A1/hands.cpp

#include "hands.h"

#include <chrono>
#include <iostream>
#include <memory>
#include <random>

#include <cstdlib>

std::unique_ptr<Hand> Hand::fromChar(const char letter) {
	switch (letter) {
		case 'R':
		case 'r':
			return std::make_unique<Rock>();
		case 'P':
		case 'p':
			return std::make_unique<Paper>();
		case 'S':
		case 's':
			return std::make_unique<Scissors>();
		default:
			std::cout << "Invalid choice" << std::endl;
			std::exit(1);
	}
}

std::unique_ptr<Hand> Hand::generateRandom() {
	std::mt19937 mt(
		std::chrono::steady_clock::now().time_since_epoch().count());
	std::uniform_int_distribution<int> intDist(0, 2);

	switch (intDist(mt)) {
		case 0:
			return std::make_unique<Rock>();
		case 1:
			return std::make_unique<Paper>();
		case 2:
			return std::make_unique<Scissors>();
		default:
			std::cerr << "An invalid random number was generated, this should "
						 "be impossible"
					  << std::endl;
			std::exit(1);
	}
}

// List of function implementations for all of the different types of Hand

std::string Rock::getHandName() const { return "rock"; }
GameResult Rock::compareAgainst(const Hand &other) {
	const std::string otherName = other.getHandName();

	if (otherName == "rock")
		return GameResult::Tie;
	if (otherName == "scissors")
		return GameResult::Win;
	else
		return GameResult::Loss;
}

std::string Paper::getHandName() const { return "paper"; }
GameResult Paper::compareAgainst(const Hand &other) {
	const std::string otherName = other.getHandName();

	if (otherName == "paper")
		return GameResult::Tie;
	if (otherName == "rock")
		return GameResult::Win;
	else
		return GameResult::Loss;
}

std::string Scissors::getHandName() const { return "scissors"; }
GameResult Scissors::compareAgainst(const Hand &other) {
	const std::string otherName = other.getHandName();

	if (otherName == "scissors")
		return GameResult::Tie;
	if (otherName == "paper")
		return GameResult::Win;
	else
		return GameResult::Loss;
}