#include <iostream>
#include <vector>
#include <random>

using namespace std;

// move class specification to header file
class Board
{
public:

  char at(int x, int y) const;

  bool game_over(char& winner) const;
  void print() const;
  bool place_brick(int column, char player);

private:
  
  bool is_horizontal_win_at(int x, int y) const;
  bool is_vertical_win_at(int x, int y) const;
  bool is_down_right_diagonal_win_at(int x, int y) const;
  bool is_up_right_diagonal_win_at(int x, int y) const;
  bool is_full_board() const;
  
};

// move class implementation to cc-file

// return character at row y and column x on the board
// return space if out of range
char Board::at(int x, int y) const
{
}

// return true if x,x+1,x+2,x+3 on row y are equal
bool Board::is_horizontal_win_at(int x, int y) const
{
  char c = at(x, y);

  for ( int i = 1; i < 4; ++i )
  {
    if ( at(x + i, y) != c )
      return false;
  }
  return true;
}

// return true if y,y+1,y+2,y+3 on column x are equal
bool Board::is_vertical_win_at(int x, int y) const
{
  char c = at(x, y);

  for ( int i = 1; i < 4; ++i )
  {
    if ( at(x, y + i) != c )
      return false;
  }
  return true;
}

// return true if four values on the diagonal down to right starting
// at x,y are equal
bool Board::is_down_right_diagonal_win_at(int x, int y) const
{
  char c = at(x, y);

  for ( int i = 1; i < 4; ++i )
  {
    if ( at(x + i, y + i) != c )
      return false;
  }
  return true;
}

// return true if four values on the diagonal up to right starting
// at x,y are equal
bool Board::is_up_right_diagonal_win_at(int x, int y) const
{
  char c = at(x, y);

  for ( int i = 1; i < 4; ++i )
  {
    if ( at(x + i, y - i) != c )
      return false;
  }
  return true;
}

// return true if no more bricks can be placed
bool Board::is_full_board() const
{
}

// return true if one player won (and set the winner)
// return true if it was a draw (but do not set the winner)
bool Board::game_over(char& winner) const
{
}

// drop players brick at colum, make sure it falls to correct place
bool Board::place_brick(int column, char player)
{
}

// print the game board
void Board::print() const
{
  cout << "|0123456|" << endl;
  for every row // fixme, still pseudo code
  {
    cout << '|';
    for every column in current row // fixme, still pseudo code
    {
      cout << col;
    }
    cout << '|' << endl;
  }
  cout << "+-------+" << endl;
}

// the main program will work if the class is okay
// no modifications needed
int main()
{
  Board board;
  
  char turn{'x'};
  char winner{' '};
  while ( ! board.game_over( winner ) )
  {
    int column;

    cout << turn << " chose column: ";
    cin >> column;
    cout << turn << " picked column " << column << endl;
    
    if ( board.place_brick( column, turn) )
    {
      board.print();

      if ( turn == 'x' )
        turn = 'o';
      else
        turn = 'x';
    }
  }

  if (winner == ' ')
    cout << "It's a draw." << endl;
  else
    cout << "'" << winner << "' wins!" << endl;
  
  cout << endl;

  return 0;
}