// SCORE FOUR! main program 
//
// ECE 2036 
// Fall 2023   
// Prof. Yoder
//
// Goals:
// 1. Provide a fun application of C++ to solving a problem from Game Theory
// 2. Demonstrate implementation of the minimax algorithm, as presented in class.
// 3. Demonstrate parallelization using native C++ threads, as presented in class. 
//
// Notes:
// 1. Default search depth is 1.
//    Larger search depths may be entered as the 2nd argument on the command line.
//    Search depths artificially limited to the range [1,9] to avoid long delays
//    waiting for the computer to move.  This range is easily expanded for use on 
//    faster computers.
// 2. Compile this together with GameBoard.cc using highest optimization level.
// 3. Minimax algorithm implemented in GameBoard.cc, parallelized using native threads
//    and future objects.

#include <iostream>
#include <chrono>
#include <cstdlib>
#include "GameBoard.h"
#include "mydefs.h"

using namespace std;

// Infer requested search depth from the command line.

int main(int argc, char **argv)
{
  GameBoard board;
  Move moveIt;
  int result, searchDepth;

  int r,c;

// Assign the search depth, keeping within reasonable bounds (1 - 9).
  switch(argc) {
     case 1:
        searchDepth = 1;
        break;
     default:
        searchDepth = MIN( atoi(argv[1]), 9);
        searchDepth = MAX(searchDepth,1);
        break;
  }

  cout << "Starting the game with search depth " << searchDepth << endl;

  while (board.movesLeft())
  {
     // Get valid move from human, and update board
     do {
       cout << "Enter a move: " ;
       cin >> r >> c;
     } while (!board.isValid(r,c));

     board.updateBoard(r,c,1);
     board.displayBoard();

     // Check for human win
     result = board.checkWinner();
     if (result == 1) {
        cout << "You win." << endl;
        return(0);
     }

     // Let's time the computer player.
     cout << "Looking for best computer move..." << flush;
     auto start = chrono::high_resolution_clock::now();

     // Find best computer move
     moveIt = board.findBestMove(searchDepth,-1);
     auto stop = chrono::high_resolution_clock::now();

     // Report the computer's move.
     cout << " and it is  ( " <<moveIt.row << ", " << moveIt.col << " )"<<endl;

     // Report the elapsed wall clock time.
     auto elapsedTime = chrono::duration_cast<chrono::milliseconds>(stop-start);
     cout << "That took me " << elapsedTime.count() << " milliseconds. " << endl;

     board.updateBoard(moveIt.row, moveIt.col, -1);
     board.displayBoard();

     // Check for computer win.
     result = board.checkWinner();
     if (result == -1) {
        cout << "I win." << endl;
        return(0);
     }

   }  
   cout << endl << "It is a tie game." << endl;
     
}