//Paul Fynn Kuemmel
// This is a code which mimics the game 21 sticks, in which 2 players take turns either taking 1, 2 or 3 sticks
// Eventually the person who's turn it is when 1 stick remains, is the loser.
#include <stdio.h>
#include <iostream>
#include <string>
using namespace std;

int main()
{
    //Declares the variables which will be used in the game.
    int GameChoice, loop, StickNum, sticksTaken, playerTurn, counter;
    string Player1Name, Player2Name, NewGame;
    //Loops while the player still wants to play the game
    loop = 1;
    while(loop == 1){

        //This is the starting menu and introduction to the game
         cout << "Hello! Welcome to 21 sticks! The rules are as following: " << endl;
    cout << "1. You can only select between 1, 2 or 3 sticks" << endl;
    cout << "2. The last person to take the stick loses" << endl;
    cout << "Game options: " << endl;
    cout << "1) Play vs Computer: " << endl;
    cout << "2) Play vs Friend: " << endl;
    cout << "Enter either 1 or 2 to choose: ";
    cin >> GameChoice;

        //This occurs when the player decides to play against a friend
        if(GameChoice==2){

            counter = 1;

            //Total number of sticks
            StickNum = 21;

            //Asks the players for  their names
            cout<<"Enter the name of Player 1: ";
            getline(cin, Player1Name);//This ensures that the data is properly collected and stored.
            getline(cin, Player1Name);


            cout<<"Enter the name of Player 2: ";
            getline(cin, Player2Name);

            cout<<"Number of sticks = "<<StickNum<<endl;

            //Gets a random number to see who will started the game
            playerTurn = (rand() % 4) + 1;

            //If the random number is either 1 or 3, then player 1 will start
            if(playerTurn == 1 or playerTurn == 3){

                //Loops uring the turn of player 1
                while(counter == 1){
                    //player 1 inputs number of sticks to take out, once a correct value is entered, the loop ends and changes the turn

                    do{
                        cout<<Player1Name<<" ,Enter number of sticks you want to take out, keep it between 1-3: ";
                        cin>>sticksTaken;
                        if(sticksTaken < 1 or sticksTaken > 3 ){
                            cout<<"The input isn't between the boundaries, so it is invalid."<<endl;
                        }
                    }while(sticksTaken < 1 or sticksTaken > 3 );

                    //Subtracts the selection from the original total
                    StickNum-=sticksTaken;
                    cout<<StickNum<<endl;

                    //If number of sticks is 1 then player 1 wins
                    if(StickNum == 1){
                        cout<<Player1Name<<" Wins!"<<endl;
                        break;
                    }

                    //If number of sticks is 0 or less than 0 then player 2 wins
                    if(StickNum <= 0){
                        cout<<Player2Name<<" Wins!"<<endl;
                        break;
                    }

                    //Now, player 2 enters their selection
                    //Loop ends when valid input is entered
                    do{
                        cout<<Player2Name<<" ,Enter the number of sticks you want to take out 1-3: ";
                        cin>>sticksTaken;
                        if(sticksTaken < 1 or sticksTaken > 3 ){
                            cout<<"Invalid input since it is not between 1-3."<<endl;
                        }
                    }while(sticksTaken < 1 or sticksTaken > 3 );

                    StickNum-=sticksTaken;
                    cout<<StickNum<<endl;

                    //If number of sticks is 1 then player 2 wins
                    if(StickNum == 1){
                        cout<<Player2Name<<" Wins!"<<endl;
                        break;
                    }

                    //If number of sticks is 0 or less than 0 then player 1 wins
                    if(StickNum <= 0){
                        cout<<Player1Name<<" Wins!"<<endl;
                        break;
                    }

                }

                //Gives the option of playing another round
                //Loop ends when vaid input is entered
                do{
                    cout<<"Do you want to play another round (Yes or No)? ";
                    cin>>NewGame;
                    if(NewGame!= "yes" and NewGame != "Yes" and NewGame != "No" and NewGame != "no"){
                        cout<<"Invalid input since you did not enter yes or no";
                    }
                }while(NewGame!= "yes" and NewGame != "Yes" and NewGame != "No" and NewGame != "no");

                //Returns to the beginning if Yes or No is entered
                if(NewGame == "yes" or NewGame == "Yes"){
                    continue;
                }

                //If yes the while loop at program restarts, and the code continues
                //If no, loop variable is set to 2 which ends the while loop
                if(NewGame == "no" or NewGame == "No"){
                    loop++;
                }
            }

            //Now this code is if player 2 starts first, with the random number being either 2 or 4
            if(playerTurn == 2 or playerTurn == 4){

                while(counter == 1){

                    //Player 2 inputs the number of sticks to be taken out
                    //Loop ends when valid input is entered
                    do{
                        cout<<Player2Name<<" ,enter number of sticks you want to take out(1-3): ";
                        cin>>sticksTaken;
                        if(sticksTaken < 1 or sticksTaken > 3 ){
                            cout<<"Invalid input since it is not inbetween 1-3."<<endl;
                        }
                    }while(sticksTaken < 1 or sticksTaken > 3 );

                    StickNum -= sticksTaken;
                    cout<<StickNum<<endl;

                    //If number of sticks remaining is 1 then player 2 wins
                    if(StickNum == 1){
                        cout<<Player2Name<<" Wins!"<<endl;
                        break;
                    }

                    //If number of sticks is 0 or less than 0 then player 1 wins
                    if(StickNum <= 0){
                        cout<<Player1Name<<" Wins!"<<endl;
                        break;
                    }

                    //Player 1 inputs the number of sticks to take out
                    //Loop ends when valid input is entered
                    do{
                        cout<<Player1Name<<" ,enter number of sticks you want to take out(1-3): ";
                        cin>>sticksTaken;
                        if(sticksTaken < 1 or sticksTaken > 3 ){
                            cout<<"Invalid input since it is not inbetween 1-3."<<endl;
                        }
                    }while(sticksTaken < 1 or sticksTaken > 3 );

                    StickNum -= sticksTaken;
                    cout<<StickNum<<endl;

                    //If number of sticks is 1 then player 1 wins
                    if(StickNum == 1){
                        cout<<Player1Name<<" Wins!"<<endl;
                        break;
                    }

                    //If number of sticks is 0 or less than 0 then player 2 wins
                    if(StickNum <= 0){
                        cout<<Player2Name<<" Wins!"<<endl;
                        break;
                    }

                }
                //Asks the user if they want to play another round, and restart the loop
                do{
                    cout<<"Do you want to play another round (yes or no) ? ";
                    cin>>NewGame;
                    if(NewGame!= "yes" and NewGame != "Yes" and NewGame != "No" and NewGame != "no"){
                        cout<<"Invalid input since you did not enter yes or no";
                    }
                }while(NewGame!= "yes" and NewGame != "Yes" and NewGame != "No" and NewGame != "no");

                if(NewGame == "yes" or NewGame == "Yes"){
                    continue;
                }

                if(NewGame == "no" or NewGame == "No"){
                    loop++;
                }

            }
        }




        //Now, this is the code which runs if the player decides to attempt to defeat the Computer.
        if(GameChoice==1){
            counter = 1;
            StickNum = 21;
            cout<<"Enter player 1 name: ";
            getline(cin, Player1Name);
            getline(cin, Player1Name);

            cout<<"Number of sticks = "<<StickNum<<endl;

            playerTurn = (rand() % 4) + 1;;


            if(playerTurn == 1 or playerTurn == 3){

                while(counter == 1){

                    //Player 1 inputs the number of sticks to take out
                    //Loop ends when valid input is entered
                    do{
                        cout<<Player1Name<<" ,Enter number of sticks you want to take out(1-3): ";
                        cin>>sticksTaken;
                        if(sticksTaken < 1 or sticksTaken > 3 ){
                            cout<<"Invalid input since it is not between 1-3."<<endl;
                        }
                    }while(sticksTaken < 1 or sticksTaken > 3 );

                    StickNum -= sticksTaken;
                    cout<<StickNum<<endl;

                    //If number of sticks is 1 then player 1 wins
                    if(StickNum == 1){
                        cout<<Player1Name<<" Wins!"<<endl;
                        break;
                    }

                    //If number of sticks is 0 or less than 0 then the computer wins
                    if(StickNum <= 0){
                        cout<<"Computer Wins!"<<endl;
                        break;
                    }

                    //Code for computer to use to win.
                    //Computer takes out the certain amount sticks so that the sticks taken over the 2 turns, always equals to 4.
                    sticksTaken = 4 - sticksTaken;
                    StickNum -= sticksTaken;
                    cout<<"Computer takes out "<<sticksTaken<<" sticks."<<endl;
                    cout<<StickNum<<endl;

                    //If number of sticks is 1 then computer wins
                    if(StickNum == 1){
                        cout<<"Computer Wins!"<<endl;
                        break;
                    }

                    //If number of sticks is 0 or less than 0 then player 1 wins
                    if(StickNum <= 0){
                        cout<<Player1Name<<" Wins!"<<endl;
                        break;
                    }

                }

                do{
                    cout<<"Do you want to play another round(yes or no): ";
                        cin>>NewGame;
                        if(NewGame!= "yes" and NewGame != "Yes" and NewGame != "No" and NewGame != "no"){
                            cout<<"Invalid input since you did not enter yes or no";
                        }
                    }while(NewGame!= "yes" and NewGame != "Yes" and NewGame != "No" and NewGame != "no");

                    if(NewGame == "yes" or NewGame == "Yes"){
                        continue;
                    }

                    if(NewGame == "no" or NewGame == "No"){
                        loop++;
                    }
            }




            //Computer goes first
            if(playerTurn == 2 or playerTurn == 4){

                while(counter == 1){

                    //If the Number of sticks is over 4 then computer takes out a random number between 1 and 3, to make it fairer
                    if(StickNum>4){
                        sticksTaken = (rand() % 3) + 1;
                    }

                    // If the Number of sticks is equal to 4 then it takes out 3
                    if(StickNum==4){
                        sticksTaken=3;
                    }

                    // If the Number of sticks is equal to 3 then it takes out 2
                    if(StickNum==3){                // All of these lines ensure victory for the Computer
                        sticksTaken=2;
                    }

                    // If the Number of sticks is equal to 2 then it takes out 1
                    if(StickNum==2){
                        sticksTaken=1;
                    }

                    StickNum-=sticksTaken;
                    cout<<"Computer removes "<<sticksTaken<<" sticks."<<endl;
                    cout<<StickNum<<endl;

                    //If number of sticks is 1 then computer wins
                    if(StickNum == 1){
                        cout<<"Computer wins!"<<endl;
                        counter = 2;
                        break;
                    }

                    //If number of sticks is 0 or less than 0 then player 1 wins
                    if(StickNum <= 0){
                        cout<<Player1Name<<" Wins!"<<endl;
                        counter = 2;
                        break;
                    }

                    /
                    do{
                        cout<<Player1Name<<" ,Enter number of sticks you want to take out(1-3): ";
                        cin>>sticksTaken;
                        if(sticksTaken < 1 or sticksTaken > 3 ){
                            cout<<"Invalid input since it is not between 1-3."<<endl;
                        }
                    }while(sticksTaken < 1 or sticksTaken > 3 );

                    StickNum-=sticksTaken;
                    cout<<StickNum<<endl;

                    //If number of sticks is 1 then player 1 wins
                    if(StickNum == 1){
                        cout<<Player1Name<<" Wins!"<<endl;
                        counter = 2;
                        break;
                    }

                    //If number of sticks is 0 or less than 0 then computer wins
                    if(StickNum <= 0){
                        cout<<"Computer Win!"<<endl;
                        counter = 2;
                        break;
                    }

                }

                do{
                    cout<<"Do you want to play another round(yes or no): ";
                        cin>>NewGame;
                        if(NewGame!= "yes" and NewGame != "Yes" and NewGame != "No" and NewGame != "no"){
                            cout<<"Invalid input since you did not enter yes or no";
                        }
                    }while(NewGame!= "yes" and NewGame != "Yes" and NewGame != "No" and NewGame != "no");

                    if(NewGame == "yes" or NewGame == "Yes"){
                        continue;
                    }

                    if(NewGame == "no" or NewGame == "No"){
                        loop++;
                    }
            }

        }

        else{
            cout<<"Invalid input since you did not enter 1, 2, or 3. "<<endl;
        }

    }
}