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

namespace GameEngine
{
    public class Gameplay_Opdracht_5 : AbstractGame
    {
        //This vector defines the SnakeSize
        private Vector2 SnakeSize = new Vector2( 64, 64);

        //This bool checks if an apple is already drawn on the screen
        private bool AppleDrawn = false;

        //This vector defines the x and y position of the apple
        private Vector2 ApplePos = new Vector2();

        //This vector defines the SnakePosition
        private Vector2 SnakePos = new Vector2(0, 64);

        //This int serves as a counter to make sure the snake moves at the right pace
        private int SnakeCounter;

        //This int keeps track of which direction the snake is heading
        private int SnakeDirection = 0;

        //This is the random number generator
        private Random Random = new Random();

        //This is the Rectanglef for the snakehead
        private Rectanglef SnakeHead;

        //This is the Rectanglef for the apple
        private Rectanglef Apple;

        //This is the apple counter
        private int AppleCounter = 0;

        //GridSizes
        private int SizeX = 30;
        private int SizeY = 16;

        public override void GameStart()
        {

            GetRandomNumberApple();
            Apple = new Rectanglef(ApplePos.X, ApplePos.Y, 64, 64);
            SnakeHead = new Rectanglef(SnakePos.X, SnakePos.Y, SnakeSize.X, SnakeSize.Y);

        }

        public override void GameEnd()
        {

        }

        public override void Update()
        {
            SnakeCounter++;

//These if-statements set the SnakeDirection

            if (GAME_ENGINE.GetKeyDown(Key.W))
            {
                if (SnakeDirection != 2)
                {
                    SnakeDirection = 1;
                }

            }

            if (GAME_ENGINE.GetKeyDown(Key.S))
            {
                if (SnakeDirection != 1)
                {
                    SnakeDirection = 2;
                }

            }

            if (GAME_ENGINE.GetKeyDown(Key.A))
            {
                if (SnakeDirection != 4)
                {
                    SnakeDirection = 3;
                }

            }

            if (GAME_ENGINE.GetKeyDown(Key.D))
            {
                if (SnakeDirection != 3)
                {
                    SnakeDirection = 4;
                }

            }

            if (AppleDrawn == true)
            {
                AppleCounter++;
            }



        }

//This function draws the apple each time it's called
        private void DrawRandomApple()
        {
                GetRandomNumberApple();
                GAME_ENGINE.FillEllipse(ApplePos.X, ApplePos.Y, 50, 50);
        }

//This function generates two random numbers for the apple each time it's called
        private void GetRandomNumberApple()
        {
            ApplePos.X = Random.Next(100, 1820);
            ApplePos.Y = Random.Next(100, 980);
        }

        public override void Paint()
        {
            GAME_ENGINE.SetColor(Color.Red);

            //This is the function that makes the snake move based on the SnakeDirection

            if ((SnakeDirection == 1) && (SnakeCounter >= 10))
            {
                SnakeCounter = 0;
                SnakeHead.Y -= 64;
            }

            if ((SnakeDirection == 2) && (SnakeCounter >= 10))
            {
                SnakeCounter = 0;
                SnakeHead.Y += 64;
            }

            if ((SnakeDirection == 4) && (SnakeCounter >= 10))
            {
                SnakeCounter = 0;
                SnakeHead.X += 64;
            }

            if ((SnakeDirection == 3) && (SnakeCounter >= 10))
            {
                SnakeCounter = 0;
                SnakeHead.X -= 64;
            }

            //This the function that makes sure that the snake re-appears on the left side of the screen when it goes off the right side

            if (SnakeHead.X > GAME_ENGINE.GetScreenWidth())
            {
                SnakeHead.X = 0;
            }

            if (SnakeHead.X < 0)
            {
                SnakeHead.X = 1920;
            }

            if (SnakeHead.Y > GAME_ENGINE.GetScreenHeight())
            {
                SnakeHead.Y = 0;
            }

            if (SnakeHead.Y < 0)
            {
                SnakeHead.Y = 1024;
            }

            //This is the function that draws the apple at random positions
            if (AppleDrawn == false)
            {
                GAME_ENGINE.SetColor(Color.Green);
                GAME_ENGINE.FillRectangle(Apple);
            }

//This is the function that checks the collission between the apple and the snake
            if ((SnakeHead.X > Apple.X) && (SnakeHead.X < (Apple.X + 64)) && (SnakeHead.Y > Apple.Y) && (SnakeHead.Y < (Apple.Y + 64)))
            {
                AppleDrawn = true;
            }

            if ((AppleDrawn == true) && (AppleCounter == 10))
            {
                AppleCounter = 0;
                AppleDrawn = false;
            }


                //This function draws the grid
                for (int x = 0; x < SizeX; x++)
            {
                for (int y = 0; y < SizeY; y++)
                {
                    GAME_ENGINE.SetColor(Color.Black);
                    GAME_ENGINE.DrawRectangle(0 + (x * 64), 0 + (y * 64), 64, 64);
                }
            }



//This is where we draw the actual snake
            GAME_ENGINE.SetColor(Color.Red);
            GAME_ENGINE.FillRectangle(SnakeHead);
        }
    }
}