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

using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using System.Windows.Forms;

namespace PokemonSpriteConverter
{
    class Program
    {
        private const string DIR_SPRITES = @"\spritesToConvert";
        private const string DIR_CONVERTED = @"\convertedSprites\";

        public static void Main(string[] args)
        {
            if (!Directory.Exists(Application.StartupPath + DIR_SPRITES))
                Directory.CreateDirectory(Application.StartupPath + DIR_SPRITES);

            if (!Directory.Exists(Application.StartupPath + DIR_CONVERTED))
                Directory.CreateDirectory(Application.StartupPath + DIR_CONVERTED);

            start();
        }

        private static void start()
        {
            Console.WriteLine("Welcome to the Pokemon Sprite Converter. Type 'start' to begin converting from the " + DIR_SPRITES + " folder to the " + DIR_CONVERTED + " folder.");
            string s = Console.ReadLine();
            if (s.Equals("start"))
            {
                DirectoryInfo dirInfo = new DirectoryInfo(Application.StartupPath + DIR_SPRITES);
                Bitmap gif = null;
                Bitmap[] frames = null;
                Bitmap converted = null;

                foreach (FileInfo file in dirInfo.GetFiles())
                {
                    gif = new Bitmap(file.FullName);
                    frames = ParseFrames(gif);
                    converted = new Bitmap(frames[0].Width * frames.Length, frames[0].Height);

                    for (int i = 0; i < frames.Length; i++)
                        using (var g = Graphics.FromImage(converted))
                            g.DrawImage(frames[i], new Rectangle(i * frames[i].Width, 0, frames[i].Width, frames[i].Height));

                    converted.Save(Application.StartupPath + @"\convertedSprites\" + file.Name.Split('.')[0] + ".png");
                }
            }
            else
            {
                start();
                return;
            }

            Console.WriteLine("Conversion complete! Press any key to continue...");
            Console.ReadLine();
        }

        // Credit: Answer from 'Neoheurist' in http://stackoverflow.com/questions/1712708/how-to-split-an-animated-gif-in-net
        private static Bitmap[] ParseFrames(Bitmap Animation)
        {
            // Get the number of animation frames to copy into a Bitmap array
            int Length = Animation.GetFrameCount(FrameDimension.Time);

            // Allocate a Bitmap array to hold individual frames from the animation
            Bitmap[] Frames = new Bitmap[Length];

            // Copy the animation Bitmap frames into the Bitmap array
            for (int Index = 0; Index < Length; Index++)
            {
                // Set the current frame within the animation to be copied into the Bitmap array element
                Animation.SelectActiveFrame(FrameDimension.Time, Index);

                // Create a new Bitmap element within the Bitmap array in which to copy the next fram
                Frames[Index] = new Bitmap(Animation.Size.Width, Animation.Size.Height);

                // Copy the current animation frame into the new Bitmap array element
                Graphics.FromImage(Frames[Index]).DrawImage(Animation, new Point(0, 0));
            }

            // Return the array of Bitmap frames
            return Frames;
        }
    }
}