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

namespace GameEngine
{
    public class Gameplay_Opdracht_5 : AbstractGame
    {
        private Vector2f SnakePos = new Vector2f(0, 0);

        private Vector2 ApplePos = new Vector2();

        private Vector2 SnakeLetterPos = new Vector2(670, 200);


        private int SnakeCounter;

        private int SnakeDirection = 0;

        private int Score = 0;


        private Random Random = new Random();


        private Rectanglef Apple;


        private bool SnakeCollission;

        private bool Collission;

        private bool Menu = true;

        private bool ScoreCollission = false;

        private bool ShowButton = true;


        private Font Score_Font = new Font("Planet Benson 2", 70);

        private Font Button_Font = new Font("Planet Benson 2", 40);


        private List<Vector2f> Snake = new List<Vector2f>();


        private Bitmap[] SnakeMenuLetters = new Bitmap[5];

        private Bitmap SnakeHead;

        private Bitmap PlayButton;


        private Audio BackgroundMusic = new Audio("SnakeMusic.wav");

        private Audio AppleBite = new Audio("AppleBite.wav");


        private Button Start = null;

        public override void GameStart()
        {
            BackgroundMusic.SetLooping(true);
            GAME_ENGINE.PlayAudio(BackgroundMusic);

            GetRandomNumberApple();
            Apple = new Rectanglef(ApplePos.X, ApplePos.Y, 32, 32);

            Snake.Add(SnakePos);

            PlayButton = new Bitmap("PlayButton3.png");

            SnakeHead = new Bitmap("SnakeGraphics.png");

            if (ShowButton == true)
            {
                Start = new Button(OnButtonClick_StartGame, "", 800, 600, 300, 100);
                Start.SetBitmap(PlayButton);
                Start.SetActive(true);
            }

            SnakeMenuLetters[0] = new Bitmap("SnakeLetters.png");
            SnakeMenuLetters[1] = new Bitmap("SnakeLetters.png");
            SnakeMenuLetters[2] = new Bitmap("SnakeLetters.png");
            SnakeMenuLetters[3] = new Bitmap("SnakeLetters.png");
            SnakeMenuLetters[4] = new Bitmap("SnakeLetters.png");


        }

        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;
                }

            }

            //This is the function that makes the snake parts follow the head
            if (SnakeCounter >= 10)
            {
                for (int i = Snake.Count - 1; i > 0; i--)
                {
                    Snake[i] = new Vector2f(Snake[i - 1].X, Snake[i - 1].Y);
                }
            }

            //This is the function that makes the snake move based on the SnakeDirection
            if ((SnakeDirection == 1) && (SnakeCounter >= 10))
            {
                SnakeCounter = 0;
                SnakePos.Y -= 64;
                Snake[0] = new Vector2f(SnakePos.X, SnakePos.Y);
            }

            if ((SnakeDirection == 2) && (SnakeCounter >= 10))
            {
                SnakeCounter = 0;
                SnakePos.Y += 64;
                Snake[0] = new Vector2f(SnakePos.X, SnakePos.Y);
            }

            if ((SnakeDirection == 4) && (SnakeCounter >= 10))
            {
                SnakeCounter = 0;
                SnakePos.X += 64;
                Snake[0] = new Vector2f(SnakePos.X, SnakePos.Y);
            }

            if ((SnakeDirection == 3) && (SnakeCounter >= 10))
            {
                SnakeCounter = 0;
                SnakePos.X -= 64;
                Snake[0] = new Vector2f(SnakePos.X, SnakePos.Y);
            }

            //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 (Snake[0].X > GAME_ENGINE.GetScreenWidth())
            {
                SnakePos.X = 0;
            }

            if (Snake[0].X < 0)
            {
                SnakePos.X = 1920;
            }

            if (Snake[0].Y > GAME_ENGINE.GetScreenHeight())
            {
                SnakePos.Y = 0;
            }

            if (Snake[0].Y < 0)
            {
                SnakePos.Y = 1080;
            }

            //This is the function that checks the collission between the apple and the snake
            if (Snake[0].X > (Apple.X + 64) || (Snake[0].X + 64) < Apple.X || Snake[0].Y > (Apple.Y + 64) || (Snake[0].Y + 64) < Apple.Y)
            {
                Collission = false;
            }
            else
            {
                Collission = true;
            }

            //This is the function that checks if the snake is colliding with itself
            for (int i = 1; i < Snake.Count; i++)
            {
                if (Snake[0].X > Snake[i].X + (i * 64) || (Snake[0].X + (i * 64)) < Snake[i].X || Snake[0].Y > (Snake[i].Y + (i * 64)) || (Snake[0].Y + (i * 64)) < Snake[i].Y)
                {
                    SnakeCollission = false;
                }
                else
                {
                    SnakeCollission = true;
                }
            }

            //This function makes the timer score work
            if (ScoreCollission)
            {
                Score += 2;

                for (int i = 0; i < 1000; i++)
                {
                    if (Score == (100 * i))
                    {
                        ScoreCollission = false;
                    }
                }

            }

        }

        private void OnButtonClick_StartGame()
        {
            Menu = false;
            Start.SetActive(false);
        }

        private void SnakeMenu()
        {

            //Drawing the snake letters
            for (int i = 0; i < 5; i++)
            {
                GAME_ENGINE.DrawBitmap(SnakeMenuLetters[i], SnakeLetterPos.X + (118 * i), SnakeLetterPos.Y, 0 + (118 * i), 0, 130, 192);
            }



        }

        //This function draws the apple each time it's called
        private void DrawRandomApple()
        {
            GetRandomNumberApple();
            Apple = new Rectanglef(ApplePos.X, ApplePos.Y, 32, 32);
        }

        //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()
        {
            if (!Menu)
            {
                ShowButton = false;

                if (ShowButton == false)
                {
                    Start.SetSize(0, 0);
                    Start.SetText("");
                }

                //This is the function that draws the apple at the start of the game
                GAME_ENGINE.SetColor(Color.Green);
                GAME_ENGINE.FillEllipse(Apple);

                if (Collission)
                {
                    //Generate new apple
                    DrawRandomApple();
                    GAME_ENGINE.SetColor(Color.Green);
                    GAME_ENGINE.FillEllipse(Apple);
                    GAME_ENGINE.PlayAudio(AppleBite);

                    Snake.Add(SnakePos);

                    ScoreCollission = true;
                }

                //This is where we draw the snake
                for (int i = 0; i < Snake.Count; i++)
                {
                    GAME_ENGINE.SetColor(Color.Red);
                    GAME_ENGINE.FillRectangle(Snake[i].X, Snake[i].Y, 64, 64);
                }

                //This is where we draw the score
                GAME_ENGINE.DrawString(Score_Font, Score.ToString(), (GAME_ENGINE.GetScreenWidth() / 2) - 50, GAME_ENGINE.GetScreenHeight() / 2, 1000, 1000);

            }

            if (GAME_ENGINE.GetKeyDown(Key.Escape))
            {
                Menu = true;
                Start = new Button(OnButtonClick_StartGame, "", 800, 600, 300, 100);
                Start.SetBitmap(PlayButton);
                Start.SetActive(true);
                Snake.Clear();
                SnakePos.X = 0;
                SnakePos.Y = 0;
                Snake.Add(SnakePos);
                Snake[0] = new Vector2f(SnakePos.X, SnakePos.Y);
                SnakeDirection = 0;
                Score = 0;
            }

            if (SnakeCollission == true)
            {
                Menu = true;
                Start = new Button(OnButtonClick_StartGame, "", 800, 600, 300, 100);
                Start.SetBitmap(PlayButton);
                Start.SetActive(true);
                Snake.Clear();
                SnakePos.X = 0;
                SnakePos.Y = 0;
                Snake.Add(SnakePos);
                Snake[0] = new Vector2f(SnakePos.X, SnakePos.Y);
                SnakeDirection = 0;
                Score = 0;
                SnakeCollission = false;
            }

            if (Menu)
            {
                SnakeMenu();
            }

        }
    }
}