#include <conio.h>
#include <iostream>
#include <locale.h>
#include <time.h>
#include <chrono>
#include <thread>
#include <vector>
#include <iomanip>
#include <array>

using std::cout; using std::cin; using std::endl; using std::string; using std::vector;
const int MAX_SIZE = 20, MAX_DIF = 3;
int tabuleiro[MAX_SIZE][MAX_SIZE];
int x, y, moveDirection, snakeLength, newx, newy, dificulty, score, timeri, deltat;
int chooseDimension(), chooseDificulty();
void chooseHorizontal(), chooseVertical(), startGame(), testHit(), theGame(), placeFood(), displayBoard(), moveSnake(), createNewPiece(), correctPlace(), displayHorizontalBorder(), addScore(), setDificulty(), displayScore(), resetArray();
bool error = false, food = false, lose = false, ate;
vector<int> xsnake, ysnake;

int main()
{
	char op;
	setlocale(LC_ALL, "");
	srand(time(NULL));
	do
	{
		system("CLS");
		cout << "Bem-vindo ao Snake!" << endl;
		cout << "Escolha as dimensões do tabuleiro:" << endl;
		chooseHorizontal();
		chooseVertical();
		setDificulty();
		startGame();
		theGame();
		deltat = time(NULL) - timeri;
		setlocale(LC_ALL, "");
		cout << "\nPerdeste! Aguentaste-te durante " << deltat << " segundos!\n";
		cout << "Queres começar de novo? Pressiona Y para jogar novamente. Tecla N para fechar.\n";
		std::this_thread::sleep_for(std::chrono::milliseconds(500));
		do
		{
			op = _getch();
		} while (!(op == 'Y' || op == 'y' || op == 'N' || op == 'n'));
	} while (op == 'Y' || op == 'y');
	return 0;
}

void setDificulty()
{
	while (true)
	{
		cout << "Dificuldade? (Maximo: " << MAX_DIF << "): ";
		int v;
		v = chooseDificulty();
		if (!error)
		{
			dificulty = v;
			break;
		}
	}
	return;
}

int chooseDificulty()
{
	int v = 0;
	cin >> v;
	cin.ignore(100, '\n');
	if (v <= 0)
	{
		cout << "Tem de escolher uma dificuldade positiva\n";
		error = true;
	}
	else if (v > MAX_DIF)
	{
		cout << "Usou um valor demasiado elevado.\n";
		error = true;
	}
	else error = false;
	return v;
}

int chooseDimension()
{
	int v = 0;
	cin >> v;
	cin.ignore(100, '\n');
	if (v <= 0)
	{
		cout << "Tem de escolher uma dimensão positiva\n";
		error = true;
	}
	else if (v > MAX_SIZE)
	{
		cout << "Usou um valor demasiado elevado.\n";
		error = true;
	}
	else error = false;
	return v;
}

void chooseHorizontal()
{
	while (true)
	{
		cout << "Dimensão horizontal (Maximo: " << MAX_SIZE << "): ";
		int v;
		v = chooseDimension();
		if (!error)
		{
			x = v - 1;
			break;
		}
	}
	return;
}

void chooseVertical()
{
	while (true)
	{
		cout << "Dimensão vertical (Maximo: " << MAX_SIZE << "): ";
		int v;
		v = chooseDimension();
		if (!error)
		{
			y = v - 1;
			break;
		}
	}
	return;
}

void startGame()
{
	resetArray();
	xsnake = {};
	ysnake = {};
	score = 0;
	snakeLength = 1;
	error = false;
	food = false;
	lose = false;
	int xpos, ypos;
	xpos = rand() % x;
	xsnake.push_back(xpos);
	ypos = rand() % y;
	ysnake.push_back(ypos);
	moveDirection = rand() % 4 + 1;
	tabuleiro[ypos][xpos] = 1;
	timeri = time(NULL);
	return;
}

void resetArray()
{
	for (int i = 0; i <= y; i++)
	for (int c = 0; c <= x; c++)
		tabuleiro[i][c] = 0;
}

void theGame()
{
	setlocale(LC_ALL, "C");
	int dif = 12 - dificulty * 3;
	while (true)
	{
		if (!food) placeFood();
		displayBoard();
		for (int i = 0; i <= dif; i++)
		{
			testHit();
			std::this_thread::sleep_for(std::chrono::milliseconds(10));
		}
		moveSnake();
		if (lose) return;
	}
}

void moveSnake()
{
	switch (moveDirection)
	{
	case 1:
		newx = xsnake[0];
		newy = ysnake[0] - 1;
		break;
	case 2:
		newx = xsnake[0] + 1;
		newy = ysnake[0];
		break;
	case 3:
		newx = xsnake[0];
		newy = ysnake[0] + 1;
		break;
	case 4:
		newx = xsnake[0] - 1;
		newy = ysnake[0];
		break;
	}
	correctPlace();
	int elem = tabuleiro[newy][newx];
	if (elem == 2)
	{
		food = false;
		ate = true;
		addScore();
		createNewPiece();
	}
	if (elem == 1)
	{
		lose = true;
		return;
	}
	else ate = false;
	if (!ate)
	{
		tabuleiro[ysnake[snakeLength - 1]][xsnake[snakeLength - 1]] = 0;
	}
	for (int i = snakeLength - 1; i >= 1; i--)
	{
		xsnake[i] = xsnake[i - 1];
		ysnake[i] = ysnake[i - 1];
	}
	xsnake[0] = newx;
	ysnake[0] = newy;
	tabuleiro[newy][newx] = 1;
	return;
}

void createNewPiece()
{
	snakeLength++;
	xsnake.push_back(xsnake[snakeLength - 2]);
	ysnake.push_back(ysnake[snakeLength - 2]);
	return;
}

void correctPlace()
{
	if (newx > x) newx = 0;
	else if (newx < 0) newx = x;
	else if (newy > y) newy = 0;
	else if (newy < 0) newy = y;
	return;
}

void placeFood()
{
	int xpos, ypos;
	do
	{
		xpos = rand() % x;
		ypos = rand() % y;
		if (!(1 == tabuleiro[ypos][xpos]))
		{
			tabuleiro[ypos][xpos] = 2;
			food = true;
			error = false;
		}
		else error = true;
	} while (error);
	return;
}

void addScore()
{
	score = score + 10 * dificulty;
	return;
}

void displayBoard()
{
	system("CLS");
	displayHorizontalBorder();
	cout << endl;
	displayScore();
	displayHorizontalBorder();
	cout << endl;
	for (int i = 0; i <= y; i++)
	{
		cout << "|";
		for (int c = 0; c <= x; c++)
		{
			int elem = tabuleiro[i][c];
			if (elem == 0) cout << " ";
			else if (1 == elem) cout << "o";
			else cout << "*";
		}
		cout << "|" << endl;
	}
	displayHorizontalBorder();
	return;
}

void displayScore()
{
	cout << "|Score: " << std::setw(x - 6) << score << "|";
	cout << endl;
}

void displayHorizontalBorder()
{
	for (int i = -2; i <= x; i++)
	{
		if (-2 == i || x == i) cout << "+";
		else cout << "-";
	}
}

void inputControl(char control)
{
	switch (control)
	{
	case 'H':
		if (3 != moveDirection) moveDirection = 1;
		break;
	case 'M':
		if (4 != moveDirection) moveDirection = 2;
		break;
	case 'P':
		if (1 != moveDirection) moveDirection = 3;
		break;
	case 'K':
		if (2 != moveDirection) moveDirection = 4;
		break;
	}
	return;
}

void testHit()
{
	if (_kbhit())
	{
		char control;
		control = (_getch(), _getch());
		inputControl(control);
	}
	return;
}