#include <iostream>
#include <cstdlib>
#include <ctime>

using namespace std;

// enums
enum Option { rock = 'R', paper = 'P', scissors = 'S' };

//functions
void displayInstrutions() {
	cout << "Lets play rock, paper, scissor against the computer" << endl;
	cout << "Rock beats scissors, scissors beats paper and paper beats rock" << endl;
}

string getMove() {
	int move;

	cout << "\nChoices:" << endl;
	cout << "R - Rock" << endl;
	cout << "P - Paper " << endl;
	cout << "S - Scissors " << endl;
	cout << "Enter your choice: " << endl;
	cin >> move;

	move = tolower(move);
	if (move == rock) {
		cout << "you choose rock" << endl;
	} else if (move == scissors) {
		cout << "you choose scissors" << endl;
	} else if (move == paper) {
		cout << "you choose paper" << endl;
	} else {
		cout << "invalid entry" << endl;
	}

	return {};
}

int getCompMove() {
	srand(time(0));

	const int MAX_VALUE = 3;
	const int MIN_VALUE = 1;
	auto c_move = (rand() % MAX_VALUE - MIN_VALUE + 1) + MIN_VALUE;

	if (c_move == 1) {
		c_move = rock;
	}

	if (c_move == 2) {
		c_move = paper;
	}

	if (c_move == 3) {
		c_move = scissors;
	}

	return c_move;
}

bool getWinner(int c_move, int userMove) {
	if ((userMove == rock) && (c_move == 3)) {
		return true;
	} else if ((userMove == rock) && (c_move == 2)) {
		return false;
	} else if ((userMove == scissors) && (c_move == 2)) {
		return true;
	} else if ((userMove == scissors) && (c_move == 1)) {
		return false;
	} else if ((userMove == paper) && (c_move == 1)) {
		return true;
	} else if (userMove == paper && c_move == 3) {
		return false;
	} else if (userMove == c_move) {
		return "its a tie";
	} else {
		cout << "Invalid entry" << endl;
	}

	return false;
}

bool playAgain(int playAnswer) {
	const char yes = 'Y';
	const char no = 'N';
	int answer;

	do {
		cin >> answer;
		answer = tolower(answer);

		if (answer != yes && answer != no) {
			cout << "invalid entry" << endl;
		}

		answer = playAnswer;
	} while (answer != yes && answer != no);
}


int main() {
	//variables
	int compMove = 0;
	int userMove = 0;

	cout << "Wanna play a game?" << endl;

	displayInstrutions();

	//user choice / function
	getMove();
	getCompMove();

	//winner
	cout << "The winner is: " << endl;
	getWinner

	cout << "would you like to play again? Y or N " << endl;
	playAgain(bool)

}

#include <iostream>
#include <random>
#include <cctype>

enum Option { rock = 'R', paper = 'P', scissors = 'S' };
enum Result {win = 0, loose, draw};

void displayInstrutions() {
	std::cout << "Lets play rock, paper, scissor against the computer\n";
	std::cout << "Rock beats scissors, scissors beats paper and paper beats rock\n";
}

void display(Option opt) {
	switch (opt) {
		case rock:
			std::cout << "rock\n";
			break;

		case paper:
			std::cout << "paper\n";
			break;

		case scissors:
			std::cout << "scissors\n";
			break;
	}
}

Option getMove() {
	char move {};

	std::cout << "\nChoices:\n"
		<< "R - Rock\n"
		<< "P - Paper\n"
		<< "S - Scissors\n";

	while (true) {
		std::cout << "Enter your choice: ";
		std::cin >> move;

		move = static_cast<char>(std::toupper(static_cast<unsigned char>(move)));

		if (move == rock || move == scissors || move == paper) {
			const auto opt {static_cast<Option>(move)};

			std::cout << "\nYou chose ";
			display(opt);
			return opt;
		}

		std::cout << "Invalid entry\n";
	}
}

Option getCompMove() {
	static constexpr int MAX_VALUE {2};
	static constexpr int MIN_VALUE {0};
	static constexpr Option opt[3] {rock, paper, scissors};
	static std::mt19937 rng(std::random_device {}());
	static std::uniform_int_distribution<int> distrib(MIN_VALUE, MAX_VALUE);

	return opt[distrib(rng)];
}

Result getWinner(Option c_move, Option userMove) {
	if (c_move == userMove)
		return draw;

	if ((c_move == rock) && (userMove == scissors))
		return win;

	if ((c_move == scissors) && (userMove == paper))
		return win;

	if ((c_move == paper) && (userMove == rock))
		return win;

	return loose;
}

bool playAgain() {
	static constexpr char yes {'Y'};
	static constexpr char no {'N'};
	char answer {};

	do {
		std::cin >> answer;
		answer = static_cast<char>(std::toupper(static_cast<unsigned char>(answer)));
	} while (answer != yes && answer != no && (std::cout << "Invalid entry. Please enter again: "));

	return answer == yes;
}

int main() {
	std::cout << "Wanna play a game?\n";
	displayInstrutions();

	do {
		const auto userMove {getMove()};
		const auto compMove {getCompMove()};

		std::cout << "Computer chose ";
		display(compMove);

		switch (getWinner(compMove, userMove)) {
			case win:
				std::cout << "Computer wins\n";
				break;

			case loose:
				std::cout << "User wins\n";
				break;

			case draw:
				std::cout << "Its a draw!\n";
				break;
		}

	} while ((std::cout << "\nWould you like to play again? Y or N: ") && playAgain());
}