (unsigned int i=0; i<fParam.size(); i++)
          std::cout << std::endl << "Par" << i+1 << " = " << fParam[i];
        std::cout << std::endl;
      }
    } else if (lines[i].find("MAP") == 0) {
      std::cout << std::endl << "this is a map line ...";
      status = sscanf(lines[i].c_str(), "MAP %d %d %d %d %d %d %d %d %d %d",
                      &val[0], &val[1], &val[2], &val[3], &val[4],
                      &val[5], &val[6], &val[7], &val[8], &val[9]);
      if (status < 0) {
        done = true;
        fValid = false;
        std::cout << std::endl << "invalid MAP line, sorry ...";
      } else { // fill map
        std::cout << std::endl << "MAP line, status = " << status;
        for (int i=0; i<status; i++)
          fMap.push_back(val[i]);
      }
    } else if (lines[i].find("FUNCTIONS") == 0) {
      std::cout << std::endl << "the functions block start ...";
      inFcnBlock = true;
    } else if (lines[i].find("END") == 0) {
      std::cout << std::endl << "end tag found; rest will be ignored";
      done = true;
    } else if (inFcnBlock) {
      fLines.push_back(lines[i]);
    }
  }

  // check if all blocks are given
  if ((fMap.size() == 0) || (fParam.size() == 0) || (fLines.size() == 0)) {
    if (fMap.size() == 0)
      std::cout << std::endl << "MAP block is missing ...";
    if (fParam.size() == 0)
      std::cout << std::endl << "PAR block is missing ...";
    if (fLines.size() == 0)
      std::cout << std::endl << "FUNCTION block is missing ...";
    fValid = false;
  }

  fValid = MapsAreValid();

  if (fValid) {
    std::cout << std::endl << "Functions: ";
    for (unsigned int i=0; i<fLines.size(); i++)
      std::cout << std::endl << fLines[i];
  }
}

//-------------------------------------------------------------
/**
 * @brief Destructor - releases all resources.
 *
 * Clears parameter, map, line, and function vectors to free memory.
 */
//-------------------------------------------------------------
PFunctionHandler::~PFunctionHandler()
{
  std::cout << std::endl << "in ~PFunctionHandler()" << std::endl << std::endl;
  fParam.clear();
  fMap.clear();
  fLines.clear();

  fFuncs.clear();
}

//-------------------------------------------------------------
/**
 * @brief Parses all function definitions using the X3 grammar.
 *
 * Iterates through all function lines, parsing each with the Spirit X3
 * grammar to create PFunction objects. Performs validation checks:
 * - All functions parse successfully
 * - Parameter and map indices are within bounds
 * - Function numbers are unique (no duplicates)
 *
 * @return true if all functions parsed and validated successfully
 */
//-------------------------------------------------------------
bool PFunctionHandler::DoParse()
{
  std::cout << std::endl << "in PFunctionHandler::DoParse() ...";

  bool success = true;

  for (unsigned int i=0; i<fLines.size(); i++) {
    std::cout << std::endl << "fLines[" << i << "] = '" << fLines[i] << "'";

    // Convert to uppercase (grammar expects uppercase tokens)
    std::string line = fLines[i];
    std::transform(line.begin(), line.end(), line.begin(), ::toupper);

    // Use new Qi-based PFunction constructor
    PFunction func(line, fParam, fMap, fDebug);

    if (func.IsValid()) {
      std::cout << std::endl << "parse successfull ..." << std::endl;
      fFuncs.push_back(func);
    } else {
      std::cout << std::endl << "parse failed ... (" << i << ")" << std::endl;
      success = false;
      break;
    }
  }

  // check that all functions are valid. It could be that parsing was fine but
  // the parameter index, or map index was out of range
  if (success) {
    for (unsigned int i=0; i<fFuncs.size(); i++) {
      if (!fFuncs[i].IsValid()) {
        std::cout << std::endl << "**ERROR**: function fun" << fFuncs[i].GetFuncNo();
        std::cout << " has a problem with either parameter or map out of range!";
        success = false;
        break;
      }
    }
  }

  // check that the function numbers are unique
  if (success) {
    for (unsigned int i=0; i<fFuncs.size(); i++) {
      for (unsigned int j=i+1; j<fFuncs.size(); j++) {
        if (fFuncs[i].GetFuncNo() == fFuncs[j].GetFuncNo()) {
          std::cout << std::endl << "**ERROR**: function number " << fFuncs[i].GetFuncNo();
          std::cout << " is at least twice present! Fix this first.";
          success = false;
        }
      }
    }
  }

  if (success) {
    for (unsigned int i=0; i<fFuncs.size(); i++)
      std::cout << std::endl << "func number = " << fFuncs[i].GetFuncNo();
  }

  return success;
}

//-------------------------------------------------------------
/**
 * @brief Evaluates a function by its function number.
 *
 * Looks up the function in the internal vector using its function number
 * (from the FUN# declaration) and evaluates it with current parameter values.
 *
 * @param i Function number to evaluate
 * @return The evaluation result, or 0.0 if function not found
 */
//-------------------------------------------------------------
double PFunctionHandler::Eval(int i)
{
  if (GetFuncIndex(i) == -1) {
    std::cout << std::endl << "**ERROR**: Couldn't find FUN" << i << " for evaluation";
    return 0.0;
  }

  return fFuncs[GetFuncIndex(i)].Eval();
}

//-------------------------------------------------------------
/**
 * @brief Gets the function number of the i-th parsed function.
 *
 * @param i Index into the internal function vector (0-based)
 * @return The function number (from FUN#), or -1 if index out of bounds
 */
//-------------------------------------------------------------
unsigned int PFunctionHandler::GetFuncNo(unsigned int i)
{
  if (i > fFuncs.size())
    return -1;

  return fFuncs[i].GetFuncNo();
}

//-------------------------------------------------------------
/**
 * @brief Reads and parses the input file.
 *
 * Opens the file specified in fFileName and extracts:
 * - PAR block: parameter values (up to 10 per line)
 * - MAP block: map indices (up to 10 per line)
 * - FUNCTIONS block: function definition lines
 *
 * Lines starting with # are treated as comments and ignored.
 * Processing stops when END tag is encountered.
 * Converts all input to uppercase for case-insensitive parsing.
 *
 * @return true if file was successfully read and all required blocks found
 */
//-------------------------------------------------------------
bool PFunctionHandler::ReadFile()
{
  std::cout << std::endl << "in ~PFunctionHandler::ReadFile()";

  if (fFileName.length() == 0) {
    std::cout << std::endl << "PFunctionHandler::ReadFile(): **ERROR**";
    std::cout << std::endl << "  no file name given :-(. Will quit";
    return false;
  }

  std::ifstream f;
  f.open(fFileName.c_str(), std::ifstream::in);

  if (!f.is_open()) {
    std::cout << std::endl << "PFunctionHandler::ReadFile(): **ERROR**";
    std::cout << std::endl << "  File '" << fFileName.c_str() << "' couldn't being opened.";
    return false;
  }

  std::string line;
  char c_line[128];
  bool done = false;
  bool success = true;
  int status;
  int val[10];
  double dval[10];
  bool inFcnBlock = false;
  while ( !f.eof() && !done) {
    f.getline(c_line, 128); // line of text excluding '\n'
    line = c_line;
    size_t pos = line.find('\r');
    line.resize(pos);
    if (line.find("#") == 0) // comment hence ignore
      continue;
    boost::to_upper(line);
    if (line.find("PAR") == 0) {
      std::cout << std::endl << "this is a parameter line ...";
      status = sscanf(line.c_str(), "PAR %lf %lf %lf %lf %lf %lf %lf %lf %lf %lf",
                      &dval[0], &dval[1], &dval[2], &dval[3], &dval[4],
                      &dval[5], &dval[6], &dval[7], &dval[8], &dval[9]);
      if (status < 0) {
        done = true;
        success = false;
        std::cout << std::endl << "invalid PAR line, sorry ...";
      } else { // fill map
        std::cout << std::endl << "PAR line, status = " << status;
        for (int i=0; i<status; i++)
          fParam.push_back(dval[i]);
        for (unsigned int i=0; i<fParam.size(); i++)
          std::cout << std::endl << "Par" << i+1 << " = " << fParam[i];
        std::cout << std::endl;
      }
    } else if (line.find("MAP") == 0) {
      std::cout << std::endl << "this is a map line ...";
      status = sscanf(line.c_str(), "MAP %d %d %d %d %d %d %d %d %d %d",
                      &val[0], &val[1], &val[2], &val[3], &val[4],
                      &val[5], &val[6], &val[7], &val[8], &val[9]);
      if (status < 0) {
        done = true;
        success = false;
        std::cout << std::endl << "invalid MAP line, sorry ...";
      } else { // fill map
        std::cout << std::endl << "MAP line, status = " << status;
        for (int i=0; i<status; i++)
          fMap.push_back(val[i]);
      }
    } else if (line.find("FUNCTIONS") == 0) {
      std::cout << std::endl << "the functions block start ...";
      inFcnBlock = true;
    } else if (line.find("END") == 0) {
      std::cout << std::endl << "end tag found; rest will be ignored";
      done = true;
    } else if (inFcnBlock) {
      fLines.push_back(line);
    }
  }


  f.close();

  // check if all blocks are given
  if ((fMap.size() == 0) || (fParam.size() == 0) || (fLines.size() == 0)) {
    if (fMap.size() == 0)
      std::cout << std::endl << "MAP block is missing ...";
    if (fParam.size() == 0)
      std::cout << std::endl << "PAR block is missing ...";
    if (fLines.size() == 0)
      std::cout << std::endl << "FUNCTION block is missing ...";
    success = false;
  }

  if (success) {
    std::cout << std::endl << "Functions: ";
    for (unsigned int i=0; i<fLines.size(); i++)
      std::cout << std::endl << fLines[i];
  }

  return success;
}

//-------------------------------------------------------------
/**
 * @brief Validates that all map indices are within parameter bounds.
 *
 * Checks that each value in the MAP block is a valid parameter index.
 * Map values use 1-based indexing, so valid values are 1 to fParam.size().
 * This validation prevents out-of-bounds access during function evaluation.
 *
 * @return true if all map indices are valid, false otherwise
 */
//-------------------------------------------------------------
bool PFunctionHandler::MapsAreValid()
{
  bool success = true;

  int maxParam = fParam.size();
  for (unsigned int i=0; i<fMap.size(); i++)
    if (fMap[i] > maxParam)
      success = false;

  if (!success)
    std::cout << std::endl << "invalid MAP found ...";

  return success;
}

//-------------------------------------------------------------
/**
 * @brief Finds the internal vector index for a function by its number.
 *
 * Searches the fFuncs vector for a function with the specified function
 * number. This maps from the user-visible function number (FUN#) to the
 * internal 0-based vector index.
 *
 * @param funcNo Function number to search for (from FUN# declaration)
 * @return Index in fFuncs vector (0-based), or -1 if not found
 */
//-------------------------------------------------------------
int PFunctionHandler::GetFuncIndex(int funcNo)
{
  int index = -1;

  for (unsigned int i=0; i<fFuncs.size(); i++) {
    if (fFuncs[i].GetFuncNo() == funcNo) {
      index = i;
      break;
    }
  }

  return index;
}