using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading;

namespace JustSnake
{
    struct Position
    {
        public int row;
        public int column;
        public Position(int row, int col)
        {
            this.row = row;
            this.column = col;
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            byte right = 0;
            byte left = 1;
            byte down = 2;
            byte up = 3;
            int lastcandyTime = 0;
            int candyDissapearTime = 10000;

            Console.BackgroundColor = ConsoleColor.Black;
            Console.CursorVisible = (false);
            Console.Title = "Spimle Snake ALPHA";

            Position[] directions = new Position[]
            {
                new Position(0, 1), // prawo
                new Position(0, -1), // lewo
                new Position(1, 0), // w dół
                new Position(-1, 0), // w górę
            };
            double sleepTime = 100;
            int direction = right;
            Random randomNumbersGenerator = new Random();
            Console.BufferHeight = Console.WindowHeight;
            lastcandyTime = Environment.TickCount;

            List<Position> obstacles =
                new List<Position>()
            {
                new Position(1, 4),
                new Position(3, 12),
                new Position(5, 20),
                new Position(7, 28),
                new Position(9, 36),
                new Position(11, 44),
                new Position(13, 52),
                new Position(15, 60),
                new Position(17, 68),
                new Position(19, 76),
                new Position(21, 84),
                new Position(23, 92),
                new Position(25, 100),
                new Position(27, 108),
            };
            foreach (Position obstacle in obstacles)            //Przeszkody
            {
                Console.ForegroundColor = ConsoleColor.DarkRed;
                Console.SetCursorPosition(obstacle.column, obstacle.row);
                Console.Write("X");
            }

            Queue<Position> snakeElements =
                new Queue<Position>();
            for (int i = 0; i <= 5; i++)
            {
                snakeElements.Enqueue(new Position(0, i));
            }

            Position candy;
            do
            {
                candy = new Position(
                    randomNumbersGenerator.Next(0, Console.WindowHeight),
                    randomNumbersGenerator.Next(0, Console.WindowWidth));
            }
            while (snakeElements.Contains(candy) || obstacles.Contains(candy));
            Console.SetCursorPosition(candy.column, candy.row);
            Console.ForegroundColor = ConsoleColor.DarkGreen;
            Console.Write("o");

            foreach (Position position in snakeElements)
            {
                Console.SetCursorPosition(position.column,position.row);
                Console.ForegroundColor = ConsoleColor.DarkGray;
                Console.Write("■");
            }

            while (true)
            {

                if (Console.KeyAvailable)
                {
                    ConsoleKeyInfo userInput = Console.ReadKey();
                    if (userInput.Key == ConsoleKey.LeftArrow)
                    {
                        if (direction != right) direction = left;
                    }
                    if (userInput.Key == ConsoleKey.RightArrow)
                    {
                        if (direction != left) direction = right;
                    }
                    if (userInput.Key == ConsoleKey.UpArrow)
                    {
                        if (direction != down) direction = up;
                    }
                    if (userInput.Key == ConsoleKey.DownArrow)
                    {
                        if (direction != up) direction = down;
                    }
                }

                Position snakeHead = snakeElements.Last();
                Position nextDirection = directions[direction];

                Position snakeNewHead = new Position(snakeHead.row + nextDirection.row,snakeHead.column + nextDirection.column);

                if (snakeNewHead.column < 0) snakeNewHead.column = Console.WindowWidth - 1;

                if (snakeNewHead.row < 0)snakeNewHead.row = Console.WindowHeight - 1;

                if (snakeNewHead.row >= Console.WindowHeight)snakeNewHead.row = 0;

                if (snakeNewHead.column >= Console.WindowWidth)snakeNewHead.column = 0;

                if (snakeElements.Contains(snakeNewHead)
                    || obstacles.Contains(snakeNewHead))
                {
                    Console.SetCursorPosition(0, 0);
                    Console.ForegroundColor = ConsoleColor.Red;
                    Console.WriteLine("KONIEC GRY!!!");
                    int userPoints = (snakeElements.Count - 6);
                    if (userPoints > 5)
                    {
                        Console.WriteLine("Liczba uzyskanych punktów to {0}, gratulacje!", userPoints);
                    }
                    else
                        Console.WriteLine("musisz sie postarac ;/ liczba twoich punktow nie przekroszyla 5! Twoj wynik to {0}", userPoints);
                    Console.ReadLine();
                    return;
                }

                Console.SetCursorPosition(snakeHead.column,snakeHead.row);
                Console.ForegroundColor = ConsoleColor.DarkGray;
                Console.Write("=");

                snakeElements.Enqueue(snakeNewHead);
                Console.SetCursorPosition(snakeNewHead.column,snakeNewHead.row);
                Console.ForegroundColor = ConsoleColor.Gray;
                if (direction == right) Console.Write(">");
                if (direction == left) Console.Write("<");
                if (direction == up) Console.Write("^");
                if (direction == down) Console.Write("v");


                if (snakeNewHead.column == candy.column &&snakeNewHead.row == candy.row)
                {
                    // Karmienie snake'a
                    do
                    {
                        candy = new Position(randomNumbersGenerator.Next(0, Console.WindowHeight), randomNumbersGenerator.Next(0, Console.WindowWidth));
                    }
                    while (snakeElements.Contains(candy) || obstacles.Contains(candy));
                    lastcandyTime = Environment.TickCount;
                    Console.SetCursorPosition(candy.column, candy.row);
                    Console.ForegroundColor = ConsoleColor.DarkGreen;
                    Console.Write("o");
                    sleepTime--;

                    Position obstacle = new Position();
                    do
                    {
                        obstacle = new Position(randomNumbersGenerator.Next(0, Console.WindowHeight), randomNumbersGenerator.Next(0, Console.WindowWidth));
                    }
                    while (snakeElements.Contains(obstacle) || obstacles.Contains(obstacle) || (candy.row != obstacle.row && candy.column != obstacle.row));
                    obstacles.Add(obstacle);
                    Console.SetCursorPosition(obstacle.column,obstacle.row);
                    Console.ForegroundColor = ConsoleColor.Red;
                    Console.Write("X");
                }
                else
                {
                    // poruszanie się
                    Position last = snakeElements.Dequeue();
                    Console.SetCursorPosition(last.column, last.row);
                    Console.Write(" ");
                }

                if (Environment.TickCount - lastcandyTime >= candyDissapearTime)
                {
                    Console.SetCursorPosition(candy.column, candy.row);
                    Console.Write(" ");
                    do
                    {
                        candy = new Position(randomNumbersGenerator.Next(0, Console.WindowHeight),randomNumbersGenerator.Next(0, Console.WindowWidth));
                    }
                    while (snakeElements.Contains(candy) || obstacles.Contains(candy));
                    lastcandyTime = Environment.TickCount;
                }

                Console.SetCursorPosition(candy.column, candy.row);
                Console.ForegroundColor = ConsoleColor.DarkGreen;
                Console.Write("o");

                sleepTime -= 0.01;

                Thread.Sleep((int)sleepTime);
            }
        }
    }
}