/*!
 * \file    main.cpp
 * \brief   Main application file
 *
 * \author
 *    Christos Choutouridis AEM:8997
 *    <cchoutou@ece.auth.gr>
 */

#include <iostream>
#include <string>
#include <exception>

#include <utils.h>
#include <config.h>

// Global session data
session_t session;
Log       logger;

/*!
 * A small command line argument parser
 * \return  The status of the operation
 */
bool get_options(int argc, char* argv[]){
   bool status =true;

   // iterate over the passed arguments
   for (int i=1 ; i<argc ; ++i) {
      std::string arg(argv[i]);     // get current argument

      if (arg == "-i" || arg == "--input") {
         session.inputMatrix = InputMatrix::MTX;
         if (i+1 < argc)
            session.mtxFile = std::ifstream(argv[++i]);
         else
            status = false;
      }
      else if (arg == "-o" || arg == "--output") {
         session.outputMode = OutputMode::FILE;
         if (i+1 < argc)
            session.outFile = std::ofstream(argv[++i]);
         else
            status = false;
      }
      else if (arg == "-g" || arg == "--generate") {
         session.inputMatrix = InputMatrix::GENERATE;
         if (i+2 < argc) {
            session.gen_size = std::atoi(argv[++i]);
            session.gen_prob = std::atof(argv[++i]);
         }
         else
            status = false;
      }
      else if (arg == "-n" || arg == "--max_trheads") {
         session.max_threads = (i+1 < argc) ? std::atoi(argv[++i]) : session.max_threads;
      }
      else if (arg == "-r" || arg == "--repeat") {
         session.repeat = (i+1 < argc) ? std::atoi(argv[++i]) : session.repeat;
      }
      else if (arg == "-t" || arg == "--timing")
         session.timing = true;
      else if (arg == "-v" || arg == "--verbose")
         session.verbose = true;
      else if (arg == "--make_symmetric")
         session.makeSymmetric = true;
      else if (arg == "--triangular_only")
         session.makeSymmetric = false;
      else if (arg == "--validate_mtx")
         session.validate_mtx = true;
      else if (arg == "--dynamic")
         session.dynamic = true;
      else if (arg == "--print_count") {
         session.print_count = true;
         session.makeSymmetric = false;
      }
      else if (arg == "--print_graph") {
         session.mtx_print = true;
         session.mtx_print_size = (i+1 < argc) ? std::atoi(argv[++i]) : session.mtx_print_size;
      }
      else if (arg == "-h" || arg == "--help") {
         std::cout << "vertex-wise triangular count utility.\n\n";
         std::cout << "tcount -i <file> | -g <size> <probability> [-o <file>] [-n <threads>] [--dynamic] [-r <times>] [-t] [-v]\n";
         std::cout << "        [--make_symmetric] [--triangular_only] [--print_count] [--validate_mtx] [--print_graph <size>]\n";
         std::cout << '\n';
         std::cout << "Options:\n\n";
         std::cout << "   -i | --input <file>\n";
         std::cout << "      Path to mtx file to load.\n\n";
         std::cout << "   -g | --generate <size> <probability>\n";
         std::cout << "      Request a random generated graph with size <size> and probability <probability>.\n";
         std::cout << "      This is very slow, use it with care.\n\n";
         std::cout << "   -o | --output <file>\n";
         std::cout << "      Select <file> as output file. Default is stdout.\n\n";
         std::cout << "   -n | --max_trheads <threads>\n";
         std::cout << "      Reduce the thread number for the execution to <threads>. <threads> must be less or equal to available CPUs.\n\n";
         std::cout << "   --dynamic\n";
         std::cout << "      Request of dynamic scheduling for OpenMP and pthreads. Does not affect cilk versions.\n\n";
         std::cout << "   -r | --repeat <times>\n";
         std::cout << "      Repeat the vector calculation <times> times.\n\n";
         std::cout << "   -t | --timing\n";
         std::cout << "      Request timing measurements output to stdout.\n\n";
         std::cout << "   -v | --verbose\n";
         std::cout << "      Request a more verbose output to stdout.\n\n";
         std::cout << "   --make_symmetric\n";
         std::cout << "      Explicitly request a symmetric graph generation. This affects only V3 versions where by default a lower\n";
         std::cout << "      triangular matrix is used.\n\n";
         std::cout << "   --triangular_only\n";
         std::cout << "      NOTE: Requires also \"--print_count\".\n";
         std::cout << "      Explicitly request to use a lower triangular matrix. This affects only V4 versions where a symmetric\n";
         std::cout << "      matrix is used by default and produce correct answer ONLY for total triangle counting (--print_count).\n\n";
         std::cout << "   --print_count\n";
         std::cout << "      NOTE: When used, also implies \"---triangular_only\" for all versions.\n";
         std::cout << "      Request a total triangle counting output.\n\n";
         std::cout << "   --validate_mtx\n";
         std::cout << "      Request an input matrix validation before execution.\n\n";
         std::cout << "   --print_graph <size>\n";
         std::cout << "      Prints the first <size> x <size> part of the matrix to stdout.\n\n";
         std::cout << "   -h | --help <size>\n";
         std::cout << "      Prints this and exit.\n";
         exit(0);
      }
      else {   // parse error
         std::cout << "Invokation error. Try -h for details.\n";
         status = false;
      }
   }

   // Input checkers
   if (session.inputMatrix == InputMatrix::UNSPECIFIED) {
      std::cout << "Error message\n";
      status = false;
   }
#if CODE_VERSION == V4
   else if (!session.makeSymmetric && !session.print_count) {
      std::cout << "\"--triangular_only\" requires \"--print_count\"\n";
      status = false;
   }
#endif
   return status;
}

/*!
 * get or generate matrix
 * \param   A     Reference to matrix for output (move using RVO)
 * \param   timer Reference to timer utility to access time printing functionality
 */
void prepare_matrix (matrix& A, Timing& timer) {
   if (session.inputMatrix == InputMatrix::GENERATE) {
      logger << "Initialize matrix with size: " << session.gen_size << " and probability: " << session.gen_prob << logger.endl;
      timer.start();
      A.size(session.gen_size);
      init_ER_graph(A, session.gen_prob);
      timer.stop();
      timer.print_dt("generate matrix");
   }
   else {
      logger << "Read matrix from file" << logger.endl;
      timer.start();
      if (session.validate_mtx && !Mtx::is_triangular<matrix::indexType> (session.mtxFile))
         throw std::runtime_error("Error: Matrix is not strictly upper or lower");
      if (!Mtx::load (A, session.mtxFile)) {
         throw std::runtime_error("Error: fail to load matrix");
      }
      timer.stop();
      logger << "Matrix size: " << A.size() << " and capacity: " << A.capacity() << logger.endl;
      timer.print_dt("load matrix");
   }

   if (session.verbose && session.mtx_print) {
      logger << "\nMatrix:" << logger.endl;
      print_graph (A);
   }
}

/*
 * main program
 */
int main(int argc, char* argv[]) try {
   Timing timer;
   matrix A;
   std::vector<value_t> c;
   index_t s;

   #if defined ELEARNING
   if (!elearn_test())  std::cout << "E-learning test: FAIL\n";
   else                 std::cout << "E-learning test: PASS\n";
   exit(0);
   #endif

   // try to read command line
   if (!get_options(argc, argv))
      exit(1);

   prepare_matrix(A, timer);
   threads_info();
   for (size_t i =0 ; i<session.repeat ; ++i) {
      // repeat calculations as requested by user
      logger << "Create vector" << logger.endl;
      timer.start();
      c = triang_v (A);
      timer.stop();
      timer.print_dt("create vector");
   }
   if (session.print_count) {
      logger << "Calculate total triangles" << logger.endl;
      timer.start();
      s = triang_count(c);
      timer.stop();
      logger << "There are " << s << " triangles" << logger.endl;
      timer.print_dt("calculate sum");
   }
   // output results
   if (session.print_count)
      triangle_out (s, (session.outputMode == OutputMode::FILE) ? session.outFile : std::cout);
   else
      vector_out (c, (session.outputMode == OutputMode::FILE) ? session.outFile : std::cout);
	return 0;
}
catch (std::exception& e) {
   //we probably pollute the user's screen. Comment `cerr << ...` if you don't like it.
   std::cerr << e.what() << '\n';
   exit(1);
}