using System;
using System.Drawing;
using System.Globalization;
using CC_Functions.Commandline;
using CC_Functions.Commandline.TUI;
using CC_Functions.Core;
using D = CC_Functions.Commandline.DiffDraw;

namespace OnScreenKeyboard
{
    class Program
    {
        private const string Keyboard = "qwertyuiop\nasdfghjkl_\nzxcvbnm,.-";
        private const int Width = 10 * 3;
        private const int Height = 4;
        private static Point _ball = new Point(0, Height - 1);
        private static Point _ballSpeed = new Point(1, -1);
        private static int _peddle = 0;
        private static string _input = "";
        static void Main(string[] a)
        {
            ArgsParse args = new ArgsParse(a);
            //args
            if (args.GetBool("help") || args.GetBool("?") || args.GetBool("h"))
            {
                Console.WriteLine(@"JF OSK v1
Shows an interactive keyboard (stdout and stdin) and logs the output to stderr

Usage:
    OSK [arguments]

Arguments:
    delay         The time to wait between ball movements.
    no-color      Do not output color. Use only if color doesn't work.
    peddle-length The length of the peddle.

Examples:
    OSK --delay:0.3 --peddle-length:3
    OSK --no-color
    OSK 2> output.txt");
                return;
            }
            TimeSpan ballSpeed = args.Get("delay", s => s == null ? new TimeSpan(0, 0, 1) : TimeSpan.Parse($"0:0:0:{s}", CultureInfo.InvariantCulture));
            bool color = !args.GetBool("no-color");
            int peddleLength = args.Get("peddle-length", s => s == null ? 4 : int.Parse(s, CultureInfo.InvariantCulture));
            if (peddleLength > Width)
                peddleLength = Width;
            //init
            Console.BackgroundColor = ConsoleColor.Black;
            Console.ForegroundColor = ConsoleColor.White;
            Console.Clear();
            bool playing = true;
            DateTime lastGameTick = DateTime.Now;
            while (playing)
            {
                //Process input
                bool left = false;
                bool right = false;
                bool select = false;
                while (Console.KeyAvailable)
                {
                    switch (Console.ReadKey().Key)
                    {
                        case ConsoleKey.LeftArrow:
                        case ConsoleKey.A:
                            left = true;
                            break;
                        case ConsoleKey.RightArrow:
                        case ConsoleKey.D:
                            right = true;
                            break;
                        case ConsoleKey.W:
                        case ConsoleKey.S:
                        case ConsoleKey.UpArrow:
                        case ConsoleKey.DownArrow:
                        case ConsoleKey.Spacebar:
                        case ConsoleKey.Enter:
                            select = true;
                            break;
                        case ConsoleKey.Escape:
                            playing = false;
                            break;
                    }
                }
                //Move peddle
                if (left)
                    _peddle--;
                if (right)
                    _peddle++;
                if (_peddle < 0)
                    _peddle = 0;
                if (_peddle > Width - peddleLength)
                    _peddle = Width - peddleLength;
                //Scheduled game tick
                if (lastGameTick + ballSpeed - DateTime.Now <= TimeSpan.Zero)
                {
                    lastGameTick = DateTime.Now;
                    //Move ball
                    ball:
                    _ball = new Point(_ball.X + _ballSpeed.X, _ball.Y + _ballSpeed.Y);
                    if (_ball.X == 0 || _ball.X == Width - 1)
                        _ballSpeed = new Point(-_ballSpeed.X, _ballSpeed.Y);
                    if (_ball.Y == 0)
                        _ballSpeed = new Point(_ballSpeed.X, -_ballSpeed.Y);
                    if (_ball.Y == Height - 1 && _ball.X >= _peddle && _ball.X < _peddle + peddleLength)
                    {
                        if (_ball.X > 0 && _ball.X < Width - 1)
                            _ball.X -= _ballSpeed.X;
                        _ball.Y -= 1;
                        _ballSpeed = new Point(_ballSpeed.X, -_ballSpeed.Y);
                        goto ball;
                    }
                    if (_ball.Y == Height) playing = false;
                }
                //Post-input pre-draw stuff
                if (!playing)
                    continue;
                Pixel[,] empty = new Pixel[Height, Width];
                empty.Populate(new Pixel(' '));
                D.Clear(empty);
                //Draw keyboard and add to output. Combined one to avoid major code duplication
                int y = 0;
                int sub = 0;
                for (int i = 0; i < Keyboard.Length; i++)
                {
                    char t = Keyboard[i];
                    if (t == '\n')
                    {
                        y++;
                        sub = i + 1;
                    }
                    else
                    {
                        Point start = new Point((i - sub) * 3, y);
                        bool selected = _ball.Y == start.Y && _ball.X >= start.X && _ball.X < start.X + 3;
                        if (selected && select)
                            _input += t;
                        DrawString(start,
                            $" {t} ",
                            selected ? Console.BackgroundColor : Console.ForegroundColor,
                            selected ? Console.ForegroundColor : Console.BackgroundColor);
                    }
                }
                //Draw ball
                D.Set(_ball, new Pixel(Console.ForegroundColor, Console.BackgroundColor, 'X'));
                //Draw paddle
                DrawString(new Point(_peddle, Height - 1), new string('█', peddleLength), Console.ForegroundColor, Console.BackgroundColor);
                //Finish frame
                D.Draw(color);
                Console.CursorLeft = 0;
                Console.CursorTop = Height;
                Console.Write(_input);
            }
            Console.ResetColor();
            Console.Clear();
            Console.Error.WriteLine(_input);
        }

        private static void DrawString(Point start, string chars, ConsoleColor foreColor, ConsoleColor backColor)
        {
            foreach (string s in chars.Split('\n'))
                for (int i = 0; i < s.Length; i++)
                {
                    char t = s[i];
                    D.Set(start.X + i, start.Y, new Pixel(backColor, foreColor, t));
                }
        }
    }
}