#include <iostream>
#include <cstdlib>
#include <ctime>
#include <fstream>
using namespace std;

const int ROW = 7;
const int COL = 8;

struct GameState
{
	char board[ROW][COL];
	char symbol;
	char nextTurn;
};


void drawHeader();
void chooseOption();
void computerMove(GameState&);
void yourMove();
void initialiseBoard(char[][COL]);
int playerMove(char[][COL], char, int);
void drawBoard(char[][COL]);
bool saveGame(GameState, char []);
bool loadGame(GameState&, char []);
int checkWinner(GameState&);


int main()
{
	drawHeader();
	
	chooseOption();
	



	return 0;
}

void chooseOption()
{
	bool unbroken = true;
	char option;
	char suboption;
	
	while(unbroken == true)
	{	 
		
		cout<<"*******************************************************************************"<<endl;
		cout<<"**************************Chooose an option************************************"<<endl;
		cout<<"*******************************************************************************"<<endl;
		cout<<"* a) Play against the computer												*"<<endl;
		cout<<"* b) Play against another player											  *"<<endl;
		cout<<"* c) Load game																*"<<endl;
		cout<<"* d) Quit																	 *"<<endl;
		cout<<"*******************************************************************************"<<endl;
		cout<<endl;
		cout<<"Enter your choice: ";
		cin>>option;
		GameState gs;
		
		if(option != 'A' && option != 'a' && option != 'B' && option != 'b' && option != 'C' && option != 'c' && option != 'D' && option != 'd')
		{
			cout<<"Invalid option, please try again!!"<<endl;
		}
		if(option == 'a' || option == 'A')
		{
			
			cout<<"You are now playing vs the computer, your symbol is: 'O'. "<<endl;
						
			char query = '?';
			bool isSaved = false;
			bool breaker2 = false;
			char filename[20];
			int move = -50;
			bool continueComp = true;
			bool isClear = true;
			int winner = 0;
			
			for(int x = 0; x < 7; x++)
			{
				for(int y = 0; y < 8; y++)
				{
					if(gs.board[x][y] == 'O' || gs.board[x][y] == 'X' )
					{
						isClear = false;
					}
						
				}
				
			}
			
			if(isClear == true)
			{
				initialiseBoard(gs.board);
			}
			
			
			
			drawBoard(gs.board);
			
			
			while(continueComp == true)
			{
				move = playerMove(gs.board, gs.symbol = 'O', 1);
				winner = checkWinner(gs);
				if(winner == 1)
				{
					cout<<"Congratulations!! You've beaten the computer !!"<<endl;
					continueComp = false;
				}
				if(winner == 3)
				{
					cout<<"Draw!!"<<endl;
					continueComp = false;
				}
				gs.nextTurn = 1;
				if(move == 0)
				{	 	 	 	 	 
					while(breaker2 == false)
					{
				
								cout<<"Do you wish to play again (y/n)?: ";
								cin>>query;
								cout<<endl<<endl;
				
								if(query == 'y')
								{	 	 	 	 	 	 	 
									initialiseBoard(gs.board);
									breaker2 = true;
								}
								if(query == 'n')
								{
									cout<<endl<<"Do you wish to save your game (y/n)?";
									cin>>query;
									if(query == 'y')
									{
										cout<<"Enter the file name (including extention .txt) for the game to be saved: ";
										cin>>filename;
										isSaved = saveGame(gs, filename);
										if(isSaved == true)
										{
											cout<<endl<<endl<<"Game saved successfully!!"<<endl<<endl;
										}
						
									 	 
										while(isSaved == false)
										{
											cout<<"ERROR: Failed to save under that file name. Please try again or type 'exit' to quit."<<endl;
											cout<<"Enter the file name (including extention .txt) for the game to be saved: ";
											cin>>filename;
																	
											isSaved = saveGame(gs, filename);
											if(isSaved == true)
											{
												cout<<endl<<endl<<"Game saved successfully!!"<<endl<<endl;
											}
									
											if(filename == "exit")
											{
												isSaved = true;
											}	 
									
										}
										initialiseBoard(gs.board);
								
							 
						
									}	 	 
							
									breaker2 = true;
									initialiseBoard(gs.board);
							
								}
								if(query != 'n' && query != 'y')
								{
									cout<<"Please enter a valid answer."<<endl;
								}
					}	   	   	   	   
											
					continueComp = false;
				}
				if(move != 0)
				{
					drawBoard(gs.board);
					computerMove(gs);
					drawBoard(gs.board);
					checkWinner(gs);
					if(winner == 2)
					{
						cout<<"Sorry... you have been beaten by the computer."<<endl;
						continueComp = false;
					}
					if(winner == 3)
					{
						cout<<"Draw!!"<<endl;
						continueComp = false;
					}	   	   	   			   	   	   	   
				}
			
			}
				
			
			option == 'd';
			
		}
		
		if(option == 'b' || option == 'B')
		{
			cout<<"You have chosen to play vs another player..."<<endl;
			cout<<"Player 1 = O"<<endl;
			cout<<"Player 2 = X"<<endl;
			
			char query = '?';
			bool isSaved = false;
			bool breaker2 = false;
			char filename[20];				  
			int move = -50;
			bool continueGame = true;
			bool isClear = true;
			int winner = 0;
			
			for(int x = 0; x < 7; x++)
			{
				for(int y = 0; y < 8; y++)
				{
					if(gs.board[x][y] == 'O' || gs.board[x][y] == 'X' )
					{
						isClear = false;
					}
						
				}
				
			}
			
			if(isClear == true)
			{
				initialiseBoard(gs.board);
				gs.nextTurn = '1';
			}
			
			drawBoard(gs.board);
			
			if(gs.nextTurn == '2')
			{
				move = playerMove(gs.board,  gs.symbol = 'X', 2);
				drawBoard(gs.board);
				checkWinner(gs);
				if(winner == 2)
				{
					cout<<"Player 2 wins!!"<<endl;
					move = 0;
				}
				if(winner == 3)
				{
					cout<<"Draw!!"<<endl;
					move = 0;
				}
				
			}
			
			if(move == 0)
			{
				gs.nextTurn == '1';
				initialiseBoard(gs.board);
				
			}
			
			if(move != 0)
			{
			
				while(continueGame == true)
				{
					move = playerMove(gs.board, gs.symbol = 'O', 1);
					gs.nextTurn = 1;
					winner = checkWinner(gs);
					if(winner == 1)
					{
						cout<<"Player 1 wins!!"<<endl;
						continueGame = false;
					}
					if(winner == 3)
					{
						cout<<"Draw!!"<<endl;
						continueGame = false;
					}
				
					if(move == 0)
					{
						while(breaker2 == false)
							{
				
								cout<<"Do you wish to play again (y/n)?: ";
								cin>>query;
								cout<<endl<<endl;
				
								if(query == 'y')
								{	 	 	 	 	 	 	 
									initialiseBoard(gs.board);
									breaker2 = true;
								}
								if(query == 'n')
								{
									cout<<endl<<"Do you wish to save your game (y/n)?";
									cin>>query;
									if(query == 'y')
									{
										cout<<"Enter the file name (including extention .txt) for the game to be saved: ";
										cin>>filename;
										isSaved = saveGame(gs, filename);
										if(isSaved == true)
										{
											cout<<endl<<endl<<"Game saved successfully!!"<<endl<<endl;
										}
						
									 	 
										while(isSaved == false)
										{
											cout<<"ERROR: Failed to save under that file name. Please try again or type 'exit' to quit."<<endl;
											cout<<"Enter the file name (including extention .txt) for the game to be saved: ";
											cin>>filename;
																	
											isSaved = saveGame(gs, filename);
											if(isSaved == true)
											{
												cout<<endl<<endl<<"Game saved successfully!!"<<endl<<endl;
											}
									
											if(filename == "exit")
											{
												isSaved = true;
											}	 
									
										}
										initialiseBoard(gs.board);
								
							 
						
									}	 	 
							
									breaker2 = true;
									initialiseBoard(gs.board);
							
								}
								if(query != 'n' && query != 'y')
								{
									cout<<"Please enter a valid answer."<<endl;
								}
							}	   	   	   	   
						continueGame = false;
						initialiseBoard(gs.board);
					}
					if(move != 0)
					{
						drawBoard(gs.board);
						move = playerMove(gs.board,  gs.symbol = 'X', 2);
						drawBoard(gs.board);
						
						gs.nextTurn = '2';
						winner = checkWinner(gs);
						if(winner == 2)
						{
							cout<<"Player 2 wins!!"<<endl;
							continueGame = false;
						}
						if(winner == 3)
						{
							cout<<"Draw!!"<<endl;
							continueGame = false;
						}
							
						
						
						if(move == 0)
						{
							while(breaker2 == false)
							{
				
								cout<<"Do you wish to play again (y/n)?: ";
								cin>>query;
								cout<<endl<<endl;
				
								if(query == 'y')
								{	 	 	 	 	 	 	 
									initialiseBoard(gs.board);
									breaker2 = true;
								}
								if(query == 'n')
								{
									cout<<endl<<"Do you wish to save your game (y/n)?";
									cin>>query;
									if(query == 'y')
									{
										cout<<"Enter the file name (including extention .txt) for the game to be saved: ";
										cin>>filename;
										isSaved = saveGame(gs, filename);
										if(isSaved == true)
										{
											cout<<endl<<endl<<"Game saved successfully!!"<<endl<<endl;
										}
						
									 	 
										while(isSaved == false)
										{
											cout<<"ERROR: Failed to save under that file name. Please try again or type 'exit' to quit."<<endl;
											cout<<"Enter the file name (including extention .txt) for the game to be saved: ";
											cin>>filename;
																	
											isSaved = saveGame(gs, filename);
											if(isSaved == true)
											{
												cout<<endl<<endl<<"Game saved successfully!!"<<endl<<endl;
											}
									
											if(filename == "exit")
											{
												isSaved = true;
											}	 
									
										}
										initialiseBoard(gs.board);
								
							 
						
									}	 	 
							
									breaker2 = true;
									initialiseBoard(gs.board);
							
								}
								if(query != 'n' && query != 'y')
								{
									cout<<"Please enter a valid answer."<<endl;
								}
							}	   	   	   	   
												
							continueGame = false;
							initialiseBoard(gs.board);
									
						}
						
				
				
					}
				
				
			}
		}
			
			
			option == 'd';
		
		}
		
		if(option == 'c' || option == 'C')
		{
			bool isLoaded = false;
			char filename[20];
			
			cout<<"Enter the file name (including extention .txt) for the game to be loaded: ";
			cin>>filename;
			
			isLoaded = loadGame(gs,filename);
			
			if(isLoaded == true)
			{
				cout<<"Game Loaded!!"<<endl<<endl;
			}
			
		}
		
		
		
		if(option == 'd' || option == 'D')
		{
			cout<<"Do you wish to play again?(y/n) ";
			cin>>suboption;
			if(suboption == 'y')
			unbroken = true;
			else if(suboption == 'n')
			{
				cout<<"Thanks for playing connect four !! The game of the clever people !!"<<endl;
				unbroken = false;
			}
		}
	
	
	}	 
	
}





void drawHeader()
{
	cout<<"*******************************************************************************"<<endl;
	cout<<"****************************Connect Four***************************************"<<endl;
	cout<<"*******************************************************************************"<<endl;
	cout<<"Welcome to the connect four computer game.You can choose to play against another"<<endl;
	cout<<"player or against the computer(not implemented in this version). In this game "<<endl;
	cout<<"the first player to position four of his/her pieces on a line will win. the "<<endl;
	cout<<"line can be horizontal, vertical or at an angle, but the 4 pieces must be next "<<endl;
	cout<<"to each other"<<endl;
	cout<<"*******************************************************************************"<<endl;
	cout<<endl<<endl;
	
}

void initialiseBoard(char board[][COL])
{
	for(int x = 0; x < ROW; x++)
	{
		for(int y = 0; y < COL; y++)
		{
			board[x][y] = '.';
		}
		
		
	}
		
			
}

void computerMove(GameState& gs)
{
	char computerMark = 'X';
	int num = 0;
	srand(time(NULL));
	bool tryagain = true;
	cout<<"Computer makes a move..."<<endl;
	
	
	while(tryagain == true)
	{
		num = (rand() % (8 - 1)) + 1;
		
		bool subBreaker = false;
		bool changeCheck = false;
		int initialRow = 6;
		while(subBreaker == false && initialRow >= 0)
		{
			if(gs.board[initialRow][num - 1] != '.')
			{
				initialRow--;
			}
			if(gs.board[initialRow][(num - 1)] == '.')
			{
				gs.board[initialRow][(num - 1)] = computerMark;
				changeCheck = true;
				subBreaker = true;
				tryagain = false;
				
			}
		}
			
		if(changeCheck == false)
		{
			tryagain = true;	
		}
		
		
	}	 
		
	cout<<"Computer move: "<<num<<endl;	   
}

int playerMove(char board[][COL], char symbol, int pn)
{
	int userInput = -1;
	char query = '?';
	bool isSaved = false;
	bool breaker = false;
	bool breaker2 = false;
	char filename[20];
	
	while(breaker == false)
	{
		cout<<"Player "<<pn<<" move (1 - 8, 0 to quit): ";
		cin>>userInput;
		cout<<endl;
	
		if(userInput > 8 || userInput < 0)
		{
			cout<<"Input entered is invalid, please try again."<<endl;
		}
		if(userInput == 0)
		{
			breaker = true;
		}
		if(userInput > 0 && userInput <= 8)
		{
			bool subBreaker = false;
			bool changeCheck = false;
			int initialRow = 6;
			while(subBreaker == false && initialRow >= 0)
			{
				if(board[initialRow][userInput - 1] != '.')
				{
					initialRow--;
				}
				if(board[initialRow][(userInput - 1)] == '.')
				{
					board[initialRow][(userInput - 1)] = symbol;
					changeCheck = true;
					subBreaker = true;
					breaker = true;
				}
			}
			
			if(changeCheck == false)
			{
				cout<<"Column is already full, please re-enter your input."<<endl;
				breaker = false;
			}	
			
		}
	}
	
return userInput;

}


		
		
	
	
	






void drawBoard(char board[][COL])
{

	for(int x = 0; x < ROW; x++)
	{
		for(int y = 0; y < COL; y++)
		{
			cout<<board[x][y];
		}
		
		cout<<endl;
	}
	cout<<"12345678"<<endl;	   



}

bool saveGame(GameState gs, char fileName[])
{
	ofstream outfile;
	
	outfile.open(fileName);
	if(!outfile)
	{
		return false;
	}
	else
	{
		for(int x = 0; x < 7; x++)
		{
			for(int y = 0; y < 8; y++)
			{
				outfile<<gs.board[x][y];	
			}	 
			outfile<<"#";
		}	  
		outfile<<endl<<gs.symbol<<gs.nextTurn;	  
	
		outfile.close();
	
		return true;
	}
}
bool loadGame(GameState& gs, char fileName[])
{
	ifstream infile;
		
	infile.open(fileName);
	
	if(!infile)
	{
		cout<<"ERROR: File not found."<<endl<<endl;
		return false;
	}
	else
	{
		
		for(int x = 0; x < 7; x++)
		{
			for(int y = 0; y < 8; y++)
			{
				infile>>gs.board[x][y];	   
			}	 
			infile.ignore(1, '#');
		}
		infile.ignore(1,'\n');
		infile>>gs.symbol>>gs.nextTurn;		
		
		return true;
	}
}

int checkWinner(GameState& gs)
{
	
	int winner = 0;

/*
	bool isDraw = true;
	
	for(int x = 0; x < 7; x++)
	{
		for(int y = 0; y < 8; y++)
		{
			if((gs.board[x][y] == gs.board[x][y + 1] == gs.board[x][y + 2] == gs.board[x][y + 3] == 'O') || (gs.board[x][y] == gs.board[x][y - 1] == gs.board[x][y - 2] == gs.board[x][y - 3] == 'O'))
			{
				winner = 1;
			}
			
			if((gs.board[x][y] == gs.board[x][y + 1] == gs.board[x][y + 2] == gs.board[x][y + 3] == 'X') || (gs.board[x][y] == gs.board[x][y - 1] == gs.board[x][y - 2] == gs.board[x][y - 3] == 'X'))
			{
				winner = 2;
			}
			
			if((gs.board[x][y] == gs.board[x + 1][y] == gs.board[x + 2][y] == gs.board[x + 3][y] == 'O') || (gs.board[x][y] == gs.board[x - 1][y] == gs.board[x - 2][y] == gs.board[x - 3][y] == 'O'))
			{
				winner = 1;
			}
			if((gs.board[x][y] == gs.board[x + 1][y] == gs.board[x + 2][y] == gs.board[x + 3][y] == 'X') || (gs.board[x][y] == gs.board[x - 1][y] == gs.board[x - 2][y] == gs.board[x - 3][y] == 'X'))
			{
				winner = 2;
			}
			if((gs.board[x][y] == gs.board[x + 1][y + 1] == gs.board[x + 2][y + 2] == gs.board[x + 3][y + 3] == 'O') || (gs.board[x][y] == gs.board[x - 1][y + 1] == gs.board[x - 2][y + 2] == gs.board[x - 3][y + 3] == 'O'))
			{
				winner = 1;
			}
			if((gs.board[x][y] == gs.board[x + 1][y + 1] == gs.board[x + 2][y + 2] == gs.board[x + 3][y + 3] == 'X') || (gs.board[x][y] == gs.board[x - 1][y + 1] == gs.board[x - 2][y + 2] == gs.board[x - 3][y + 3] == 'X'))
			{
				winner = 2;
			}
			
				   
		
		}
		
		
			  
		
	}
	
	for(int x = 0; x < 7; x++)
	{
		for(int y = 0; y < 8; y++)
		{
			
			if(gs.board[x][y] == '.')
			{
				isDraw = false;
			}
			
		}
		
	}
	
	if(isDraw == true)
	{
		winner = 3;
	}
*/
	return winner;
}