using laba3.Subprograms;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using static System.Formats.Asn1.AsnWriter;

namespace ProgLab1.GUI
{
    public partial class SnakeForm : Form
    {
        private System.Windows.Forms.Timer gameTimer = new System.Windows.Forms.Timer();
        private List<Point> snake = new List<Point>();
        private Point food = Point.Empty;
        private int tileSize = 20;
        private string direction = "Right";
        private string nextDirection = "Right";
        private bool isGameOver = false;
        private int score = 0;

        private Level level;
        private int sizex;
        private int sizey;

        private Random rand = new Random();

        public SnakeForm(Level level, int sizex, int sizey, Form onCloseForm)
        {
            this.level = level;
            this.sizex = sizex;
            this.sizey = sizey;
            InitializeComponent();
            InitializeGame();

            this.FormClosing += new FormClosingEventHandler((object sender, FormClosingEventArgs e) => {onCloseForm.Show();});
        }

        private void InitializeGame()
        {
            this.Text = "Snake Game";
            this.ClientSize = new Size(sizex*tileSize, sizey*tileSize);
            this.DoubleBuffered = true;
            this.KeyDown += OnKeyDown;
            this.Paint += OnPaint;

            gameTimer.Interval = level switch
            {
                Level.Low => 250,
                Level.Medium => 125,
                Level.High => 50,
                _ => 500,
            }; ;
            gameTimer.Tick += OnGameTick;
            gameTimer.Start();

            ResetGame();
        }

        private void ResetGame()
        {
            snake.Clear();
            snake.Add(new Point(2, sizey/2)); // Initial snake head
            snake.Add(new Point(1,   sizey/2)); // Initial snake body
            snake.Add(new Point(0, sizey/2)); // Initial snake tail
            direction = "Right";
            nextDirection = "Right";
            isGameOver = false;
            SpawnFood();
        }

        private void SpawnFood()
        {
            int maxX = sizex;
            int maxY = sizey;
            do
            {
                food = new Point(rand.Next(0, maxX), rand.Next(0, maxY));
            } while (snake.Contains(food));
        }

        private void OnGameTick(object sender, EventArgs e)
        {
            if (isGameOver) return;

            // Update direction
            direction = nextDirection;

            // Calculate new head position
            Point newHead = snake[0];
            switch (direction)
            {
                case "Up": newHead.Y--; break;
                case "Down": newHead.Y++; break;
                case "Left": newHead.X--; break;
                case "Right": newHead.X++; break;
            }

            // Check collisions
            if (newHead.X < 0 || newHead.Y < 0 ||
                newHead.X >= sizex ||
                newHead.Y >= sizey ||
                snake.Contains(newHead))
            {
                isGameOver = true;
                gameTimer.Stop();
                Dialogs.GameOver($"Счёт: {score}");
                this.Close();
                return;
            }

            // Move snake
            snake.Insert(0, newHead);
            if (newHead == food)
            {
                SpawnFood();
                addScore();
            }
            else
            {
                snake.RemoveAt(snake.Count - 1); // Remove tail
            }

            this.Invalidate(); // Redraw
        }

        private void OnPaint(object sender, PaintEventArgs e)
        {
            Graphics g = e.Graphics;

            // Draw snake
            foreach (Point p in snake)
            {
                DrawTile(g, p.X, p.Y, Brushes.Green);
            }

            // Draw food
            DrawTile(g, food.X, food.Y, Brushes.Red);

            // Draw grid (optional)
            for (int x = 0; x < this.ClientSize.Width; x += tileSize)
            {
                for (int y = 0; y < this.ClientSize.Height; y += tileSize)
                {
                    g.DrawRectangle(Pens.Gray, x, y, tileSize, tileSize);
                }
            }
        }

        private void DrawTile(Graphics g, int x, int y, Brush brush)
        {
            g.FillRectangle(brush, x * tileSize, y * tileSize, tileSize, tileSize);
        }

        private void OnKeyDown(object sender, KeyEventArgs e)
        {
            if (isGameOver && e.KeyCode == Keys.R)
            {
                ResetGame();
                gameTimer.Start();
                return;
            }

            switch (e.KeyCode)
            {
                case Keys.Up: if (direction != "Down") nextDirection = "Up"; break;
                case Keys.Down: if (direction != "Up") nextDirection = "Down"; break;
                case Keys.Left: if (direction != "Right") nextDirection = "Left"; break;
                case Keys.Right: if (direction != "Left") nextDirection = "Right"; break;
            }
        }

        private void addScore()
        {
            score += level switch
            {
                Level.Low => 50,
                Level.Medium => 100,
                Level.High => 250,
                _ => 1,
            };
        }
        public enum Level
        {
            Low,
            Medium,
            High
        }
    }
}