// Uppgift: Slumpar ut N heltal i ett intervall [A, B] och N flyttal normalfördelade runt M med standardavvikelse D och skriver ut en "bild" av fördelningen.
// Nyckelord: slumgenerering, slumpfördelning, kommandoradsargument, std::map, std::vector, std::max_element, std::stoi, lambda-funktioner
#include <iostream>
#include <iomanip>
#include <random>
#include <map>
#include <algorithm>

#include <ctime>

using namespace std;

void read_arguments(int argc, char* argv[], int& a, int& b, int& m, int& d, int& n);

int main(int argc, char* argv[])
{
  int A, B, MEAN, DEV, N;

  read_arguments(argc, argv, A, B, MEAN, DEV, N);

// Choose random number generator:
//  mt19937 rnd(int(time(nullptr)));
//  default_random_engine rnd(int(time(nullptr))); // pseudo-random numbers
  random_device rnd; // uses true random device if possible

  cout << "Random entropy: " << rnd.entropy() << endl; // prints 0 if pseudo-random, >0 if better quality randomness
  
  uniform_int_distribution<int> uniform(A, B);
  normal_distribution<float>    normal(MEAN, DEV);

  vector<int> uniform_stat(B-A+1, 0);
  map<int, int> normal_stat;

  for (int i = 0; i < N; ++i)
  {
    ++uniform_stat.at( uniform(rnd) - A );
    // For students to think of: You will notice a peak at 0. Zero
    // will occur twice the times it should. Why? How do you fix it?
    ++normal_stat[ normal(rnd) ];
  }

  auto uniform_max = max_element(uniform_stat.begin(), uniform_stat.end(),
                                 [](int a, int b)->bool
                                 { return a < b; });

  cout << left << endl;
  cout << "---- Uniform distribution: " << endl;
  for (int i = A; i <= B; ++i)
  {
    cout << setw(3) << i << ":"
         << setfill('#')
         << setw( uniform_stat[i-A]*75/(*uniform_max) )
         << uniform_stat[i-A]
         << setfill(' ')
         << endl;
  }
  
  auto normal_max = max_element(normal_stat.begin(), normal_stat.end(),
                                [](std::pair<int, int> const& a,
                                   std::pair<int, int> const& b)->bool
                                { return a.second < b.second; });
  
  cout << endl;
  cout << "---- Normal distribution: " << endl;
  for (auto i : normal_stat)
  {
    cout << setw(3) << i.first << ":"
         << setfill('#')
         << setw( i.second*75/(*normal_max).second )
         << i.second
         << setfill(' ')
         << endl;
  }
  
  return 0;
}

void read_arguments(int argc, char* argv[], int& a, int& b, int& m, int& d, int& n)
{
  // default values
  a = 1;
  b = 10;
  m = 3;
  d = 5;
  n = 100000;
  
  for (int i = 1; i < argc-1; ++i)
  {
    if ( string(argv[i]) == "-n" )
      n = stoi(argv[i+1]);
    
    if ( string(argv[i]) == "-m" )
      m = stoi(argv[i+1]);
    
    if ( string(argv[i]) == "-d" )
      d = stoi(argv[i+1]);

    if ( string(argv[i]) == "-a" )
      a = stoi(argv[i+1]);

    if ( string(argv[i]) == "-b" )
      b = stoi(argv[i+1]);
  }
  if ( a > b )
    swap(a, b);
}